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Did Mars ever support life of any sort?  Why is Mars so different from Earth? Can we deduce its history from current conditions?

NASA's Curiosity rover is using a new experiment to better understand the history of the Martian atmosphere by analyzing xenon. 

While NASA's Curiosity rover concluded its detailed examination of the rock layers of the "Pahrump Hills" in Gale Crater on Mars this winter, some members of the rover team were busy analyzing the Martian atmosphere for xenon, a heavy noble gas. 

Curiosity's Sample Analysis at Mars (SAM) experiment analyzed xenon in the planet's atmosphere. Since noble gases are chemically inert and do not react with other substances in the air or on the ground, they are excellent tracers of the history of the atmosphere. Xenon is present in the Martian atmosphere at a challengingly low quantity and can be directly measured only with on-site experiments such as SAM.

Research led by a University of New Hampshire professor has identified a new source of methane for gas hydrates -- ice-like substances found in sediment that trap methane within the crystal structure of frozen water -- in the Arctic Ocean. The findings, published online now in the May 2015 journal Geology, point to a previously undiscovered, stable reservoir for abiotic methane -- methane not generated by decomposing carbon -- that is "locked" away from the atmosphere, where it could impact global climate change.

"We've found an example where methane produced at a mid-ocean ridge is locked up in stable, deep water gas hydrate, preventing it from possibly getting out of the seafloor," says lead author Joel Johnson, associate professor of geology at UNH and guest researcher at the Center for Arctic Gas Hydrate, Environment and Climate (CAGE) at UiT The Arctic University of Norway in Tromsø. Johnson notes that the findings, which pinpointed a source of abiotic methane ¬produced in seafloor crust, indicate gas hydrates throughout the Arctic may be supplied by a significant portion of abiotic gas.

Fracking doesn’t appear to be allowing methane to seriously contaminate drinking water in Pennsylvania, a new study finds—contrary to some earlier, much publicized research that suggested a stronger link. But the lead authors of the two bodies of research are sparring over the validity of the new results.

The Amazon rainforest teems with animal activity throughout the day and night. When animals suddenly withdraw and go silent, however, something unusual is going on. Many believe that this reaction can mean an earthquake is imminent.

Scientists now say they’ve got proof this belief is true. They’ve published their study’s findings in the journal Physics and Chemistry of the Earth.

Researchers set up a series of motion-activated camera traps in Peru’s Yanachanga National Park to observe animal activity at ground level. They filmed rodents and other ground dwellers as they went about their busy forest lives.

Nearly two-thirds of tropical forests in Southeast Asia have been degraded by logging, agriculture and other human uses, and their fauna have been decimated by hunting and the bushmeat trade. But if those degraded tropical forests are to recover naturally, they will need to rely on their remaining large wild animals to disperse large tree seeds, according to a new study. The study published in mongabay.org's open-access journal Tropical Conservation Science examined the importance of large mammals such as wild primates, deer, civets, wild pigs, and tapirs to the dispersion of large seeds throughout the Harapan Rainforest of Sumatra, which has been degraded by logging and agriculture.