Atmospheric Entry Survival and the Possibility of Stratospheric Collection of Modern Interstellar Dust
Abstract
Taylor et al. (1996) detected the ion trails of dust particles, estimated to range from 15 to 45 microns in diameter, entering the Earth's atmosphere with velocities of about 100 km/s. Since this velocity significantly exceeds the solar system escape velocity, these particles were identified as interstellar. Taylor et al. observed a seasonal peak in the detected flux, and interpreted this peak to indicate the time of year when the Earth, in its heliocentric orbit, is moving directly towards a stream of incoming interstellar dust, increasing the geocentric velocity of the particles so that particles as small as 15 to 45 microns in diameter produce micrometeors detectable by Taylor et al.'s radar system. Six months later, when the Earth's heliocentric motion is directly opposite the direction of the interstellar flux, the atmospheric entry velocity of these interstellar grains will be reduced by twice the Earth's orbital velocity, and, instead of producing ion trails, some of these interstellar grains may enter the Earth's atmosphere without melting or vaporizing. Those interstellar grains which enter the atmosphere without melting will settle into the Earth's stratosphere in the same manner as the interplanetary dust particles, which are routinely collected by NASA stratospheric sampling aircraft. Thus, interstellar dust particles in the 5-20 micron size range may be present on the NASA stratospheric collection surfaces flown during the favorable collection season.
- Publication:
-
Lunar and Planetary Science Conference
- Pub Date:
- March 1997
- Bibcode:
- 1997LPI....28..361F
- Keywords:
-
- Interstellar Matter;
- Cosmic Dust;
- Atmospheric Entry;
- Stratosphere;
- Ion Motion;
- Solar Orbits;
- Micrometeoroids;
- Radar Measurement;
- Orbital Velocity;
- Nasa Programs;
- Air Sampling;
- Astrophysics;
- ENTRY HEATING;
- INTERSTELLAR DUST;
- MICROMETEORS