Asteroid Vesta is 'last of a kind' rock
A computer generated perspective of Rhea Silvia basin, which was dug out by an impact a billion years ago
Vesta is the only remaining example of the original objects that came together to form the rocky planets, like Earth and Mars, some 4.6 billion years ago.
This assessment is based on data from the Dawn probe which has been orbiting the second largest body in the asteroid belt for the past 10 months.
The findings from the Nasa mission are reported in Science magazine.
They confirm that Vesta has a layered interior with a metal-rich core, just as Earth, Mars, Venus and Mercury do.
Using information about the shape of the asteroid and its gravity field, scientists can even say something about the likely size of this core.
The Dawn team calculates it to be about 220km (135 miles) across, representing about 40% of the radius of Vesta, or roughly 18% of its total mass.
Cutaway model: Data indicates Vesta has an iron core that is about 220km across
"This mission at Vesta has been a spectacular success," said Carol Raymond, Dawn's deputy principal investigator from Nasa's Jet Propulsion Laboratory in Pasadena, California.
"It's transformed Vesta from a fuzzy orb into a planetary body, which has exceeded our expectations in many ways."
Dawn has studied in detail the pattern of minerals exposed in Vesta's surface by innumerable impacts through the eons. It has also mapped the diverse geological features that shape its surface.
These observations have enabled scientists to elucidate a history for the colossal rock, which is second in size only to Ceres in the band of material moving between Mars and Jupiter.
The researchers believe Vesta formed within two million years of the first solids coming together in the Solar System, before the planets we know today were assembled.
Short-lived radioactive materials would have generated enough heat to melt Vesta's insides, producing a subsurface ocean of magma.
This melting would have led to differentiation, to denser materials like iron falling to the asteroid's centre.
Other such bodies in the infant Solar System with magma oceans ended up becoming parts of Earth and the other planets. Somehow, Vesta did not; somehow, it survived obliteration in the cascade of impacts that would have marked those early times. Nothing telescopes see today in the asteroid belt quite matches what Dawn has seen at Vesta, suggesting the mighty rock is unique hangover.
"Vesta is special because it has survived the intense collisional environment of the asteroid belt for billions of years, allowing us to interrogate a key witness to the events at the very beginning of the Solar System," said Dr Raymond.
The crystalline structure in HED meteorites: These common meteorites can now be tied definitively to Vesta
Another in a series of stand-out discoveries about Vesta is the definitive association that can now be made between it and the howardite-eucrite-diogenite, or HED, class of meteorites.
Based on telescopic observations, researchers had always suspected these common meteorites came from Vesta. But the signatures of pyroxene - a mineral rich in iron and magnesium - in those meteorites have now been matched precisely with the mineral signatures spied in Vesta's surface by Dawn's instruments.
The HED meteorites account for about 6% of all the meteorites seen falling to Earth.
Common they may be, but their value to science is greatly increased following the Dawn mission because researchers now know they offer some remarkable insights into the earliest epoch of planetary formation.
Much of the HED material is likely to have come from two huge impact basins at Vesta's southern pole.
The Rhea Silvia crater measures some 475km in diameter, and gives Vesta the look of a punctured football in global images.
It overlies the Veneneia basin, which is a little less extensive at 375km across.
"Our estimate [is that] about 250,000 cubic miles [were] excavated from Rhea Silvia," said Dr David O'Brien, from the Planetary Science Institute in Tucson, Arizona.
"To put this into another perspective - 250,000 cubic miles is enough to fill the Grand Canyon a thousand times over."
Some of that excavated material lies just outside Rhea Silvia crater, but a lot of it would have gone into space to form the group of much smaller Vesta-like objects seen in the asteroid belt and, of course, those HED meteorites that have fallen to Earth.
The pattern of craters on Vesta has allowed the Dawn team to age Rhea Silvia and Veneneia. The former was created about a billion years ago; the latter was dug out by an impact around two billion years ago.
The ages are much younger than had previously been supposed.
The other great impact basins in the inner Solar System, such as the ones that pock Earth's Moon, are considerably older, dating to a period about 3.8 billion years ago.
Scientists suspect this period to have been a very dynamic phase in the early evolution of the Solar System and even have a name for it - the "late heavy bombardment".
The size of Vesta compared with the other asteroids visited by spacecraft
The ages of Vesta's big impact basins put some new constraints on the timing of that bombardment and and the region within the inner Solar System affected by it.
Dawn continues to study Vesta. It has an extension on its mission that will allow it to stay at the asteroid until at least 26 August, when it is due to leave on a three-year cruise to Ceres.
The Dawn team is hoping to be able get images of the north pole, which, as a result of the seasonal angle to the Sun, is currently in darkness.
Dr Jim Green, the head of planetary science at Nasa, indicated that the team would be given sufficient time to complete its work.
There is considerable excitement about what might be found at the north pole, with the suspicion being that the terrain may reflect in some way the seismic repercussions from the Rhea Silvia impact at the opposite pole.
"With Dawn's ion engines, which are running much better than predicted, it really enables us to stay at Vesta longer," Dr Green told BBC News.
"We're very excited about that because it will enable us to map the unknown region. That region is very important to look at now that we know about the Rhea Silvia impact basin. How that impact might affect the northern hemisphere will now be revealed."
Crater counting is used to date the surface of asteroid Vesta. Rhea Silvia and Veneneia appear as undulating lines. Note how the terrain of the north pole has yet to be revealed
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter
“Far Out!”
ReplyDeleteNow there is an expression worthy of a comeback. Deliciously naive isn’t it? Wasn’t it?
When it was exclaimed by those fresh sixties, under thirty faces, space was already an old floppy hat, but Vesta, whodaguesta?
Hark! I say to you. Hark to this sh*t: We do have such a rule! It was passed by Congress and signed by President George W. Bush! It’s on the books, the law of the land. Specifically, it is Section 433 of the Energy Independence and Security Act of 2007. It says that new federal buildings, or major renovations ($2.5 million or more) of federal buildings, must reduce their consumption of fossil-fuel energy (relative to a similar building in 2003) 55 percent by 2010, 80 percent by 2020, and 100 percent by 2030. (It hasn’t been funded yet, so that 2010 target is, er, no longer operational.)
ReplyDeleteIt’s an audacious goal, basically Architecture 2030′s “2030 Challenge” put into law.
“Holy crap,” you’re saying, “if we have a law that awesome, surely come powerful constituency must be trying to screw it up!”
Right you are. On April 12, representatives from the American Gas Association (AGA) and the Federal Performance Contracting Coalition (FPCC) met at the White House with administration officials from DOE, CEQ, and OMB. At that meeting they offered this issue brief [PDF], which called on Congress to “substantially modify or eliminate EISA section 433.” You can bet that issue brief hit all the relevant congressional offices as well.
Oil and Gas - still trying to screw us
If Obama rolls on that one, he will roll on anything. The techology to meet most of those goals exists. It would be huge boost to construction with many by-product techologies. It would obviously reduce government spending and taxes. That seems to be the objection.
ReplyDeleteI have a horse in this race.
ReplyDeleteThe American Institute of Architects (AIA) has come out in opposition to a House proposal to eliminate Section 433 of the Energy Independence and Security Act (EISA) of 2007.
According to the AIA, the bill is helping spur the development of new materials, construction techniques, and technologies to make buildings more energy efficient. And it is showing that significant energy reductions are both practical and cost-effective.
The result is better energy performance for federal agencies and lower overall costs for taxpayers, according to the organization, which says that private sector owners are increasingly adopting these technologies and strategies for their buildings.
"Weakening or repealing Sec. 433 with no deliberation or discussion will dramatically harm the federal government's ability to design and build facilities that use less energy and protect the environment," said AIA EVP and Chief Executive Officer Robert Ivy, FAIA in a statement. "According to the DOE's Energy Information Administration, buildings account for almost 40 percent of total U.S. energy consumption, more than both the transportation and industry sectors.”
I'll bet he "rolls" on coal, too. W. Va. is almost surely gone, but he Has to salvage Pa, and Oh.
ReplyDeleteSeven Days That Shook Europe - Financial Times
Look for Obammie to resurrect GWB's Clean Coal canard.
ReplyDeleteAs for "funding," that has to go through the House of Representatives. I'm quite sure that that's impossible at present.
ReplyDeleteOne of the most amazing accomplishments of humanity is science and the gathering of knowledge about the universe. It should persuade people that there is a longer timeline than next Friday night. Proponents of any fossil fuel talk about the wonderment of a one hundred year supply. That coming from a generation with 100,000 generations behind it and a universe of 4 billion years.
ReplyDeleteThe post shows a space body permanently devoid of life. We live in a garden amidst an ignorance as cold as the Asteroid Vesta. No big deal. We are going to a better place under the eternal rule of our heavenly slave master.
Vesta is Consciousness veiled.
