Solar wind at 50-year low, scientists say

Other News Materials 24 September 2008 03:59 (UTC +04:00)

The solar wind is at a 50-year low, potentially opening up the solar system to more dangerous rays from outer space, researchers said Tuesday, according to dpa.

Data from the joint NASA and European Space Agency Ulysses solar mission show the cyclical wind - as the plasma and magnetic fields sent out by the sun are called - are at their lowest level since scientists first gathered information on the matter.

The solar wind creates a "protective bubble" called the heliosphere around the planets in the solar system, helping to shield them from dangerous particles from other parts of space, so-called cosmic rays.

These rays pose health threats to astronauts and can wreak havoc with electronics, so must be taken into account when launching satellites.

The solar wind is "now lower since any time since the space age began," Ed Smith, a scientist at NASA's Jet Propulsion Laboratory, said in a conference call with reporters.

Researchers were not surprised that the solar wind has decreased. In fact, the amount of radiation sent off by the sun operates in an 11-year cycle, but this dip is lower than those recently observed. Still, it may be in line with centuries-long patterns, said Nancy Crooker, a research professor at Boston University.

"This is not a good time to be travelling in space," Crooker said, but noted that astronauts travelling to the International Space Station are in no additional danger because the ISS is close enough to Earth to be protected by its magnetic shield.

However, the lower solar wind and resulting exposure to cosmic rays will have to be considered as NASA plans to return astronauts to the Moon and beyond.