Featured Research

from universities, journals, and other organizations

Astronomers Baffled By Basalt In The Outer Asteroid Belt

Date:
August 25, 2007
Source:
European Planetology Network
Summary:
Analysis of the chemical make up of two asteroids in the outer asteroid belt has thrown the classification system for these small bodies, which orbit between Mars and Jupiter, into disorder. The presence of basalt means that the asteroid must have melted partially at some time in the past, which implies that it was once part of a larger body which had internal heating processes. However, there do not appear to be other basaltic fragments in the region and, from spectral analysis, it is not clear whether the two are fragments of the same parent body or not.

Asteroid Vesta
Credit: Copyright P. Thomas (Cornell University), B. Zellner (Georgia Southern University) and NASA

Analysis of the chemical make up of two asteroids in the outer asteroid belt has thrown the classification system for these small bodies, which orbit between Mars and Jupiter, into disorder.

Dr Rene Duffard, who is presenting results at the European Planetary Science Congress in Potsdam on Wednesday 22nd August, said, "We appear to have detected basalt on the surface of these asteroids, which is very unusual for this part of the asteroid belt. We do not know whether we have discovered two basaltic asteroids with a very particular and previously unseen mineralogical composition or two objects of non basaltic nature that have to be included in a totally new taxonomic class."

The presence of basalt means that the asteroid must have melted partially at some time in the past, which implies that it was once part of a larger body which had internal heating processes. However, there do not appear to be other basaltic fragments in the region and, from spectral analysis, it is not clear whether the two are fragments of the same parent body or not.

Until recently, most of the known basaltic asteroids, which are classified as V-type, were thought to be fragments of Vesta, the second largest object in the asteroid belt. Since 2001, several V-type asteroids have been identified as not belonging to this Vesta family, including (1459) Magnya, the first basaltic object to be detected in the outer asteroid belt.

Dr Duffard, of the Instituto de Astrofisica de Andalucia in Spain, and his colleague, Dr Fernando Roig, from the Observatorio Nacional in Rio de Janeiro, Brazil, selected the two asteroids, (7472) Kumakiri and (10537) 1991 RY16, for investigation by from a group of six candidate V-type asteroids identified using photometric data from the Sloan Digital Sky Survey (SDSS).

The reflectance spectra of the two bodies seem to show the characteristics of a V-type asteroid. However, there is a shallow absorption band around the wavelength of red visible light, which has never been observed before in other V-type spectra. This means that these objects have a slightly different chemical composition and do not fit into any existing category of asteroid. The unexpected dip in the spectra could have two sources: it could be due to impacts with other asteroids or comets "shocking" iron-rich compounds into a oxidized state, or it could indicate the presence of olivine, a green mineral that is also known as the semi-precious gemstone.

Dr Duffard said, "We need now to observe both objects in the near-infrared range to confirm whether they have a basaltic surface. If they do, we will need to try and work out where they came from and the fate of their parent objects. If they do not, we will have to come up with a new class of asteroid."


Story Source:

The above story is based on materials provided by European Planetology Network. Note: Materials may be edited for content and length.


Cite This Page:

European Planetology Network. "Astronomers Baffled By Basalt In The Outer Asteroid Belt." ScienceDaily. ScienceDaily, 25 August 2007. <www.sciencedaily.com/releases/2007/08/070824130652.htm>.
European Planetology Network. (2007, August 25). Astronomers Baffled By Basalt In The Outer Asteroid Belt. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2007/08/070824130652.htm
European Planetology Network. "Astronomers Baffled By Basalt In The Outer Asteroid Belt." ScienceDaily. www.sciencedaily.com/releases/2007/08/070824130652.htm (accessed July 29, 2014).

Share This




More Space & Time News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com
NASA EDGE: OCO-2 Launch

NASA EDGE: OCO-2 Launch

NASA (July 25, 2014) NASA EDGE webcasts live from Vandenberg AFB for the launch of the Oribiting Carbon Observatory-2 (OCO) launch. Video provided by NASA
Powered by NewsLook.com
This Week @ NASA, July 25, 2014

This Week @ NASA, July 25, 2014

NASA (July 25, 2014) Apollo 11 celebration, Next Giant Leap anticipation, ISS astronauts appear in the House and more... Video provided by NASA
Powered by NewsLook.com
Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
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