Featured Research

from universities, journals, and other organizations

Mars formed from similar building blocks to that of Earth, reveals study of Martian meteorites

Date:
November 19, 2012
Source:
Carnegie Institution
Summary:
A team of scientists studied the hydrogen in water from the Martian interior and found that Mars formed from similar building blocks to that of Earth, but that there were differences in the later evolution of the two planets. This implies that terrestrial planets, including Earth, have similar water sources.

Composite image of Earth and Mars. The Earth image was acquired from the Galileo orbiter on Dec. 11, 1990, when the spacecraft was about 1.3 million miles from the planet during the first of two Earth flybys on its way to Jupiter. The Mars image was acquired by the Mars Global Surveyor in April of 1999.
Credit: NASA/JPL

A team of scientists, including Carnegie's Conel Alexander and Jianhua Wang, studied the hydrogen in water from the Martian interior and found that Mars formed from similar building blocks to that of Earth, but that there were differences in the later evolution of the two planets. This implies that terrestrial planets, including Earth, have similar water sources--chondritic meteorites. However, unlike on Earth, Martian rocks that contain atmospheric volatiles such as water, do not get recycled into the planet's deep interior.

Their work will be published in the December 1 issue of Earth and Planetary Science Letters.

Much controversy surrounds the origin, abundance and history of water on Mars. The sculpted channels of the Martian southern hemisphere speak loudly of flowing water, but this terrain is ancient. Consequently, planetary scientists often describe early Mars as "warm and wet" and current Mars as "cold and dry."

Debate in the scientific community focuses on how the interior and crust of Mars formed, and how they differ from those of Earth. To investigate the history of Martian water and other volatiles, scientists at NASA's Johnson Space Center in Houston, Carnegie, and the Lunar and Planetary Institute in Houston studied water concentrations and hydrogen isotopic compositions trapped inside crystals within two Martian meteorites. The meteorites, called shergottites, were of the same primitive nature, but one was rich in elements such as hydrogen, whereas the other was depleted.

The meteorites used in the study contain trapped basaltic liquids, and are pristine samples that sampled various Martian volatile element environments. One meteorite appears to have changed little on its way from the Martian mantle up to the surface of Mars. It has a hydrogen isotopic composition similar to that of Earth. The other meteorite appears to have sampled Martian crust that had been in contact with the Martian atmosphere. Thus, the meteorites represent two very different sources of water. One sampled water from the deep interior and represents the water that existed when Mars formed as a planet, whereas the other sampled the shallow crust and atmosphere.

"There are competing theories that account for the diverse compositions of Martian meteorites," said lead Tomohiro Usui. "Until this study there was no direct evidence that primitive Martian lavas contained material from the surface of Mars."

Because the hydrogen isotopic compositions of the two meteorites differ, the team inferred that martian surface water has had a different geologic history than Martian interior water. Most likely, atmospheric water has preferentially lost the lighter hydrogen isotope to space, and has preferentially retained the heavier hydrogen isotope (deuterium).

That the enriched meteorite has incorporated crustal and atmospheric water could help to solve an important mystery. Are Martian meteorites that are enriched in components, such as water, coming from an enriched, deep mantle, or have they been overprinted by interaction with the Martian crust?

"The hydrogen isotopic composition of the water in the enriched meteorite clearly indicates that they have been overprinted, so this meteorite tells scientists more about the Martian crust than about the Martian mantle," Alexander said. "Conversely, the other meteorite yields more information about the Martian interior."

The concentrations of water in the meteorites are also very different. One has a rather low water concentration and that means that the interior of Mars is rather dry. Conversely, the enriched basalt has 10 times more water than the other one, suggesting that the surface of Mars could have been very wet at one time. Therefore, scientists are now starting to learn which meteorites tell us about the Martian interior and which samples tell us about the Martian surface.

"To understand the geologic history of Mars, more information about both of these environments is needed," Alexander said.


Story Source:

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


Journal Reference:

  1. Tomohiro Usui, Conel M.O'D. Alexander, Jianhua Wang, Justin I. Simon, John H. Jones. Origin of water and mantle–crust interactions on Mars inferred from hydrogen isotopes and volatile element abundances of olivine-hosted melt inclusions of primitive shergottites. Earth and Planetary Science Letters, 2012; 357-358: 119 DOI: 10.1016/j.epsl.2012.09.008

Cite This Page:

Carnegie Institution. "Mars formed from similar building blocks to that of Earth, reveals study of Martian meteorites." ScienceDaily. ScienceDaily, 19 November 2012. <www.sciencedaily.com/releases/2012/11/121119163500.htm>.
Carnegie Institution. (2012, November 19). Mars formed from similar building blocks to that of Earth, reveals study of Martian meteorites. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2012/11/121119163500.htm
Carnegie Institution. "Mars formed from similar building blocks to that of Earth, reveals study of Martian meteorites." ScienceDaily. www.sciencedaily.com/releases/2012/11/121119163500.htm (accessed April 23, 2014).

Share This



More Space & Time News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Raw: Easter Morning Delivery for Space Station

Raw: Easter Morning Delivery for Space Station

AP (Apr. 20, 2014) Space station astronauts got a special Easter treat: a cargo ship full of supplies. The SpaceX company's cargo ship, Dragon, spent two days chasing the International Space Station following its launch from Cape Canaveral. (April 20) Video provided by AP
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:

More Coverage


Meteorite Samples Provide Evidence of Water and Rock Types on Mars

Nov. 21, 2012 Researchers report on geochemical studies that help towards settling the controversy that surrounds the origin, abundance, and history of water on ... read more
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