Solar System News (miscellaneous articles)

[Draggendrop Veteran]

New Ceres Views as Dawn Moves Higher

 

Occator Crater, home of Ceres' intriguing brightest areas, is prominently featured in this image from NASA's Dawn spacecraft.
Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

 

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The brightest area on Ceres stands out amid shadowy, cratered terrain in a dramatic new view from NASA's Dawn spacecraft, taken as it looked off to the side of the dwarf planet. Dawn snapped this image on Oct. 16, from its fifth science orbit, in which the angle of the sun was different from that in previous orbits. Dawn was about 920 miles (1,480 kilometers) above Ceres when this image was taken -- an altitude the spacecraft had reached in early October.

    

Occator Crater, with its central bright region and secondary, less-reflective areas, appears quite prominent near the limb, or edge, of Ceres. At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor.

 

The impact that formed the crater millions of years ago unearthed material that blanketed the area outside the crater, and may have triggered the upwelling of salty liquid. 

 

"This image captures the wonder of soaring above this fascinating, unique world that Dawn is the first to explore," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

 

Dawn scientists also have released an image of Ceres that approximates how the dwarf planet's colors would appear to the human eye. This view, produced by the German Aerospace Center in Berlin, combines images taken from Dawn's first science orbit in 2015, using the framing camera's red, green and blue filters. The color was calculated based on the way Ceres reflects different wavelengths of light.

 

The spacecraft has gathered tens of thousands of images and other information from Ceres since arriving in orbit on March 6, 2015. After spending more than eight months studying Ceres at an altitude of about 240 miles (385 kilometers), closer than the International Space Station is to Earth, Dawn headed for a higher vantage point in August. In October, while the spacecraft was at its 920-mile altitude, it returned images and other valuable insights about Ceres.

 

On Nov. 4, Dawn began making its way to a sixth science orbit, which will be over 4,500 miles (7,200 kilometers) from Ceres. While Dawn needed to make several changes in its direction while spiraling between most previous orbits at Ceres, engineers have figured out a way for the spacecraft to arrive at this next orbit while the ion engine thrusts in the same direction that Dawn is already going. This uses less hydrazine and xenon fuel than Dawn's normal spiral maneuvers. Dawn should reach this next orbit in early December.

 

One goal of Dawn's sixth science orbit is to refine previously collected measurements. The spacecraft’s gamma ray and neutron spectrometer, which has been investigating the composition of Ceres' surface, will characterize the radiation from cosmic rays unrelated to Ceres. This will allow scientists to subtract "noise" from measurements of Ceres, making the information more precise.

 

The spacecraft is healthy as it continues to operate in its extended mission phase, which began in July. During the primary mission, Dawn orbited and accomplished all of its original objectives at Ceres and protoplanet Vesta, which the spacecraft visited from July 2011 to September 2012.

https://www.nasa.gov/feature/jpl/new-ceres-views-as-dawn-moves-higher

 

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Ceres in Color

 

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

 

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This image of Ceres approximates how the dwarf planet's colors would appear to the eye. This view of Ceres, produced by the German Aerospace Center in Berlin, combines images taken during Dawn's first science orbit in 2015 using the framing camera's red, green and blue spectral filters. The color was calculated using a reflectance spectrum, which is based on the way that Ceres reflects different wavelengths of light and the solar wavelengths that illuminate Ceres.

https://www.nasa.gov/image-feature/jpl/pia21079/ceres-in-color

 

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Ceres Feature Names: September 2016
This topographical map of Ceres, made with images from NASA's Dawn spacecraft, shows all of the dwarf planet  NASA/JPL

 

http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA20918

 

 

 

The Case of the Missing Ceres Craters

Scientists with NASA's Dawn mission have found that, surprisingly, Ceres lacks any truly large impact basins.  NASA/JPL

 

http://dawn.jpl.nasa.gov/news/news-detail.html?id=6577

 

 

 

 

Flight Over Ceres
This frame is from a simulated flight of NASA's Dawn over Ceres which emphasizes the most prominent craters, as well as the mountain Ahuna Mons. NASA/JPL

 

http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA20019

 

DAWN

https://www.nasa.gov/mission_pages/dawn/main/index.html

 

DAWN

http://dawn.jpl.nasa.gov/mission/

 

Images....

http://dawn.jpl.nasa.gov/multimedia/images/ceres.html

 

[Jim K Global Moderator]

Cassini preparing for 'Ring-Grazing Orbits'

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First Phase in Dramatic Endgame for Long-Lived Cassini Spacecraft

 

A thrilling ride is about to begin for NASA's Cassini spacecraft. Engineers have been pumping up the spacecraft's orbit around Saturn this year to increase its tilt with respect to the planet's equator and rings. And on Nov. 30, following a gravitational nudge from Saturn's moon Titan, Cassini will enter the first phase of the mission's dramatic endgame.

 

Launched in 1997, Cassini has been touring the Saturn system since arriving there in 2004 for an up-close study of the planet, its rings and moons. During its journey, Cassini has made numerous dramatic discoveries, including a global ocean within Enceladus and liquid methane seas on Titan.

Between Nov. 30 and April 22, Cassini will circle high over and under the poles of Saturn, diving every seven days -- a total of 20 times -- through the unexplored region at the outer edge of the main rings.

 

"We're calling this phase of the mission Cassini's Ring-Grazing Orbits, because we'll be skimming past the outer edge of the rings," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. "In addition, we have two instruments that can sample particles and gases as we cross the ringplane, so in a sense Cassini is also 'grazing' on the rings."

On many of these passes, Cassini's instruments will attempt to directly sample ring particles and molecules of faint gases that are found close to the rings. During the first two orbits, the spacecraft will pass directly through an extremely faint ring produced by tiny meteors striking the two small moons Janus and Epimetheus. Ring crossings in March and April will send the spacecraft through the dusty outer reaches of the F ring.

 

"Even though we're flying closer to the F ring than we ever have, we'll still be more than 4,850 miles (7,800 kilometers) distant. There’s very little concern over dust hazard at that range," said Earl Maize, Cassini project manager at JPL.

 

The F ring marks the outer boundary of the main ring system; Saturn has several other, much fainter rings that lie farther from the planet. The F ring is complex and constantly changing: Cassini images have shown structures like bright streamers, wispy filaments and dark channels that appear and develop over mere hours. The ring is also quite narrow -- only about 500 miles (800 kilometers) wide. At its core is a denser region about 30 miles (50 kilometers) wide.

 

Cassini's ring-grazing orbits offer unprecedented opportunities to observe the menagerie of small moons that orbit in or near the edges of the rings, including best-ever looks at the moons Pandora, Atlas, Pan and Daphnis.

 

 

/snip

More at NASA

 

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Margaret Hamilton (Apollo Software Engineer) has been awarded the Presidential Medal of Freedom.  The Presidential Medal of Freedom (and the comparable Congressional Gold Medal) is the Nation’s highest civilian honor, presented to individuals who have made especially meritorious contributions to the security or national interests of the United States, to world peace, or to cultural or other significant public or private endeavors.

