Featured Research

from universities, journals, and other organizations

It's complicated: Dawn spacecraft spurs rewrite of asteroid Vesta's story

Date:
November 8, 2013
Source:
NASA/Jet Propulsion Laboratory
Summary:
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, that's not what Dawn's visible and infrared mapping spectrometer (VIR) instrument found.

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.
Credit: NASA/JPL-Caltech/UCLA/ASI/INAF

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 northern hemisphere 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 southern hemisphere was later covered by a layer of other material, which prevented Dawn from seeing the olivine below it.

"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 main asteroid belt between Mars and Jupiter. It will arrive at Ceres in early 2015.

The Dawn mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate, Washington, D.C. It is a project of the Discovery Program managed by NASA's Marshall Space Flight Center, Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft. The visible and infrared mapping spectrometer was provided by the Italian Space Agency and is managed by Italy's National Institute for Astrophysics, Rome, in collaboration with Selex Galileo, where it was built.


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. E. Ammannito, M. C. De Sanctis, E. Palomba, A. Longobardo, D. W. Mittlefehldt, H. Y. McSween, S. Marchi, M. T. Capria, F. Capaccioni, A. Frigeri, C. M. Pieters, O. Ruesch, F. Tosi, F. Zambon, F. Carraro, S. Fonte, H. Hiesinger, G. Magni, L. A. McFadden, C. A. Raymond, C. T. Russell, J. M. Sunshine. Olivine in an unexpected location on Vesta’s surface. Nature, 2013; DOI: 10.1038/nature12665

Cite This Page:

NASA/Jet Propulsion Laboratory. "It's complicated: Dawn spacecraft spurs rewrite of asteroid Vesta's story." ScienceDaily. ScienceDaily, 8 November 2013. <www.sciencedaily.com/releases/2013/11/131108091328.htm>.
NASA/Jet Propulsion Laboratory. (2013, November 8). It's complicated: Dawn spacecraft spurs rewrite of asteroid Vesta's story. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2013/11/131108091328.htm
NASA/Jet Propulsion Laboratory. "It's complicated: Dawn spacecraft spurs rewrite of asteroid Vesta's story." ScienceDaily. www.sciencedaily.com/releases/2013/11/131108091328.htm (accessed April 19, 2014).

Share This



More Space & Time News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Space X Launches to Space Station

Raw: Space X Launches to Space Station

AP (Apr. 18, 2014) On it's second attempt this week, The Space X company launched Friday from Cape Canaveral to ferry supplies to the International Space Station. (April 18) Video provided by AP
Powered by NewsLook.com
Unmanned Falcon 9 Rocket Blasts Off from Cape Canaveral Air Force Station in Florida

Unmanned Falcon 9 Rocket Blasts Off from Cape Canaveral Air Force Station in Florida

Reuters - US Online Video (Apr. 18, 2014) The rocket, built and operated by Space Exploration Technologies, carries a Dragon cargo ship loaded with supplies and equipment destined for the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Earth's Near-Twin Found Orbiting Red Dwarf

Earth's Near-Twin Found Orbiting Red Dwarf

Newsy (Apr. 17, 2014) The newly-discovered planet is roughly the size of Earth and could have liquid water on its surface. Video provided by Newsy
Powered by NewsLook.com
New Baby Moon 'Peggy' Spotted In Saturn's Rings

New Baby Moon 'Peggy' Spotted In Saturn's Rings

Newsy (Apr. 15, 2014) A bump in the rings could be a half-mile-wide miniature moon. It was found by accident in Cassini probe images. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins