From: | NewsProfiles@aol.net |
Title: | GALILEO SCIENTISTS REPORT NEW JUPITER FINDINGS |
Source: | Reuter |
Date: | March 19, 1996 |
back by the U.S. space agency's Galileo probe suggest that the
planet's bulk composition has not changed since it formed
several billion years ago, scientists said on Monday.
Scientists analysing data from the Galileo probe revised
some of the initial findings they had announced in January, one
month after the probe made a suicidal plunge into Jupiter's
hostile atmosphere.
The scientists, who presented the updated findings at a
conference in Houston, also estimated that winds on Jupiter can
rage at more than 400 miles (640 km) per hour, higher than their
earlier estimates of up to 330 miles (530 km) an hour.
The scientists said they now believe that the ratio of
helium to hydrogen by mass in Jupiter's atmosphere is about 24
percent, similar to that of the sun. In January, they had
estimated the ratio for Jupiter, the solar system's largest
planet, at about 14 percent.
The new ratio between helium and hydrogen, elements that
make up 99 percent of Jupiter's atmosphere, suggests Jupiter's
bulk composition has not changed since the planet formed several
billion years ago, National Aeronautics and Space Administration
(NASA) scientists said.
``This then confirms that Jupiter is much hotter in its
interior than its neighbour Saturn, the next largest planet in
the solar system,'' Galileo probe project scientist Richard
Young said. ``It also may force scientists to revise their
projections for the size of the rocky core believed to exist
deep in the centre of Jupiter.''
Jupiter, a giant gas planet, has no surface like Earth's.
The scientists said that several heavy elements including
carbon, nitrogen and sulphur are more abundant on Jupiter than
in the sun.
``This implies that the influx of meteorites and other small
bodies into Jupiter over the aeons since its formation has
played an important role in how Jupiter has evolved,'' said
Young, a scientist at NASA's Ames Research Centre near San
Francisco.
However, minimal organic compounds were detected suggesting
the chances of finding biological activity on Jupiter similar to
that found on Earth are extremely remote, the scientists said.
Further analysis of probe data has confirmed the preliminary
report that the Jovian atmosphere appears to be relatively dry,
they said.
Previous studies had predicted a water abundance for the
planet of twice the solar level, based on the sun's oxygen
content. But actual probe measurements suggest Jupiter's
atmosphere contains less water than the sun.
Galileo, launched from the space shuttle Atlantis in 1989,
took six years to travel to Jupiter. The spacecraft released a
probe which entered Jupiter's atmosphere last December, sending
back 57 minutes of data before disintegrating.
The spacecraft itself is set to continue orbiting Jupiter
for the next two years, sending back more information.
The project has cost about $1.35 billion.