baalke@mars.jpl.nasa.gov (Ron Baalke) (11/09/90)
Associated Press -- 11/8/90
"Magellan"
By Lee Siegel
"The Magellan spacecraft has found evidence that ocean-sized
floods of molten rock once inundated more than half the
surface of Venus."
AP reports that NASA scientists do not yet know if there was
one great outpouring of lava from cracks in Venus or a series
of smaller flows, each hundreds of thousands of square miles,
that engulfed parts of the planet at different times.
The wire service says that geologist and Magellan project
scientist Steve Saunders believes that lava gushed out of cracks
called vents in a global set of eruptions that happened all at
once, perhaps 400 million years ago. Saunders is quoted by the
AP as saying "there's no question that the vast majority of the
surface of Venus has been formed by lava flows and volcanic
activity. But the question is, did it all happen
catastrophically?"
According to the story, the lava covers more than sixty percent
of the surface of Venus and accounts for the lack of craters
resulting from meteoritic impacts, as the lava flows would
eradicate any evidence of impact cratering.
The story says that Venus's widespread lava flooding was
similar to, but much larger than, the vast deposits of basalt in
India's Deccan Traps and the Pacific Northwest's Columbia
River basin.
According to the report, the Indian Deccan Traps occurred
when the crust split open as the Indian continental plate
drifted away from Africa about 66 million years ago. The
Columbia River basin deposits occurred, again according to
the AP, when massive eruptions rent much of the Pacific
Northwest east of the Cascade Range about 20 million years.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |baalke@mars.jpl.nasa.gov (Ron Baalke) (12/14/90)
Associated Press -- 12/12/90
"Venus Magellan"
"An alignment of the planets will interfere with the Magellan
spacecraft's ability to send pictures of Venus back to Earth for
the next six weeks beginning Sunday, NASA says."
The AP reports that in late October and early November the
sun was between Venus and Earth, forcing a two-week halt to
Magellan's $744 million mission to use radar to map the
surface of cloud-shrouded Venus.
Now, the AP says, it is the planet Venus itself which is getting
in the way, although the mapping mission will continue.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |