Astrophysics

07/08/2014 - 14:09

Planet Mercury's unusual metal-rich composition has been a longstanding puzzle in planetary science. According to a study published online in Nature Geoscience July 6, Mercury and other unusually metal-rich objects in the solar system may be relics left behind by collisions in the early solar system that built the other planets.

 

06/17/2014 - 20:24

It is likely that most of the large impact craters on Earth have already been discovered and that others have been erased, according to a new calculation by a pair of Purdue University graduate students.

05/01/2014 - 09:08

Out on the edge of the universe, 75,000 light years from us, a galaxy known as Segue 1 has some unusual properties: It is the faintest galaxy ever detected. It is very small, containing only about 1,000 stars. And it has a rare chemical composition, with vanishingly small amounts of metallic elements present.

 

04/23/2014 - 17:23

Studies have shown that impulsive Solar Energetic Particle (SEP) events emit Fe ions with QFe < 14 at the lowest energies (E ≤ 0.1 MeV/nuc) that are consistent with typical corona source material (DiFabio et al., ApJ, 687, 623, 2008). However, the occasional observation of Fe with QFe > 16 in solar wind associated with active regions (Lepri et al., JGR, 106, 29231, 2001) led to a search for acceleration of high charge state Fe in all SEP events observed with ACE SEPICA.

 

04/18/2014 - 09:20

Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists exploring large fields of impact glass in Argentina suggest that what happened on Earth might well have happened on Mars millions of years ago. Martian impact glass could hold traces of organic compounds.

04/03/2014 - 12:19

Mercury was long thought to be lacking volatile compounds that cause explosive volcanism. That view started to change when the MESSENGER spacecraft returned pictures of pyroclastic deposits — the telltale signature of volcanic explosions. Now more detailed data from MESSENGER shows that volcanoes exploded on Mercury for a substantial portion of the planet’s history. The findings suggest Mercury not only had volatiles but held on to them for longer than scientists had expected.