Mars has lost much of its original atmosphere, but what’s left remains active, according to recent findings from the Mars Science Laboratory.
Curiosity’s Sample Analysis at Mars (SAM) instrument, parts of which were built by SPRL, analyzed an atmosphere sample last week using a process that concentrates selected gases. The results provided the most precise measurements ever made of isotopes of argon in the Martian atmosphere. Isotopes are variants of the same element with different atomic weights.
“We found arguably the clearest and most robust signature of atmospheric loss on Mars,” said AOSS Professor Sushil Atreya, a SAM co-investigator.
Curiosity measures several variables in today’s Martian atmosphere with the Rover Environmental Monitoring Station (REMS), provided by Spain. While daily air temperature has climbed steadily since the measurements began eight months ago and is not strongly tied to the rover’s location, humidity has differed significantly at different places along the rover’s route. These are the first systematic measurements of humidity on Mars.
Trails of dust devils have not been seen inside Gale Crater, but REMS sensors detected many whirlwind patterns during the first hundred Martian days of the mission, though not as many as detected in the same length of time by earlier missions. “A whirlwind is a very quick event that happens in a few seconds and should be verified by a combination of pressure, temperature and wind oscillations and, in some cases, a decrease is ultraviolet radiation,” said Javier Gómez-Elvira, REMS principal investigator, of the Centro de Astrobiología, Madrid.
Dust distributed by the wind has been examined by Curiosity’s laser-firing Chemistry and Camera (ChemCam) instrument. Initial laser pulses on each target hit dust. The laser’s energy removes the dust to expose underlying material, but those initial pulses also provide information about the dust. “We knew that Mars is red because of iron oxides in the dust,” said Sylvestre Maurice, ChemCam deputy principal investigator, of the Institut de Recherche en Astrophysique et Planétologie in Toulouse, France. “ChemCam reveals a complex chemical composition of the dust that includes hydrogen, which could be in the form of hydroxyl groups or water molecules.”
Possible interchange of water molecules between the atmosphere and the ground is studied by a combination of instruments on the rover, including the Dynamic Albedo of Neutrons (DAN), provided by Russia under the leadership of DAN Principal Investigator Igor Mitrofanov.
NASA’s Mars Science Laboratory Project is using Curiosity to investigate the environmental history within Gale Crater, a location where the project has found that conditions were long ago favorable for microbial life. Curiosity, carrying 10 science instruments, landed in August 2012 to begin its two-year prime mission. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the project for NASA’s Science Mission Directorate in Washington.