Asteroids: how, what are they made of?

I am interested in the structure and composition of asteroids as of late after reading about the near earth orbit chunks we are looking out for and those who plan to mine them in space. As I understand it comets are balls of primordial stuff {ice, "rocks", dust} that first formed the planets and then there are rock and metallic chunks zipping about our solar system. I wonder if it is known if some are made from concentrated rocks & minerals precipitated out of cooling magmas or metamorphosed from the pressure of being part of a planet{oid} and then blasted apart or if they are conglomerates of interstellar dust from supernovae.


Kind of a simplistic topic heading but I thought it might be fun to post about features that come to light.

This Space.com article struck my fancy recently "A team of scientists is mapping out a mission to the huge metallic asteroid Psyche {wiki link}, which is thought to be the exposed iron core of a battered and stripped protoplanet"


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Aha! After tirelessly searching for 3 minutes I found an article that explained a little about whether or not asteroids like Psyche would be radioactive if all the heavier elements sank to the center - something I had been wondering about. A quote from the April 7, 2011 article in MIT news :

"A new analysis of one of the most well-known meteorites on Earth provides strong evidence that the prevailing view of many asteroids is wrong. Rather than randomly mixed blobs of rock and dust stuck together, it appears that the asteroid that was the source of the Allende meteorite {my wiki link}was large enough to have had a molten core, even though its surface remained cold and solid. The new view also suggests that astronomers’ view of how planets like the Earth formed may need revision. "

Edited in one more quote from the article:

"The new analysis shows that while newly formed asteroids melted from the inside out because of their radioactive elements, their surfaces, exposed to the cold of space and continuing to accumulate layers of new, cold fragments, remained cold. Computer modeling of the cooling process by Elkins-Tanton clearly shows this disparity of a molten interior and cold, unmelted crust, she says."

....And speaking of "natural nuclear events" , I knew I had seen articles here and there about geologic nuclear events on earth & here is a "guest article" from Scientific American a few years ago. The comments afterwards are interesting - a lot of them touch on the topic of storage of nuclear waste. I took a course on that topic crafted by a geology professor back in the 1970's & some of the commentors are missing a lot of facts.

Nature’s Nuclear Reactors: The 2-Billion-Year-Old Natural Fission Reactors in Gabon, Western Africa

Looks like NASA is progressing on its endeavor to capture an asteroid {Link to NASA Asteroid Initiative } and whats more they are looking for ideas on how to do that. NASA Seeks Proposals on Asteroid Redirect Mission Concepts Development is the web page where they explain up to $6,000,000 is available for successful proposals.

Another way to combine an interest with a payoff is to participate in the "Be an Asteroid Hunter in NASA's First Asteroid Grand Challenge Contest Series" which has $35,000 available for the math inclined to improve NASA's ability to "develop improved algorithms that can be used to identify asteroids."

This recent article on Space.com tipped me off to the NASA proposals. It also has a neat animation of one method to capture an asteroid and leave it in orbit around the moon - which is the plan with astronauts to visit the rock at a later time.

The European Space Agency's Rosetta Satellite {link to official site w/ neat stuff} has noticed a change in its targeted landing site, the comet 67P/Churyumov–Gerasimenko, it is starting to look more like a traditional comet with the obligatory tail/coma as it nears the Sun. Graphic below:

>5 DugsBooks:

That is wicked cool!

My husband's Ph.D. is in planetary science specializing in asteroids. In his dissertation research, it turned out that one of his targets, which was thought to be an asteroid, turned out to be a comet -- it "lit up" as it got close to the sun.

It's neat to see this "illustration" of the same thing!

Rosetta arrival at comet Date: 4-Aug-2014 (UTC) Distance to comet: 314 km Days to arrival: 2

Rosetta nears its destination for the Aug 4th 6th rendezvous, this Wednesday, with the comet. More info at the official ESA
webpage.

comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM

>7 DugsBooks: Since early May, Rosetta’s controllers have been pacing it through a tightly planned series of manoeuvres designed to slow its speed with respect to the comet by about 2800 km/h, or 775 m/s, to ensure its arrival on 6 August.

Although converting the date to UTC could change it, it wouldn't change it by 2 days.

Well darn, I cut n pasted to avoid any errors and still screwed up. Anyway, as I understand it this Wednesday August 6th is the official meeting up day for the event. Space.com has a graphic video showing how the satellite will be spiraling in a tubular flight path around that of comet as they meet up { the same vid might also be at the ESA site}.

I look forward to the close up photos & other information on the comet!

The ESA will announce the "touchdown area" of the Philae lander on the comet Sept. 15th according to their website. Can't wait to see the close up photos from the surface of the comet and not the "artists impressions" {not that those aren't pretty neat}



"Artist’s impression of Rosetta’s lander Philae (front view) on the surface of comet 67P/Churyumov-Gerasimenko. Philae will be deployed to the comet in November 2014 where it will make in situ observations of the comet surface, including drilling 23cm into the subsurface to extract material for analysis in its on board laboratory."

Image & heading cut n pasted from the ESA site.

Vesta Sizes Up

"This composite image shows the comparative sizes of eight asteroids. Up until now, Lutetia, with a diameter of 81 miles (130 kilometers), was the largest asteroid visited by a spacecraft, which occurred during a flyby.

Vesta, which is also considered a protoplanet because it's a large body that almost became a planet, dwarfs all other small bodies in this image, with its diameter sizing up at approximately 330 miles (530 kilometers)."