 

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Forty-seven years ago, humans first set foot on the Moon during the Apollo 11 mission. That success would not have been possible if not for the team of 400,000 people who worked to ensure the success of the mission and the safety of astronauts Neil Armstrong, Buzz Aldrin and Michael Collins. One of those 400,000 people was Margaret Hamilton. On November 22, 2016, President Barack Obama awarded Hamilton the Presidential Medal of Freedom for her contribution that led to Apollo 11's successful landing. 

The very first contract NASA issued for the Apollo program (in August 1961) was with the Massachusetts Institute of Technology to develop the guidance and navigation system for the Apollo spacecraft. Hamilton, a computer programmer, would wind up leading the Software Engineering Division of the MIT Instrumentation Laboratory (now Draper Labs). Computer science, as we now know it, was just coming into existence at the time. Hamilton led the team that developed the building blocks of software engineering – a term that she coined herself. Her systems approach to the Apollo software development and insistence on rigorous testing was critical to the success of Apollo. As she noted, “There was no second chance. We all knew that.”

Her approach proved itself on July 20, 1969, when minutes before Armstrong and Aldrin landed on the Moon, the software overrode a command to switch the flight computer’s priority system to a radar system. The override was announced by a “1202 alarm” which let everyone know that the guidance computer was shedding less important tasks (like rendezvous radar) to focus on steering the descent engine and providing landing information to the crew. Armstrong and Aldrin landed on the Moon, rather than aborting the approach due to computer problems. In fact, the Apollo guidance software was so robust that no software bugs were found on any crewed Apollo missions, and it was adapted for use in Skylab, the Space Shuttle, and the first digital fly-by-wire systems in aircraft. Hamilton was honored by NASA in 2003, when she was presented a special award recognizing the value of her innovations in the Apollo software development. The award included the largest financial award that NASA had ever presented to any individual up to that point.

 

NASA
 

1:32:14 into the video 

 

 

Other names receiving the medal this year: Kareem Abdul-Jabbar, Tom Hanks, Bill and Melinda Gates and others.  The full list can be viewed here.

https://www.whitehouse.gov/the-press-office/2016/11/16/president-obama-names-recipients-presidential-medal-freedom

 

Very cool.  

[Jim K Global Moderator]

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Cassini Beams Back First Images from New Orbit

 

NASA's Cassini spacecraft has sent to Earth its first views of Saturn’s atmosphere since beginning the latest phase of its mission. The new images show scenes from high above Saturn's northern hemisphere, including the planet's intriguing hexagon-shaped jet stream.

 

Cassini began its new mission phase, called its Ring-Grazing Orbits, on Nov. 30. Each of these weeklong orbits -- 20 in all -- carries the spacecraft high above Saturn's northern hemisphere before sending it skimming past the outer edges of the planet's main rings.

 

Cassini’s imaging cameras acquired these latest views on Dec. 2 and 3, about two days before the first ring-grazing approach to the planet. Future passes will include images from near closest approach, including some of the closest-ever views of the outer rings and small moons that orbit there.

"This is it, the beginning of the end of our historic exploration of Saturn. Let these images -- and those to come -- remind you that we’ve lived a bold and daring adventure around the solar system’s most magnificent planet," said Carolyn Porco, Cassini imaging team lead at Space Science Institute, Boulder, Colorado.

 

The next pass by the rings' outer edges is planned for Dec. 11. The ring-grazing orbits will continue until April 22, when the last close flyby of Saturn's moon Titan will once again reshape Cassini's flight path. With that encounter, Cassini will begin its Grand Finale, leaping over the rings and making the first of 22 plunges through the 1,500-mile-wide (2,400-kilometer) gap between Saturn and its innermost ring on April 26.

 

On Sept. 15, the mission's planned conclusion will be a final dive into Saturn's atmosphere. During its plunge, Cassini will transmit data about the atmosphere's composition until its signal is lost.

Launched in 1997, Cassini has been touring the Saturn system since arriving in 2004 for an up-close study of the planet, its rings and moons. Cassini has made numerous dramatic discoveries, including a global ocean with indications of hydrothermal activity within the moon Enceladus, and liquid methane seas on another moon, Titan.

 

This collage of images from NASA's Cassini spacecraft shows Saturn's northern hemisphere and rings as viewed with four different spectral filters. Each filter is sensitive to different wavelengths of light and reveals clouds and hazes at different altitudes.

 

For details about Cassini's ring-grazing orbits, visit:

https://saturn.jpl.nasa.gov/news/2966/ring-grazing-orbits

 

This view from NASA's Cassini spacecraft was obtained about half a day before its first close pass by the outer edges of Saturn's main rings during its penultimate mission phase.

 

The view shows part of the giant, hexagon-shaped jet stream around the planet's north pole. Each side of the hexagon is about as wide as Earth. A circular storm lies at the center, at the pole (see PIA14944).

 

The image was taken with the Cassini spacecraft wide-angle camera on Dec. 3, 2016, at a distance of about 240,000 miles (390,000 kilometers) from Saturn. Image scale is 14 miles (23 kilometers) per pixel.

Source: NASA

 

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Chaos at Hyperion

 

 

The moon Hyperion tumbles as it orbits Saturn. Hyperion's (168 miles or 270 kilometers across) spin axis has a chaotic orientation in time, meaning that it is essentially impossible to predict how the moon will be spinning in the future. So far, scientists only know of a few bodies with such chaotic spins.

 

The image was taken in green light with the Cassini spacecraft narrow-angle camera on Aug. 22, 2016.

 

The view was acquired at a distance of approximately 203,000 miles (326,000 kilometers) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 10 degrees. Image scale is 1 mile (2 kilometers) per pixel.

Source: NASA

 

 

[Jim K Global Moderator]

Mars has some neat looking landscapes.

 

 

Many Martian landscapes contain features that are familiar to ones we find on Earth, like river valleys, cliffs, glaciers and volcanos.

 

However, Mars has an exotic side too, with landscapes that are alien to Earthlings. This image shows one of these exotic locales at the South Pole. The polar cap is made from carbon dioxide (dry ice), which does not occur naturally on the Earth. The circular pits are holes in this dry ice layer that expand by a few meters each Martian year.

 

New dry ice is constantly being added to this landscape by freezing directly out of the carbon dioxide atmosphere or falling as snow. Freezing out the atmosphere like this limits how cold the surface can get to the frost point at -130 degrees Celsius (-200 F). Nowhere on Mars can ever get any colder this, making this this coolest landscape on Earth and Mars combined.

 

This is a stereo pair with ESP_047237_0930.

 

NASA

 

 

Opportunity View of 'Private Joseph Field' on Mars

 

 

This image of a target called "Private Joseph Field" combines four images from the microscopic imager on the robotic arm of NASA's Mars Exploration Rover Opportunity, with enhanced color information added from the rover's panoramic camera.

