An assessment of the meteoritic contribution to the Martian soil
- State Univ. of New York, Plattsburgh (USA)
- NASA Johnson Space Center, Houston, TX (USA)
The addition of meteoritic material to the Mars soils should perturb their chemical compositions, as has been detected for soils on the Moon and sediments on Earth. Using the measured mass influx at Earth and estimates of the Mars/Earth flux ratio, the authors estimate the continuous, planet-wide meteoritic mass influx on Mars to be between 2,700 and 59,000 t/yr. If distributed uniformly into a soil with a mean planetary production rate of 1 m/b.y., consistent with radar estimates of the soil depth overlaying a bouldered terrain in the Tharsis region, their estimated mass influx would produce a meteoritic concentration in the Mars soil ranging from 2 to 29% by mass. Analysis of the Viking X ray fluorescence data indicates that the Mars soil composition is inconsistent with typical basaltic rock fragments but can be fit by a mixture of 60% basaltic rock fragments and 40% meteoritic material. The meteoritic influx they calculate is sufficient to provide most or all of the material required by the Clark and Baird model. Particles in the mass range from 10{sup {minus}7} to 10{sup {minus}3} g, about 60-1,200 {mu}m in diameter, contribute 80% of the total mass flux of meteoritic material in the 10{sup {minus}13} to 10{sup 6} g mass range at Earth. On Earth atmospheric entry all but the smallest particles (generally {le} 50 {mu}m in diameter) in the 10{sup {minus}7} to 10{sup {minus}3} g mass range are heated sufficiently to melt or vaporize. Mars, because of its lower escape velocity and larger atmospheric scale height, is a much more favorable site for unmelted survival of micrometeorites on atmospheric deceleration. They calculate that a significant fraction of particles throughout the 60-1,200 {mu}m diameter range will survive Mars atmospheric entry unmelted.
- OSTI ID:
- 5384812
- Report Number(s):
- CONF-9001119-; CODEN: JGREA; TRN: 91-023778
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 95:B9; Conference: 4. international conference on Mars, Tucson, AZ (United States), 10-13 Jan 1990; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MARS PLANET
SOILS
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
EARTH PLANET
MASS
MASS TRANSFER
METEORITES
MODIFICATIONS
MOON
PARTICLE SIZE
PLANETARY ATMOSPHERES
VIKING SPACE PROBES
ATMOSPHERES
EVALUATION
PLANETS
SATELLITES
SIZE
SPACE VEHICLES
VEHICLES
640107* - Astrophysics & Cosmology- Planetary Phenomena