home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Space & Astronomy
/
Space and Astronomy (October 1993).iso
/
mac
/
TEXT
/
JPLNEWS1
/
0938.PR
< prev
next >
Wrap
Text File
|
1993-04-23
|
4KB
|
141 lines
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (213) 354-5011
FOR RELEASE JUNE 20, 1980
Rare Martian meteorological phenomena have been ì
ì
found in pictures of Mars taken by the Viking Orbiter 1 ì
ì
spacecraft, managed for NASA by the Jet Propulsion ì
ì
Laboratory, Pasadena, Calif.
Weather activity never before observed on Mars was ì
ì
discovered in images taken on an exceptionally clear Martian
day on Feb. 22, 1980.
Several prominent Martian features and at least two ì
ì
meterological anomalies are visible in a mosaic of 102 frames ì
ì
taken that day. The photo-mosaic is probably the best wide- ì
ì
area view of the Mars surface yet obtained.
The most remarkable weather activity in the mosaic ì
ì
appears as a sharp, dark line which curves north and east ì
ì
from the huge volcano Arsia Mons in the Tharsis Ridge. ì
ì
Scientists believe this line is either a weather front or ì
ì
atmospheric shock wave. Nothing like this weather phenomenon ì
ì
has ever been seen before on Mars.
The second unusual weather activity consists of ì
ì
four small clouds that hover just north of the Lowell crater. ì
ì
Though two of the clouds are so close together as to be ì
ì
almost inseparable even in high enlargement, four clearly ì
ì
separate cloud shadows are cast on the planet surface. The ì
ì
largest cloud is about 32 kilometers (20 miles) in length. ì
Judging from the distance between the clouds and ì
ì
shadows, the clouds float at an altitude of nearly 28 ì
ì
kilometers (91,000 feet). The shadows, which are cast to the ì
ì
south of the clouds, indicate that the photographs near the ì
ì
center of the mosaic were taken close to noon, local Martian ì
ì
time. Distinct cloud pattern shadows are rarely apparent on ì
ì
the face of Mars.
Viking Orbiter 1, which entered Mars orbit June 19, ì
ì
1976, is nearing the end of four years of planetary ì
ì
operations, but continues to transmit an average of 30 ì
ì
pictures a day to mission control at the Jet Propulsion ì
ì
Laboratory.
#####
#938
6/5/80DB
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (213) 354-5011
PHOTO CAPTION (TOP) 211-5912
6/20/80
This mosaic of 102 photos of Mars was taken Feb. 22, 1980, by ì
ì
Viking Orbiter 1. Several prominent Martian features and at ì
ì
least two rare weather phenomena are visible. Valles ì
ì
Marineris, as long as the North American continent from coast ì
ì
o coast, stretches across the center. Three huge volcanoes ì
ì
of the Tharsis Ridge are at left: Arsia Mons, Pavonis Mons ì
ì
and Ascraeus Mons (from south to north). A sharp line, ì
ì
either a weather front or an atmospheric shock wave, curves ì
ì
north and east from Arsia Mons. This is the first time a ì
ì
feature like this has been seen. Four tiny clouds can be ì
ì
seen in the southernmost frame, just north of a large crater ì
ì
named Lowell. While the clouds are too close together to be ì
ì
resolved, even under high magnification, their shadows can be ì
ì
separated easily. The largest cloud is nearly 32 kilometers ì
ì
(20 miles) long. Measurements show the clouds' elevation as ì
ì
nearly 28 kilometers (9l,000 feet). Such distinct cloud-ì
ì
shadow patterns are extremely rare on Mars. Viking Orbiter 1 ì
ì
has operated at Mars for almost four years and is nearing the ì
ì
end of its operational life. It continues to send about 30 ì
ì
pictures a day to controllers at Jet Propulsion Laboratory.
#####