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Solar System News (miscellaneous articles)

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Draggendrop    5,747

Yes...magnetic fields are key to "conventional carbon based life" ...and/or...a form of shielding to reduce the dangers of cosmic radiation, such as heavy ice sheets....looking better out there from time with science.

 

:D 

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Unobscured Vision    2,678
8 minutes ago, Draggendrop said:

Yes...magnetic fields are key to "conventional carbon based life" ...and/or...a form of shielding to reduce the dangers of cosmic radiation, such as heavy ice sheets....looking better out there from time with science.

 

:D 

True, but Jupiter's magnetic field is actually in direct contact with Europa ("connected"), and such contact is in these cases detrimental. Could the very thick ice sheet insulate Europa from this effect? possibly; the salt ocean beneath it is generating a pretty substantial magnetic field of its' own around Europa (and the Scientists know that it's a salt ocean due to the presence of the Europan field; fresh water can't really generate one). That field is interacting with Jupiter's field and that's where the "direct contact" part happens.

 

I agree that magnetic fields are necessary to protect conventional carbon-based life from radiation; and Europa is definitely in a "no-mans' land" due to nearby Jupiter and needs all the shielding it can get. On the other hand, I also think that Europa faces several key disadvantages that could make life almost impossible there. It's a "great moon, bad location" scenario.

 

From: https://en.wikipedia.org/wiki/Europa_(moon)#Surface_features

a) The radiation level at the surface of Europa is equivalent to a dose of about 5400 mSv (540 rem) per day,[40] an amount of radiation that would cause severe illness or death in human beings exposed for a single day.[41]

 

b) Recent magnetic-field data from the Galileo orbiter showed that Europa has an induced magnetic field through interaction with Jupiter's, which suggests the presence of a subsurface conductive layer.[31]

... The Galileo orbiter found that Europa has a weak magnetic moment, which is induced by the varying part of the Jovian magnetic field. The field strength at the magnetic equator (about 120 nT) created by this magnetic moment is about one-sixth the strength of Ganymede's field and six times the value of Callisto's.[63] ... 

 

But ... factoring Jupiter's magnetic field in the area of Europa's orbit, literally shearing away at it:

 

425px-Europa_field.thumb.png.0e2ff3f658d

Magnetic field around Europa. The red line shows a trajectory of the Galileo spacecraft during a typical flyby (E4 or E14).

 

https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter#Interaction_with_rings_and_moons is a fascinating read -- it describes in more detail how Jupiter's magnetic field interacts with it's moons.

 

Enceladus, on the other hand, is in a way better spot. Protected by the Enceladus Torus (a strong node of Saturn's magnetic field) that keeps the radiation to a minimum, not to mention that Enceladus itself has a bit of a magnetic field due to its' iron core (like Earth, but much smaller and weaker), and because of the geysers reinforcing the Enceladus Torus, the location is quite ideal.

 

csa-mapping-plasmaprod.jpg

Image courtesy of UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS / MULLARD SPACE SCIENCE LABORATORY | https://www.ucl.ac.uk/mssl/planetary-science/nuggets/mssl-planetary-science-nuggets/csa-mapping-saturn-magnetosphere

 

:yes: That's why I favor Enceladus over Europa.

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Draggendrop    5,747

You must have had Europa on your mind...I went back a few pages and could not find anything other.......than everything else.......so I chuckled and figured you had a project on the go.......or were messing with me.  :woot:

 

When I mentioned the Earth's magnetic field, it is assumed a closed system. It's strength (at the surface, is 25 to 65 microTesla ) and serves the purpose for what our sun throws at us...most of the time. Since our core is above the "curie temperature", an external current outside of the immediate core, is responsible for our magnetic field. The core, and anomalous ferrous products can still focus the field. When two fields are in proximity, we can have constructive and/or destructive effects, due to "many" variables.

 

With the case of Enceladus, as you mentioned, it has a magnetic moment off core. Earth also has an off center moment. The cause of this moment depends on the science available such as the type of core, core temperature ( for curie temperature), anomalous ferromagnetic deposits, and/or a form of current to generate a weak field, which it has, by your data, and the added downfall of what looks like the possibility of destructive and/or constructive interference in various locations...either way, too weak to shield against cosmic radiation. Same issue with Mars and it can be dealt with. When you look at magnetic patterns, they can distort and or take a different path in a closed system, but will not shear. A shear is a tendril, not part of a closed system.

 

For a planet/moon, the trick is to have a magnetic field capable of repelling cosmic radiation AND whatever is being thrown at you on a regular basis by your friendly sun, whose strength, composition and age, along with your distance (and magnetic field strength ) from said offender.

 

Habitable "goldilock's zone" in my book, means more than just temperature, it is having a closed magnetic field which is not disrupted by a neighbor, and the field is capable of protection. If not, is the radiation capable of being mitigated for "life forms" to exist, where, as a colonizer or miner, human life form?

 

Besides, you know about the Europa warning...I won't step foot on it.

 

:D

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Unobscured Vision    2,678

I was super tired last night, and trying to make points that I had no Earthly (or Europan) business trying to make. Sometimes my brain just won't shut up when I get on a tangent. ;) 

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Jim K    13,735

Cool picture of 67P.  Unfortunately they didn't identify any other objects in the image (if they know what they are).

 

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In this CometWatch image, the small comet lobe is on the left and the large one on the right. The image was taken at a very large phase angle of about 159 degrees, meaning that the comet lies between the spacecraft and the Sun, and that all three are very close to being on the same line.

 

In this configuration, the nucleus appears backlit, with only a few portions of the illuminated surface visible from this view – in the upper and upper right part of the nucleus.

 

Thanks to the combination of a long, four-second exposure, no attenuation filter and a low-gain setting on the analogue signal processor of NAVCAM (a setting that is used to image bright targets), the image reveals the bright environment of the comet, displaying beautiful outflows of activity streaming away from the nucleus in various directions.

http://blogs.esa.int/rosetta/2016/04/01/cometwatch-27-march/

Comet_on_27_March_2016_NavCam_article_mob.jpg

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Draggendrop    5,747

Mars rover re-routed after spinning wheels on steep hillside

 

mars-rover-opportunity-shadow-PIA20328-b

A shadow and tracks of NASA’s Mars rover Opportunity appear in this March 22, 2016, image, which has been rotated 13.5 degrees to adjust for the tilt of the rover. The hillside descends to the left into “Marathon Valley.” The floor of Endeavour Crater is seen beneath the underside of a solar panel. Credit: NASA/JPL-Caltech

 

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NASA’s intrepid Opportunity rover, in its 13th year driving across the deserted landscapes of Mars, tried to climb a 32-degree incline a few weeks ago to reach a piece of terrain scientists think formed billions of years ago in the presence of water.

 

The mobile robot, which has outlived its original 90-day design life nearly 50 times over, has never attempted to scale such a steep hillside before.

 

Opportunity could not make it up the incline, and ended up spinning its wheels and slipping on the slope March 10, according to managers at NASA’s Jet Propulsion Laboratory in Pasadena, California, where the rover is managed and operated.

 

“Engineers anticipated that Opportunity’s six aluminum wheels would slip quite a bit during the uphill push, so they commanded many more wheel rotations than would usually be needed to travel the intended distance,” NASA said in a press release Wednesday.

 

Commanding the rover via time-delayed remote control, Opportunity’s Earth-based drivers programmed the robot to rotate its wheels enough to move the vehicle 66 feet (20 meters) on flat terrain. It turns out the rover only moved 3.5 inches (9 centimeters) due to slippage on the incline.

 

“This was the third attempt to reach the target and came up a few inches short,” NASA officials said.

 

Scientists hoped Opportunity could get close enough to touch the rock target, located at the top of “Knudsen Ridge” on the southern edge of a region dubbed “Marathon Valley,” for detailed analysis by the rover’s instruments.

 

Marathon Valley sits on the western rim of Endeavour Crater, which spans about 14 miles (22 kilometers) in diameter.

 

Rover drivers sent Opportunity back downhill 27 feet (8.2 meters), then about 200 feet (60 meters) southeast and uphill toward another rock target, according to NASA.

http://spaceflightnow.com/2016/04/01/mars-rover-re-routed-after-spinning-wheels-on-steep-hillside/

 

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The Moon thought to play a major role in maintaining Earth's magnetic field

 

gravitational-effects-lunar-sun-cyclical

The gravitational effects associated with the presence of the Moon and Sun cause cyclical deformation of the Earth's mantle and wobbles in its rotation axis. This mechanical forcing applied to the whole planet causes strong currents in the outer core, which is made up of a liquid iron alloy of very low viscosity. Such currents are enough to generate the Earth's magnetic field. Image courtesy Julien Monteux and Denis Andrault.

 

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The Earth's magnetic field permanently protects us from the charged particles and radiation that originate in the Sun. This shield is produced by the geodynamo, the rapid motion of huge quantities of liquid iron alloy in the Earth's outer core. To maintain this magnetic field until the present day, the classical model required the Earth's core to have cooled by around 3,000C over the past 4.3 billion years.

 

Now, a team of researchers from CNRS and Universite Blaise Pascal1 suggests that, on the contrary, its temperature has fallen by only 300C. The action of the Moon, overlooked until now, is thought to have compensated for this difference and kept the geodynamo active. Their work is published on 30 march 2016 in the journal Earth and Planetary Science Letters.

 

The classical model of the formation of Earth's magnetic field raised a major paradox. For the geodynamo to work, the Earth would have had to be totally molten four billion years ago, and its core would have had to slowly cool from around 6800C at that time to 3,800C today.

 

However, recent modeling of the early evolution of the internal temperature of the planet, together with geochemical studies of the composition of the oldest carbonatites and basalts, do not support such cooling. With such high temperatures being ruled out, the researchers propose another source of energy in their study.

 

The Earth has a slightly flattened shape and rotates about an inclined axis that wobbles around the poles. Its mantle deforms elastically due to tidal effects caused by the Moon. The researchers show that this effect could continuously stimulate the motion of the liquid iron alloy making up the outer core, and in return generate Earth's magnetic field.

 

The Earth continuously receives 3 700 billion watts of power through the transfer of the gravitational and rotational energy of the Earth-Moon-Sun system, and over 1,000 billion watts is thought to be available to bring about this type of motion in the outer core.

 

This energy is enough to generate the Earth's magnetic field, which together with the Moon, resolves the major paradox in the classical theory. The effect of gravitational forces on a planet's magnetic field has already been well documented for two of Jupiter's moons, Io and Europa, and for a number of exoplanets.

 

Since neither the Earth's rotation around its axis, nor the direction of its axis, nor the Moon's orbit are perfectly regular, their combined effect on motion in the core is unstable and can cause fluctuations in the geodynamo. This process could account for certain heat pulses in the outer core and at its boundary with the Earth's mantle.

 

Over the course of time, this may have led to peaks in deep mantle melting and possibly to major volcanic events at the Earth's surface. This new model shows that the Moon's effect on the Earth goes well beyond merely causing tides.

http://www.space-travel.com/reports/The_Moon_thought_to_play_a_major_role_in_maintaining_Earths_magnetic_field_999.html

 

This is extremely interesting. The "paper" is behind a paywall presently. I will look for a common access depository when it eventually gets released and will post when found.

 

:D

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Draggendrop    5,747

Mars topics....

 

Opportunity rover snaps photo of Martian dust devil

 

Opportunity-Sol-4332_1b_Ken-Kremer--768x

Credit: NASA / JPL / Cornell / Ken Kremer (kenkremer.com) / Marco Di Lorenzo

 

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NASA’s Opportunity Mars rover has captured a dust devil spinning across the barren floor of Endeavour Crater, an impact basin the robot has explored since 2011 in the mission’s long-lived second act.

 

The color mosaic presented here, created by Dr. Ken Kremer and Marco Di Lorenzo from publicly-available NASA imagery, show the dust devil swirling in the distance with the rover’s tracks in the foreground.

http://spaceflightnow.com/2016/04/03/opportunity-rover-snaps-photo-of-martian-dust-devil/

 

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Mile-high Mars mounds built by wind and climate change

 

112174_web.jpg

Gale Crater, the landing spot of the Mars rover Curiosity, has a three-mile-high mound at its center called Mount Sharp. The circle is the landing place of Curiosity. The blue line is its path.
CREDIT
NASA/JPL

 

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New research has found that wind carved massive mounds of more than a mile high on Mars over billions of years. Their location helps pin down when water on the Red Planet dried up during a global climate change event.

 

The research was published in the journal Geophysical Research Letters, a journal of the American Geophysical Union, on March 31.

 

The findings show the importance of wind in shaping the Martian landscape, a force that, on Earth, is overpowered by other processes, said lead author Mackenzie Day, a graduate student at The University of Texas at Austin Jackson School of Geosciences.

 

"On Mars there are no plate-tectonics, and there's no liquid water, so you don't have anything to overprint that signature and over billions of years you get these mounds, which speaks to how much geomorphic change you can really instigate with just wind," Day said. "Wind could never do this on Earth because water acts so much faster, and tectonics act so much faster."

 

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First spotted during NASA's Viking program in the 1970s, the mounds are at the bottom of craters. Recent analysis by the Mars rover Curiosity of Mount Sharp, a mound over three miles high inside Gale Crater, has revealed that the thickest ones are made of sedimentary rock, with bottoms made of sediments carried by water that used to flow into the crater and tops made of sediments deposited by wind. However, how the mounds formed inside craters that were once full of sediments was an open question.

 

"There's been a theory out there that these mounds formed from billions of years of wind erosion, but no one had ever tested that before," Day said. "So the cool thing about our paper is we figured out the dynamics of how wind could actually do that."

 

To test whether wind could create a mound, the researchers built a miniature crater 30 centimeters wide and 4 centimeters deep, filled it with damp sand, and placed it in a wind tunnel. They tracked the elevation and the distribution of sand in the crater until all of it had blown away. The model's sediment was eroded into forms similar to those observed in Martian craters, forming a crescent-shaped moat that deepened and widened around the edges of the crater. Eventually all that was left of the sediment was a mound -- which, in time, also eroded away.

 

"We went from a filled crater layer cake to this mounded shape that we see today," Day said.

 

To understand the wind dynamics, researchers also built a computer model that simulated how the wind flowed through the crater at different stages of erosion.

 

The mounds' structure helps link their formation to climate change on Mars, Kocurek said, with the bottom being built during a wet time, and the top built and mound shaped in a dry time.

 

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The research helped scientists home in on Mars' Noachian period, a geologic era that began about 3.7 billion years ago, as the period when Mars started to change from a wet world to a dry one. Scientists were able to link the climate change to the Noachian by studying the location of more than 30 mounds and finding that sedimentary mounds were only present on terrain that was exposed during that period.

 

112176_web.jpg

This images shows sediment-filled craters on Mars (top) in different stages of erosion compared with results of a crater model in a wind tunnel experiment (bottom). Warm colors reflect high elevation, and cool colors low elevation.
CREDIT
Mackenzie Day

 

http://www.eurekalert.org/pub_releases/2016-03/uota-mmm033016.php

 

http://www.marsdaily.com/reports/Martian_winds_slowly_build_enormous_mounds_over_billions_of_years_999.html

 

:)

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Draggendrop    5,747

At Venus, a Japanese Spacecraft is Almost Ready for Big Science

 

akatsuki-venus-jaxa.jpg?interpolation=la

This test image of Venus was captured in December 2015 by the Longwave IR camera aboard Japan's Akatsuki spacecraft.
Credit: JAXA

 

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A Japanese spacecraft's long-awaited Venus campaign is finally about to begin.

 

Japan's Akatsuki probe was originally supposed to arrive at Venus in December 2010, but an engine failure caused the spacecraft to miss its target and zoom off into orbit around the sun. But this past December, Akatsuki's handlers managed to guide the craft back to Venus, and now the probe is just about ready to start science operations.

 

"Akatsuki has been performing test observations by turning on its onboard observation instruments one by one," Japan Aerospace Exploration Agency (JAXA) officials wrote in an update on Friday (April 1).  [Japan at Venus: See the photos from Akatsuki]

 

"The instruments are starting up normally, and we have already conducted successful observations that are equivalent to a 'minimum success,'" they added. "Thus we will move to regular operations in mid-April."

 

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The $300 million Akatsuki spacecraft, whose name means "dawn" in Japanese, was designed to study Venus' clouds, weather and atmosphere up close using six different instruments. The probe's observations should help researchers better understand how Venus, which may have been quite Earth-like billions of years ago, became so hot and seemingly inhospitable to life, JAXA officials have said. 

 

The original plan called for Akatsuki to orbit Venus once every 30 hours, at a maximum distance (apoapsis) of about 50,000 miles (80,000 kilometers). But the second-chance run at Venus put the probe in a 13-day orbit that took Akatsuki as far as 273,000 miles (440,000 km) from the planet's surface, JAXA officials said.

 

Over the past few months, Akatsuki has been working to get to a less elliptical orbit; JAXA has stated that it wants the probe to be in a nine-day orbit with an apoapsis of about 193,000 miles (310,000 km) by the time regular operations begin.

 

Akatsuki should still be able to accomplish most of its original science goals from such an orbit, JAXA officials have said. The vessel launched in May 2010 along with JAXA's Ikaros probe, which became the first spacecraft ever to deploy and use a solar sail in interplanetary space.

http://www.space.com/32461-japan-venus-probe-akatsuki-science-ready.html

 

Japan at Venus: Photos from the Akatsuki Spacecraft's Mission

 

slide show with 18 images and descriptors

http://www.space.com/31325-venus-photos-by-japan-akatsuki-spacecraft.html

 

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Cassini conducting fly-by of Titan to sniff its atmosphere

 

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The Cassini spacecraft is conducting a fly-by pass of Titan on Monday, a pass that will involve two major science observations. Known as the “T-118” Titan encounter, two Cassini instruments are being employed to sniff and observe the moon’s atmosphere before beaming the information back to Earth for evaluation by scientists.

 

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Titan’s upper atmosphere is an active place where methane molecules are being broken apart by solar ultraviolet light and the byproducts combine to form compounds like ethane and acetylene.

 

Data from the pass will hopefully provide scientists with new insights about the density and composition of Titan’s atmosphere.

 

Cassini’s successful mission is heading towards its final year, itself part of an extension known as the “Solstice Mission”. Cassini’s fate involves controlled descent into Saturn’s atmosphere in September 2017.

more at the link...

https://www.nasaspaceflight.com/2016/04/cassini-fly-by-of-titan-sniff-atmosphere/

 

:)

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Draggendrop    5,747

One year on station at Ceres

 

PIA20355.jpg

Occator crator     NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI/LPI

 

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One year after taking up its new residence in the solar system, Dawn is continuing to witness extraordinary sights on dwarf planet Ceres. The indefatigable explorer is carrying out its intensive campaign of exploration from a tight orbit, circling its gravitational master at an altitude of only 240 miles (385 kilometers).

 

Even as we marvel at intriguing pictures and other discoveries, scientists are still in the early stages of putting together the pieces of the big puzzle of how (and where) Ceres formed, what its subsequent history has been, what geological processes are still occurring on this alien world and what all that reveals about the solar system.

 

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We now have high resolution pictures of essentially all of Ceres save the small area around the south pole cloaked in the deep dark of a long winter night. Seasons last longer on Ceres than on Earth, and Dawn may not operate there long enough for the sun to rise at the south pole. By the beginning of southern hemisphere spring in November 2016, Dawn's mission to explore the first dwarf planet discovered may have come to its end. In addition to photographing Ceres, Dawn conducts many other scientific observations, as we described in December and January. Among the probe's objectives at Ceres is to provide information for scientists to understand how much water is there, where it is, what form it is in and what role it plays in the geology.

 

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Dawn is now performing measurements that were not envisioned long in advance but rather developed only in the past two months, when it was apparent that the expedition could continue. And since March 19, Dawn has been following a new strategy to use even less hydrazine. Instead of pointing its sensors straight down at the scenery passing beneath it as the spacecraft orbits and Ceres rotates, the probe looks a little to the left.

 

The angle is only five degrees (equal to the angle the minute hand of a clock moves in only 50 seconds, or less than the interval between adjacent minute tick marks), but that is enough to decrease the use of hydrazine and thus extend the spacecraft's lifetime. (We won't delve into the reason here. But for fellow nerds, it has to do with the alignment of the axes of the operable reaction wheels with the plane in which Dawn rotates to keep its instruments pointed at Ceres and its solar arrays pointed at the sun. The hydrazine saving depends on the wheels' ability to store angular momentum and applies only in hybrid control, not in pure hydrazine control. Have fun figuring out the details. We did!)

 

The angle is small enough now that the pictures will not look substantially different, but they will provide data that will help determine the topography. (Measurements of gravity and the neutron, gamma ray and infrared spectra are insensitive to this angle.) Dawn took pictures at a variety of angles during the third mapping orbit at Ceres (and in two of the mapping orbits at Vesta, HAMO1 and HAMO2) in order to get stereo views for topography. That worked exceedingly well, and photos from this lower altitude will allow an even finer determination of the three dimensional character of the landscape in selected regions. Beginning on April 11, Dawn will look at a new angle to gain still another perspective.

 

That will actually increase the rate of hydrazine expenditure, but the savings now help make that more affordable. Besides, this is a mission of exploration and discovery, not a mission of hydrazine conservation. We save hydrazine when we can in order to spend it when we need it. Dawn's charge is to use the hydrazine to accomplish important scientific objectives and to pursue bold, exciting goals that lift our spirits and fuel our passion for knowledge and adventure. And that is exactly what it is has done and what it will continue to do.

 

Dawn is 240 miles (385 kilometers) from Ceres. It is also 3.90 AU (362 million miles, or 583 million kilometers) from Earth, or 1,505 times as far as the moon and 3.90 times as far as the sun today. Radio signals, traveling at the universal limit of the speed of light, 

more at the link...

http://www.spacedaily.com/reports/One_year_on_station_at_Ceres_999.html

 

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Saturn Is Absolutely Gorgeous in This Photo from NASA's Cassini Probe

 

saturn-askew.jpg?interpolation=lanczos-n

An image of Saturn, taken by the Cassini probe on Feb. 19, 2016. The spacecraft captured this image from roughly 1.2 million miles, at 7 degrees above the ring plane using its wide-angle camera. The moon Dione can be seen in the lower left of the image.
Credit: NASA/JPL-Caltech/Space Science Institute

 

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Saturn, the jewel of our solar system, reigns supreme in this spectacular new photo from NASA's Cassini spacecraft, which also captured the planet's stunning rings and the tiny moon Dione.

 

Typically, images of Saturn snapped by Cassini are oriented north up. But in this rarely seen image, which NASA released on Monday (April 4), Cassini reveals the massive planet, its rings and the terminator — the dividing line between darkness and light — at a 20-degree slant. As the planet approaches the northern summer solstice, Saturn's northern pole is sunlit the entire duration of the planet's day. 

 

In the black-and-white image, the diminuitive moon Dione  — one of Saturn's 62 known satellites — can be seen only as a tiny speck of light at 698 miles (1,123 kilometers) across in the lower left corner.

 

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Cassini captured this view of Saturn on Feb. 19 using its wide-angle camera. At the time, Cassini was about 1.2 million miles (1.9 million km) away from Saturn and had a view of the sunlit side of the planet from about 7 degrees above the ring plane, according to a NASA image description.

 

A combined initiative of NASA, ESA (the European Space Agency) and the Italian Space Agency, the Jet Propulsion Laboratory in California oversees the Cassini mission. From detecting liquid water on the moon Enceladus to a monster methane lake on Titan, countless revelations about Saturn and its system  have been returned to Earth by the Cassini orbiter and its two onboard cameras. 

http://www.space.com/32468-saturn-rings-gorgeous-cassini-photo.html

 

Photos: Saturn's Glorious Rings Up Close

slide show, 42 images with descriptors...

http://www.space.com/15218-saturn-rings-photos-space-gallery.html

 

:)

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Draggendrop    5,747

Are You Ready for the Transit of Mercury? Rare Event Occurs in May

 

mercury-transit-sun-2016.jpg?interpolati

On Monday, May 9, the planet Mercury will pass in front of the sun. Are you ready to watch it?
Credit: Starry Night Software

 

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Start preparing now for one of the major astronomical events of 2016: On May 9, Mercury will pass across the face of the sun in a rare sight.

 

From time to time, the inner planets, Mercury and Venus, pass between Earth and the sun and are visible as tiny black dots on the sun’s face.

 

Because their orbits are tilted at different angles from that of the Earth's, such transits do not occur very often, and those who want to watch these events should use specialized telescope equipment.

 

Transits of Venus occur less than twice a century. The last one occurred in 2012, and the next one won't be until 2117.

 

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The transit of Mercury on May 9 will begin just after 7 a.m. EDT and will end just before 3 p.m. The exact times for any location will vary slightly because of parallax effects. Use a planetarium program like Starry Night to get more exact times and to learn the position angle on the sun’s face where Mercury will first appear.

 

The entire transit is visible all over eastern North America, most of South America, western Europe, and the west coast of Africa. Parts of the transit are visible from western North America, southern South America, all of Africa and most of Asia. The only places where none of it is visible is in eastern Asia (including Japan), Indonesia, and Australasia. (Here's a map of its visibility.)

