Category Astronomy/Space

Single-event noise discrimination. Credit: (c) Science 11 December 2015: Vol. 350 no. 6266 pp. 1343-1346, DOI: 10.1126/science.aac8446 Read more at: http://phys.org/news/2015-12-optical-technique-radio-background-noise.html#jCp

A small team of researchers with the University of California has found a way to pick out a single short radio signal burst among a barrage of background noise. Currently it is impossible to separate out a unique signal if there is just one burst present—there needs to be multiple examples. That could change in the near future as the researchers on this new effort have developed a way to convert radio signals to optical signals that can be processed to filter, separate and identify individual components.

The team started with converting the radio signals to optica...

The Milky Way arcs into a panorama in the southern sky, taken from the Paranal Observatory, Chile. Credit: ESO/H.H. Heyer

When our galaxy was born, ~13B yrs ago, a plethora of clusters containing millions of stars emerged. But over time, they have been disappearing. However, hidden behind younger stars that were formed later, some old and dying star clusters remain, eg E 3. European astronomers have now studied this testimony to the beginnings of our galaxy.

Globular clusters are spherical-shaped or globular stellar groupings which can contain millions of stars. There are about 200 of them in the Milky Way, but few are as intriguing to astronomers as the E 3 cluster. It is 30,000 light years away, in the southern constellation of Chameleon...

This representation of Ceres’ Occator Crater in false colors shows differences in the surface composition. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

2 new studies from NASA’s Dawn spacecraft show insights about mysterious bright features found all over the dwarf planet’s surface. In one study, scientists identify this bright material as a kind of salt. The 2nd study suggests the detection of ammonia-rich clays, raising questions about how Ceres formed.

Ceres has more than 130 bright areas, and most of them are associated with impact craters. The bright material is consistent with a type of magnesium sulfate, hexahydrite.
Nathues and colleagues, using images from Dawn’s framing camera, suggest these salt-rich areas were left behind when water-ice sublimated in the past...

A diagram showing how the meteors will appear to emanate from a radiant in the constellation of Gemini, located in the east in the evening sky. Credit: Greg Smye-Rumsby / Astronomy Now

From 13 to 15 Dec, weather permitting, skywatchers across the world will be looking up as the Geminid meteor shower reaches its peak, in potentially one of the best night sky events of the year. Tens of ‘shooting stars’ or meteors may be visible each hour (the theoretical maximum under ideal conditions is about 120/hr). Meteors are the result of small (mm- to cm-sized) particles entering the Earth’s atmosphere at high speed, burning up and superheating the air around them, which then shines as a characteristic short-lived streak of light...