Deleteb
Or a Charlie Sheen commercial:
DeleteLINK
How is the Obama ordered NASA outreach to muslims coming along?
ReplyDeleteWasn't NASA supposed to help improve the muslim self image or something as their new mission statement?
b
" Proponents of any fossil fuel talk about the wonderment of a one hundred year supply. That coming from a generation with 100,000 generations behind it and a universe of 4 billion years."
ReplyDeleteAmen, Brudda.
Little doubt, an ALEC-inspired event (American Legislative Exchange Council to which top 4 oil companies claim membership, energy policy being a prime ALEC target)
ReplyDelete(dollars to doughnuts - somethings are too obvious to look up - staff!! get me that reference!)
Another blatant - show me the numbers - ideologically polarizing accusation: pull back the curtain and who do you find behind these energy shenanigans:
Less than a month later, Rep. Rodney Alexander (R-La.) of the House Appropriations Committee offered an amendment to the Fiscal Year 2013 Energy and Water Appropriations Bill that would “prohibit funding” to implement Section 433.
Voters need to keep a keen eye on the Congressional races since domestic policy is running neck and neck with foreign policy demands for attention.
RE Clean Coal
ReplyDeleteDisagree with you on this one Rufus. IMO the coal gasification technology is realistic and should be pursued.
There are some technical challenges:
"Gasification happens in an extreme environment so the lifespan of refractories is historically low," said S.K. Sundaram, PNNL staff scientist. "Refractory lifespan must be increased before we can realize the promise of clean coal."
LINK
Renewable technologies reside on the upswing of the technical learning curve as well.
As I expect you may already know, USA has two commercial plants on-line - Tamps, FL and Terre Haute, IN: LINK which means the technical glitches have a wealth of operating data to work off of.
It makes some sense to develop coal gasification as an 'interim' technology - technically more feasible than the Marlstone/kerogen extraction/refining and USA has some god-awful amount of coal.
One word: employment.
Two words: domestic employment
ReplyDeleteExpensive Energy is not the path to "employment," Max.
ReplyDeleteAnd, we don't have nearly as much Coal as the Peabody/Massy guys claim. An ex: We get 40% of our thermal coal from Powder River Basin mines that will be played-out within 20 yrs.
Expensive Energy is not the path to "employment," Max.
DeleteLabor-intensive build-out not quite as expensive with 20% unemployment.
It is not either or and one beggaring the other. Use the renewables and stretch out the consumables for as long as they can possibly last. Using oil by burning it is like breaking up your furniture for a fire. There are unimaginable uses besides the burning and they all have their uses present and in the future. The World is more the the latest flash trading wonder.
ReplyDeleteMy work here is done. :)
ReplyDeleteShoot, I had to laugh when I read that. BC has a small handful of regulars who fall pretty consistently on the right side of sanity. Their "we need a policy mix" mantra was substantial - until a couple of O&G guys took over. Most of the moderate guys went over to the dark side under the suasion of the O&G arguments.
DeleteEIA estimates are in the "hundreds of years" range (LINK):
ReplyDeleteU.S. Resources
The United States has enormous coal "resources" and "recoverable reserves." { Map Terms Defined } The most reliable information about coal is published by the Energy Information Administration (EIA). The most recent figures available from the EIA, show that America's estimated recoverable reserves of coal --
Stand at 275 billion tons, an amount that is greater than any other nation in the world. { Chart }
Are capable of meeting domestic demand for more than 250 years at current rates of consumption.
One more:
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World Resources
Many large countries contain significant proven reserves of coal. While data quality varies widely, the countries with the greatest estimated recoverable reserves of coal are --
United States 273 billion tons
Russia 173 billion tons
China 126 billion tons
India 93 billion tons
Australia 90 billion tons
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What's the design life of an IGCC plant relative to a pipeline? I won't throw numbers around but one is an industry, with economic multipliers. The other is a 'one-off.'
Also, wading into the weeds which are a little over my head at this point, but my understanding is that coal can be used as a feed stock in some of the heavy crude refineries with some "slight" modifications at the front end.
All of which suggests some better ways of being smart with our energy and economic base loads as exogenous events accelerate and compromise the tried and true "planning" needed for energy build-out. Perfect information no longer being a luxury that we have or can afford to acquire.
The problem, Max, is when you leave Wyoming, and the Powder River Basin, you get into highly sulfurized coal. Also, coal-to-liquid is extremely expensive, and an environmental nightmare.