 

A transit of Mercury is not something you can decide to observe at the last minute, because it requires a certain amount of specialized equipment. The basic requirement is a properly equipped solar telescope. [How to Safely Photograph the Sun (A Photo Guide)]

 

Any attempt to observe the sun can be dangerous, and should only be attempted by observers who have the proper equipment and are aware of the dangers.

much more at the link, equipment required as well....

http://www.space.com/32476-mercury-transit-may-2016-rare-event.html

 

:)

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Draggendrop    5,747

Mars Longevity Champion Launched 15 Years Ago

 

PIA20331_ip.jpg

2001 Mars Odyssey launch     Image credit: NASA/JPL-Caltech/Arizona State University

 

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The NASA spacecraft that was launched 15 years ago this week carried the name 2001 Mars Odyssey and the hopes for reviving a stymied program of exploring the Red Planet.

 

Back-to-back failures of two Mars missions launched in 1999 had prompted an overhaul of NASA's Mars plans. It worked: Not only has Odyssey itself operated successfully longer than any other spacecraft ever sent to Mars, but during Odyssey's lifespan so far, all six subsequent NASA missions sent to Mars have also succeeded.

 

A Delta II launch vehicle lifted Odyssey from Cape Canaveral Air Force Station, Florida, on April 7, 2001. When the spacecraft reached Mars on Oct. 24, 2001, it fired its main engine to enter orbit. A three-month "aerobraking" phase followed, using carefully controlled dips into the upper atmosphere of Mars to adjust the size and shape of the orbit in preparation for systematic mapping of the Red Planet.

 

The year of the launch and arrival played into NASA naming the mission 2001 Mars Odyssey as a tribute to the vision and spirit of space exploration portrayed in the works of science-fiction author Arthur C. Clarke, including the best-seller "2001: A Space Odyssey." Clarke (1917-2008) endorsed the mission's naming before the launch.

 

Odyssey completed its prime mission in 2004. With repeated mission extensions, it became the longevity champion of Mars spacecraft in December 2010.

 

"Every day for more than five years, Odyssey has been extending its record for how long a spacecraft can keep working at Mars," said Odyssey Project Manager David Lehman of NASA's Jet Propulsion Laboratory, Pasadena, California. "The spacecraft is remarkably healthy, and we have enough fuel to last for several more years."

 

Lockheed Martin Space Systems, Denver, built the Odyssey spacecraft and collaborates with JPL in mission operations.

 

"In addition to the quality of this spacecraft, the careful way it is operated has been crucial to how it has stayed so productive so long," said Odyssey Project Scientist Jeffrey Plaut of JPL. "Odyssey was designed for a four-year mission. We're in the 15th year, and it keeps doing everything we ask it to do."

more at the link...

http://www.marsdaily.com/reports/Mars_Longevity_Champion_Launched_15_Years_Ago_999.html

 

-------------------------------

 

Help keep heat on Mars Express through data mining

 

Mars_Express_node_full_image_2.jpg

Artist's impression of Mars Express                 Alex Lutkus

 

Quote

Mars Express has been orbiting the Red Planet for 12 years. While its controllers know the spacecraft inside out, additional valuable insights may well be hidden within the mounds of telemetry the mission generates - inspiring the first of ESA's new data mining competitions, open to all.

 

"The goal of this Mars Express Power Challenge is to predict Mars Express's thermal power consumption during the martian year ahead, based on its past telemetry," explains Joerg Mueller, a Young Graduate Trainee in ESA's Advanced Concepts Team.

 

"Our intended audience for the competition is the international data mining and machine learning community - whether students, research groups or companies".

 

Data mining involves taking large amounts of data and applying sophisticated computer programs to search out previously hidden patterns, associations or anomalies.

 

The results can be used for machine learning - teaching computers to gain understanding of such patterns - and forecasting the data-generating system's future performance.

 

Such an apparently abstract discipline often produces extremely useful results in practical terms, across a wide variety of fields: sifting through astronomical observations for signs of dark matter, smarter text prediction, pinpointing adverse drug combinations within medical data or performing regional flood risk assessment.

 

"Competitors gain data to hone their techniques on challenging and useful space problems," comments Dario Izzo, ACT's scientific coordinator.

"This is the first of a number of planned competitions, in an attempt to demonstrate the usefulness of the approach and to establish a community of participants.

more at the link...

http://www.marsdaily.com/reports/Help_keep_heat_on_Mars_Express_through_data_mining_999.html

 

-----------------------------

 

Ancient Mars bombardment likely enhanced life-supporting habitat

 

112495_web.jpg

Ancient impacts on Mars likely enhanced climate conditions for life.
CREDIT
NASA

 

Quote

The bombardment of Mars some 4 billion years ago by comets and asteroids as large as West Virginia likely enhanced climate conditions enough to make the planet more conducive to life, at least for a time, says a new University of Colorado Boulder study.

 

CU-Boulder Professor Stephen Mojzsis said if early Mars was as barren and cold as it is today, massive asteroid and comet impacts would have produced enough heat to melt subsurface ice. The impacts would have produced regional hydrothermal systems on Mars similar to those in Yellowstone National Park, which today harbor chemically powered microbes, some of which can survive boiling in hot springs or inhabiting water acidic enough to dissolve nails.

 

Scientists have long known there was once running water on Mars, as evidenced by ancient river valleys, deltas and parts of lake beds, said Mojzsis. In addition to producing hydrothermal regions in portions of Mars' fractured and melted crust, a massive impact could have temporarily increased the planet's atmospheric pressure, periodically heating Mars up enough to "re-start" a dormant water cycle.

 

"This study shows the ancient bombardment of Mars by comets and asteroids would have been greatly beneficial to life there, if life was present," said Mojzsis, a professor in the geological sciences department. "But up to now we have no convincing evidence life ever existed there, so we don't know if early Mars was a crucible of life or a haven for life."

 

Published in Earth and Planetary Science Letters, the study was conducted by Mojzsis and Oleg Abramov, a researcher at the U.S. Geological Survey in Flagstaff, Arizona and a former CU-Boulder research scientist under Mojzsis.

 

Much of the action on Mars occurred during a period known as the Late Heavy Bombardment about 3.9 billion years ago when the developing solar system was a shooting gallery of comets, asteroids, moons and planets. Unlike Earth, which has been "resurfaced" time and again by erosion and plate tectonics, heavy cratering is still evident on Mercury, Earth's moon and Mars, Mojzsis said.

 

Mojzsis and Abramov used the Janus supercomputer cluster at the University of Colorado Computing facility for some of the 3-D modeling used in the study. They looked at temperatures beneath millions of individual craters in their computer simulations to assess heating and cooling, as well as the effects of impacts on Mars from different angles and velocities. A single model comprising the whole surface of Mars took up to two weeks to run on the supercomputer cluster, said Mojzsis.

 

The study showed the heating of ancient Mars caused by individual asteroid collisions would likely have lasted only a few million years before the Red Planet - about one and one-half times the distance to the sun than Earth - defaulted to today's cold and inhospitable conditions.

 

"None of the models we ran could keep Mars consistently warm over long periods," said Mojzsis.

 

While Mars is believed to have spent most of its history in a cold state, Earth was likely habitable over almost its entire existence. A 2009 study by Mojzsis and Abramov showed that the Late Heavy Bombardment period in the inner solar system nearly 4 billion years ago did not have the firepower to extinguish potential early life on Earth and may have even given it a boost if it was present.

 

"What really saved the day for Earth was its oceans," Mojzsis said. "In order to wipe out life here, the oceans would have had to have been boiled away. Those extreme conditions in that time period are beyond the realm of scientific possibility."

http://www.marsdaily.com/reports/Ancient_Mars_bombardment_likely_enhanced_life_supporting_habitat_999.html

 

:)

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+Mirumir    5,636
Quote

 

A renaissance for Russian space science

 

Russia’s renewed interest in the moon came after a Russian instrument hitched a ride in 2009 with NASA’s Lunar Reconnaissance Orbiter. The instrument, a neutron detector, spotted pockets of subsurface water ice. Russia’s leadership had rekindled dreams of putting cosmonauts on the moon—and here was a potential source of water. The Institute of Space Research (IKI) now has five lunar missions planned from 2018 to 2025, starting with Luna-25, a spacecraft that would land near the moon’s south pole. The European Space Agency (ESA) will take part in the first three missions. A highlight is a drill it’s designing for Luna-27, which would penetrate a meter into the regolith—the surface layer of dust and rock debris—to take samples. “We don’t know if the regolith is soft or hard. If it’s saturated with ice, it could be like drilling into concrete,” says James Carpenter, ESA’s lead scientist on Luna in Noordwijk, the Netherlands.

