From: LARRY KLAES (ljk4_at_msn.com)
Date: Thu Nov 06 2003 - 06:53:28 PST
This article is also available on the web at:
http://www.spacetoday.net/getsummary.php?id=2012 .
Voyager approaches limits of solar system
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Posted: Thu, Nov 6 6:38 AM ET (1138 GMT)
NASA's Voyager 1 spacecraft, launched over 25 years ago, may
have reached the boundary between the solar system and
interstellar space, although scientists are not in agreement
about the claim. In one paper published in Thursday's issue
of the journal Nature, a team of scientists led by Stamatios
Krimigis of the Johns Hopkins University Applied Physics
Laboratory argued that between August 2002 and February 2003
Voyager 1 may have reached the "termination shock", a
turbulent region where the solar wind abruptly slows from
1-2 million kmph to a fraction of that speed. Voyager 1 is
currently about 90 astronomical units, or 13.5 billion
kilometers, from the Sun. The solar wind velocity
measurement was made indirectly since the spacecraft's
instrument that directly measures the speed no longer
functions. Another paper by Frank McDonald of the
University of Maryland, also published in Nature, as well as
a third paper published last month in Geophysical Research
Letters, dispute the claim, saying that the unusual magnetic
field variations noted by the first group had
characteristics seen in past years. The other papers do
note, though, that the more recent observations have a much
higher intensity of charged particles. Project officials
hope that Voyager 2, whose instruments are in better
condition, might be able to better measure the location of
the termination shock once it reaches it.
Related Links:
--------------
NASA press release:
http://www.nasa.gov/home/hqnews/2003/nov/HQ_03354_voyager_ssu.html
SPACE.com article:
http://space.com/scienceastronomy/voyager_mystery_031105.html
New York Times article:
http://www.nytimes.com/2003/11/06/science/06VOYA.html
Washington Post article:
http://www.washingtonpost.com/wp-dyn/articles/A6146-2003Nov5.html
New Scientist article:
http://www.newscientist.com/news/news.jsp?id=ns99994350
Visit http://www.spacetoday.net/ to get the latest space
news summaries and links to space news articles published
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