Physics and Astronomy

Belt tightening cloud could have silver-lining for Europe’s planet hunters

European planet hunters are rallying round a beleaguered effort to launch the first spacecraft that might detect Earth-like planets beyond our own Solar System. Meeting in London last week they agreed that the low-cost, low-risk mission has a lot to offer.

The planet-spotting mission Eddington has been approved by the European Space Agency (ESA), but is currently on hold awaiting funds; unless they ma

The astronomy textbooks will have to be rewritten, say astrophysicists at the University of Sussex who have re-examined standard calculations about solar evolution and the distant future of the Earth.

The textbooks tell us that one day the Sun will burn up its nuclear fuel and expand to an enormous size, finally engulfing its inner planets including Earth. However, using the latest data based on real stars, the University of Sussex researchers suggest a (slightly) less catastrophic future f

Satellites have detected the shifting forces that weave the Northern Lights.

A group of four spacecraft has given scientists their first glimpse of the immense electrical circuit above the Earth that creates the shimmering veil of the aurora borealis, or Northern Lights 1 .

In January 2001 the four satellites of the European Space Agency’s Cluster mission encountered a beam of electrons moving away from the Earth near the North Pole. The beam was on the outwa

American Geophysical Society Meeting, San Francisco, December 2001

The Sun’s violent outbursts have deep and twisted origins.

The Sun’s violent eruptions of material and magnetic energy have deep and twisted origins, researchers told this week’s American Geophysical Union Meeting in San Francisco, California.

These coronal mass ejections (CMEs) cause the aurora, seen at the Earth’s poles, and can knock out spacecraft. An understanding of what drives CMEs may one da

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