 

Some researchers are unimpressed with that science plan. “All that was done before—in the 1970s,” scoffs one Russian scientist. Carpenter disagrees. “The moon is not old hat,” he says. All lunar samples have come from a region that’s “not representative of the whole. If you want to understand all the science that has come before, you have to go to new places and take samples.” 

 

Humans won’t follow for a while. Russia’s budget woes will slow the human exploration program beyond the first mission’s stated target of 2025, Zelenyi says. But he denies rumors that Luna-25 will be delayed.

 

lunar_w_0.jpg?itok=OK4I4nP2&timestamp=14

 

 

Two other cornerstones of the Russian space revival are Mars and astrophysics. Phobos-Grunt, Russia’s next attempt to reach the Red Planet after Mars-96, brought back bad memories when it broke up after launch in 2011. Like Mars-96, it ended in a fiery crash in the Pacific Ocean—the subject of “jokes mixed with tears,” Zelenyi says. But Russia is teaming up with Europe on ExoMars, a twospacecraft mission. The first probe, designed to sniff for methane, was launched last month and is now en route to Mars, salving some of the sting of the earlier failures. And IKI and NASA are in early discussions on a possible joint mission to Venus after 2025.

 

Funds permitting, Russian astrophysics is poised for revival as well. On deck is SPEKTR-RG, a pair of x-ray telescopes that would map x-ray sources such as black holes and neutron stars. First conceived 25 years ago, the long-delayed project, now a joint effort with Germany, was revised twice. It’s become even more important to astronomers worldwide after last week’s possible loss of Japan’s x-ray telescope. “We found a niche, and there will be new physics,” Zelenyi promises. Launch is slated for September 2017, but that may slip, he says.

 

After that will come Gamma-400, “one of most ambitious projects in the world in next 10 years,” declares Nikolai Kolachevsky, director of the P.N. Lebedev Physical Institute (LPI) here. LPI is taking the lead on the gamma-ray telescope, slated for launch in 2022. Gamma-400 aims to probe the nature of dark matter and the origins of extragalactic cosmic rays, and will search for high-energy gamma-ray bursts. Along with technical hurdles and budget worries, the mission faces the impact of international sanctions imposed on Russia for annexing Crimea. Components that also have military uses, such as equipment for protecting the spacecraft from radiation, now are difficult to procure, Kolachevsky says.

 

Budget realities may yet force some missions onto the back burner. But for the first time since the Soviet breakup, Zelenyi says, Russian space scientists can look ahead with confidence. “Even though scientists want to have much more than the country can afford,” he says, “the next decade will be quite busy for us.”

 

 

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Draggendrop    5,747

Past and Present Moons of Saturn

 

ooSaturnspast.jpg

Saturn's rings, Titan, and Enceladus        NASA/JL/SSI

 

Quote

Saturn's beautiful rings form a striking feature, cutting across this image of two of the planet's most intriguing moons.

 

The rings have been a source of mystery since their discovery in 1610 by Galileo Galilei. There is not full agreement on how they formed, but among the possibilities are that they may have formed along with Saturn, or that they are debris of a former moon that strayed too close to the planet and was ripped apart.

 

The rings are now shepherded by the gravity of some of the planet's surviving moons. Of more than 60 known natural satellites, two of the most fascinating are also pictured in this image: Titan and Enceladus.

 

At 5150 km across, Titan is 10 times larger than Enceladus, which measures just 505 km in diameter. Titan is seen as a disc because light from the distant Sun is being refracted through the moon's dense atmosphere.

 

Somewhere on Titan's surface rests the Huygens probe. On 25 December 2004, Huygens detached from the Cassini mothership and, a few weeks later, parachuted through the dense atmosphere to return the first pictures of Titan's rugged landscape of icy mountains.

 

Although Enceladus is a smaller moon, it has as much character. The restless interior means that water constantly jets through cracks in the icy surface. In some images, these geysers can be glimpsed at the south pole.

 

The image was taken on 10 June 2006 in red light with the Cassini spacecraft's narrow-angle camera, and is orientated with north facing up. The spacecraft was some 3.9 million km from Enceladus and 5.3 million km from Titan.

 

Cassini itself is nearing the end of its mission, after 12 years exploring Saturn's system. It will be guided to a dramatic end, plunging into Saturn's atmosphere on 15 September 2017. Before then it will be moved into closer and closer orbits to the giant planet. Known as the Cassini Grand Finale, the spacecraft's movements will reveal details of Saturn's gravitational field.

 

As well as providing a way to determine the mass of the rings themselves, this will also tell scientists whether the ringed planet has a dense core of rocks and metal. If it does, it confirms that planets build up through the collision of smaller asteroid-like planetesimals.

http://spaceref.com/saturn/past-and-present-moons-of-saturn.html

 

----------------------

 

Coronal Hole Observed On The Sun

 

Quote

A long coronal hole can be seen right down the middle of the sun in this video captured by NASA's Solar Dynamics Observatory on March 23-25, 2016.

 

Coronal holes are areas on the sun where the solar magnetic field extends up and out into interplanetary space, sending solar material speeding out in a high-speed stream of solar wind. Scientists study these fast solar wind streams because they sometimes interact with Earth's magnetic field, creating what's called a geomagnetic storm, which can expose satellites to radiation and interfere with communications signals.

 

This video was captured in extreme ultraviolet wavelengths of 193 angstroms - a type of light that is typically invisible to our eyes, but is colorized here in bronze.

http://spaceref.com/space-weather-2/coronal-hole-observed-on-the-sun.html

 

NASA’s SDO Spies an Elongated Coronal Hole

video is 0:12 min.

 

 

:)

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Draggendrop    5,747

Alpha Centauri As Seen From Saturn

 

 

ooPIA10406.jpg

Alpha Centauri             NASA

 

Quote

The nearest star system (and the destination of Breakthrough Starshot) the trinary star Alpha Centauri, hangs above the horizon of Saturn.

 

Both Alpha Centauri A and B - stars very similar to our own - are clearly distinguishable in this image. The third star in the Alpha Centauri system, the red dwarf Proxima Centauri, is not visible here.

 

From the orbit of Saturn, light (as well as Cassini's radio signal) takes a little more than an hour travel to Earth. The distance to Alpha Centauri is so great that light from these stars takes more than four years to reach our Solar System. Thus, although Saturn seems a distant frontier, the nearest star is almost 30,000 times farther away.

 

This image is part of a stellar occultation sequence, during which Cassini watches as a star (or stars) as it passes behind Saturn. Light from the stars is attenuated by the uppermost reaches of Saturn's gaseous envelope, revealing information about the structure and composition of the planet's atmosphere.

 

The view was captured from about 66 degrees above the ringplane and faces southward on Saturn. Ring shadows mask the planet's northern latitudes at bottom.

 

The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on May 17, 2008. The view was obtained at a distance of approximately 534,000 kilometers (332,000 miles) from Saturn. Image scale on Saturn is about 3 kilometers (2 miles) per pixel.

http://spaceref.com/interstellar/alpha-centauri-as-seen-from-saturn.html

 

http://photojournal.jpl.nasa.gov/catalog/PIA10406

 

---------------------------------

 

Interstellar Dust Intercepted at Saturn

 

Interstellar_dust_at_Saturn_large.jpg

Interstellar dust at Saturn           NASA/ESA

 

Quote

14 April 2016
The international Cassini spacecraft has detected the faint but distinct signature of dust coming from outside our Solar System.

 

Cassini has been flying around the Saturnian system for 12 years, studying the giant planet and its rings and satellites. It has also found millions of ice-rich dust grains with its Cosmic Dust Analyser, the vast majority of which are from icy satellite Enceladus and which make up one of Saturn’s outer rings.

 

Amongst the grains detected, 36 stick out from the crowd – and scientists conclude they came from beyond our Solar System.

 

Alien dust in the Solar System is not entirely unexpected. In the 1990s, the ESA/NASA Ulysses mission made the first in-situ discovery of interstellar dust, later confirmed by NASA’s Galileo spacecraft.

 

The dust was traced back to the local interstellar cloud: an almost empty bubble of gas and dust we are travelling through with a distinct direction and speed.

 

The tiny dust grains were speeding through at over 72 000 km/h, fast enough to avoid being trapped inside the Solar System by Saturn’s – or even the Sun’s – gravity.

