Solar System News (miscellaneous articles)

[Draggendrop]

1 minute ago, LOC said:

Carl Sagan, sigh. If he would have lived a bit longer, I could literally imagine his head exploding with all the things we've discovered over the last 15 years or so. He was such an important part of not only science education, but science in general. Plus, we got Contact out of him. One of my favorite movies ever. (and yes, I've read the novel as well :))

Quite right, Carl Sagan got me hooked......great mind and missed.....

[patseguin]

I always wondered why there are only still images and no video of solar system/universe stuff. Surely it's not all frozen in time right?

[Draggendrop]

Just now, patseguin said:

I always wondered why there are only still images and no video of solar system/universe stuff. Surely it's not all frozen in time right?

There are a few stitched ones and a few simulations derived from actual shots...good idea though...I will try to round up a few.....

[patseguin]

Just now, Draggendrop said:

There are a few stitched ones and a few simulations derived from actual shots...good idea though...I will try to round up a few.....

I meant in general, not just here. NASA always shows still images of exploding stars and such. Shouldn't we be able to see it as it happens and not just like it froze in time? Even if it was millions of years ago, it should still be moving right?

[Draggendrop]

For real time video, the problem is bandwidth. They have a tough time with images  due to weak signals and it takes time to receive all the data to complete the mission segments and priorities...payload power supply determines the type of science missions and transmission equipment for DSN (Deep Space Network) for standard planetary images. Others are done outside of visible light and masked for presentation. Another obstacle is the very long time frame for galactic events, where sporadic shots are taken over years and then assembled.

 

I like to use an analogy where human lifespan is micro seconds compared to decades for action concerning a lot of galactic events. The majority of events happen too slow for our time frame. Hope that helps....

 

few examples:

 

1) A star, far away explodes. We have no idea until the brightest light happens to be captures, and this may only happen for a few days and the cooling debris fades and the show is over. The event is in "history", distance determining the actual time in the past that this occurred.

 

2) The universe is extremely vast. Two galaxies that are colliding,could be separated by 200 light years...so we have a bit of a wait till the event happens. The galaxies may be traveling near the speed of light, but the distances are so vast, it takes a long time compared to our lifetime.

 

3) Expansion of the universe, the farther out, the faster the expansion and the longer to view anything, till we reach the end of the "visible universe" where upon, after that limit, we cannot use light as the reference...a visibility wall.

 

4) Relativity paradox's. where is the observer and what is he seeing. If you are somewhere else, you are seeing something in a different time context. 

Edited February 3, 2016 by Draggendrop

[Draggendrop]

Saturn's Rings - Less than Meets the Eye?

 

Saturn's rings    NASA/JPL

 

Quote

It seems intuitive that an opaque material should contain more stuff than a more translucent substance.

 

For example, muddier water has more suspended particles of dirt in it than clearer water. Likewise, you might think that, in the rings of Saturn, more opaque areas contain a greater concentration of material than places where the rings seem more transparent.

 

But this intuition does not always apply, according to a recent study of the rings using data from NASA's Cassini mission. In their analysis, scientists found surprisingly little correlation between how dense a ring might appear to be -- in terms of its opacity and reflectiveness -- and the amount of material it contains.

 

The new results concern Saturn's B ring, the brightest and most opaque of Saturn's rings, and are consistent with previous studies that found similar results for Saturn's other main rings.

 

The scientists found that, while the opacity of the B ring varied by a large amount across its width, the mass -- or amount of material -- did not vary much from place to place. They "weighed" the nearly opaque center of the B ring for the first time -- technically, they determined its mass density in several places -- by analyzing spiral density waves. These are fine-scale ring features created by gravity tugging on ring particles from Saturn's moons, and the planet's own gravity. The structure of each wave depends directly on the amount of mass in the part of the rings where the wave is located.

 

"At present it's far from clear how regions with the same amount of material can have such different opacities. It could be something associated with the size or density of individual particles, or it could have something to do with the structure of the rings," said Matthew Hedman, the study's lead author and a Cassini participating scientist at the University of Idaho, Moscow. Cassini co-investigator Phil Nicholson of Cornell University, Ithaca, New York, co-authored the work with Hedman.

 

"Appearances can be deceiving," said Nicholson. "A good analogy is how a foggy meadow is much more opaque than a swimming pool, even though the pool is denser and contains a lot more water."

More at the link...

http://spaceref.com/saturn/saturns-rings---less-than-meets-the-eye.html

 

 

 

Tethys is at the top left.....

 

[DocM]

This image from NASA's Dawn spacecraft shows Kupalo Crater, one of the youngest craters on Ceres. The crater has bright material exposed on its rim and walls, which could be salts. Its flat floor likely formed from impact melt and debris.

Kupalo, which measures 16 miles (26 kilometers) across and is located at southern mid-latitudes, is named for the Slavic god of vegetation and harvest.

Kupalo was imaged earlier in Dawn's science mission at Ceres -- during Survey orbit (seePIA19624) and from the high altitude mapping orbit, or HAMO (see PIA20124).

