Asteroid Vesta's mysterious olivine

Nov 07, 2013
This image shows infrared views of two craters at the giant asteroid Vesta that NASA's Dawn mission has found to sport the mineral olivine. These craters, Bellicia (left) and Arruntia (right), are in the northern hemisphere, where Dawn scientists didn't expect to find olivine. If Vesta's formation had followed the script for the formation of rocky planets like our own, heat from the interior would have created distinct, separated layers of rock (generally, a core, mantle and crust). In that story, the mineral olivine should concentrate in the mantle. However, Dawn's visible and infrared mapping spectrometer (VIR) did not find olivine at the huge craters in Vesta's southern hemisphere that exposed Vesta's mantle. Instead, scientists found signatures of olivine in the surface material in the northern hemisphere, at Bellicia and Arruntia craters. These images were taken between June 15 and July 25, 2012, from an altitude of 420 miles (680 kilometers). Scientists assigned red to the 1.25-micron range of the infrared radiation spectrum, green to the 1.93-micron range, and blue to the 1.64-micron range. Green areas show where Vesta's surface is rich in olivine. Credit: NASA/JPL-Caltech/UCLA/ASI/INAF

(Phys.org) —Just when scientists thought they had a tidy theory for how the giant asteroid Vesta formed, a new paper from NASA's Dawn mission suggests the history is more complicated.

If Vesta's formation had followed the script for the formation of rocky planets like our own, heat from the interior would have created distinct, separated layers of rock (generally, a core, mantle and crust). In that story, the mineral olivine should concentrate in the mantle.

However, as described in a paper in this week's issue of the journal Nature, that's not what Dawn's visible and infrared mapping spectrometer (VIR) instrument found. The observations of the huge craters in Vesta's southern hemisphere that exposed the lower crust and should have excavated the mantle did not find evidence of olivine there. Scientists instead found clear signatures of olivine in the surface material in the northern hemisphere.

"The lack of pure olivine in the deeply excavated basins in Vesta's southern hemisphere and its unexpected discovery in the indicate a more complex evolutionary history than inferred from models of Vesta before Dawn arrived," said Maria Cristina De Sanctis, Dawn co-investigator and VIR leader at the National Institute for Astrophysics in Rome, Italy.

Perhaps Vesta only underwent partial melting, which would create pockets of olivine rather than a global layer. Perhaps the exposed mantle in Vesta's was later covered by a layer of other material, which prevented Dawn from seeing the olivine below it.

This colorized map from NASA's Dawn mission shows the types of rocks and minerals distributed around the surface of the giant asteroid Vesta. In this color scheme, red shows diogenite, a type of mineral thought to be formed through magmatic processes deep in the crust. Green shows howardite, a type of surface rock that is made of broken bits of different materials that are excavated, ejected and mixed by meteor impacts. These types of rocks are the most abundant observed on Vesta's surface. Blue shows eucrite, a type of rock formed in the crust of Vesta that isn't as deep down as diogenite. For example, Vesta's equatorial region is replete with eucrites. Yellow areas show regions with diogenite and howardite. The yellow and red areas have large quantities of the magnesium-and silicate-rich mineral diogenite, especially in the southern hemisphere. Cyan areas show regions with eucrite and howardite. Many howardite, eucrite and diogenite meteorites have been found on Earth, and earlier work from Dawn confirmed theories that they came from Vesta. The location of two craters, Arruntia and Bellicia, are noted in the annotated version. At these craters, scientists unexpectedly found the mineral olivine. The outlines of the giant craters Rheasilvia and Veneneia are also noted. Scientists thought they'd find olivine in those locations but have not. The data for this map were obtained by Dawn's visible and infrared mapping spectrometer (VIR) during Dawn's orbital measurements of Vesta from 2011 to 2012. Credit: NASA/JPL-Caltech/UCLA/ASI/INAF

"These latest findings from Dawn stimulate us to test some different ideas about Vesta's origin," said Carol Raymond, Dawn's deputy principal investigator at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "They also show us what additional information we can learn by going into orbit around places like Vesta to complement the bits that come to us as meteorites or observations from long distances."

Dawn is currently cruising toward its second destination, the dwarf planet Ceres, which is the biggest member of the between Mars and Jupiter. It will arrive at Ceres in early 2015.

Explore further: Dawn reality-checks telescope studies of asteroids

More information: Paper: dx.doi.org/10.1038/nature12665

Related Stories

Vesta in Dawn's rear view mirror

Sep 11, 2012

(Phys.org)—NASA's Dawn mission is releasing two parting views of the giant asteroid Vesta, using images that were among the last taken by the spacecraft as it departed its companion for the last year.

Dawn mission video shows Vesta's coat of many colors

Jun 07, 2012

(Phys.org) -- A new video from NASA's Dawn mission reveals the dappled, variegated surface of the giant asteroid Vesta. The animation drapes high-resolution false color images over a 3-D model of the Vesta ...

Dawn reality-checks telescope studies of asteroids

Sep 30, 2013

(Phys.org) —Tantalized by images from NASA's Hubble Space Telescope and ground-based data, scientists thought the giant asteroid Vesta deserved a closer look. They got a chance to do that in 2011 and 2012, ...

Dawn spacecraft prepares for trek toward dwarf planet

Aug 30, 2012

(Phys.org)—NASA's Dawn spacecraft is on track to become the first probe to orbit and study two distant solar system destinations, to help scientists answer questions about the formation of our solar system. ...

Dawn Engineers Assess Reaction Wheel

Aug 14, 2012

Engineers working on NASA's Dawn spacecraft are assessing the status of a reaction wheel -- part of a system that helps the spacecraft point precisely -- after onboard software powered it off on Aug. 8. ...

Recommended for you

Informing NASA's Asteroid Initiative: A citizen forum

7 hours ago

In its history, the Earth has been repeatedly struck by asteroids, large chunks of rock from space that can cause considerable damage in a collision. Can we—or should we—try to protect Earth from potentially ...

Image: Rosetta's comet looms

12 hours ago

Wow! Rosetta is getting ever-closer to its target comet by the day. This navigation camera shot from Aug. 23 shows that the spacecraft is so close to Comet 67P/Churyumov-Gerasimenko that it's difficult to ...

A salty, martian meteorite offers clues to habitability

13 hours ago

Life as we know it requires energy of some sort to survive and thrive. For plants, that source of energy is the Sun. But there are some microbes that can survive using energy from chemical reactions. Some ...

User comments : 21

Adjust slider to filter visible comments by rank

Display comments: newest first

Egleton
1.4 / 5 (10) Nov 07, 2013
Very good. Can we build space colonies with it?
cantdrive85
1 / 5 (13) Nov 07, 2013
Such a discovery is no "mystery" from the EU POV, it's quite easily explain actually.
Squirrel
1.3 / 5 (9) Nov 07, 2013
cantdrive85--it is a puzzle. Nature would not have published this unless the astronomers in their peer review thought it was an exceptional finding with high odds of getting highly cited in future years.
cantdrive85
1 / 5 (13) Nov 07, 2013
It's a puzzle for the "standard" theory and it's explanations, the Electric Universe theory has simple explanation.
HannesAlfven
1 / 5 (11) Nov 07, 2013
Re: "Nature would not have published this unless the astronomers in their peer review thought it was an exceptional finding with high odds of getting highly cited in future years."

Peer reviewers are not all that different from people who vote down competing worldviews on physorg. They just know more about conventional theory, on average. There's no reason to confuse that with awareness of competing worldviews.

Scientometrics is, btw, an awful system for evaluating innovation in science which leads to quantity-over-quality as well as bandwagon effects where researchers who are on the bandwagon go out of their way to trash competing ideas (which are oftentimes better). The problem is that scientometrics is only relevant at the (convergent) model-building level of scientific discourse. It offers nothing that we can use to guide us in our conversations about competing worldviews or even innovative ideas (divergent processes).

True innovation involves both convergence & divergence.
Gigel
5 / 5 (3) Nov 07, 2013
It's a puzzle for the "standard" theory and it's explanations, the Electric Universe theory has simple explanation.

Design a test that clearly cuts between the 2 theories (either one is true in the test, not both), run it and we'll talk afterwards. Make it cut clearly between, without doubts.
Torbjorn_Larsson_OM
5 / 5 (6) Nov 07, 2013
That Vesta isn't fully differentiated would be funny, seeing how it was originally spherical so melted. A later covering wouldn't be surprising, seeing how it has been hit multiply times.

