|
|
| 11:28, September 24, 2008 |
JPL scientists: sun produces less solar wind
|
The sun has reduced its output of solar wind to the lowest level since readings became available, Jet Propulsion Laboratory (JPL) scientists announced Tuesday.
"With the solar wind at an all-time low, there is an excellent chance the heliosphere will diminish in size and strength," said JPL researcher Dave McComas, citing data from the Ulysses spacecraft, a joint NASA-European space agency mission.
In this graphic illustration released by NASA to Reuters Sept. 23, 2008, the heliosphere that is created by solar winds is depicted as a bubble surrounding the solar system. Measurements from the spacecraft Ulysses show the wind's pressure has dropped 20 percent since the mid-1990s. As the solar wind weakens, the heliosphere is expected to dwindle in size and strength as well, allowing more cosmic radiation -- super high-energy electrons and protons zipping through interstellar space -- to reach the inner solar system. (Xinhua/Reuters Photo)
"If that occurs, more galactic cosmic rays will make it into the inner part of our solar system," said McComas, principal investigator of Ulysses solar wind instrument.
"The sun's million mile-per-hour solar wind inflates a protective bubble around the solar system. It influences how things work here on earth and even out at the boundary of our solar system," McComas said.
The sun's solar wind plasma is a stream of charged particles ejected from the sun's upper atmosphere. The solar wind interacts with every planet in our solar system, and it also defines the border between our solar system and interstellar space.
In this graphic illustration released by NASA to Reuters Sept. 23, 2008, the heliosphere that is created by solar winds is depicted as a bubble surrounding the solar system. Measurements from the spacecraft Ulysses show the wind's pressure has dropped 20 percent since the mid-1990s. (Xinhua/Reuters Photo)
"Galactic cosmic rays carry with them radiation from other parts of our galaxy," said Ed Smith, who is in charge of NASA's Ulysses project at the JPL, headquartered in Pasadena, Los Angeles.
Galactic cosmic rays are linked to engineering decisions for unmanned interplanetary spacecraft and exposure limits for astronauts traveling beyond low earth orbit.
Source:Xinhua
|
| Your Message: |
Most Popular Photos |
|
Comment
Tell A Friend
Print Format
Save Article