Dawn took this image on Dec. 21 from its low-altitude mapping orbit (LAMO) at an approximate altitude of 240 miles (385 kilometers) above Ceres. The image resolution is 120 feet (35 meters) per pixel.

 

 

 

[LOC]

That's an amazing picture. It makes me think back to when I was in college studying Astrophysics at the time, thinking we'd never do any of this kind of amazing stuff in my lifetime, or if we did it'd be way way into the 21st century. Stunning that we can have  spacecraft fly above a stinking rock in the middle of space only 200 some odd miles above its surface. That we'd be sending probes to Pluto and beyond and flinging others into the atmosphere of this or that until it gives out.

 

But hey, science isn't important right. Evolution isn't real and we didn't land on the moon. Also, we didn't actually find the Higgs Boson....Ugh I hate the anti-science stuff going on in America right now. Makes me honestly feel ill.

[Unobscured Vision]

27 minutes ago, LOC said:

That's an amazing picture. It makes me think back to when I was in college studying Astrophysics at the time, thinking we'd never do any of this kind of amazing stuff in my lifetime, or if we did it'd be way way into the 21st century. Stunning that we can have  spacecraft fly above a stinking rock in the middle of space only 200 some odd miles above its surface. That we'd be sending probes to Pluto and beyond and flinging others into the atmosphere of this or that until it gives out.

 

But hey, science isn't important right. Evolution isn't real and we didn't land on the moon. Also, we didn't actually find the Higgs Boson....Ugh I hate the anti-science stuff going on in America right now. Makes me honestly feel ill.

I know. This "devolution" is making me sick as well. Weren't the various "sixties movements" meant to increase the open-mindedness of people? Aside from the "brain-cell-killing" activities, of course -- that didn't need to happen. I thought in the mid-and-late 90's we were finally on the right track, and then 9-11 happened ... and poof, it was 'murica! [expletive] yeah!! (drink beer and fire your shotgun while listening to George Noory and Alex Jones or whatever his name is, then impregnate your cousin). That's what it's become now.  

 

At least the science returns of missions and science in general have been pretty good the past 5 years, and NewSpace has been getting more and more people interested in Space again.

[DocM]

And in about 10-12 years we should have a manned spacecraft which can fly to and land on Ceres or some other body and come home. Relatively quickly.

 

I say this because SpaceX's Gwynne Shotwell let it slip earlier this week that their (enormous) BFS could have other destinations than Mars. They're planning a Mars landing around 2025, and some in NASA's manned exploration program say SpaceX will have a base on Mars long before NASA will. 

 

Also in development is MSNW's Electrodeless Lorentz Force (ELF) thruster, which could have a higher thrust and Isp than VASIMR and run on most any gas or fluid; air, water, CO2, nobel gases, deuterium, hydrazine etc. Just feed it electricity. Now NASA funded.

 

Things are starting to move quickly.

 

ELF running with various propellants

Edited February 5, 2016 by DocM

[Unobscured Vision]

Is there any data on the ISP's for each fuel source? I'm really interested to know what the findings were.

 

And Gwynne let the cat out of the bag, I think.  Manned missions to Ceres and other interesting places ... yeah. Now we're talking.  

[DocM]

I don't have the numbers per propellant, but generally ELF delivers an Isp of 1,500s to 8,000s while chemical propellants deliver about 250s to 450s.  

 

Efficiency

 

ELF: 85%

VASIMR: 60%.

 

Thrust at Isp (250 kW)

5000 Isp
ELF: 8.67N
VASIMR: 5.38N

3000 Isp
ELF: 14.46N
VASIMR: 8.98N

 

ELF is an extremely interesting tech, usable in the vacuum of space, higher up in Earths atmosphere (using air)  and on the surface of places like Mars. The USAF is interested, and the AFRL has smiled at it.

Edited February 5, 2016 by DocM

[Unobscured Vision]

Oh holy hell, it's orders of magnitude better. They need to be pushing this tech, pronto. And since it can refuel virtually anywhere there's an atmosphere .. yeah. I could see Probes equipped with it skimming the upper atmosphere of Gas Giants like Jupiter and Saturn, and Ice Giants like Uranus and Neptune to refuel, while at the same time getting a gravity-assisted slingshot away from said planet. It'd be a nice trick.

[LOC]

Maybe then we can find planet 9! Or as I used to call it, Pluto....

[Draggendrop]

First locks released from LISA Pathfinder's cubes

 

Artist's impression of LISA Pathfinder, ESA's mission to test technology for future gravitational-wave observatories in space. LISA Pathfinder operates from a vantage point in space about 1.5 million km from Earth towards the Sun, orbiting the first Sun-Earth Lagrangian point, L1. Image courtesy ESA-C.Carreau.

 

Quote

Today, the lock fingers that kept the two test masses on LISA Pathfinder secure during the launch and cruise phase were successfully unlocked. As planned, the two cubes are still attached to the spacecraft via an additional mechanism that will hold them in place until mid February, as the teams carry on with the spacecraft and payload commissioning.

 

Tests on LISA Pathfinder are proceeding on schedule. The spacecraft completed its six-week journey in space, reaching its operational location in orbit around the Lagrange point L1 on 22 January 2016.