DeleteAs for the EIA, you have to take their pronouncements with a Mighty Grain of Salt. Some (a lot) of the coal that is technically usable is buried deep, or is in the mountain ranges of Alaska.
And, of course, don't overlook that China, India, and the rest of the world are going to be helping us use that coal.
There's a lot of disingenuity, obtuseness, and flat-out lying going on with respect to All fossil fuels. Caveat Emptor.
The "environmental nightmare" part isn't quite true, until you get into the subject of CO2, and even there it's not a slam dunk:
DeleteThe U.S. Environmental Protection Agency (EPA) has established New Source Performance Standards for large-scale, combustion-based powerplants that use coal. As illustrated below, present and next-generation IGCC facilities: (1) meet or exceed the EPA’s standards; (2) emit fewer criteria air pollutants than SCPC plants; and (3) compare favorably with natural gas combined cycle (NGCC) facilities.
LINK
The other thing - moving back up the "Big Picture" scale, is that fossil fuels will be required until the energy "density" and "scaling" problems are solved, as per Steven den Beste who presented a lot of work on renewables and alternative energy back in the 2002-2004 time frame. I won't link directly to his articles since he's 'wordy' and possibly not to your taste but it's there if you search (USS Clueless his old site.)
(One LINK here.)
The IGCC plants seem to fit that bill.
Anyway, enough of that.
(And no, I wasn't calling anyone "clueless" - his site, not mine.)
DeleteThis is what An energy plan coming together looks like.
ReplyDeleteYou'll notice Ca gets quite a bit of their electricity from the "ever-stealthy Geothermal."
DeleteWhat I notice is that when they plot renewables vs total load, they have to break the vertical scale to fit the chart on a manageable page view. In other words, your rent seeking massively subsidised renewable wet dreams produce a vanishingly small component of the required energy budget at an exhorbitant cost to the consuming public.
DeleteIf you wish to argue it's prudent to mix sensible renewables and conservation into the energy budget to ultimately save potentially vanishing (someday) fossil fuels, I'd not argue. As long as the energy source is competitive without massive government subsidies. Don't blow your greenie bullshit my way, however. You're just continuing your usual puffing of the green agenda that only favors the rent seekers like yourself. How's your backyard still coming along? Powering up the old flex-fuel Impala are you? Not yet you say? Maybe a nice federal grant would speed up development?
Here's what a real energy plan looks like, Rufus II.
DeleteSaudi Arabia's King Abdullah has dismissed an ultraconservative adviser after he publicly criticized reforms aimed at easing restrictions on women. Sheik Abdul-Mohsen al-Obeikan had told a local radio station that officials were working to Westernize and secularize the country's laws by "legalizing taboos." The "situation is a very dangerous one that is linked to schemes by influential people to corrupt Muslim society by removing women from their natural position," he said.
ReplyDeleteKing Abdullah has irked the country's hardline clerics by easing some restrictions and allowing women to vote and run in 2015 municipal elections. After his dismissal, al-Obeikan posted on his Twitter account a statement saying he hopes that the kingdom's rulers are kept away from "bad advisers." This year, the kingdom began to apply a 2006 law that allows women to work in lingerie and female apparel stores, despite disapproval from the country's top clerics.
That al-Ob. What a card. Someone ring up Cele!bitchy.
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ReplyDeleteEisenhower Memorial
What do you think of the design for the Eisenhower Memorial (#19), Deuce? Based on the rendering, I don't like it at all; but then, you are the architect.
Looking at the slide show, I like a few of the buildings Gehry has designed (9, 15) but others (16, 17) not so much.
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President Obama has done for Mitt Romney what Romney hasn't been able to do for himself: get evangelicals to rally behind the Republican candidate, reports the Washington Post. The president's public backing of gay marriage has fired up Christian conservatives, and pastors in swing states have Sunday sermons ready to roll against same-sex marriage. Activist groups also plan a barrage of media campaigns in those same states.
ReplyDelete“So many people were rather lukewarm toward governor Romney and were really looking for some more tangible reasons to support him,” says the leader of the Citizens for Community Values. "Then lo and behold, it just fell out of the sky when Obama came out and endorsed same-sex marriage." Of course, Obama is seeing a boost among his own base, notes AP, with donations on the rise since his ABC interview. (Click to read about one columnist's warning that Republicans better pay heed to the long-term cultural shift going on in the country.)
Not sure what happened to "it's the economy stupid" but the Huffington Post headline piece is heading straight for the red zone, approaching 4000 comments.
