News24

Asteroid Vesta like 'a small planet'

2012-05-11 10:15

Washington - The giant asteroid Vesta more closely resembles a small planet or the moon than other asteroids, data returned by Nasa's Dawn spacecraft show.

Images taken by the Dawn, which has been orbiting Vesta since 2011, provide key clues into the early universe when the asteroid formed and show it began its life as a planetary building block.

Results of the report appeared in the journal Science on Thursday.

The 4.56-billion-year-old asteroid has a rare iron core, and a crust and mantle like a planet, forming in a similar way to the Earth and its moon. It likely once harboured a sub-surface magma ocean, a feature that often leads to the formation of layers that form planets.

Vesta is also the largest source of meteorites that reach Earth, providing scientists with the first up-close look of the source of such space rocks. The meteorites' composition matches that of Vesta, which scientists said provides 6% of Earth's meteorites.

Scientists got a close look at Vesta's craters, slopes and peaks and were able to date two basins created by large impacts to one billion years ago.

Dawn, which was launched in 2007 by the US space agency, is to offer insights into the beginning of the universe by examining rocky objects that date to the time when planets were forming in the solar system.

After examining Vesta, Dawn will continue on to the dwarf planet Ceres elsewhere in the asteroid belt.

Comments
  • Shaun - 2012-05-11 10:45

    Biiiilllllllllllliiiiooonnnssss of years..... Oooooooooooooooooooo *stands in awh* The call this science... PFfffft.... But it is pretty cool to see a moon like asteroid out there... :-)

      E=MC2 - 2012-05-11 11:20

      hahahaha... "Scientists got a close look at Vesta's craters, slopes and peaks and were able to date two basins created by large impacts to one billion years ago." wow these guys must be talented to be able to date something just by looking at it... fascinating rubbish.

      J-Man - 2012-05-11 11:40

      Wow you people are clueless. At least they actually SEE something. Just wow.

      Fascisti - 2012-05-11 12:45

      I dont see how they could have dated impact craters without actually taking a sample and doing radiometric dating on it. Maybe the News24 article is over simplified. Btw Shaun, rocks have been conclusively dated here on earth. In SA we have some of the oldest rocks dated around 3.5-3.6 BILLION years.

      Zing - 2012-05-11 13:25

      A crater can be dated by counting new craters inside the crater. A new crater obviously has 0. It is not an entirely accurate measurement, so if they say it's 1b yr old craters, it would be give or take. I doubt whether it's age is less than 10,000 years though ;)

      Zing - 2012-05-11 14:10

      Agreed - sample dating is absolute. This is a little bit of intelligent guessing. Picture a new crater - no other craters inside it. Brand new and squeaky clean inside. It had to happen, well yesterday or last year, right? It's a close enough estimate - to within a few thousand years. The more craters inside a crater, the older it is. Again it is a bit of guesswork, and you need an idea of how often it would get hit to be more specific. Around 4b yrs ago, there was stuff flying everywhere in our solar system, and any crater that old will be riddled like my grandma's thighs. It would have filled up quick with the amount of impacts happening at that time. If a crater is not completely riddled (4b yrs ++) or completely clean (0 yrs ++) then you make an estimate compared to how full the crater is, compared to another crater that is "full" of pockmarks on the same asteroid. Hell, I just read this again and I apologise if I'm causing more confusion. I'll try find a link :)

      Fascisti - 2012-05-11 14:29

      No man, I got it. Makes sense.

  • Coenraad - 2012-05-11 13:29

    Ignorance sure is BLISS. NASA spends years and millions of dollars to build an exploratory probe that can travel millions of kilometers over a span of several years and then equip it with only a camera? Boy! Those fellas at NASA must be really damn stupid, eh? There are cupboards there stuffed with Gamma & Neutron detectors, Mass spectrometers and other scientific goodies! Why not put that in there next to the camera and the picnic basket? Oh wait! They DID? Sure thing, trolls! Them boys over at NASA knows the difference between a turd and a rocketship. You idiots don't...

      Fascisti - 2012-05-11 13:45

      they must be dating the craters relatively, not absolutely.

      Raven - 2012-05-11 14:19

      @ AT - well reading "a billion" is a lot less work than reading 985,458,345,751,113,952,145,625,489,625,451,258,753,958,685.0154 seconds. I'm pretty sure it's relative and not absolute

      Zing - 2012-05-11 14:19

      That's the word I was looking for :D Relative dating. ok, 2 words :P

      Fascisti - 2012-05-11 14:31

      Raven you dont seem to know the difference between to terms "relative dating" and "absolute dating".

  • ryanholdstock - 2012-09-27 08:17

    Hectic!

  • pages:
  • 1