********
And is the nuts trolling geology now? What's next, trolling ads for soap?

But the "we have the answer for every observation that science doesn't yet know (but we won't tell with a quantitative theory)" con game is as old as crackpottery. Also stupid here, because _two_ simple predictions ("explanations") were already given.
HannesAlfven
1 / 5 (12) Nov 07, 2013
Re: "Design a test that clearly cuts between the 2 theories (either one is true in the test, not both), run it and we'll talk afterwards. Make it cut clearly between, without doubts."

This line of reasoning works great within paradigms where there are lots of constraints & consensus, but not generally between them.

Take the Deep Impact mission as an example: Two separate flashes at the moment of impact was predicted by Wal Thornhill because it was clear that Tempel 1 should exhibit high charge density. But, nobody could know exactly how much extra charge was there.

When two separate flashes were observed, Wal was the only theorist who predicted more than just one flash. But, the response was not, "This is something we might look into …" The response was that he failed to quantify the flashes.

And a suggestion was made that the impactor flashed multiple times due to contact with different layers in Tempel 1. But, the impacter's enormous speed precluded this explanation.
barakn
5 / 5 (1) Nov 07, 2013
And a suggestion was made that the impactor flashed multiple times due to contact with different layers in Tempel 1. But, the impacter's enormous speed precluded this explanation.

If that's the case, then it will be easy for you to post a sequence of images clearly showing multiple flashes.
HannesAlfven
1 / 5 (11) Nov 07, 2013
Re: "If that's the case, then it will be easy for you to post a sequence of images clearly showing multiple flashes."

"What you see is something really surprising. First, there is a small flash, then there's a delay, then there's a big flash and the whole thing breaks loose." -- Peter Schultz, Stardust-NeXT team

See The Electric Comet documentary which Dave Talbott put together at http://www.youtub...t2EUToo.

If you are looking for empirical evidence for the EU, then you will want to start with comets. And if you want the fastest review for why the EU can explain comets better, then watch this video.
HannesAlfven
1 / 5 (11) Nov 08, 2013
This might be of interest as well ...

Some years ago Charles Ginenthal (ed. of The Velikovskian) proposed that orbital eccentricity is strongly influenced by charge. The greater the charge, the more eccentric the orbit. Venus has a nearly circular orbit because its magnetic field is weak. Comets have highly eccentric orbits because they are highly charged.

Vol. IV, No. 3. (1999) of The Velikovskian is devoted to Ginenthal's "Electro-Gravitic Theory of Celestial Motion & Cosmology"

"… This Motion Theory can be tested in space by placing a highly magnetic, low-mass ball outside the Earth's magnetosphere in a highly circular orbit and observing if there is a change of that orbit. If there is any change in the orbit, it will either demonstrate the validity of the theory or destroy it. The evidence is laid out in clear, understandable terms with footnotes and a scientific Appendix which formulates the experiment to be carried out in space."
HannesAlfven
1 / 5 (11) Nov 08, 2013
It's not clear to me, however, to what extent this matches Wal Thornhill's theory of comets. It is clear that in the electrical worldview, eccentricity is generally tied to cometary displays. Once a person tunes into this correlation, they will start to notice it pop up repeatedly in comet and even asteroid press releases. Asteroids on eccentric orbits routinely flare up like comets.

The problem with worldviews is that they are very difficult to judge from afar. So, the brave explorer may try out a strange worldview long enough to realize that, "Hey, these people aren't completely crazy for pursuing this." And the high of seeing the universe in a new light can be exhilarating. But, you will also inevitably discover how difficult it is to convince others to question their own worldviews.

Figuring out the experiment will prove to be anti-climactic, for the more difficult battle is convincing people to question their own worldviews.
cantdrive85
1 / 5 (11) Nov 08, 2013
And a suggestion was made that the impactor flashed multiple times due to contact with different layers in Tempel 1. But, the impacter's enormous speed precluded this explanation.

If that's the case, then it will be easy for you to post a sequence of images clearly showing multiple flashes.

It would take about five minutes on the Deep Impact website to verify his claim, however some prefer the security ignorance offers them.
barakn
5 / 5 (2) Nov 09, 2013
Re: "If that's the case, then it will be easy for you to post a sequence of images clearly showing multiple flashes."
...
See The Electric Comet documentary which Dave Talbott put together at http://www.youtub...t2EUToo.