 

With the spacecraft settling into its new home, teams from ESA, Airbus Defence and Space (the prime contractor) and the institutes that provided the payload hardware continue to perform tests on the various systems, subsystems and instruments in preparation for when science operations will begin on 1 March.

 

At the centre of the spacecraft is the LISA Technology Package, which houses the two test masses that will be put in the most precise free-fall motion ever obtained in space. The position and attitude of these two identical gold-platinum cubes is monitored by a laser interferometer to estimate how much their motion is affected by other forces beyond gravity.

more at...

http://www.spacedaily.com/reports/First_locks_released_from_LISA_Pathfinders_cubes_999.html

 

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NASA's Juno Spacecraft Burns for Jupiter

 

Launching from Earth in 2011, the Juno spacecraft will arrive at Jupiter in 2016 to study the giant planet from an elliptical, polar orbit. Image courtesy NASA/JPL-Caltech.

 

Quote

NASA's solar-powered Juno spacecraft successfully executed a maneuver to adjust its flight path today, Feb. 3. The maneuver refined the spacecraft's trajectory, helping set the stage for Juno's arrival at the solar system's largest planetary inhabitant five months and a day from now.

 

"This is the first of two trajectory adjustments that fine tune Juno's orbit around the sun, perfecting our rendezvous with Jupiter on July 4th at 8:18 p.m. PDT [11:18 p.m. EDT]," said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio.

 

The maneuver began at 10:38 a.m. PST (1:38 p.m. EST). ). The Juno spacecraft's thrusters consumed about 1.3 pounds (0.6 kilograms) of fuel during the burn, and changed the spacecraft's speed by 1 foot (0.31 meters), per second. At the time of the maneuver, Juno was about 51 million miles (82 million kilometers) from Jupiter and approximately 425 million miles (684 million kilometers) from Earth. The next trajectory correction maneuver is scheduled for May 31.

 

Juno was launched on Aug. 5, 2011. The spacecraft will orbit the Jovian world 33 times, skimming to within 3,100 miles (5,000 kilometers) above the planet's cloud tops every 14 days. During the flybys, Juno will probe beneath the obscuring cloud cover of Jupiter and study its aurorae to learn more about the planet's origins, structure, atmosphere and magnetosphere.

 

Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife - the goddess Juno - was able to peer through the clouds and reveal Jupiter's true nature.

http://www.spacedaily.com/reports/NASAs_Juno_Spacecraft_Burns_for_Jupiter_999.html

 

[Unobscured Vision]

And the scary part is I know what all of this means. I've got this image in my minds' eye of a Kerbal Space Program HUD + Main Map with the Orbital Track of Juno ... hehe.

 

Hope it's using MechJeb.  

 

(Yes, I've been playing KSP on my off-hours)

[LOC]

I love watching the Giantbomb East guys playing KSP. Its so god damn funny sometimes, especially when they don't expect a horrible outcome. But hey, space travel is dangerous folks! In gaming and in real life

[Draggendrop]

Moon Zoo Citizen Science Project: Preliminary Apollo 17 Landing Site Results

 

Apollo 17 Landing Site    NASA

 

Quote

Moon Zoo is a citizen science project that utilises internet crowd-sourcing techniques.

 

Moon Zoo users are asked to review high spatial resolution images from the Lunar Reconnaissance Orbiter Camera (LROC), onboard NASAs LRO spacecraft, and perform characterisation such as measuring impact crater sizes and identify morphological features of interest. The tasks are designed to address issues in lunar science and to aid future exploration of the Moon. We have tested various methodologies and parameters therein to interrogate and reduce the Moon Zoo crater location and size dataset against a validated expert survey.

 

We chose the Apollo 17 region as a test area since it offers a broad range of cratered terrains, including secondary-rich areas, older maria, and uplands.

 

The assessment involved parallel testing in three key areas: (1) filtering of data to remove problematic mark-ups; (2) clustering methods of multiple notations per crater; and (3) derivation of alternative crater degradation indices, based on the statistical variability of multiple notations and the smoothness of local image structures. We compared different combinations of methods and parameters and assessed correlations between resulting crater summaries and the expert census.

 

We derived the optimal data reduction steps and settings of the existing Moon Zoo crater data to agree with the expert census. Further, the regolith depth and crater degradation states derived from the data are also found to be in broad agreement with other estimates for the Apollo 17 region. Our study supports the validity of this citizen science project but also recommends improvements in key elements of the data acquisition planning and production.

 

Roberto Bugiolacchi, Steven Bamford, Paul Tar, Neil Thacker, Ian A. Crawford, Katherine H. Joy, Peter M. Grindrod, Chris Lintott
(Submitted on 4 Feb 2016)

Comments:    Accepted for publication in Icarus
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
DOI:    10.1016/j.icarus.2016.01.021
Cite as:    arXiv:1602.01664 [astro-ph.EP] (or arXiv:1602.01664v1 [astro-ph.EP] for this version)

Submission history
From: Ian Crawford 
[v1] Thu, 4 Feb 2016 13:05:41 GMT (3179kb)
http://arxiv.org/abs/1602.01664

http://spaceref.com/moon/moon-zoo-citizen-science-project-preliminary-apollo-17-landing-site-results.html

 

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Mars Curiosity Rover Selfie With a Sand Dune

 

Mars    NASA

 

Quote

The latest self-portrait from NASA's Curiosity Mars rover shows the car-size mobile laboratory beside a dark dune where it has been scooping and sieving samples of sand.

 

The new selfie combines 57 images taken by the Mars Hand Lens Imager (MAHLI) camera at the end of Curiosity's arm on Jan. 19. It is online at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA20316

 

The rover has been investigating a group of active sand dunes for two months, studying how the wind moves and sorts sand particles on Mars. The site is part of Bagnold Dune Field, which lines the northwestern flank of Mars' Mount Sharp.

 

When the component images were taken, the rover had scuffed the edge of "Namib Dune" and collected the first of three scoops of sand from that dune. It used its scoop later to collect a second sample on Jan. 19, and a third on Jan. 22.

 

During processing of the third sample, an actuator in the sample-processing device did not perform as expected when commanded. This week, the Curiosity team is identifying possible reasons for the actuator's performance.

 

The processing device on the arm is named CHIMRA, for Collection and Handling for In-situ Martian Rock Analysis. The component that was commanded to open, but did not, is called the CHIMRA tunnel. It is opened by using the thwack actuator, a motorized component that also can deliver a firm tap to help clean sample material from a nearby sieve. Part of the third scooped sample is inside the CHIMRA tunnel after passing through a sieve. If the tunnel had opened via the thwack actuator as planned, the next step would have been to take an image of the sand inside it.

 

"The rover responded properly to this unexpected event," said Steve Lee, deputy project manager for Curiosity at NASA's Jet Propulsion Laboratory, Pasadena, California. "It stopped moving the actuator and halted further use of the arm and sampling system."

more at the link...

http://spaceref.com/mars/mars-curiosity-rover-selfie-with-a-sand-dune.html

 

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

 

Opportunity climbing steeper slopes to reach science targets

 

file image  NASA

 

Quote

Opportunity is exploring 'Marathon Valley' on the rim of Endeavour crater. The rover is climbing up steep slopes to reach high-value science targets up on 'Knudsen Ridge.'

 

Opportunity performed the first of two steep climbs on Sol 4269 (Jan. 26, 2016), with just less than 16 feet (5 meters) for progress on slopes nearing 30 degrees.

 

On the next sol, the rover ascended further up slope about 14 feet (4.4 meters) reaching tilts just under 30 degrees.

 

For the next fives sols Opportunity conducted extensive Navigation Camera (Navcam) and Panoramic Camera (Pancam) imaging surveys of the potential rock targets and ridge outcrop in front of the rover in preparation for extensive in-situ (contact) science campaigns on the geologic units high up on this ridge line.

 

As of Sol 4275 (Feb. 2, 2016), the solar array energy production was 498 watt-hours with an atmospheric opacity (Tau) of 0.459 and a solar array dust factor of 0.683.

 

Total odometry is 26.51 miles (42.66 kilometers), more than a marathon.

http://www.marsdaily.com/reports/Opportunity_climbing_steeper_slopes_to_reach_science_targets_999.html

 

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NASA Working on the Coolest Spacecraft/Rover Hybrids You’ve Ever Seen

 

Quote

The answer may be a bit both — a spacecraft/rover hybrid.

 

Exploring small bodies like comets and asteroids could shed light on the origin and evolution of the solar system and even the origin of life on our planet.

 

Watch as Marco Pavone, Stanford University, and Ben Hockman, student, Stanford University, discuss their NASA Innovative Advanced Concept (NIAC) for spacecraft/rover hybrids.

 

This video was developed from a live recording at the 2015 NIAC Fall Symposium in October, 2015. To watch the full original talk please visit: http://bit.ly/1GGh5r8

 

To learn more about NIAC visit: www.nasa.gov/niac

http://www.parabolicarc.com/2016/02/05/nasa-working-coolest-spacecraftrover-hybrids-youve/

 

Spacecraft/Rover Hybrids

video is 3:58 min.

 

 

 

[Draggendrop]

A few times a month, I usually check in with my "little buddies", which are, and will always be, Carl Sagan's "pets".......yes........ Voyager 1 and Voyager 2. Generally, I check with DSN to see who's communicating, the comm spec's and then JPL to see where the boys are, as they venture farther than anything ever made by mere earthlings. These guys are really in the new frontier, advancing our knowledge of what is beyond the heliosphere and what the effects of the bow shock are. These guys were launched in 1977 and, like the energizer bunny, still going.

 

Quote

As of 2015 Voyager 1 and Voyager 2 continue to monitor conditions in the outer expanses of the Solar System. The Voyager spacecraft are expected to be able to operate science instruments through 2020, when limited power will require instruments to be deactivated one by one. Sometime around 2025, there will no longer be sufficient power to operate any science instruments

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

 

We are receiving data from Voyager 2, tonight from the Canberra DSN dish.....