 

This target is within the "Marathon Valley" area of the western rim of Endeavour Crater. The component images were taken on May 29, 2016, during the 4,389th Martian day, or sol, of Opportunity's work on Mars. The mosaic shows an area spanning about 2 inches (5 centimeters).

 

Geochemical data indicate the presence of magnesium and iron sulfates at this location, most likely corresponding to the white pebble visible near the center of the image. These sulfates may have formed by the interaction of acidic fluids with the rocks along the rim of Endeavour crater.

 

JPL

 

[Jim K Global Moderator]

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This image from NASA's Cassini spacecraft is one of the highest-resolution views ever taken of Saturn's moon Pandora. Pandora (52 miles, 84 kilometers) across orbits Saturn just outside the narrow F ring.

 

The spacecraft captured the image during its closest-ever flyby of Pandora on Dec. 18, 2016, during the third of its grazing passes by the outer edges of Saturn's main rings. (For Cassini's closest view prior to this flyby, see PIA07632, which is also in color.)

 

The image was taken in green light with the Cassini spacecraft narrow-angle camera at a distance of approximately 25,200 miles (40,500 kilometers) from Pandora. Image scale is 787 feet (240 meters) per pixel.

 

/snip

 

This was taken by Voyager 2 of Pandora in 1981

 

NASA

 

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Erosion-carved troughs that grow and branch during multiple Martian years may be infant versions of larger features known as Martian "spiders," which are radially patterned channels found only in the south polar region of Mars.

 

Researchers using NASA's Mars Reconnaissance Orbiter (MRO) report the first detection of cumulative growth, from one Martian spring to another, of channels resulting from the same thawing-carbon-dioxide process believed to form the spider-like features.

 

The spiders range in size from tens to hundreds of yards (or meters). Multiple channels typically converge at a central pit, resembling the legs and body of a spider. For the past decade, researchers have checked in vain with MRO's High Resolution Imaging Science Experiment (HiRISE) camera to see year-to-year changes in them.

 

"We have seen for the first time these smaller features that survive and extend from year to year, and this is how the larger spiders get started," said Ganna Portyankina of the University of Colorado, Boulder. "These are in sand-dune areas, so we don't know whether they will keep getting bigger or will disappear under moving sand."

 

Dunes appear to be a factor in how the baby spiders form, but they may also keep many from persisting through the centuries needed to become full-scale spiders. The amount of erosion needed to sculpt a typical spider, at the rate determined from observing active growth of these smaller troughs, would require more than a thousand Martian years. That is according to an estimate by Portyankina and co-authors in a recent paper in the journal Icarus. One Martian year lasts about 1.9 Earth years.

 

/snip

 

These five images from the HiRISE camera on NASA's Mars Reconnaissance Orbiter show different Martian features of progressively greater size and complexity, all thought to result from thawing of seasonal carbon dioxide ice that covers large areas near Mars' south pole during winter.

 

Full article at NASA

 

 

 

Also ... 48 years ago today ... the first manned launch (Frank Borman, James Lovell and William Anders) aboard the Saturn V ... and the first manned flight to the moon.  Amazing that only 7 and half years separated Alan Shepard's flight (May, '61) aboard a Mercury-Redstone to this beast of a rocket.

 

 

...and they gave us this.

 

[Jim K Global Moderator]

Earth/Moon as seen from the Mars Reconnaissance Orbiter currently orbiting ... Mars.  

 

 

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This composite image of Earth and its moon, as seen from Mars, combines the best Earth image with the best moon image from four sets of images acquired on Nov. 20, 2016, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

 

Each was separately processed prior to combining them so that the moon is bright enough to see. The moon is much darker than Earth and would barely be visible at the same brightness scale as Earth. The combined view retains the correct sizes and positions of the two bodies relative to each other.

 

HiRISE takes images in three wavelength bands: infrared, red, and blue-green. These are displayed here as red, green, and blue, respectively. This is similar to Landsat images in which vegetation appears red. The reddish feature in the middle of the Earth image is Australia. Southeast Asia appears as the reddish area (due to vegetation) near the top; Antarctica is the bright blob at bottom-left. Other bright areas are clouds.

 

These images were acquired for calibration of HiRISE data, since the spectral reflectance of the Moon's near side is very well known. When the component images were taken, Mars was about 127 million miles (205 million kilometers) from Earth. A previous HiRISE image of Earth and the moon is online at PIA10244.

NASA JPL

[LOC Veteran]

Even though you can tell that that is Earth, its still kinda interesting that (to me at least) it also sorta makes Earth look like Mars quite a bit. The Moon, not so much

[Draggendrop Veteran]

Turtle the Size of 2 Earths: Stunning Sunspot Revealed in New Radio Images

 

ESOcast 92 Light: ALMA Starts Observing the Sun

video is 1:14 min.

 

 

 

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New images taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed otherwise invisible details of our Sun, including a new view of the dark, contorted centre of a sunspot that is nearly twice the diameter of the Earth. The images are the first ever made of the Sun with a facility where ESO is a partner. The results are an important expansion of the range of observations that can be used to probe the physics of our nearest star. The ALMA antennas had been carefully designed so they could image the Sun without being damaged by the intense heat of the focussed light.

 

Astronomers have harnessed ALMA's capabilities to image the millimetre-wavelength light emitted by the Sun's chromosphere -- the region that lies just above the photosphere, which forms the visible surface of the Sun. The solar campaign team, an international group of astronomers with members from Europe, North America and East Asia [1], produced the images as a demonstration of ALMA's ability to study solar activity at longer wavelengths of light than are typically available to solar observatories on Earth.

 

Astronomers have studied the Sun and probed its dynamic surface and energetic atmosphere in many ways through the centuries. But, to achieve a fuller understanding, astronomers need to study it across the entire electromagnetic spectrum, including the millimetre and submillimetre portion that ALMA can observe.

 

Since the Sun is many billions of times brighter than the faint objects ALMA typically observes, the ALMA antennas were specially designed to allow them to image the Sun in exquisite detail using the technique of radio interferometry -- and avoid damage from the intense heat of the focussed sunlight [2]. The result of this work is a series of images that demonstrate ALMA's unique vision and ability to study our Sun.The data from the solar observing campaign are being released this week to the worldwide astronomical community for further study and analysis.

 

The team observed an enormous sunspot at wavelengths of 1.25 millimetres and 3 millimetres using two of ALMA's receiver bands. The images reveal differences in temperature between parts of the Sun's chromosphere [3]. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed in the future using ALMA.

 

Sunspots are transient features that occur in regions where the Sun's magnetic field is extremely concentrated and powerful. They are lower in temperature than the surrounding regions, which is why they appear relatively dark.

 

The difference in appearance between the two images is due to the different wavelengths of emitted light being observed. Observations at shorter wavelengths are able to probe deeper into the Sun, meaning the 1.25 millimetre images show a layer of the chromosphere that is deeper, and therefore closer to the photosphere, than those made at a wavelength of 3 millimetres.

 

ALMA is the first facility where ESO is a partner that allows astronomers to study the nearest star, our own Sun. All other existing and past ESO facilities need to be protected from the intense solar radiation to avoid damage. The new ALMA capabilities will expand the ESO community to include solar astronomers.

 

The ALMA radio telescope captured this image of a large sunspot Dec. 18, 2015, taken at a wavelength of 1.25 millimeters, which reveals the blazing-hot chromosphere located just above the photosphere (the sun's visible surface). The darker areas are cooler, including the sunspot that is nearly 2 times Earth's diameter.
Credit: ALMA (ESO/NAOJ/NRAO)

 

 

The large sunspot, imaged at a radio wavelength of 3 mm. This image shows a layer of the chromosphere higher up than the last, obscuring the sunspot's distinct shape.

Credit: ALMA (ESO/NAOJ/NRAO)

 

 

A full map of the sun at 1.25 mm wavelength taken using the ALMA telescope using a "fast-scanning technique" that uses only one of the observatory's 66 antennas, creating a low-resolution map of the disk in a few minutes.
Credit: ALMA (ESO/NAOJ/NRAO)

 

http://www.space.com/35353-stunning-sunspot-new-alma-images.html

 

https://www.eurekalert.org/pub_releases/2017-01/e-aso011717.php

 

As a side note...

 

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[2] Indeed, this lesson has been learned the hard way: the Swedish-ESO Submillimetre Telescope (SEST) had a fire in its secondary mirror assembly after the telescope was accidentally pointed at the Sun

https://www.eurekalert.org/pub_releases/2017-01/e-aso011717.php

 

ESO

 

ESO

 

from...

https://www.eso.org/public/images/?search=%2Bsest+%2Bfire

 

[Unobscured Vision]

Cool! (figuratively )

[Draggendrop Veteran]

Daphnis Up Close

 

Image credit: NASA/JPL-Caltech/Space Science Institute

 

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The wavemaker moon, Daphnis, is featured in this view, taken as NASA's Cassini spacecraft made one of its ring-grazing passes over the outer edges of Saturn's rings on Jan. 16, 2017. This is the closest view of the small moon obtained yet.

 

Daphnis (5 miles or 8 kilometers across) orbits within the 42-kilometer (26-mile) wide Keeler Gap. Cassini's viewing angle causes the gap to appear narrower than it actually is, due to foreshortening.

 

The little moon's gravity raises waves in the edges of the gap in both the horizontal and vertical directions. Cassini was able to observe the vertical structures in 2009, around the time of Saturn's equinox (see PIA11654).

 

Like a couple of Saturn's other small ring moons, Atlas and Pan, Daphnis appears to have a narrow ridge around its equator and a fairly smooth mantle of material on its surface -- likely an accumulation of fine particles from the rings. A few craters are obvious at this resolution. An additional ridge can be seen further north that runs parallel to the equatorial band.

 

Fine details in the rings are also on display in this image. In particular, a grainy texture is seen in several wide lanes which hints at structures where particles are clumping together. In comparison to the otherwise sharp edges of the Keeler Gap, the wave peak in the gap edge at left has a softened appearance. This is possibly due to the movement of fine ring particles being spread out into the gap following Daphnis' last close approach to that edge on a previous orbit.

 

A faint, narrow tendril of ring material follows just behind Daphnis (to its left). This may have resulted from a moment when Daphnis drew a packet of material out of the ring, and now that packet is spreading itself out.

 

The image was taken in visible (green) light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 17,000 miles (28,000 kilometers) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 71 degrees. Image scale is 551 feet (168 meters) per pixel.

 

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

various image sizes are available at the link...

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21056

 

[Draggendrop Veteran]

The Peak on Saturn's 'Death Star' Moon Mimas

 

Saturn's icy moon Mimas highlights with shadows the vast size of Herschel Crater and its centerpiece Herschel peak. The image was captured by Cassini's narrow-angle camera on October 22, 2016 using several of its spectral filters.
Credit: NASA/JPL-Caltech/Space Science Institute

 

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Saturn's moon Mimas glows a shining white in this photo from NASA's Cassini spacecraft. Dominating the image is Mimas' defining feature Herschel Crater, named after the astronomer William Herschel who first discovered the moon, where shadows offer a clue into how large the cavity actually is. 

 

The crater is 88 miles (140 kilometers) wide -- close to one-third the diameter of Mimas itself. Herschel peak, the central mountain feature common in large impact craters, stands a similar height to Earth's Mount Everest on Earth. The distinctive Herschel Crater gives Mimas more than a passing resemblance to the fictional Death Star from the "Star Wars" science fiction universe. You can see more photos of Mimas in our gallery here.

 

The Cassini spacecraft imaged the icy moon's hemisphere opposite Saturn with north being up and roughly 21 degrees left. Cassini's narrow-angle camera utilized a combination of its special filters to capture the image on Oct. 22, 2016, though NASA only released the image this month. Cassini was almost 115,000 miles (185,000 kilometers) from the moon. 

 

Cassini, a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency and managed by Jet Propulsion Laboratory in California, has been on its mission to gather data about the outer planets for nearly 20 years. In late 2016, the craft began the first portion of its Grand Finale where it will orbit Saturn more than 20 times gathering data about the planet, its moons and its rings before diving into the planet in late 2017.

http://www.space.com/35283-saturn-moon-mimas-crater-mountain-photo.html

 

The Cassini spacecraft : Mimas with its large crater Herschel.

video is 1:50 min.

 

 

 

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HiRise link for software

 

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What HiView Does 

 

HiView is the best way to explore HiRISE images of the Martian surface at the full resolution of the imagery. Tracks of boulders that have fallen down crater walls, delicate rays of ejecta from fresh impact craters, and the unearthly formations created by carbon dioxide ice on the Martian south pole are just a few of the things that are waiting to be discovered by anyone using a tool like HiView with HiRISE imagery. 

 

Once the application has been downloaded to your computer, all that is needed to get started after launching the application, is a quick drag and drop of any of the links to the JP2 files on the HiRISE website to the HiView application window, and HiView will take care of the rest. No downloading of multigigabyte files required! 

 

Whether you are just interested in exploring HiRISE images, or a scientist wanting to get valuable information from an observation, HiView is a versatile and powerful application. It is the ideal tool for exploring the imagery produced by HiRISE.  

 

Powerful tools 

 

HiView provides dynamically generated statistics about the current area of an image being viewed, whether it’s the entire original source at a low resolution, or a small area that has been expanded to full resolution. Multiband histograms can be used to enhance the color stretch and contrast of the currently viewed area, and can be reapplied to other areas of an image or to different images. Applying the default contrast stretch repeatedly on an image while zooming, provides a quick way to enhance the current area being viewed without having all the statistics and data mapping tools taking up screen space.

