Astronomy

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.

 

03/27/2014 - 14:48

It has been established that the Heliospheric Magnetic Field (HMF) intensity fluctuates with the solar cycle. During the recent protracted solar minimum of cycle 24, the HMF intensity fell to a record observed low. As well, after the relatively small maximum of cycle 24, it has been shown that the magnetic and particle fluxes only made a partial recovery. Building on Schwadron et al. [2010], we show that the decreased flux levels at maximum will lead to an even lower coming minimum.