 

Quote

SPACECRAFT

NAME
Voyager 2

RANGE
16.61 billion km

ROUND-TRIP LIGHT TIME
1.28 days

ANTENNA

NAME
DSS 34
AZIMUTH
220.83 deg
ELEVATION
33.89 deg
WIND SPEED
9.88 km/hr
MODE
ARRAY
DOWN SIGNAL

SOURCE
VOYAGER 2
TYPE
DATA
DATA RATE
159.00 b/sec
FREQUENCY
8.42 GHz
POWER RECEIVED
-158.63 dBm
(1.37 x 10-22 kW)
 

https://eyes.nasa.gov/dsn/dsn.html

 

location...

http://voyager.jpl.nasa.gov/where/

 

 

 

Quote

The twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing on their more-than-37-year journey since their 1977 launches, they each are much farther away from Earth and the sun than Pluto. In August 2012, Voyager 1 made the historic entry into interstellar space, the region between stars, filled with material ejected by the death of nearby stars millions of years ago. Scientists hope to learn more about this region when Voyager 2, in the “heliosheath" -- the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar medium -- also reaches interstellar space. Both spacecraft are still sending scientific information about their surroundings through the Deep Space Network, or DSN.
 
The primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there -- such as active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings -- the mission was extended. Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets. The adventurers' current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun's domain. And beyond.

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

 

Voyager 1 in 1977 during vibration testing  NASA/JPL

 

This is how we make probes that last..... smooth sailing boys......

 

Edited February 7, 2016 by Draggendrop
added last image

[Draggendrop]

Consistency of Earth's magnetic field history surprises scientists

 

 

CAPTION
This figure illustrates superchrons of both normal and reversed polarity over time as the Earth's molten core formed and solidified. It is provided courtesy of Peter Driscoll and David Evans

 

Quote

Earth's magnetic field is generated by the motion of liquid iron in the planet's core. This "geodynamo" occasionally reverses its polarity - the magnetic north and south poles swap places. The switch occurs over a few thousand years, and the time between reversals can vary from some tens of thousands to tens of millions of years.

 

When magnetic polarity remains stable in one orientation for more than 10 million years the interval is dubbed a "superchron." Within the last 540 million years - the time when animals have roamed the Earth's land and seas - there are three known superchron periods, occurring about once every 200 million years.

 

The question of how frequently reversals and superchrons occurred over a longer segment of Earth's history is important for understanding the long-term evolution of the internal and surface conditions of our planet. But so far, such information has only been pieced together by fragmentary evidence.

 

New work from Carnegie's Peter Driscoll and David Evans of Yale University now identifies as many as 10 additional superchrons over a 1.3 billion-year stretch of time during the Proterozoic Eon, or Earth's middle age, which occurred 2.5 to 0.54 billion years ago. Their work is published in the March 1st issue of Earth and Planetary Science Letters.

 

Records of magnetic field reversals can be found in rocks that maintain the magnetic polarity of the era in which they formed. In order to establish evidence of a polarity shift, this kind of ancient magnetic, or "paleomagnetic," data must be gathered from around the globe, ideally sampling every tectonic plate.

 

Driscoll and Evans compiled a database of global paleomagnetic data from the Proterozoic, and coordinated their reversal records with the movements of the tectonic plates to look for long periods with either strongly northern or southern polarity dominance. These super-long periods of polarity bias then revealed the previously unknown ancient superchrons.

 

"Our study points the way towards new questions about fundamental aspects of Earth's evolution," Driscoll said. "One of the major implications of these findings is that geodynamo-driven superchrons have occurred at a similar rate for most of the past two billion years."

 

This was surprising, because geophysicists have good reason to suspect that there was a major change in Earth's core within that time interval. Due to Earth steadily cooling, losing heat to space since the time of its formation, the planet's inner core - a giant mass of solid iron at the center of the planet - should have started to crystallize between about a half billion and one billion years ago.

 

The growth of the solid inner core is fundamental to the physics of the geodynamo. Computer simulations of reversal rates are very different depending on whether or not the planet has a solid inner core.

 

One possible explanation for Driscoll and Evans's new result is that the Earth's inner core is actually much older than has been previously estimated, but this idea would conflict strongly with the most-reasonable planetary cooling models. Another explanation invokes an unexpected resilience of the geodynamo in the face of dramatic changes to its structure, including something as fundamental as the solidification of the inner core.

 

"We think the latter is more likely," Driscoll added. "But regardless of which answer is correct, these results mean that we may need to rethink our models for either core evolution or the geodynamo process."

http://www.spacedaily.com/reports/Consistency_of_Earths_magnetic_field_history_surprises_scientists_999.html

 

http://www.eurekalert.org/multimedia/pub/108180.php

 

IMHO, the Earth's magnetic field is it's most valuable resource. Without it, no atmosphere and no conventional life. We need to know as much as possible about our "guardian".

