Featured Research

from universities, journals, and other organizations

Dawn suggests special delivery of hydrated material to Vesta

Date:
September 26, 2012
Source:
Europlanet Media Centre
Summary:
The mechanism by which water is incorporated into the terrestrial planets is a matter of extensive debate for planetary scientists. Now, observations of Vesta by NASA's Dawn mission suggest that hydrous materials were delivered to the giant asteroid mainly through a build-up of small particles during an epoch when the Solar System was rich in dust.

The map from NASA's Dawn mission of the giant asteroid Vesta indicates the presence of hydrated minerals in white, with areas with high concentrations circled with a yellow dotted line in the annotated version. The data were obtained by VIR, Dawn's visible and infrared mapping spectrometer, in August 2011 from an altitude of 2700 meters. The data included in the map are from Survey and are limited to 30 degrees north latitude because of the poor illumination condition above that latitude (Vesta winter season).
Credit: NASA/JPL-Caltech/UCLA/INAF

The mechanism by which water is incorporated into the terrestrial planets is a matter of extensive debate for planetary scientists. Now, observations of Vesta by NASA's Dawn mission suggest that hydrous materials were delivered to the giant asteroid mainly through a build-up of small particles during an epoch when the Solar System was rich in dust.

This is a radically different process from the way in which hydrous materials are deposited on the moon and may have implications for the formation of terrestrial planets, including the delivery of the water that forms Earth's oceans. Maria Cristina De Sanctis and the Dawn team will present the scenarios at the European Planetary Science Congress in Madrid on Sept. 26.

De Sanctis, of the Institute of Astrophysics and Space Planetology in Rome, said, "Vesta's surface shows distinct areas enriched with hydrated materials. These regions are not dependent on solar illumination or temperature, as we find in the case of the Moon. The uneven distribution is unexpected and indicates ancient processes that differ from those believed to be responsible for delivering water to other airless bodies, like the Moon."

A team led by De Sanctis studied data from Dawn's visible and infrared (VIR) mapping spectrometer. Analysis showed large regional concentrations of hydroxyl -- a hydrogen and an oxygen atom bound together -- clearly associated with geological features including ancient, highly-cratered terrains and the Oppia crater.

Hydroxyl on the surface of the Moon is thought to be created continuously by the interaction of protons from the solar wind with the lunar regolith. Highest concentrations are found in areas near the lunar poles and in permanently shadowed crater where it is very cold. By contrast, the distribution of hydroxyl on Vesta is not dependent on significant shadowing or unusual cold temperatures. It is also stable over time, so its origin does not appear to be due to short-term processes.

The hydroxyl-rich regions on Vesta broadly correspond to its oldest surfaces. Around relatively large and young impact craters, hydroxyl detections are weak or absent, suggesting that the delivery of hydroxyl is not an ongoing process.

The evidence from VIR suggests that much of Vesta's hydroxyl was delivered by small particles of primitive material, less than a few centimeters in diameter, over a time-limited period. This period may have occurred during the primordial solar system, around the time it is believed water was accreted on Earth, or during the Late Heavy Bombardment, when collisions would have produced a significant amount of primitive material dust.

However, this is not the whole story of hydrous materials on Vesta. The Oppia Crater is hydroxyl-rich, but not covered with the primitive material. This suggests that there is more than one mechanism at work for depositing hydroxyl on Vesta's surface.

De Sanctis said, "The origin of Vesta's hydroxyl is certainly complex and possibly not unique: there could be various sources, like formation of hydroxyl actually on Vesta, in addition to the primordial impactors. Vesta is providing new insights into the delivery of hydrous materials in the main asteroid belt, and may offer new scenarios on the delivery of hydrous minerals in the inner Solar System, suggesting processes that may have played a role in the formation of terrestrial planets."


Story Source:

The above story is based on materials provided by Europlanet Media Centre. Note: Materials may be edited for content and length.


Cite This Page:

Europlanet Media Centre. "Dawn suggests special delivery of hydrated material to Vesta." ScienceDaily. ScienceDaily, 26 September 2012. <www.sciencedaily.com/releases/2012/09/120926092624.htm>.
Europlanet Media Centre. (2012, September 26). Dawn suggests special delivery of hydrated material to Vesta. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2012/09/120926092624.htm
Europlanet Media Centre. "Dawn suggests special delivery of hydrated material to Vesta." ScienceDaily. www.sciencedaily.com/releases/2012/09/120926092624.htm (accessed April 24, 2014).

Share This



More Space & Time News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nuclear-Level Asteroids Might Be More Common Than We Realize

Nuclear-Level Asteroids Might Be More Common Than We Realize

Newsy (Apr. 23, 2014) The B612 Foundation says asteroids strike Earth much more often than previously thought, and are hoping to build an early warning system. Video provided by Newsy
Powered by NewsLook.com
NASA Chief Outlines Plan for Human Mission to Mars

NASA Chief Outlines Plan for Human Mission to Mars

AFP (Apr. 22, 2014) NASA administrator Charles Bolden, speaking at the 'Human to Mars Summit' in Washington, says that learning more about the Red Planet can help answer the 'fundamental question' of 'life beyond Earth'. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Nasa Gives You An Excuse to Post a Selfie on Earth Day

Nasa Gives You An Excuse to Post a Selfie on Earth Day

TheStreet (Apr. 22, 2014) NASA is inviting all social media users to take a selfie of themselves alongside nature and to post it to Twitter, Facebook, Flickr, Instagram, or Google Plus with the hashtag #globalselfie. NASA's goal is to crowd-source a collection of snapshots of the earth, ground-up, that will be used to create one "unique mosaic of the Blue Marble." This image will be available to all in May. Since this is probably one of the few times posting a selfie to Twitter won't be embarrassing, we suggest you give it a go for a good cause. Video provided by TheStreet
Powered by NewsLook.com
SpaceX's Dragon Spacecraft Captured by International Space Station

SpaceX's Dragon Spacecraft Captured by International Space Station

Reuters - US Online Video (Apr. 20, 2014) SpaceX's unmanned Dragon spacecraft makes a scheduled Easter Sunday rendezvous with the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
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