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The team made this determination from the latest results, which reveal that about 65 percent of the argon that was ever in the atmosphere has been lost to space.
Jakosky is lead author of a paper on this research to be published in Science on Friday, March However, evidence such as features resembling dry riverbeds and minerals that only form in the presence of liquid water indicates the ancient Martian climate was much different — warm enough for water to flow on the surface for extended periods.
The new result reveals that solar wind and radiation were responsible for most of the atmospheric loss on Mars, and the depletion was enough to transform the Martian climate. The solar wind is a thin stream of electrically conducting gas constantly blowing out from the surface of the sun.
As the planet cooled off and dried up, any life could have been driven underground or forced into rare surface oases. Jakosky and his team got the new result by measuring the atmospheric abundance of two different isotopes of argon gas.
Isotopes are atoms of the same element with different masses. Since the lighter of the two isotopes escapes to space more readily, it will leave the gas remaining behind enriched in the heavier isotope.
The team used the relative abundance of the two isotopes measured in the upper atmosphere and at the surface to estimate the fraction of the atmospheric gas that has been lost to space.
As a "noble gas" argon cannot react chemically, so it cannot be sequestered in rocks; the only process that can remove noble gases into space is a physical process called "sputtering" by the solar wind. In sputtering, ions picked up by the solar wind can impact Mars at high speeds and physically knock atmospheric gas into space.
The team tracked argon because it can be removed only by sputtering.
Once they determined the amount of argon lost by sputtering, they could use this information to determine the sputtering loss of other atoms and molecules, including carbon dioxide CO2."The launch energy to reach the Sun is 55 times that required to get to Mars, and two times that needed to get to Pluto," said Yanping Guo from the Johns Hopkins Applied Physics Laboratory, who designed the mission trajectory.
The American and Soviet/Russian Mars exploration programs are reviewed and the course incorporates the most recent results from spacecraft missions such as Mars Global Surveyor, Mars Odyssey, the Mars Exploration Rovers, Mars Reconnaissance Orbiter, and Mars .
Juno, NASA’s next big mission bound for the outer planets, has arrived at the Kennedy Space Center to kick off the final leg of launch preparations in . The USSR copied the reusable Space Shuttle orbiter, pad workers were killed by a nitrogen-rich atmosphere in the aft engine compartment of the Space Shuttle Columbia at the Kennedy Space Center Launch Will Commercial Space Travel Blast Off in ?.
kaja-net.com Retrieved on Boyle, Alan (8 March ). "Jeff Bezos lifts. One famous failure was the Mars Climate Orbiter, which lost contact with Earth because of a failure to convert between standard and metric units.
A Delta 2 rocket blasted off Saturday and successfully boosted two NASA science satellites into space to kick off an ambitious $ million mission to map the moon's gravity and internal structure.