 

Local_interstellar_cloud_medium.jpg

Local interstellar cloud   NASA/ESA

 

Quote

Importantly, unlike Ulysses and Galileo, Cassini analysed the composition of the dust for the first time, showing them to be made of a very specific mixture of minerals, not ice.

 

They all had a surprisingly similar chemical make-up, containing major rock-forming elements like magnesium, silicon, iron and calcium in average cosmic proportions. Conversely, more reactive elements like sulphur and carbon were found to be less abundant compared to the average.

 

“Cosmic dust is produced when stars die, but with the vast range of types of stars in the Universe we naturally expected to encounter a huge range of dust types over the long period of our study,” says Frank Postberg, co-author on the paper and co-investigator of Cassini’s dust analyser, of the University of Heidelberg.

 

“Surprisingly, the grains we’ve detected aren’t old, pristine and compositionally diverse like the stardust grains we find in ancient meteorites,” says Mario Trieloff, a co-author also at the University of Heidelberg. “They have apparently been made rather uniform through some repetitive processing in the interstellar medium.”

 

The team speculate that dust in a star-forming region could be destroyed and recondense multiple times as the shockwaves from dying stars passed through, before the resulting similar grains ended up streaming towards our Solar System.

 

“The long duration of the Cassini mission has enabled us to use it like a micrometeorite observatory, providing us privileged access to the contribution of dust from outside our Solar System that could not have been obtained in any other way,” adds Nicolas.

http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens/Interstellar_dust_intercepted_at_Saturn

 

---------------------------

 

Europa's heaving ice might make more heat than scientists thought

 

113306_web.jpg

As the moon Europa's icy shell is pushed and pulled by Jupiter's gravity, it heaves up and down. That process creates enough heat, scientists think, to create a global subsurface ocean on Europa. Experiments by Brown University researchers suggests that this heating process, known as tidal dissipation, creates more heat in ice that scientists have generally assumed. The insight could help scientists model the thickness of Europa's icy shell.
CREDIT
NASA/JPL

 

Quote

PROVIDENCE, R.I. [Brown University] -- Jupiter's moon Europa is under a constant gravitational assault. As it orbits, Europa's icy surface heaves and falls with the pull of Jupiter's gravity, creating enough heat, scientists think, to support a global ocean beneath the moon's solid shell.

 

Now, experiments by geoscientists from Brown and Columbia universities suggest that this process, called tidal dissipation, could create far more heat in Europa's ice than scientists had previously assumed. The work could ultimately help researchers to better estimate the thickness of moon's outer shell.

 

Quote

The only way to create enough heat for these active processes so far from the sun is through tidal dissipation. The effect, McCarthy says, is a bit like what happens when someone repeatedly bends a metal coat hanger.

 

"If you bend it back and forth, you can feel it making heat at the junction," she said. "The way it does that is that internal defects within that metal are rubbing past each other, and it's a similar process to how energy would be dissipated in ice."

 

However, the details of the process in ice aren't very well understood, and modeling studies that try to capture those dynamics on Europa had yielded some puzzling results, the researchers say.

 

"People have been using simple mechanical models to describe the ice," McCarthy said. While those calculations suggested liquid water under Europa's surface, "they weren't getting the kinds of heat fluxes that would create these tectonics. So we ran some experiments to try to understand this process better."

 

Working with Reid Cooper, professor of Earth, environmental and planetary sciences at Brown, McCarthy loaded ice samples into a compression apparatus. She subjected the samples to cyclical loads similar to those acting on Europa's ice shell. When the loads are applied and released, the ice deforms and then rebounds to a certain extent. By measuring the lag time between the application of stress and the deformation of the ice, McCarthy could infer how much heat is generated.

 

The experiments yielded surprising results. Modeling approaches had assumed that most of the heat generated by the process comes from friction at the boundaries between the ice grains. That would mean that the size of the grains influences the amount of heat generated. But McCarthy found similar results even when she substantially altered the grain size in her samples, suggesting that grain boundaries are not the primary heat-generators in the process.

 

The work suggests that most of the heat actually comes from defects that form in the ice's crystalline lattice as a result of deformation. Those defects, the research showed, create more heat than would be expected from the grain boundaries.

 

"Christine discovered that, relative to the models the community has been using, ice appears to be an order of magnitude more dissipative than people had thought," Cooper said.

 

More dissipation equals more heat, and that could have implications for Europa.

 

"The beauty of this is that once we get the physics right, it becomes wonderfully extrapolative," Cooper said. "Those physics are first order in understanding the thickness of Europa's shell. In turn, the thickness of the shell relative to the bulk chemistry of the moon is important in understanding the chemistry of that ocean. And if you're looking for life, then the chemistry of the ocean is a big deal."

 

McCarthy and Cooper hope that modelers will make use of these findings as they try to unravel the mysteries of Europa's hidden ocean.

"This provides modelers with a new physics to apply," McCarthy said.

http://www.eurekalert.org/pub_releases/2016-04/bu-ehi041416.php

 

abstract at the link....paper at a paywall for now...

http://www.sciencedirect.com/science/article/pii/S0012821X16300930

 

:)

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Draggendrop    5,747

Heart-Shaped Sunspot Fires Off Powerful Flare

 

Quote

A huge, heart-shaped sunspot shot off a strong solar flare Sunday evening (April 17), temporarily disrupting radio communications here on Earth.

 

The flare erupted at 8:29 p.m. EDT Sunday (0029 GMT on Monday) from a giant sunspot known as active region (AR) 2529, which is currently big enough to fit nearly five Earths inside it. NASA's Solar Dynamics Observatory spacecraft captured amazing video of the solar flare as it happened.

 

The eruption caused moderate radio blackouts in some places, which have since cleared up, according to officials with the National Oceanic and Atmospheric Administration's Space Weather Prediction Center.

 

Sunday's flare clocked in at M6.7 on the three-tiered classification scale scientists use. In this system, C flares are the weakest, M flares are medium-strength and X flares are the most powerful. X flares are 10 times more potent than M flares, which, in turn, are 10 times stronger than C eruptions.

(And an M6 flare is six times more intense than an M1 event.)

 

Sunspots are dark areas on the surface of the sun that are slightly cooler than surrounding regions. Sunspots serve as launchpads for solar flares and coronal mass ejections (CMEs), which blast gigantic clouds of solar plasma into space at millions of miles per hour. (Flares, by contrast, are bursts of extremely energetic radiation.) 

http://www.space.com/32608-heart-sunspot-intense-solar-flare-video.html

 

solar-flare-heart-shaped-sunspot.gif?146

This footage from NASA’s Solar Dynamics Observatory spacecraft shows the heart-shaped sunspot AR 2529 firing off an M6.7 solar flare on April 17, 2016.
Credit: NASA/SDO/Goddard

 

 

heart-shaped-sunspot-ar2529.jpg?14610067

The heart-shaped sunspot AR 2529 is visible in the upper right of this image captured by NASA's Solar Dynamics Observatory. AR 2529 poduced a solar flare at 8:29 p.m. EDT on April 17, 2016.
Credit: NASA/SDO/Goddard

 

:)

 

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Unobscured Vision    2,678

Significant, but not anything to be concerned about. Those make decent photos, though; and help the Helio-Specialists with their research. :yes: 

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Jim K    13,735

Venus is coold (well in the polar region).  The polar atmosphere has an average temperature of -157 and is less dense than thought previously.  This is data from ESA's Venus Express.

 

Quote

When Müller-Wodarg and colleagues gathered their observations Venus Express was orbiting at an altitude of between 130 and 140 kilometres near Venus' polar regions, in a portion of Venus' atmosphere that had never before been studied in situ.

 

Previously, our understanding of Venus' polar atmosphere was based on observations gathered by NASA's Pioneer Venus probe in the late 1970s. These were of other parts of Venus' atmosphere, near the equator, but extrapolated to the poles to form a complete atmospheric reference model.

 

These new measurements, taken as part of the Venus Express Atmospheric Drag Experiment (VExADE) from 24 June to 11 July 2014, have now directly tested this model – and reveal several surprises.

 

For one, the polar atmosphere is up to 70 degrees colder than expected, with an average temperature of -157°C (114 K). Recent temperature measurements by Venus Express' SPICAV instrument (SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Venus) are in agreement with this finding.

 

The polar atmosphere is also not as dense as expected; at 130 and 140 km in altitude, it is 22% and 40% less dense than predicted, respectively. When extrapolated upward in the atmosphere, these differences are consistent with those measured previously by VExADE at 180 km, where densities were found to be lower by almost a factor of two.