 

[LOC]

I wonder how much we owe to planet-smash right into us head on in that regard. I mean, we got the Moon out of it, but what about the iron-ness of the planet before the collision etc. Makes you wonder how much different things would be without it, or if there would be things to ponder aka life might not have come about

[DocM]

And magnesium has a central role in creating the geomagnetic field

 

http://www.smithsonianmag.com/science-nature/humble-magnesium-could-be-powering-earths-magnetic-field-180957883/

[LOC]

Ha, I just read that on Smartnews earlier today. It'd make sense if it had a central role in the magnetic field.

[Draggendrop]

The generation of the earth's magnetic field is still a quandary to test and explain though research still continues. The core is presumed solid and consisting mainly of heavy elements, primarily iron. The inner core, over 4.3 billion years has cooled to become a solid mass and pressures may be over 300 Gpa with a solid core temperature above 6000K. This exceeds the Curie temperature of iron, therefore the core itself cannot be a magnet, but can still act as a conventional core to harness and focus radial fields. This leaves us with a rotational fluid comprising of charged carriers to produce an electric field. The Earth's rotation is key to this. This is evidenced by Venus not having a magnetic field with a rotational period of around 243 days. Mars has sporadic patches of field activity, but this may be due to excess cooling. We then have a dilemma of phase transitions and associated properties of elements. At the extreme pressures involved at the cores, transition melt temperatures can vary drastically. Do we have deposition rates onto the solid core which apply directional changes to convection currents or is it an imbalance of charged carriers which causes a magnetic reversal, which has occurred many times in a relatively timely fashion. Do impurities cause these phase transitions to change, yes, in a lab environment.

 

We can be considered fortunate to have a magnetic field, such as ours, to allow life to continue, but at times, it to is breached and the result is the trapped particles and creation of  the Van Allen belts.Research is ongoing and simulations are ever broadening our understanding. Now, if someone could come up with "unobtainium", we could go and find out for ourselves.

 

 

[Draggendrop]

Here are a few shots, from HiRISE, of the Curiosity rover.

 

http://www.planetary.org/blogs/emily-lakdawalla/2016/01291546-hirise-image-coverage-curiosity.html?referrer=http://planetary.org/

 

Quote

Detailed HiRISE view of Curiosity, sol 1094 (September 4, 2015)

In this unusually sharp HiRISE image of Curiosity, you can even make out Curiosity's right-side wheels as distinct objects. Visit this page for a wider context view.

 

 

 

 

 

 

Quote

HiRISE Digital Terrain Models (DTMs) covering the Curiosity field site

Digital Terrain Models (DTMs) are high-resolution topographic data computed from stereo pairs of HiRISE images.

 

 

Good thing we didn't have an ooops, and off the cliff face.....  " I've fallen and can't get up"

 

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

 

Last night, while perusing the news articles, I came across a preliminary report of an individual killed by a possible meteroid. Experts have not done an investigation to verify the object, at the immediate time of occurrence, so I am somewhat skeptical, as many incidents can be attributed to aircraft parts, aircraft waste debris, satellite fused debris...etc.

 

first terminology, as the MSN routinely butchers this...

 

 

now a few headlines...

 

Indian man could be first recorded human fatality due to a meteorite

 

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Indian officials say a meteorite struck the campus of a private engineering college on Saturday, killing one person. If scientists confirm the explosion was due to a meteorite, it would be the first recorded human fatality due to a falling space rock.

 

According to local reports, a bus driver was killed on Saturday when a meteorite landed in the area where he was walking, damaging the window panes of nearby buses and buildings. Three other people were injured.

 

On Sunday, various Indian publications, including The Hindu, reported that the chief minister of Tamil Nadu, Jayalalithaa, issued a statement confirming the death: "A mishap occurred yesterday when a meteorite fell in the campus of a private engineering college in Vellore district's K Pantharappalli village." Tamil Nadu is located in southern India, and has a population of more than 70 million people.

 

There have been no confirmed human deaths due to meteorite strikes, although there have been a number of interesting close calls, based upon a list kept by International Comet Quarterly. For example, meteorites have landed in homes and hit people as they have slept, but have not killed them.

 

In our most recent close call, a bright fireball created a huge airblast over Chelyabinsk, Russia, in 2013. The resulting shock damaged thousands of buildings and injured more than 1,000 people. But there were no fatalities.

http://arstechnica.com/science/2016/02/indian-man-could-be-first-recorded-human-fatality-due-to-a-meteorite/

 

 

then this...

 

Meteorite Like Object Kills Man in Vellore

 

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VELLORE/CHENNAI/BENGALURU:  It came from the sky and killed a man on the campus of a private engineering college in Vellore district on Saturday. The  irregular-shaped object recovered from the college campus by a team led by an  Indian Space Research Organisation (ISRO) expert is barely 2 cm in width, weighs about 50 grams and looks like a meteorite. Chief Minister J Jayalalithaa too described it that way.

 

To get the theory validated, the Vellore district police have sought the help of experts from the Indian Institute of Astrophysics (IIA), Bengaluru. “We have requested experts from IIA, to come over to Vellore to examine the object and identify whether it is a meteorite. They have agreed to come here on Monday,” Superintendent of Police (SP) of Vellore P K Senthil Kumari told Express.

 

The object is brownish-black in colour and has air bubbles on its rigid surface. It was found by the police with the help of a four-member team from ISRO, led by an expert Balamurugan, behind the college canteen around 4 pm on Saturday. The college is located at Natrampalli, about 85 km from Vellore town. The spot is about 18-20 km from Bethaveppampattu, where a similar object, suspected to be a meteorite, fell on January 26. It created a perfect circle in a farmland and fortunately there was no casualty.

One school of thought suggests that it couldn’t have been a meteor because their showers were not expected till April.

this is the picture attached to the article, does not appear to be "brownish-black"...unless camera filtered...?

 

This is apparently a piece of the as-yet unidentified object that fell from the sky killing a person in Vellore. | EPS

 

Hopefully today, we will have the facts, either way, condolences to the man's family and this was real bad luck.

 

As a footnote, other people and animals have been hit by orbital debris....

 

The True Story of History's Only Known Meteorite Victim

 

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Take the true story of Ann Hodges, the only confirmed person in history to have been hit by a meteorite.

 

On a clear afternoon in Sylacauga, Alabama (see map), in late November 1954, Ann was napping on her couch, covered by quilts, when a softball-size hunk of black rock broke through the ceiling, bounced off a radio, and hit her in the thigh, leaving a pineapple-shaped bruise.

details and image at the link....

http://news.nationalgeographic.com/news/2013/02/130220-russia-meteorite-ann-hodges-science-space-hit/

 

and an "unofficial list" of similar events through history...take with a grain of salt....

 

http://www.icq.eps.harvard.edu/meteorites-1.html

 

