European Association for Astronomy Education

Credit: ESA

Arabia Terra on Mars. Image credits: ESA/DLR/FU Berlin (G. Neukum).

ESA’s Mars Express has returned new views of pedestal craters in the Red Planet’s eastern Arabia Terra.

Craters are perhaps the quintessential planetary geological feature. So much so that early planetary geologists expended a lot of effort to understand them. You could say they put craters on a pedestal. This latest image of Mars shows how the Red Planet does it in reality.

Craters are the result of impacts by asteroids, comets and meteorites. In a pedestal crater, the surrounding terrain is covered by pulverised rock thrown out of the crater. This material creates a platform or pedestal around the crater often with steep cliffs, and is usually rich in volatile materials such as water and ice.

Arabia Terra is part of the highlands of Mars, stretching east to west across 4500 km in the northern hemisphere, and named for a feature drawn on Giovanni Schiaparelli’s 19th-century map of Mars.

The whole area is characterised by steep-sided hills, valleys and ancient impact craters that have been extensively resurfaced by old lava flows and modified by profound erosion over millions of years. The eastern areas rise up to 4 km above the low-lying north-western parts. To the north, Arabia Terra drops and blends into the northern lowlands.

Pedestal craters are visible in this new view of a 159 km by 87 km region of eastern Arabia Terra, taken by the High Resolution Stereo Camera on ESA’s Mars Express orbiter.(read hole article at ESA)

Source: NASA News

NASA will score big on super SUN-day at 11 a.m. EST, Sunday, Feb. 6, with the release online of the first complete view of the sun's entire surface and atmosphere.

Seeing the whole sun front and back simultaneously will enable significant advances in space weather forecasting for Earth, and improve planning for future robotic or crewed spacecraft missions throughout the solar system.

These views are the result of observations by NASA's two Solar TErrestrial Relations Observatory (STEREO) spacecraft. The duo are on diametrically opposite sides of the sun, 180 degrees apart. One is ahead of Earth in its orbit, the other trailing behind.(read more)

Source: NASA/Cassini

Titan, the orange moon peeks from behind two of Saturn's rings.
Small, battered Epimetheus appears just above the rings.
Credit: NASA/JPL/Space Science Institute

Every day is a bad-air day on Saturn's largest moon, Titan. Blanketed by haze far worse than any smog belched out in Los Angeles, Beijing or even Sherlock Holmes's London, the moon looks like a dirty orange ball. Described once as crude oil without the sulfur, the haze is made of tiny droplets of hydrocarbons with other, more noxious chemicals mixed in. Gunk.

Icky as it may sound, Titan is really the rarest of gems: the only moon in our solar system with an atmosphere worthy of a planet. This atmosphere comes complete with lightning, drizzle and occasionally a big, summer-downpour style of cloud made of methane or ethane -- hydrocarbons that are best known for their role in natural gas.

Now, thin, wispy clouds of ice particles, similar to Earth's cirrus clouds, are being reported by Carrie Anderson and Robert Samuelson at NASA's Goddard Space Flight Center in Greenbelt, Md. The findings, published February 1 in Icarus, were made using the Composite Infrared Spectrometer (CIRS) on NASA's Cassini spacecraft.

Unlike Titan's brownish haze, the ice clouds have the pearly white appearance of freshly fallen snow. Their existence is the latest clue to the workings of Titan's intriguing atmosphere and its one-way "cycle" that delivers hydrocarbons and other organic compounds to the ground as precipitation. Those compounds don't evaporate to replenish the atmosphere, but somehow the supply has not run out (read more).