 

Additionally, the polar region was found to be dominated by strong atmospheric waves, a phenomenon thought to be key in shaping planetary atmospheres – including our own.

More at the ESA

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Draggendrop    5,747
On 4/19/2016 at 2:01 AM, Unobscured Vision said:

Significant, but not anything to be concerned about. Those make decent photos, though; and help the Helio-Specialists with their research. :yes: 

Yes, for those of us down here, no "Carrington event", for sure...but it did cause short wave issues. I usually follow these developments for communications. Orbital platforms have different issues with flares. We have the ISS personnel who may not want a "free tanning solution" as they circle the planet every 90 minutes,  comm and broadcast satellites issues which crop up once in a while and then we have project cube sats which usually don't have the extra protective goodies. It would be a pain to work for over a year to get your project cube sat up...only to have Murphy's Law teach gambling strategy.

 

This sun spot that generated the flare was 5 times the size of Earth and the bets were on for an "event", it was just a matter of the roulette wheel, and we took a bit of a shot. Will probably here about minor damage in the months to come. :(

 

----------------------------

 

Y Marks the Spot

 

pia18366-1041.jpg

Image courtesy NASA/JPL-Caltech/Space Science Institute.

 

Quote

A sinuous feature snakes northward from Enceladus' south pole like a giant tentacle. This feature, which stretches from the terminator near center, toward upper left, is actually tectonic in nature, created by stresses in Enceladus' icy shell.

 

Geologists call features like these on Enceladus (313 miles or 504 kilometers across) "Y-shaped discontinuities." These are thought to arise when surface material attempts to push northward, compressing or displacing existing ice along the way.

 

Such features are also believed to be relatively young based on their lack of impact craters - a reminder of how surprisingly geologically active Enceladus is.

 

This view looks towards the trailing hemisphere of Enceladus. North is up. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Feb. 15, 2016.

 

The view was obtained at a distance of approximately 60,000 miles (100,000 kilometers) from Enceladus. Image scale is 1,900 feet (580 meters) per pixel.

http://www.spacedaily.com/reports/Y_Marks_the_Spot_999.html

 

--------------------------

 

New Ceres Images Show Bright Craters

 

oocerescolor.jpg

Ceres                 NASA

 

Quote

Craters with bright material on dwarf planet Ceres shine in new images from NASA's Dawn mission.

 

In its lowest-altitude mapping orbit, at a distance of 240 miles (385 kilometers) from Ceres, Dawn has provided scientists with spectacular views of the dwarf planet.

 

Haulani Crater, with a diameter of 21 miles (34 kilometers), shows evidence of landslides from its crater rim. Smooth material and a central ridge stand out on its floor. An enhanced false-color view allows scientists to gain insight into materials and how they relate to surface morphology. This image shows rays of bluish ejected material. The color blue in such views has been associated with young features on Ceres.

 

"Haulani perfectly displays the properties we would expect from a fresh impact into the surface of Ceres. The crater floor is largely free of impacts, and it contrasts sharply in color from older parts of the surface," said Martin Hoffmann, co-investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Gttingen, Germany.

 

The crater's polygonal nature (meaning it resembles a shape made of straight lines) is noteworthy because most craters seen on other planetary bodies, including Earth, are nearly circular. The straight edges of some Cerean craters, including Haulani, result from pre-existing stress patterns and faults beneath the surface. 

 

A hidden treasure on Ceres is the 6-mile-wide (10-kilometer-wide) Oxo Crater, which is the second-brightest feature on Ceres (only Occator's central area is brighter). Oxo lies near the 0 degree meridian that defines the edge of many Ceres maps, making this small feature easy to overlook. Oxo is also unique because of the relatively large "slump" in its crater rim, where a mass of material has dropped below the surface. Dawn science team members are also examining the signatures of minerals on the crater floor, which appear different than elsewhere on Ceres.

http://spaceref.com/ceres/new-ceres-images-show-bright-craters.html

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Draggendrop    5,747

Perigee Moon & Apogee Moon

 

mLF73KY.jpg

Credit    Bartosz Wojczyński

 

and.....

 

World's largest Moon photo, taken from Earth.

"scroll to zoom"

link to image, data and downloadable version

download image is 14000 x 14000, 18.9MB

or

1600 x 1600 with scroll zoom

 

160119-bigmoon.jpg

Credit   Bartosz Wojczyński

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DocM    16,611

USAF Vandenberg AFB, 30th Space Wing web banner

 

"to and from Space"

"Most Innovative Launch and Landing Team"

 

My, how things have changed....

 

AFG-140903-021.jpg

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Unobscured Vision    2,678

*snicker* ....

 

Makes ya wonder about the other 29 Space Wings ... :shifty: ... Sorry, I had to.

 

You're right, things really have changed compared to 20, 25 years ago. Back then, any of the Civilians on-Station who weren't part of the CSD (or who didn't have clearance -- but then again, to work at VAS you needed clearance, generally) would have been restricted to just a dozen or so locales, and then kindly asked to leave when the particular event they were there for had concluded. Now there are always civvies, and they work there. Sign of the times. :yes: 

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Draggendrop    5,747

Distant Dwarf Planet Makemake Has Its Own Moon!

 

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The dwarf planet Makemake has some company out in the cold, dark depths of the outer solar system.

 

Astronomers using NASA's Hubble Space Telescope have discovered a moon orbiting Makemake, which is the second-brightest object in the distant Kuiper Belt beyond Neptune. (Pluto is the brightest of these bodies.)

 

The newfound satellite — the first ever spotted around Makemake — is 1,300 times fainter than the dwarf planet and is thought to be about 100 miles (160 kilometers) in diameter, researchers said. The moon was spotted 13,000 miles (20,900 km) from the surface of Makemake, which itself is 870 miles (1,400 km) wide. [See images of the dwarf planet Makemake]

 

"Makemake is in the class of rare Pluto-like objects, so finding a companion is important," Alex Parker of the Southwest Research Institute (SwRI) in Boulder, Colorado, who led the image analysis for the Hubble observations, said in a statement today (April 26).

 

"The discovery of this moon has given us an opportunity to study Makemake in far greater detail than we ever would have been able to without the companion," Parker added.

 

makemake-moon-hubble.jpg?1461697641?inte

This photo by NASA’s Hubble Space Telescope reveals the first moon ever discovered around the dwarf planet Makemake. The 100-mile-wide (160 kilometers) satellite is barely visible just above Makemake, almost lost in the glare of the bright dwarf planet.
Credit: NASA, ESA, and A. Parker and M. Buie (SwRI)

 

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MK 2 was spotted in observations made by Hubble's Wide Field Camera 3 in April 2015, after several previous Makemake observation campaigns had failed to turn up any satellites.

 

"Our preliminary estimates show that the moon's orbit seems to be edge-on, and that means that often when you look at the system you are going to miss the moon because it gets lost in the bright glare of Makemake," Parker said.

 

makemake-moon-artist-concept.jpg?1461697

Artist's concept of the dwarf planet Makemake and its newfound moon, which has been nicknamed MK 2.
Credit: NASA, ESA, and A. Parker (Southwest Research Institute)

 

dwarf-planets-121120b-02.jpg?1353517196

 

http://www.space.com/32702-dwarf-planet-makemake-moon-hubble-discovery.html

 

also...

 

Hubble discovers moon orbiting the dwarf planet Makemake

http://www.spacedaily.com/reports/Hubble_discovers_moon_orbiting_the_dwarf_planet_Makemake_999.html

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Draggendrop    5,747

I made a boo boo ^ by not noticing that Space.com had an old infographic in the article above. We know now, via New Horizons, that Pluto is larger than Eris.

My apologies....diameter is 2370 km (1473 miles)

Dwarf Planet Pluto: Facts About the Icy Former Planet

http://www.space.com/43-pluto-the-ninth-planet-that-was-a-dwarf.html

 

---------------------------

 

Spectacular NASA Videos Reveal a Sun Storm in Jaw-Dropping 4K HD

 

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A spectacular new video of the sun captured by a NASA spacecraft puts you up close and personal with a fiery storm on our closest star — all in mind-boggling 4K resolution.

 

The video, taken by NASA's powerful Solar Dynamics Observatory (SDO), was recorded on April 17 as an active sunspot unleashed an intense solar flare. The heart-shaped sunspot AR 2529 fired off a moderate M6.7-class solar flare during the eruption. It appears in the video as a brilliant flash of light. 

 

"Solar flares are powerful bursts of radiation," NASA officials wrote in a video description. "Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel." 