Save to Various Formats 

HiView can save the area of an image currently displayed as a TIFF, JPEG, PNG or other format for use in different image editing applications for further enhancement of any particular region of interest at full resolution.

And, It’s Free 
Developed by HiRISE team members, HiView is a free viewing tool, so download your copy today. 

http://www.uahirise.org/hiview/

 

I'll have to try this out later.....

[Draggendrop Veteran]

NASA's Fermi Sees Gamma Rays from 'Hidden' Solar Flares

 

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An international science team says NASA's Fermi Gamma-ray Space Telescope has observed high-energy light from solar eruptions located on the far side of the sun, which should block direct light from these events. This apparent paradox is providing solar scientists with a unique tool for exploring how charged particles are accelerated to nearly the speed of light and move across the sun during solar flares.

 

"Fermi is seeing gamma rays from the side of the sun we're facing, but the emission is produced by streams of particles blasted out of solar flares on the far side of the sun," said Nicola Omodei, a researcher at Stanford University in California. "These particles must travel some 300,000 miles within about five minutes of the eruption to produce this light."

 

Omodei presented the findings on Monday, Jan. 30, at the American Physical Society meeting in Washington, and a paper describing the results will be published online in The Astrophysical Journal on Jan. 31.

 

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Fermi has doubled the number of these rare events, called behind-the-limb flares, since it began scanning the sky in 2008. Its Large Area Telescope (LAT) has captured gamma rays with energies reaching 3 billion electron volts, some 30 times greater than the most energetic light previously associated with these "hidden" flares.

 

Thanks to NASA's Solar Terrestrial Relations Observatory (STEREO) spacecraft, which were monitoring the solar far side when the eruptions occurred, the Fermi events mark the first time scientists have direct imaging of beyond-the-limb solar flares associated with high-energy gamma rays.

 

Fermi Sees Gamma Rays from Far Side Solar Flares

video is 2;38 min.

 

 

 

These solar flares were imaged in extreme ultraviolet light by NASA's STEREO satellites, which at the time were viewing the side of the sun facing away from Earth. All three events launched fast coronal mass ejections (CMEs). Although NASA's Fermi Gamma-ray Space Telescope couldn't see the eruptions directly, it detected high-energy gamma rays from all of them. Scientists think particles accelerated by the CMEs rained onto the Earth-facing side of the sun and produced the gamma rays. The central image was returned by the STEREO A spacecraft, all others are from STEREO B.
Credits: NASA/STEREO

 

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"Observations by Fermi's LAT continue to have a significant impact on the solar physics community in their own right, but the addition of STEREO observations provides extremely valuable information of how they mesh with the big picture of solar activity," said Melissa Pesce-Rollins, a researcher at the National Institute of Nuclear Physics in Pisa, Italy, and a co-author of the paper.

 

The hidden flares occurred Oct. 11, 2013, and Jan. 6 and Sept. 1, 2014. All three events were associated with fast coronal mass ejections (CMEs), where billion-ton clouds of solar plasma were launched into space. The CME from the most recent event was moving at nearly 5 million miles an hour as it left the sun. Researchers suspect particles accelerated at the leading edge of the CMEs were responsible for the gamma-ray emission.

 

Large magnetic field structures can connect the acceleration site with distant part of the solar surface. Because charged particles must remain attached to magnetic field lines, the research team thinks particles accelerated at the CME traveled to the sun's visible side along magnetic field lines connecting both locations. As the particles impacted the surface, they generated gamma-ray emission through a variety of processes. One prominent mechanism is thought to be proton collisions that result in a particle called a pion, which quickly decays into gamma rays.

 

In its first eight years, Fermi has detected high-energy emission from more than 40 solar flares. More than half of these are ranked as moderate, or M class, events. In 2012, Fermi caught the highest-energy emission ever detected from the sun during a powerful X-class flare, from which the LAT detected high­energy gamma rays for more than 20 record-setting hours.

 

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

 

Combined images from NASA's Solar Dynamics Observatory (center) and the NASA/ESA Solar and Heliospheric Observatory (red and blue) show an impressive coronal mass ejection departing the far side of the sun on Sept. 1, 2014. This massive cloud raced away at about 5 million mph and likely accelerated particles that later produced gamma rays Fermi detected.

Credits: NASA/SDO and NASA/ESA/SOHO

 

https://www.nasa.gov/feature/goddard/2017/nasas-fermi-sees-gamma-rays-from-hidden-solar-flares

 

Awesome....

[Draggendrop Veteran]

Close Views Show Saturn's Rings in Unprecedented Detail

 

This Cassini image features a density wave in Saturn's A ring (at left) that lies around 134,500 km from Saturn. Density waves are accumulations of particles at certain distances from the planet. This feature is filled with clumpy perturbations, which researchers informally refer to as "straw." The wave itself is created by the gravity of the moons Janus and Epimetheus, which share the same orbit around Saturn. Elsewhere, the scene is dominated by "wakes" from a recent pass of the ring moon Pan.
Credits: NASA/JPL-Caltech/Space Science Institute

 

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This Cassini image features a density wave in Saturn's A ring (at left) that lies around 134,500 km from Saturn. Density waves are accumulations of particles at certain distances from the planet. This feature is filled with clumpy perturbations, which researchers informally refer to as "straw." The wave itself is created by the gravity of the moons Janus and Epimetheus, which share the same orbit around Saturn. Elsewhere, the scene is dominated by "wakes" from a recent pass of the ring moon Pan.

 

Two versions of this image are available. This is a lightly processed version, with minimal enhancement, preserving all original details present in the image. The other version (Figure 1) has been processed to remove the small bright blemishes caused by cosmic rays and charged particle radiation near the planet -- a more aesthetically pleasing image, but with a slight softening of the finest details.

 

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 18, 2016. The view was obtained at a distance of approximately 34,000 miles (56,000 kilometers) from the rings and looks toward the unilluminated side of the rings. Image scale is about a quarter-mile (340 meters) per pixel.

 

This is the "cleaned version"

 

Image credit: NASA/JPL-Caltech/Space Science Institute

 

 

This image shows a region in Saturn's outer B ring. NASA's Cassini spacecraft viewed this area at a level of detail twice as high as it had ever been observed before.

Credits: NASA/JPL-Caltech/Space Science Institute

 

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This image shows a region in Saturn's outer B ring. NASA's Cassini spacecraft viewed this area at a level of detail twice as high as it had ever been observed before.

 

The view here is of the outer edge of the B ring, at left, which is perturbed by the most powerful gravitational resonance in the rings: the "2:1 resonance" with the icy moon Mimas. This means that, for every single orbit of Mimas, the ring particles at this specific distance from Saturn orbit the planet twice. This results in a regular tugging force that perturbs the particles in this location.

