This image shows the first holes into rock drilled by NASA’s Mars rover Curiosity, with drill tailings around the holes plus piles of powdered rock collected from the deeper hole and later discarded after other portions of the sample had been delivered to analytical instruments inside the rover. Image credit: NASA/JPL-Caltech/MSSS

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VIENNA — Mars has lost much of its original atmosphere, but what’s left remains quite active, recent findings from NASA’s Mars rover Curiosity indicate. Rover team members reported diverse findings today at the European Geosciences Union 2013 General Assembly, in Vienna.

Evidence has strengthened this month that Mars lost much of its original atmosphere by a process of gas escaping from the top of the atmosphere.

Curiosity’s Sample Analysis at Mars (SAM) instrument 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 Sushil Atreya, a SAM co-investigator at the University of Michigan, Ann Arbor.

SAM found that the Martian atmosphere has about four times as much of a lighter stable isotope (argon-36) compared to a heavier one (argon-38). This removes previous uncertainty about the ratio in the Martian atmosphere from 1976 measurements from NASA’s Viking project and from small volumes of argon extracted from Martian meteorites. The ratio is much lower than the solar system’s original ratio, as estimated from argon-isotope measurements of the sun and Jupiter. This points to a process at Mars that favored preferential loss of the lighter isotope over the heavier one.

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.

via NASA – Remaining Martian Atmosphere Still Dynamic.

This Friday April 12 at 7:00 pm, join the SIUE STEM Center’s CosmoQuest

and the River Bend Astronomy Club in celebrating Yuri’s Night at Annie’s Frozen Custard in Edwardsville (original location on Buchanan St.)! Yuri’s Night is a global celebration of humanity’s past, present, and future in space. This world wide space party commemorates April 12, 1961, the day of cosmonaut Yuri Gagarin’s first manned spaceflight, and April 12, 1981, the inaugural launch of NASA’s Space Shuttle.

View the night sky through telescopes and binoculars, learn how to find your way around the constellations, and just hang out with other space and astronomy (and frozen custard) enthusiasts!

 If you’d like to help or want last-minute go/cancel information if things are looking stormy, please contact Georgia at gbracey@siue.edu. Unless we’re faced with big storms, we’ll be there. Hope to see you there, too.

 

Blog about last year’s Yuri’s night… use anything you like from that:

http://cosmoquest.org/blog/2012/04/yuris-night-in-edwardsville-who-needs-dark-or-clear-skies/

Credit: ESA/Hubble and NASA › Larger image

Visible as a small, sparkling hook in the dark sky, this beautiful object is known as J082354.96+280621.6, or J082354.96 for short. It is a starburst galaxy, so named because of the incredibly (and unusually) high rate of star formation occurring within it.

One way in which astronomers probe the nature and structure of galaxies like this is by observing the behavior of their dust and gas components; in particular, the Lyman-alpha emission. This occurs when electrons within a hydrogen atom fall from a higher energy level to a lower one, emitting light as they do so. This emission is interesting because this light leaves its host galaxy only after extensive scattering in the nearby gas — meaning that this light can be used as a pretty direct probe of what a galaxy is made up of.

The study of this Lyman-alpha emission is common in very distant galaxies, but now a study named LARS (Lyman Alpha Reference Sample) is investigating the same effect in galaxies that are closer by. Astronomers chose fourteen galaxies, including this one, and used spectroscopy and imaging to see what was happening within them. They found that these Lyman-alpha photons can travel much further if a galaxy has less dust — meaning that we can use this emission to infer how dusty the source galaxy is.

Hubble/European Space Agency

via NASA – Hubble Sees Light and Dust in a Nearby Starburst Galaxy.