Astronomy

08/18/2014 - 07:01

A new search for dark matter will soon be underway after a second generation experiment was selected by US funding agencies. Most physicists believe that dark matter particles make up most of the mass of the universe, but these particles have never been observed directly since they neither emit nor absorb light at any wavelength.

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.

 

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.

 

04/03/2014 - 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.

 

03/31/2014 - 08:11

Scientists have developed a way of reading the universe's 'cosmic barometer' to learn more about ancient violent events in space. Exploding stars, random impacts involving comets and meteorites, and even near misses between two bodies can create regions of great heat and high pressure.