Perhaps it was somewhere in the 1.5 hours of video, but there's no way I'm wasting my time watching it. So I'll provide it: http://www.nasa.g...2144.jpg This series of images should profoundly bother you. Because the impactor was separated by the comet by a near perfect vacuum and because it approached so fast, an electric discharge between the two would have been a sharp, nearly instantaneous, impulsive event rather than a long-duration current. Which leaves frames _064 - _066 impossible to explain: before the first bright flash, a relatively weak spot of light of linearly increasing with time. Now I leave you to come up with some lamb-brained, half-assed solution to this puzzling behavior.
barakn
5 / 5 (2) Nov 09, 2013
And a suggestion was made that the impactor flashed multiple times due to contact with different layers in Tempel 1. But, the impacter's enormous speed precluded this explanation.

If that's the case, then it will be easy for you to post a sequence of images clearly showing multiple flashes.

It would take about five minutes on the Deep Impact website to verify his claim, however some prefer the security ignorance offers them. -cantdrive85

Sucker. Nowhere did I state there weren't multiple flashes.
HannesAlfven
1 / 5 (9) Nov 09, 2013
Re: "there's no way I'm wasting my time watching it … Now I leave you to come up with some lamb-brained, half-assed solution to this puzzling behavior."

You seem to be discounting your own case. It stands to reason that to rule something out, we must first put some effort into understanding what it is we are ruling out, which suggests that your logic here ...

… "Because the impactor was separated by the comet by a near perfect vacuum and because it approached so fast, an electric discharge between the two would have been a sharp, nearly instantaneous, impulsive event rather than a long-duration current." …

… is based entirely upon the gravitational worldview you've thus far become fluent in. You can't have it both ways: Either you spend the very modest amount of time to become fluent in the changes which are being suggested for cometary theory, OR you perhaps accept that arguing against something you refuse to learn about is creating noise.
cantdrive85
1 / 5 (9) Nov 09, 2013
Because the impactor was separated by the comet by a near perfect vacuum and because it approached so fast, an electric discharge between the two would have been a sharp, nearly instantaneous, impulsive event rather than a long-duration current.

As HA pointed out, you have imparted your own assumptions of the environment and the expected outcome. The plasma is far more complex than you envision, not to mention this would be well within the comet's coma where the particle would have been much higher. Your ignorance is showing again.

Now I leave you to come up with some lamb-brained, half-assed solution to this puzzling behavior.

Baaa, baaaa, OBAAAAMMMMAAA.
Or did you want a LAME-brained response, similar to your own?
HannesAlfven
1.5 / 5 (8) Nov 10, 2013
Cantdrive, can you please be respectful? When future journalists strive to understand why it is that people today preferred to talk about weakly-supported scientific constructs in astrophysics & cosmology over exploring the known red flags suggesting that the cosmic plasma models are highly idealized & flawed, it would be preferable if they didn't find somebody insulting the people they are trying to convince. There are really important lessons here to be learned about trust in expert opinion, how we train scientists, how to teach critical thinking in science, the role of debate in science education, and so on, which we can become distracted from when tribalism is introduced into the picture. There is no us vs them; it's all of us trying to figure out the universe together.

After all, the EU has much work to go itself, and it will take a large community many years and much effort to reproduce the amount of work which has gone into the conventional theories.
HannesAlfven
1 / 5 (7) Nov 10, 2013
For those interested in seeing experimental results supporting the EU, there will be an announcement of interest on this subject in just a couple of days. The EU will be offering an "Innovative Experiment Prize". The URL is still under construction ...
barakn
1 / 5 (1) Nov 10, 2013
Because the impactor was separated by the comet by a near perfect vacuum and because it approached so fast, an electric discharge between the two would have been a sharp, nearly instantaneous, impulsive event rather than a long-duration current.

this would be well within the comet's coma where the particle would have been much higher. Your ignorance is showing again.
A comet coma's density is so low it puts laboratory vacuums to shame, but that's besides the point - a lightning stroke leader forms a kilometers long structure in a few milliseconds at atmospheric pressure.
barakn
5 / 5 (1) Nov 10, 2013
To summarize, EU has never bothered to put forward a physical model that explains the observations and yet claims the flash as an EU phenomenon. Were EU a real science, and were you real scientists, the fact that you are using phrases like "plasma is far more complex" as an excuse not to do the work would really bother you. But I'm sure you'll sleep well tonight and soon forget about this gaping hole in one of the "pillars" of your "theory."