 

The April 17 solar flare triggered only brief radio blackouts, NASA officials said. The SDO spacecraft, which keeps constant watch on the sun, recorded video of the event in several wavelengths of extreme ultraviolet light, they added.

more at the link...

http://www.space.com/32753-spectacular-nasa-solar-flare-4k-videos.html

 

'Heart Shaped' Sunspot's Big Blast Displayed in NASA UHD Montage

video is 1:19 min.

 

 

Full 4K at...

http://www.space.com/32733-heart-shaped-sunspot-s-big-blast-displayed-in-nasa-uhd-montage-video.html

 

:)

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Draggendrop    5,747

NASA's Curiosity Rover on Mars Is Climbing a Mountain Despite Wheel Damage

 

mars_rover_wheel_wear_tear.jpg?interpola

The team operating NASA's Curiosity Mars rover uses the MAHLI camera on the rover's arm to check the condition of the wheels at routine intervals.
Credit: NASA/JPL-Caltech/MSSS

 

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The rugged terrain on Mars is taking its toll on the six wheels of NASA's Curiosity rover, but the Red Planet robot should be able to complete its mountain-climbing science mission regardless, NASA officials said.

 

NASA's car-size Curiosity rover has been exploring the lower reaches of Mars' 3-mile-high (5 kilometers) Mount Sharp since September 2014, gathering data that mission scientists hope will shed light on the Red Planet's past potential to host microbial life.

 

Careful monitoring of the rover's aluminum wheels suggests that Curiosity should be able to get high enough up the mountain to complete this task, said Curiosity deputy project manager Steve Lee, of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. [Amazing Mars Photos by NASA's Curiosity Rover (Latest Images)]

 

"Cracks and punctures have been gradually accumulating at the pace we anticipated, based on testing we performed at JPL," Lee said in a statement. "Given our longevity projections, I am confident these wheels will get us to the destinations on Mount Sharp that have been in our plans since before landing."

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Curiosity touched down inside Mars' 96-mile-wide (154 km) Gale Crater in August 2012 and soon found evidence that the area could have supported microbial life in the ancient past. In July 2013, the rover set out for the base of Mount Sharp, initiating a 5-mile-long (8 km) journey that would take 14 months to complete.

 

The driving in Gale Crater has been rough. Holes and punctures in the robot's aluminum wheels, whose skin is just half as thick as a dime, became noticeable in 2013; Curiosity's handlers responded by routing the rover over gentler terrain to the extent possible and ramping up wheel testing at JPL.

 

This Earth-based work suggested that the 20-inch-tall (51 centimeters) wheels reach about 60 percent of their mileage limit at a specific point: when three of their 19 grousers — the zigzag treads that provide traction and bear most of Curiosity's weight — have broken, NASA officials said.

 

So far, the mission team has seen no evidence of any broken grousers, the officials added. (Curiosity takes photos of its wheels every 1,650 feet, or 500 meters.) The rover, NASA officials said, should therefore be able to make it to three key sites that Curiosity team members have been targeting for quite some time: an area rich in hematite, an iron-oxide mineral; a rock unit located farther on that hosts lots of clay minerals; and another rock site beyond that containing sulfates.

 

"At a current odometry of 7.9 miles (12.7 km) since its August 2012 landing, Curiosity's wheels are projected to have more than enough life remaining to investigate the hematite, clay and sulfate units ahead, even in the unlikely case that up to three grousers break soon," NASA officials wrote in the same statement. "The driving distance to the start of the sulfate-rich layers is roughly 4.7 miles (7.5 km) from the rover's current location."

 

nauklift_plateau_mars.jpg?1462245386?int

This 360-degree panorama from the Mastcam on NASA's Curiosity Mars rover shows the rugged surface of "Naukluft Plateau" plus upper Mount Sharp at right and part of the rim of Gale Crater.
Credit: NASA/JPL-Caltech/MSSS

 

gale_crater_mars_morning.jpg?1462245538?

This early-morning view from the Mastcam on NASA's Curiosity Mars rover on March 16, 2016, covers a portion of the inner wall of Gale Crater. At right, the image fades into glare of the rising sun.
Credit: NASA/JPL-Caltech/MSSS

 

http://www.space.com/32774-mars-rover-curiosity-mountain-climb-wheel-damage.html

 

It's just my opinion, but those wheels should have been designed and tested in a more rigorous fashion....to prevent this wear.

 

------------------------------------

 

Clues about Volcanoes Under Ice on Ancient Mars

 

PIA20335-16.jpg

Evidence of ancient subgalcial Martian volcanoes                NASA

 

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Volcanoes erupted beneath an ice sheet on Mars billions of years ago, far from any ice sheet on the Red Planet today, new evidence from NASA's Mars Reconnaissance Orbiter suggests.

 

The research about these volcanoes helps show there was extensive ice on ancient Mars. It also adds information about an environment combining heat and moisture, which could have provided favorable conditions for microbial life.

 

Sheridan Ackiss of Purdue University, West Lafayette, Indiana, and collaborators used the orbiter's mineral-mapping spectrometer to investigate surface composition in an oddly textured region of southern Mars called "Sisyphi Montes." The region is studded with flat-topped mountains. Other researchers previously noted these domes' similarity in shape to volcanoes on Earth that erupted underneath ice.

 

Clues about Volcanoes Under Ice on Ancient Mars

 

"Rocks tell stories. Studying the rocks can show how the volcano formed or how it was changed over time," Ackiss said. "I wanted to learn what story the rocks on these volcanoes were telling."

 

When a volcano begins erupting beneath a sheet of ice on Earth, the rapidly generated steam typically leads to explosions that punch through the ice and propel ash high into the sky. For example, the 2010 eruption of ice-covered Eyjafjallajkull in Iceland lofted ash that disrupted air travel across Europe for about a week.

 

Characteristic minerals resulting from such subglacial volcanism on Earth include zeolites, sulfates and clays. Those are just what the new research has detected at some flat-topped mountains in the Sisyphi Montes region examined with the spacecraft's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), providing resolution of about 60 feet (18 meters) per pixel.

 

"We wouldn't have been able to do this without the high resolution of CRISM," Ackiss said.

 

The Sisyphi Montes region extends from about 55 degrees to 75 degrees south latitude. Some of the sites that have shapes and compositions consistent with volcanic eruptions beneath an ice sheet are about 1,000 miles (about 1,600 kilometers) from the current south polar ice cap of Mars. The cap now has a diameter of about 220 miles (about 350 kilometers).

 

The Mars Reconnaissance Orbiter Project has been using CRISM and five other instruments on the spacecraft to investigate Mars since 2006. The project is managed by NASA's Jet Propulsion Laboratory, Pasadena, California, for the agency's Science Mission Directorate, Washington. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, provided and operates CRISM. Lockheed Martin Space Systems in Denver built the orbiter and supports its operations.

 

NASA has three active orbiters and two rovers at Mars that are advancing knowledge about the Red Planet that is useful in planning future missions that will take humans there.

http://spaceref.com/mars/clues-about-volcanoes-under-ice-on-ancient-mars.html

 

:D

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Draggendrop    5,747

First Global Topographic Map of Mercury Released

 

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Release Date: MAY 6, 2016
The first topographic map of Mercury was released today by the U.S. Geological Survey, Arizona State University, Carnegie Institute of Washington, Johns Hopkins University Applied Physics Laboratory and NASA.

 

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This high-resolution map provides the first comprehensive view of Mercury’s entire surface, illustrating the planet’s craters, volcanoes and tectonic landforms. This product brings together observations and scientific findings from NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which was the first spacecraft to orbit Mercury.

 

Scientists used data from the MESSENGER spacecraft to produce a highly detailed topographic map, similar to the type of map used by hikers to illustrate elevation changes and landforms. The spacecraft's cameras and sophisticated instruments collected unprecedented images during MESSENGER’s mission, which began in 2011 and included 4,104 orbits around Mercury. The new USGS map and rotating animation of the planet are available online.

https://www.usgs.gov/news/first-global-topographic-map-mercury-released

Mercury_DEM_white_robinson_grid_nomen%20

The full Topographic Map of Mercury with labeled features. The highest elevation on the planet is located just south of the equator, and about 2.5 miles above Mercury's average elevation. The lowest elevation, which is more than three miles below Mercury’s average, is found on the floor of Rachmaninoff basin, a basin suspected to host some of the most recent volcanic deposits on the planet.

 

video and maps...

http://astrogeology.usgs.gov/maps/mercury-messenger-global-digital-elevation-model

 

Mercury's Global Topography Model Revealed In New Animation

video is 1:16 min.

 

 

 

:D

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