Category Astronomy/Space

The hazy globe of Titan hangs in front of Saturn and its rings in this natural color view from NASA’s Cassini spacecraft. Image credit: NASA/JPL-Caltech/Space Science Institute

The puzzling appearance of an ice cloud seemingly out of thin air has prompted NASA scientists to suggest that a different process than previously thought – possibly similar to one seen over Earth’s poles – could be forming clouds on Saturn’s moon Titan. Located in Titan’s stratosphere, the cloud is made of a compound of carbon and nitrogen known as dicyanoacetylene (C4N2), an ingredient in the chemical cocktail that colors the giant moon’s hazy, brownish-orange atmosphere. Decades ago, the infrared instrument on NASA’s Voyager 1 spacecraft spotted an ice cloud just like this one on Titan...

Types of galaxies (Credit: NASA)

In the late 1970s, astronomers Vera Rubin and Albert Bosma independently found that spiral galaxies rotate at a nearly constant speed: the velocity of stars and gas inside a galaxy does not decrease with radius, as one would expect from Newton’s laws and the distribution of visible matter, but remains approximately constant. Such ‘flat rotation curves’ are generally attributed to invisible, dark matter surrounding galaxies and providing additional gravitational attraction. Now a team led by Case Western Reserve University researchers has found a significant new relationship in spiral and irregular galaxies: the acceleration observed in rotation curves tightly correlates with the gravitational acceleration expected from visible mass only.

“If you measure the...

These pseudotachylites — fine grained rocks — are from the British Isles. Credit: Image courtesy of Yale University

A new study shows that rocks formed by the grinding together of other rocks during earthquakes are rich in trapped hydrogen – a finding that suggests similar seismic activity on Mars may produce enough hydrogen to support life. Researchers from Yale, the University of Aberdeen, and Brock University studied rock formations around active fault lines in the Outer Hebrides, off the coast of Scotland. “Previous work has suggested that hydrogen is produced during earthquakes when rocks fracture and grind together. Our measurements suggest that enough hydrogen is produced to support the growth of microorganisms around active faults,” said Yale geologist Sean McMahon.

While humans an...