Data from NASA's Phoenix Mars Lander suggest liquid water has interacted with the Martian surface throughout the planet's history and into modern times. The research also provides new evidence that volcanic activity has persisted on the Red Planet into geologically recent times, several million years ago. Although the lander, which arrived on Mars on May 25, 2008, is no longer operating, NASA scientists continue to analyze data gathered from that mission. These recent findings are based on data about the planet's carbon dioxide, which makes up about 95 percent of the Martian atmosphere. "Atmospheric carbon dioxide is like a chemical spy," said Paul Niles, a space scientist at NASA's Johnson Space Center in Houston. "It infiltrates every part of the surface of Mars and can indicate the presence of water and its history."
Phoenix precisely measured isotopes of carbon and oxygen in the carbon dioxide of the Martian atmosphere. Isotopes are variants of the same element with different atomic weights. Niles is lead author of a paper about the findings published in Thursday's online edition of the journal Science. The paper explains the ratios of stable isotopes and their implications for the history of Martian water and volcanoes. "Isotopes can be used as a chemical signature that can tell us where something came from, and what kinds of events it has experienced," Niles said. This chemical signature suggests that liquid water primarily existed at temperatures near freezing and that hydrothermal systems similar to Yellowstone’s hot springs have been rare throughout the planet's past.
Measurements concerning carbon dioxide showed Mars is a much more active planet than previously thought. The results imply Mars has replenished its atmospheric carbon dioxide relatively recently, and the carbon dioxide has reacted with liquid water present on the surface. Measurements were performed by an instrument on Phoenix called the Evolved Gas Analyzer. The instrument was capable of doing more accurate analysis of carbon dioxide than similar instruments on NASA's Viking landers in the 1970s. The Viking Program provided the only previous Mars isotope data sent back to Earth. The low gravity and lack of a magnetic field on Mars mean that as carbon dioxide accumulates in the atmosphere, it will be lost to space. This process favors loss of a lighter isotope named carbon-12 compared to carbon-13.
NASA has selected Orbital Sciences Corp. of Dulles, Va., to launch the Orbiting Carbon Observatory-2 (OCO-2) mission. The spacecraft will fly in February 2013 aboard a Taurus XL 3110 rocket launched from Vandenberg Air Force Base in California. The total cost of the OCO-2 launch services is approximately $70 million.
The estimated cost includes the task ordered launch service for a Taurus XL 3110 rocket, plus additional services under other contracts for payload processing, OCO-2 mission unique support, launch vehicle integration, and tracking, data and telemetry support. OCO-2 is a NASA's first mission dedicated to studying atmospheric carbon dioxide. Carbon dioxide is the leading human-produced greenhouse gas driving changes in the Earth's climate.
OCO-2 will provide the first complete picture of human and natural carbon dioxide sources and "sinks," the places where the gas is pulled out of the atmosphere and stored. It will map the global geographic distribution of these sources and sinks and study their changes over time. The OCO-2 spacecraft will replace OCO-1, lost during a launch vehicle failure in 2009.
Crafty detective work based on data from NASA's Mars rover Spirit has uncovered huge amounts of a rare type of Martian rock that adds more proof that the red planet may have harbored liquid water in the ancient past.The rock projection is rich in carbonate minerals and was found in the Columbia Hills, an "island" of low hills at Spirit's Gusev crater home on Mars. Spirit visited the projection in 2005, before it got permanently stuck in its current Martian resting spot.
Carbonates are minerals that enclose carbon dioxide and form readily in the presence of water. So, if the conditions were such that carbonate-bearing rocks were able to form, this would propose that at one point, water – and possibly an environment favorable to primitive life – was likely present in the region."Carbonate forms as a rain product from water, so there has to be water around for them to form in the first place," the study's lead author Richard Morris, a planetary scientist at NASA's Johnson Space Center in Houston, Texas.
Until now, geologic clues for the presence of carbonates on the Martian surface have been comparatively scarce. In contrast, carbonate-rich rocks are plentiful on Earth, where liquid water abounds. The discovery of the carbonate-rich projection came as a surprise to researchers, since plenty of rocksthat did not contain carbonates were previously found in the surrounding area.
Data from NASA's Phoenix Mars Lander suggest liquid water has interacted with the Martian surface throughout the planet's history and into modern times. The research also provides new evidence that volcanic activity has persisted on the Red Planet into geologically recent times, several million years ago. Although the lander, which arrived on Mars on May 25, 2008, is no longer operating, NASA scientists continue to analyze data gathered from that mission. These recent findings are based on data about the planet's carbon dioxide, which makes up about 95 percent of the Martian atmosphere. "Atmospheric carbon dioxide is like a chemical spy," said Paul Niles, a space scientist at NASA's Johnson Space Center in Houston. "It infiltrates every part of the surface of Mars and can indicate the presence of water and its history." 