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Date	Location	Remarks	Ref.
1807 12 14	Weston, CT, USA	meteor visible half a minute, loud sounds heard, many stones found scattered over 6-10 miles, weighing as much as 200 lbs. total (largest meteorite weighed 35 lbs)	[21]
1825 01 16	Oriang, Malwate, India	man killed, woman injured in meteorite fall [considered "possible" by LaPaz (1958)]	[14, 17, 25]
1827 02 16	Mhow, India	man wounded "severely in the arm" when hit by meteorite	[12, 17, 25]
1836 11 11	Macau, Brazil	cattle killed when hit by shower of meteorites [considered "possible" by LaPaz (1958)]	[12, 17, 25]
1847 07 14	Hauptmannsdorf, Braunau, Bohemia	37-pound Braunau iron meteorite smashed into a room, covering three children with ceiling debris but not hurting them	[12, 17, 25]
1860 05 01	New Concord, OH, USA	horse struck and killed by meteorite	[12, 17, 25]
1863 08 08	Pillistfer, Latvia	5.4-kg stony meteorite penetrated tile roof and floor of building	[25]
1868 01 30	Pultusk, Poland	meteorite shower of more than 100,000 fragments	[12]
1882 02 03	Mocs, Romania	meteorite shower of thousands of fragments	[12]
1890 05 02	Forest City, IA, USA	meteorite shower of some 2000 fragments; one fragment fell into a pile of hay (no fire)	[12]
1893 09 02	Zabrodje, White Russia	3-kg stony meteorite fell through house roof	[25]
1906 11 04	Constantia, South Africa	1-kg stony meteorite smashed through roof and ceiling (2-pound piece recovered)	[25]
1907 09 05	Hsin-p-ai Wei, Weng-li, China	meteorite caused a house to collapse, killing a family; evidently no evidence	[1]
1908 06 30	Tunguska, Siberia	apparent airblast (no recovered meteorites) of an object entering Earth's atmosphere; leveled hundreds of square miles of forest, killing two men and hundreds of reindeer	[15]
1911 06 16	Kilbourn, WI, USA	772-gm stony meteorite passed through roof and floorboard of barn, penetrated 2.5 inches into clay floor	[25]
1911 06 28	Nakhla, Egypt	dog struck and killed by meteorite (part of meteorite shower)	[12, 17, 25]
1912 07 19	Holbrook, AZ, USA	meteorite shower of more than 14000 fragments; meteorite fell a few meters from a person; largest fragment 9 pounds	[12, 13]
1915 04 25	Ta-yang, east of Mai-po, China	meteorite tore off a woman's arm; several meteorites, ranging from about 2 to about 3.5 kg	[1]
1916 01 18	Baxter, MO, USA	611-gm stony meteorite penetrated roof of house	[25]
1921 12 31	Beyrout, Syria	1.1-kg stony meteorite fell through hut roof	[25]
1924 07 06	Johnstown, CO, USA	meteorites fell within a few feet of two men; 50-pound stone went 5 feet into wet soil	[13]
1927 04 28	Aba-mura, Inashiki-gun, Ibaragi-ken, Japan	young girl suffered two head injuries when struck by a stony meteorite	[16, 25]
1932 08 10	Archie, MO, USA	meteorite fell less than 1 m from person	[12, 13]
1936 04 02	Yurtuk, Ukraine	2-kg stony meteorite smashed hole in roof of house	[25]
1938 03 31	Kasamatsu, Japan	721-gm stony meteorite penetrated house roof, landed on floor	[25]
1938 06 16	Pantar, Philippines	numerous buildings hit by thousands of meteorites "as big as corn and rice grains"	[12, 25]
1938 06 24	Chicora, PA, USA	cow's hide injured, presumably by a fragment belonging to the meteorite shower in that area on that day	[17, 25]
1938 09 29	Benld, IL, USA	building and car hit by stony meteorites; the car was hit by a 4-pound fragment after it crashed through the roof of a garage, then through roof, seat, and floorboards of car	[12, 13, 25]
1947 02 12	Sikhote-Alin, south-eastern Siberia	largest meteorite shower on record; estimated 100 tons of total debris fell, the largest weighing 1745 kg; some 9000 fragments weighing about 28 tons recovered; largest crater 28 m wide	[2]
1949 09 21	Beddgelert, N. Wales	794-gm stony meteorite broke through roof and fell into hotel room	[25]
1950 09 20	Murray, KY, USA	five buildings hit by meteorites	[12]
1950 12 10	St. Louis, MO, USA	car hit by meteorite	[12]
1954 11 30	Sylacauga, AL, USA	woman in home hit by meteorite after breaking through roof	[3, 12, 25]
1965 12 24	Barwell, England	two buildings and a car hit by by meteorites	[12]
1971 04 08	Wethersfield, CT, USA	12-ounce meteorite entered house through roof, lodged in living-room ceiling; ordinary chondrite; less than two miles away, another house was hit 11.5 yr later	[4, 12]
1976 03 08	Jilin City, Jilin, China	largest stony-meteorite shower in recent times; more than 100 fragments, the largest being 1770 kg in weight and making an impact crater 6 m deep; H5 chondrite	[1, 12]
1977 01 31	Louisville, KY, USA	three buildings and a car hit by meteorites	[12]
1982 11 08	Wethersfield, CT, USA	meteorite entered house through roof; second house hit in same town in 11.5 years; L6 chondrite	[4, 12]
1984 09 30	Binningup, WA, Australia	meteorite fell 4-5 m from two sunbathers on soft beach sand	[12]
1984 12 10	Claxton, GA, USA	mailbox hit by meteorite	[12]
1986 07 29	Kokubunji, Japan	several buildings hit by meteorites	[12]
1991 08 31	Noblesville, IN, USA	meteorite fell 3.5 m from two children outside; ordinary stony chondrite	[5]
1992 08 14	Mbale, Uganda	meteorite shower; boy hit on head by 3.6-g fragment after it hit tree first	[6]
1992 10 09	Peekskill, NY, USA	car hit by meteorite, which passed through steel trunk and impacted ground underneath; fireball widely visible and imaged along east coast	[7]
1992 12 10	Mihonoseki, Honshu, Japan	6.5-kg L6 ordinary chondrite meteorite crashed through house to ground	[10]
1994 06 14	St-Robert, QC, Canada	meteorite shower caused sonic boom in Montreal; scattered strewnfield in rural area; more than 25 kg recovered; H5 chondrite	[8]
1994 06 21	near Getafe, Spain	12-cm-wide, 1.4-kg meteorite broke windshield and bent steering wheel of moving car, breaking finger of driver; more than 50 kg of meteorites found within 200 m of accident	[11]
2003 03 26	Chicago, IL, USA	meteorite shower; buildings hit in Park Forest, IL; ordinary chondrites	[9]
2003 09 27	Mayurbhanj, Orissa, India	bright fireball(s) lit up sky just after sunset; widely observed meteorite shower yielding numerous highly magnetic meteorites	[18]
2004 06 12	Ellerslie, suburban Auckland, N.Z.	1.3-kg (2.8-lb) 7-cm x 13-cm meteorite broke through roof of house and bounced off sofa	[19]
2007 09 15	Carancas, Peru (near Lake Titicaca at alt. 3824 m)	13.5-m-diameter crater created by mid-day visible fireball meteorite, numerous ordinary chondrites H4-5 recovered; made international news when local people complained of illness -- not yet definitively explained	[22]
2008 10 06	Nubian desert, northern Sudan (Almahata Sitta)	47 meteorites weighing 3.95 kg were found in Dec. 2008 via a systematic search along the suspected debris path for the small minor planet 2008 TC3, discovered 20 hours prior to impact by R. A. Kowalski with the 1.5-m telescope at Mt. Lemmon in Arizona, when it was about 370000 miles from the earth; a bright fireball was seen by airline pilots and orbiting satellites when the object entered the Earth's atmosphere; the largest earth's atmosphere; the largest recovered meteorite weights 1.5 g (classified as a polymict ureilite, an achondrite)	[23]
2013 02 15	near Chelyabinsk, south-central Russia	extremely bright fireball (apparent brightness rivalling that of the apparent brightness of the sun) entered atmosphere over Alaska and moving westward toward Chelyabinsk, near its termination point shortly before sunrise, creating a huge airblast shock that damaged thousands of buildings in Chelyabinsk (mostly broken glass) and injuring more than 1000 people; apparently meteorites were found in water under a large circular broken- ice feature found soon after the event	[20]

details at the above link...food for thought.