Image credit and caption: NASA/JPL-Caltech/JAXA/ESA

Safe Mode Slows Dawn Mission's Progress to Ceres; is an interesting article at Space.com on the results of the exploratory satellite "Dawn" as it encountered "the giant asteroid Vesta" and the technical problems it has encountered as it continues its journey to the, even larger, mini planet Ceres.

This is a link to a just over 2 minute video from the article about info gained at Vesta by Dawn using great graphics and a guitar hero background.
http://www.space.com/17459-asteroid-vesta-revealed-dawn-probe-s-greatest-hits-vi...

And the best, a link to the NASA Dawn spacecraft home webpage site: http://dawn.jpl.nasa.gov/

From Space.com "On Nov. 12, the European Space Agency's Rosetta spacecraft will release its Philae lander to make space history: the first soft-landing on a comet. If all goes well, Philae will make a seven-hour descent from Rosetta to the surface of Comet 67P/Churyumov-Gerasimenko and land at 10:35 a.m. EST (1535 GMT), with confirmation expected by 11:03 a.m. EST. "

http://www.esa.int/Our_Activities/Space_Science/Rosetta

:crossposted this from SF group/movies::

XKCDupdates on the drop

wait for it...

Touchdown!

Checks ongoing, but it's there, and has been for the 28mins it took to tell us.

I just heard that the harpoons didn't fire and they're not sure how secure the probe is on the comet.

I copied this from my Twitter post, so if you'll pardon the hashtags and just follow the link, you may have an entertaining and enlightening few minutes.

#CometLanding Clever #Philae landing by xkcd comics transformed into equally clever gif by @tanyaofmars: http://t.co/7BbZTo9DFs

I hope there will be photos from the lander? Anyone know if it has any cameras? Aha found a diagram..


Rosetta will deploy the Philae lander to the surface of comet 67P/Churyumov-Gerasimenko for in situ analysis with its 10 instruments:

APXS: Alpha Proton X-ray Spectrometer (studying the chemical composition of the landing site and its potential alteration during the comet's approach to the Sun)
CIVA: Comet Nucleus Infrared and Visible Analyser (six cameras to take panoramic pictures of the comet surface)
CONSERT: COmet Nucleus Sounding Experiment by Radiowave Transmission (studying the internal structure of the comet nucleus with Rosetta orbiter)
COSAC: The COmetary SAmpling and Composition experiment (detecting and identifying complex organic molecules)
PTOLEMY: Using MODULUS protocol (Methods Of Determining and Understanding Light elements from Unequivocal Stable isotope compositions) to understand the geochemistry of light elements, such as hydrogen, carbon, nitrogen and oxygen.
MUPUS: MUlti-PUrpose Sensors for Surface and Sub-Surface Science (studying the properties of the comet surface and immediate sub-surface)
ROLIS: Rosetta Lander Imaging System (providing the first close-up images of the landing site)
ROMAP: Rosetta Lander Magnetometer and Plasma Monitor (studying the magnetic field and plasma environment of the comet)
SD2: Sampling, drilling and distribution subsystem (drilling up to 23 cm depth and delivering material to onboard instruments for analysis)
SESAME: Surface Electric Sounding and Acoustic Monitoring Experiment (probing the mechanical and electrical parameters of the comet)

Cut N paste from ESA ....LInk http://www.esa.int/spaceinimages/Images/2013/12/Philae_s_instruments_white_backg...

Aha, I read this article some time ago and forgot to bookmark it. The Dawn mission has evidently figured out that the mineral serpentine is present on the protoplanet Vesta. This is an excerpt from the article on the theory of how it was formed there:

“The only possible explanation is the impact of an asteroid,” says Hoffmann, who points out that some primitive meteorites contain serpentine. These meteorites are regarded as fragments of carbon-rich asteroids. The impact must have been a comparatively slow one, because an asteroid crashing at high speeds would have produced temperatures too high to sustain serpentine. In a previous study, scientists from the MPS had calculated how dark material would be distributed on Vesta as a result of a low-speed oblique impact. Their results are consistent with the distribution of dark material on the edge of one of the two large impact basins in the southern hemisphere. " -

Seems odd but interesting as I was under the impression a big chunk of earth's mantle is serpentine and was formed there.

See more at: http://dawn.jpl.nasa.gov/feature_stories/vestas_rocky_history.asp#sthash.2kYRFVx...

Some new "close up" photos of the ESA's comet. I hope the lander is reactivated by sunshine soon.

Four-image montage of Comet 67P/Churyumov–Gerasimenko comprising images taken on 14 February 2015 during the first dedicated close flyby

>6 amysisson: Under the "better late than never" heading; thanks for the post, if your husband has time you guys chip in anything that is of particular interest. We could use the expertise.

Aha, things are beginning to perk up in Dawn's mission to the asteroid Ceres . The "bright spots" seen in many photos reminded me of a 2001 Space Odyssey - Sentinel and I was fairly certain that all the media attention had died down because of Earth leaders' hush hush negotiations with the aliens to retain their positions within the E.T. controlled New World Order. However, when I saw this quote about Ceres:.

"He then focused on the most famous complex of bright spots, in Occator crater. This group is also known as “Spot 5” from earlier Hubble Space Telescope observations. Russell said that a “haze” was visible in this crater at certain times of day, and that it was seen more than once. A follow-up question, the only one there was time for, established that the haze was confined to the crater itself."

I knew it was something I had heard of before:


https://www.nasa.gov/jpl/dawn/pia19617/occator-crater-enhanced-view