 

A lot of structure is visible in the zone near the edge on the left. This is likely due to some combination of the gravity of embedded objects too small to see, or temporary clumping triggered by the action of the resonance itself. Scientists informally refer to this type of structure as "straw."

 

This image was taken using a fairly long exposure, causing the embedded clumps to smear into streaks as they moved in their orbits. Later Cassini orbits will bring shorter exposures of the same region, which will give researchers a better idea of what these clumps look like. But in this case, the smearing does help provide a clearer idea of how the clumps are moving.

 

This image is a lightly processed version, with minimal enhancement; this version preserves all original details present in the image. Another other version (Figure 1) has been processed to remove the small bright blemishes due to cosmic rays and charged particle radiation near the planet -- a more aesthetically pleasing image, but with a slight softening of the finest details.

 

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 18, 2016. The view was obtained at a distance of approximately 32,000 miles (52,000 kilometers) from the rings and looks toward the unilluminated side of the rings. Image scale is about a quarter-mile (360 meters) per pixel.

 

 

Image credit: NASA/JPL-Caltech/Space Science Institute

 

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This image shows a region in Saturn's outer B ring. NASA's Cassini spacecraft viewed this area at a level of detail twice as high as it had ever been observed before. And from this view, it is clear that there are still finer details to uncover.

 

Researchers have yet to determine what generated the rich structure seen in this view, but they hope detailed images like this will help them unravel the mystery.

 

In order to preserve the finest details, this image has not been processed to remove the many small bright blemishes, which are created by cosmic rays and charged particle radiation near the planet.

 

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 18, 2016. The view was obtained at a distance of approximately 32,000 miles (51,000 kilometers) from the rings, and looks toward the unilluminated side of the rings. Image scale is about a quarter-mile (360 meters) per pixel.

 

 

Image credit: NASA/JPL-Caltech/Space Science Institute

 

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This image from NASA's Cassini mission shows a region in Saturn's A ring. The level of detail is twice as high as this part of the rings has ever been seen before. The view contains many small, bright blemishes due to cosmic rays and charged particle radiation near the planet.

 

The view shows a section of the A ring known to researchers for hosting belts of propellers -- bright, narrow, propeller-shaped disturbances in the ring produced by the gravity of unseen embedded moonlets. Several small propellers are visible in this view. These are on the order of 10 times smaller than the large, bright propellers whose orbits scientists have routinely tracked (and which are given nicknames for famous aviators).

 

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 18, 2016. The view was obtained at a distance of approximately 33,000 miles (54,000 kilometers) from the rings and looks toward the unilluminated side of the rings. Image scale is about a quarter-mile (330 meters) per pixel.

 

Figure 1 Image credit: NASA/JPL-Caltech/Space Science Institute

 

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Three versions of this image are available. This image is a lightly processed version, with minimal enhancement, preserving all original details present in the image. A second version has circles to indicate the locations of many of the small propellers in the image (Figure 1). The third version has been processed to remove the bright blemishes due to cosmic rays and charged particle radiation -- a more aesthetically pleasing image, but with a slight softening of the finest details

 

Figure 2 Image credit: NASA/JPL-Caltech/Space Science Institute

 

https://www.nasa.gov/feature/jpl/close-views-show-saturns-rings-in-unprecedented-detail

 

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21060

 

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21059

 

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21058

 

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21057

 

 

 

[Unobscured Vision]

Wow. Saturn could have hundreds of moons. These still count as moons, do they not? 

[Draggendrop Veteran]

The definition of a moon

 

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There is no established lower limit on what is considered a "moon". Every natural celestial body with an identified orbit around a planet of the Solar System, some as small as a kilometer across, has been considered a moon, though objects a tenth that size within Saturn's rings, which have not been directly observed, have been called moonlets. Small asteroid moons (natural satellites of asteroids), such as Dactyl, have also been called moonlets.[12]

 

The upper limit is also vague. Two orbiting bodies are sometimes described as a double body rather than primary and satellite. Asteroids such as 90 Antiope are considered double asteroids, but they have not forced a clear definition of what constitutes a moon. Some authors consider the Pluto–Charon system to be a double (dwarf) planet. The most common[citation needed] dividing line on what is considered a moon rests upon whether the barycentre is below the surface of the larger body, though this is somewhat arbitrary, because it depends on distance as well as relative mass.

more at the link...

https://en.wikipedia.org/wiki/Natural_satellite

 

Our Solar System: Moons

https://solarsystem.nasa.gov/planets/solarsystem/moons

 

There are better sources, but it appears that a satellite is a satellite, ie..moon or moonlet, just pick a size and use it as a ref, but it's still a moon.

 

[Draggendrop Veteran]

Data Suggests Organic Materials Native to Dwarf Planet Ceres

 

Organics on Ceres  Credit SWRI

SwRI scientists are studying the geology associated with the organic-rich areas on Ceres. Dawn spacecraft data show a region around the Ernutet crater where organic concentrations have been discovered (labeled “a” through “f”). The color coding shows the strength of the organics absorption band, with warmer colors indicating the highest concentrations.  SWRI

http://www.swri.org/press/2017/ceres-organic-materials.htm

 

 

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NASA's Dawn spacecraft recently detected organic-rich areas on Ceres.

 

Scientists evaluated the geology of the regions to conclude that the organics are most likely native to the dwarf planet. Data from the spacecraft suggest that the interior of Ceres is the source of these organic materials, as opposed to arriving via impacting asteroids or comets, according to a paper published in the Feb. 17, 2017, issue of Science. 

 

"This discovery of a locally high concentration of organics is intriguing, with broad implications for the astrobiology community," said Dr. Simone Marchi, a senior research scientist at Southwest Research Institute and one of the authors of the paper. "Ceres has evidence of ammonia-bearing hydrated minerals, water ice, carbonates, salts, and now organic materials. With this new finding Dawn has shown that Ceres contains key ingredients for life."

 

Ceres is believed to have originated about 4.5 billion years ago at the dawn of our solar system. Studying its organics can help explain the origin, evolution, and distribution of organic species across the solar system. Data from Dawn's visible and infrared mapping spectrometer show an unusually high concentration of organic matter close to the 50-km diameter Ernutet crater in the northern hemisphere of Ceres. The distribution and characteristics of the organics seem to preclude association with any single crater. The largest concentration appears to drape discontinuously across the southwest floor and rim of Ernutet and onto an older, highly degraded crater. Other organic-rich areas are scattered to the northwest. While other scientists looked at the distribution and spectra of the materials, Marchi focused on the geological settings.

 

"The overall region is heavily cratered and appears to be ancient; however, the rims of Ernutet crater appear to be relatively fresh," Marchi said. "The organic-rich areas include carbonate and ammoniated species, which are clearly Ceres' endogenous material, making it unlikely that the organics arrived via an external impactor."

