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.