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. It is available online.
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.
To read more, click here.