 

Ceres shows clear signatures of pervasive hydrothermal activity, aqueous alteration and fluid mobility, so the organic-rich areas may be the result of internal processes. Dawn scientists will continue to study the dwarf planet to identify a viable method for transporting such material from the interior to the surface in the pattern observed.

 

These findings appear in the paper "Localized aliphatic organic material on the surface of Ceres" published in the Feb. 17, 2017, edition of the journal Science. Dawn's mission to Ceres and Vesta, the two most massive bodies in the asteroid belt, is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington, D.C. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science.

http://spaceref.com/ceres/data-suggests-organic-materials-native-to-dwarf-planet-ceres.html

 

SwRI scientist studies geology of Ceres to understand origin of organics

https://www.eurekalert.org/pub_releases/2017-02/sri-sss021517.php

 

Ceres hosts organic compounds, and they formed on the asteroid, not beyond

https://www.eurekalert.org/pub_releases/2017-02/aaft-cho021317.php

 

SwRI scientist studies geology of Ceres to understand origin of organics

http://www.swri.org/9what/releases/2017/ceres-organic-materials.htm

 

reference...

 

http://photojournal.jpl.nasa.gov/catalog/PIA20918

 

[Unobscured Vision]

Well, well.  Guess we'll have to add Ceres to the "short list" of places that NASA has deemed "we shouldn't go". Awesome finding, though. This is the first I'm reading about organic materials on Ceres ... neat!

 

I'd love to get a Curiosity-class Rover there. Unmanned, of course. Do a lot of science. See what's what.

[Unobscured Vision]

Juno to remain in elongated Jupiter orbit for full mission duration, NASA decides

Article link | Ars Technica Website

Juno, shown here in an artist's concept image, arrived in the Jupiter system on July 4, 2016 | Image (C) NASA

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When NASA sent a series of commands to the Juno spacecraft’s main engine last October, the spacecraft did not respond properly: two helium check valves that play an important role in its firing opened sluggishly. Those commands had been sent in preparation for a burn of the spacecraft’s Leros 1b engine, which would have brought Juno—a $1.1 billion mission to glean insights about Jupiter—into a significantly shorter orbital period around the gas giant.

 

Due to concerns about the engine, NASA held off on a “period reduction maneuver” that would shorten Juno’s orbital period from 53.4 to 14 days. When the next chance to do so came in December, again NASA held off. Now the space agency has made it official—Juno will remain in a longer, looping orbit around Jupiter for the extent of its lifetime observing the gas giant.

 

“During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The bottom line is a burn represented a risk to completion of Juno’s science objectives.”

 

In announcing the decision Friday, space agency scientists took pains to emphasize the benefits of a longer orbit around Jupiter. For example, the “bonus science” will allow Juno to further explore the outer reaches of the Jovian magnetosphere and better understand the interaction of these regions with the solar wind. Spending more time farther away from Jupiter will also lessen the spacecraft’s exposure to the gas giant’s harmful radiation, scientists said.

 

That being said, longer orbits increase other risks for the spacecraft. NASA had hoped Juno would make 36 close flybys of Jupiter during the next 20 months. Now, making all of those orbits will require nearly four additional years. Whether a spacecraft and its scientific equipment designed for less than two years of observations will be able to hold up for that long remains to be seen.

 

(article continues a bit ...)

Well ... we called it, gents. Leave Juno as-is, get a lot more science (and some extra science to boot) and a lot more longevity out of the probe too. I'm calling this a win-win. I didn't like the idea of shortening the orbit anyway. 

[Draggendrop Veteran]

First solar images from NOAA's GOES-16 satellite

 

These images of the sun were captured at the same time on Jan. 29, 2017 by the six channels on the SUVI instrument on board GOES-16 and show a large coronal hole in the sun's southern hemisphere. Each channel observes the sun at a different wavelength, allowing scientists to detect a wide range of solar phenomena important for space weather forecasting.
CREDIT
NOAA

 

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The first images from the Solar Ultraviolet Imager or SUVI instrument aboard NOAA's GOES-16 satellite have been successful, capturing a large coronal hole on Jan. 29, 2017.

 

The sun's 11-year activity cycle is currently approaching solar minimum, and during this time powerful solar flares become scarce and coronal holes become the primary space weather phenomena - this one in particular initiated aurora throughout the polar regions. Coronal holes are areas where the sun's corona appears darker because the plasma has high-speed streams open to interplanetary space, resulting in a cooler and lower-density area as compared to its surroundings.

 

SUVI is a telescope that monitors the sun in the extreme ultraviolet wavelength range. SUVI will capture full-disk solar images around-the-clock and will be able to see more of the environment around the sun than earlier NOAA geostationary satellites.

 

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Data from SUVI will provide an estimation of coronal plasma temperatures and emission measurements which are important to space weather forecasting. SUVI is essential to understanding active areas on the sun, solar flares and eruptions that may lead to coronal mass ejections which may impact Earth. Depending on the magnitude of a particular eruption, a geomagnetic storm can result that is powerful enough to disturb Earth's magnetic field. Such an event may impact power grids by tripping circuit breakers, disrupt communication and satellite data collection by causing short-wave radio interference and damage orbiting satellites and their electronics. SUVI will allow the NOAA Space Weather Prediction Center to provide early space weather warnings to electric power companies, telecommunication providers and satellite operators.

 

SUVI replaces the GOES Solar X-ray Imager (SXI) instrument in previous GOES satellites and represents a change in both spectral coverage and spatial resolution over SXI.

 

NASA successfully launched GOES-R at 6:42 p.m. EST on Nov. 19, 2016, from Cape Canaveral Air Force Station in Florida and it was renamed GOES-16 when it achieved orbit. GOES-16 is now observing the planet from an equatorial view approximately 22,300 miles above the surface of Earth.

 

NOAA's satellites are the backbone of its life-saving weather forecasts. GOES-16 will build upon and extend the more than 40-year legacy of satellite observations from NOAA that the American public has come to rely upon.

more at the link...

https://www.eurekalert.org/pub_releases/2017-03/nsfc-fsi030117.php

[Jim K Global Moderator]

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NASA's MAVEN spacecraft performed a previously unscheduled maneuver this week to avoid a collision in the near future with Mars' moon Phobos.

 

The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been orbiting Mars for just over two years, studying the Red Planet's upper atmosphere, ionosphere and interactions with the sun and solar wind. On Tuesday, Feb. 28, the spacecraft carried out a rocket motor burn that boosted its velocity by 0.4 meters per second (less than 1 mile per hour). Although a small correction, it was enough that -- projected to one week later when the collision would otherwise have occurred -- MAVEN would miss the lumpy, crater-filled moon by about 2.5 minutes.

 

This is the first collision avoidance maneuver that the MAVEN spacecraft has performed at Mars to steer clear of Phobos. The orbits of both MAVEN and Phobos are known well enough that this timing difference ensures that they will not collide.