(Is "far out" becoming the new Republican mantra??)
I guess we can be grateful that Gehry’s design doesn't look like a building on an acid trip. I am usually not wild about overly literal monuments, we’ve had enough of them but on a fast glance going by at 50 miles an hour it looks overly generic.
ReplyDeleteOne thing I will say ...
ReplyDeleteI don't read the Huffington Post comments. I looked at a few just to get a sense of things, but "chatty" is the word that leaped out.
Now, BC, they are erudite, if not outright thoughtful, but the drumbeat (that dismal drumbeat) is monotonous.
And intractable.
And uncompromising.
And dogmatic.
And ... unforgiving.
I was thinking one can (kind of) see this in the Republican response to the gay marriage issue.
Anyway, neither here nor there really. Just saying.
(OTOH, the LGBT community is guilty of collective immaturity by not accepting the civil union arrangement conferring equal rights under the law, preferring instead to nyah-nyah their way to some imagined next level. Childish politics in my view.)
Now, BC, they are erudite, if not outright thoughtful,
ReplyDeleteThat is of course the problem with insanity - it comes disguised as Barney Fife.
Sometimes Gomer Pyle.
Or Aunt Bee!!!!!
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Delete"Far out" is usually in the eye of the beholder just as insane usually means (in blogspeak) 'he just said something I don't agree with'.
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If Obama said, "baseball is a stupid sport and should be outlawed," and Romney in turn praised at as America's past time, there would be much screaming and gnashing of teeth for about 2 weeks, then it would all go away. Such is the queer marriage issue.
ReplyDeleteI haven't spent any time at BC in quite awhile but I found the commenters and wretched himself to be faux intellectuals. So many tipping points were reached it became laughable. In general they argue very very seriously from horribly flawed assumptions colored by their prejudices. Then they get their knickers in a knot when challenged.
ReplyDeleteTipping points in Iraq that is
ReplyDeleteRE: faux intellectuals
ReplyDeleteMy heart isn't in this (right now) but, short and sweet of it is, Fernandez is far from a "faux intellectual." My take is that he transposes the experience in the Philippines to USA, which is a mistake. His "voice" is legitimate, but some of the commentariat ... less so.
Habu? Peter Boston? Desert Rat? Buddy Larsen? It was interesting :)
ReplyDeleteAsperger's gentleman. Without peer.
Deleteand Ash and Trish of course.
ReplyDeleteThere hasn't been a truly great poster since Squishy.
Deleteb
Gertrude Steins's salon.
ReplyDeleteThe real question for today is, will Lady Gaga get out (or into) Indonesia alive?
ReplyDeleteDiva risks life for fans -
"Lady Gaga is not an ordinary human being. She uses her popularity to defend minority groups, especially gays and lesbians," said Hartoyo, general secretary of gay rights group OurVoice, who goes by one name.
"I would die for her," he said....
That could happen.
And fans reciprocate.
http://www.jihadwatch.org/2012/05/indonesia-islamic-supremacists-vow-to-mobilize-30000-demonstrators-to-prevent-jihad-violence-lady-ga.html
b
How is the writing project going, Quirk? Any chance you can give us even a few paragraphs of the work in progress? You know, some of the old boys used to do that. James Joyce, excerpts from a work in progress, that sort of thing. But not the contemplative parts. Give us some spicy stuff, the real steamy. Thanks, bob.
ReplyDelete.
ReplyDeleteIt appears it is not just long-term GOP incumbants that have to worry this year.
Rangel has many allies in the Latino community. The current Bronx president, Ruben Diaz, is endorsing him Friday.
“Just about all the major Latino congressional leaders are endorsing Congressman Rangel,” said the congressman’s campaign spokesman, Moises Perez. “It’s as close to a full consensus as you can get that it is vitally important to retain him in Congress.”
But Rangel can no longer argue, as he could in past years, that he is the powerful chairman of the Ways and Means Committee. He lost that gavel when Democrats lost the House in 2010. And he recently underwent back surgery that took him off the campaign trail, in a year when he needs to campaign more than ever. He also missed more than 100 votes on the Hill.
“He’s older and frailer than he has been in the past and therefore has not been the campaigner of old,” said Douglas Muzzio, a political science professor at Baruch. “I think that’s a problem for him.”
Chuckin Charlie Rangel
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ReplyDeleteIslamist group al-Nusra Front claims responsibility for Damascus bombings
Syria: Pick a Side (doesn't matter which, they all seem nutz).
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