Physics and Astronomy

Mars’ polar ice caps are slowly melting.

The martian ice caps are shrinking. As they are made mostly of frozen carbon dioxide, this evaporation could trigger an increase in Mars’ own greenhouse effect.

Images from the Mars Global Surveyor spacecraft show that ice ridges and escarpments have retreated over the past two years or so. The orbiting probe has also captured the ice thickening and thinning with the passing seasons.

The reason for the change is not yet clea

In any computer’s hard drive, magnetic fields spin electrons this way or that. Now physicists have demonstrated that an electric field can do the same when applied to electrons in semiconductors. And unlike the older magnetic approach, their new device, called a spin gate, is capable of easily imparting a range of spin values. The team’s results, described in a report appearing today in the journal Nature, may one day help to scientists realize the ideal of spintronics—quantum computing based on ele

Astronomers from the University of Pennsylvania, in collaboration with an international team of researchers, have made the first direct detection and measurement of the properties of a dark matter object in the Milky Way.
This observation of a gravitational microlensing event — a temporary increase in the brightness of a background star during the time it takes dark matter to pass in front of it — is reported in today’s issue of Nature.

“By measuring its mass, distance and velocity, w

Hubble spots atmosphere on planet 150 light years away.

Astronomers have glimpsed the atmosphere of a planet in a solar system other than our own for the first time. The feat is a first step towards detecting planets capable of supporting life elsewhere in the Universe.

David Charbonneau, of the California Institute of Technology, Pasadena, and colleagues, pointed the Hubble space telescope at the planet, which lies 150 light years away in the constellation Pegasus. Of the 7

Some galaxies may have torus envy, if a new study is any indication. The most sensitive imaging yet of nearby galaxy M87’s core reveals that the black hole residing there has either a nonexistent or much fainter ring of dust around it compared with its peers. Scientists had thought that these rings were key features of such highly energetic galaxies. The puzzling finding appears today in the Astrophysical Journal Letters .

The current model of active galaxies such as M87 posits that

Cosmic lens magnifies faint galactic building-block.

Astronomers have peered deep into space and time and spotted a baby galaxy. Their results suggest that the tiny star-forming region may have helped to build today’s Universe 1 .

“We believe this is one of the galactic building-blocks that join together to make larger galaxies,” says Konrad Kuijken, of the Kapteyn Institute in Groningen, the Netherlands, a member of the team that found the object. The mergin