From: European Space Agency
Posted: Wednesday, February 19, 2003
Comet C/2002 V1 (NEAT) is putting on a fine show for
ESA/NASA's Solar and Heliospheric Observatory (SOHO) space
probe. As the comet swings closer to the Sun, it has gotten
brighter. Now it is the brightest comet ever observed by
SOHO's LASCO instrument.
The show became even more spectacular in the early hours of 18 February 2003, when the Sun unleashed a storm of charged particles, known as a Coronal Mass Ejection (CME). It looked as if this ejection was heading for the comet. Astronomers are trying to find out if there was a head-on collision. The comet will remain in the LASCO field of view until Thursday 20 February 2003.
First recognised in the 1970s, CMEs play an important role in space weather. They occur when the magnetic field of the Sun whiplashes, sending a cloud of super-hot gaseous debris flying off into space. When a CME occurs very fast and powerfully and stretches out in the direction of our planet, it can cause a chain of effects. What can happen? The effects can affect satellites in orbit, burn out power station transformers on Earth, and endanger orbiting astronauts. Studying CMEs and their effects is an important goal for modern science.
USEFUL LINKS FOR THIS STORY
* More about SOHO
* SOHO hotshots
* More about Comet C/2002 V1 (NEAT)
* Surf the Web to see the Sun-dancing comet
* SOHO discovers 500th new comet
* In SOHO's pictures, watch a comet passing near the Sun
* SOHO's private view of a sunbathing comet
* SOHO's unique view of a comet that fell to pieces
* SOHO analyses a kamikaze comet
* ESA Science homepage
* Comet C/2002 V1 NEAT
* ESA's SOHO science website
* SOHO Science Web Site
* How to discover comets with SOHO
* The very latest SOHO images
* LASCO homepage
Comet C2002/V1 (NEAT) is very close to the Sun.
SOHO is well placed to monitor the Sun's coronal mass ejections. SOHO is stationed 1.5 million kilometres away from the Earth, directly in line of the Sun. There, it constantly watches the Sun for activity, returning spectacular pictures and data of the storms that rage across its surface. SOHO was launched in 1995 by a NASA Atlas-IIAS/Centaur rocket and was designed to work for three years. It is still working today.
This illustration shows a CME blasting off the Sun's surface in the direction of Earth. This left portion is composed of an EIT 304 image superimposed on a LASCO C2 coronagraph. Two to four days later, the CME cloud is shown striking and beginning to be mostly deflected around the Earth's magnetosphere. The blue paths emanating from the Earth's poles represent some of its magnetic field lines. The magnetic cloud of plasma can extend to 30 million miles wide by the time it reaches earth. These storms, which occur frequently, can disrupt communications and navigational equipment, damage satellites, and even cause blackouts. (Objects in the illustration are not drawn to scale.)
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