 

MAVEN, with an elliptical orbit around Mars, has an orbit that crosses those of other spacecraft and the moon Phobos many times over the course of a year. When the orbits cross, the objects have the possibility of colliding if they arrive at that intersection at the same time. These scenarios are known well in advance and are carefully monitored by NASA's Jet Propulsion Laboratory in Pasadena, California, which sounded the alert regarding the possibility of a collision.

 

With one week's advance notice, it looked like MAVEN and Phobos had a good chance of hitting each other on Monday, March 6, arriving at their orbit crossing point within about 7 seconds of each other. Given Phobos' size (modeled for simplicity as a 30-kilometer sphere, a bit larger than the actual moon in order to be conservative), they had a high probability of colliding if no action were taken.

 

Said MAVEN Principal Investigator Bruce Jakosky of the University of Colorado in Boulder, "Kudos to the JPL navigation and tracking teams for watching out for possible collisions every day of the year, and to the MAVEN spacecraft team for carrying out the maneuver flawlessly."

NASA

 

That would have been a tad bit embarrassing...slamming into a moon. 

[Unobscured Vision]

Which could be avoided altogether if they can be bothered to raise MAVEN's orbit 40 km above Phobos's apoapse.  Then it's a non-issue and all they need to do afterwards are the standard orbital corrections to keep it there (which they do anyway). Should have been like this from the beginning ... /shrug

[Unobscured Vision]

2 hours ago, DocM said:

Seems like it. Hell, last Thursday we were hit by  68 mph winds and over a million people are without power. Not us though - and we have a big natural gas generator with an LP reserve tank.

Yeah, we got walloped too. 300,000 people in the county without power at its' worst, about double that without cable/internet. Still about 90k are dark, according to the map. Lot of single traffic lights are out too from swinging around violently -- about one out of eight in my locale here. And of course people seem to have forgotten the rules about four-way stops when the lights are out .... *sigh* .... rather annoying when they jump out of their vehicles and start raging at other drivers -- and no telling if they're ones without power, so they're already pissy. Been quite a week here.

[Draggendrop Veteran]

Asteroid clay is a better space radiation shield than aluminium

 

Space rock clay is rich in hydrogen, which blocks harmful cosmic rays
Danielle Futselaar/SETI Institute

 

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The huge rocks that hurtle through space may prove to be lifesavers for astronauts. Clays extracted from asteroids could be used on deep space missions to shield against celestial radiation.

 

Radiation from cosmic rays is one of the biggest health risks astronauts will face on long space missions, such as a proposed trip to Mars or settlement on the moon. A 2013 study suggested that a return trip to Mars would expose astronauts to a lifetime’s dose in one go.

 

But the heavy aluminium shields currently used for short missions would be too expensive to ship. For a long-term presence on the moon or Mars, we will need to use materials found in space, says Daniel Britt at the University of Central Florida.

 

“Eventually everything should be able to be produced off Earth if any serious size outpost, base or colony is to be considered,” says Paul van Susante at Michigan Technological University.

 

Asteroids could provide the answer, says Britt. Clays in asteroids are rich in hydrogen, which is the most effective shielding material for protons and cosmic rays. Britt and his colleague Leos Pohl found that the clays are up to 10 per cent more effective than aluminium – which is used in most current shields – at stopping the high-energy charged particles given off by the sun and other cosmic bodies.

 

Exactly how the clays could be extracted from the asteroids is still up for discussion. “No current machines exist for actual mining in zero gravity,” says van Susante.

 

But there are a few ways it could be done. For example, the clays are non-magnetic, so they could be separated from other materials in an asteroid using massive magnets.

 

“Doing anything in space is not trivial, but there are several paths forward,” Britt says.

https://www.newscientist.com/article/2124676-asteroid-clay-is-a-better-space-radiation-shield-than-aluminium/?utm_medium=Social&utm_campaign=Echobox&utm_source=Twitter&utm_term=Autofeed&cmpid=SOC|NSNS|2017-Echobox#link_time=1489545124

 

 

The radiation shielding potential of CI and CM chondrites

 

Quote

Highlights
•
The feasibility of using asteroidal material as a shield against radiation is studied.
•
Clays are a significant component of certain asteroid types (CIs and CMs).
•
Clays have better stopping power compared to lunar and generally “dry” minerals.
•
Asteroidal material can have better stopping power than Aluminium.
•
Benefaction and shield construction can significantly affect the stopping power.

Abstract here...

http://www.sciencedirect.com/science/article/pii/S0273117716307505

 

[DocM]

 

[Draggendrop Veteran]

 

 

 

A Stunning Video of Mars That Took Three Months to Stitch Together—by Hand

 

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IF YOU SHOULD one day find yourself in a spacecraft circling Mars, don’t count on a good view. The Red Planet’s dusty atmosphere will probably obscure any window-seat vistas of its deep valleys and soaring mesas. “The best way to see the planet’s surface would be to take a digital image and enhance it on your computer,” says planetary geologist Alfred McEwen, principle investigator on NASA’s High Resolution Imaging Science Experiment. He would know: In the past 12 years, the powerful HiRISE camera has snapped 50,000 spectacular, high-resolution stereo images of the Martian terrain from the planet’s orbit, creating anaglyphs that anyone can view in 3D using special glasses. The highly detailed stereograms depict the planet’s surface in remarkable detail—but 3D glasses aren’t always handy, and still images can only convey so much about Mars’ varied topography.

 

To fully appreciate the Martian landscape, one needs dimension and movement. In the video you see here, Finnish filmmaker Jan Fröjdman transformed HiRISE imagery into a dynamic, three-dimensional, overhead view of the Red Planet—no glasses required.

 

For Fröjdman, creating the flyover effect was like assembling a puzzle. He began by colorizing the photographs (HiRISE captures images in grayscale). He then identified distinctive features in each of the anaglyphs—craters, canyons, mountains–and matched them between image pairs. To create the panning 3-D effect, he stitched the images together along his reference points and rendered them as frames in a video. “It was a very slow process,” he says.

 

 

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Some geographic features take more work than others to render. Flat regions require a few hundred reference points, while topographically complex ones—like Mars’ Inca City—can take thousands. “There might be software that does this work, but I haven’t found it,” Fröjdman says. For the film you see here, the self-described space enthusiast hand-selected more than 33,000 reference points. It took him three months to complete.

 

It turns out there is software that does this work. “He did it the hard way,” says McEwen, whose lab uses special terrain-modeling programs to match reference points on stereo images automatically. Not that that detracts from Fröjdman’s homespun version. If anything, it makes his labor of love all the more endearing. “There are so many great scenes on Mars,” he says. “The more work I do, the more I learn that this planet is amazing.”

https://www.wired.com/2017/03/stunning-video-mars-took-three-months-stitch-together-hand/

 

 

A FICTIVE FLIGHT ABOVE REAL MARS

video is 4:32 min.

 

 

Awesome...this planet is just plain awesome.