Jerry Coffey
Artist illustration of space dust being blown in the winds of a quasar. Image credit: NASA/JPL-Caltech
Space dust is a general term for all debris up to 0.1 mm and could be as small as just a few molecules. Space dust is also called cosmic dust. It can be differentiated by it area of origin: intergalactic dust, interstellar dust, interplanetary dust, and circumplanetary(usually in a ring system) dust. Sources can dust from comets, asteroids, the Kuiper belt, and asteroid impacts.
At one time space dust was an annoyance to astronomers, since it obscures objects they wish to observe. After infrared astronomy, those particles were found to be significant, vital components of astrophysical processes. This dust can drive mass loss at the end of a star‘s life or play a part in the early stages of stellar and planetary formation. In the Milky Way space dust is a major component of the zodiacal light, Saturn’s rings and the outer rings of Jupiter, Uranus, and Neptune.
Space dust traces out paths detailing how the universe recycles material: production, storage, processing, collection, consumption, and discarding. Observation and measurement of cosmic dust in different regions provides an important insight into the universe‘s recycling processes. Astronomers accumulate observational data of dust at different stages of its life and are able to form a more complete theory of the universe’s complicated recycling steps.
Space dust also acts as photons. Once it is detected, the problem becomes an inverse problem to determine what processes brought that encoded photon-like object (dust) to the detector. Parameters such as the particle’s initial motion, material properties, intervening plasma and magnetic field determined the dust particle’s arrival at the dust detector. Slightly changing any of these parameters can give significantly different dust dynamical behavior. Therefore one can learn about where that object came from, and what the intervening medium is.Space dust particles can scatter light in any direction or manner without a uniform pattern. Forward-scattered light means that light is redirected slightly by diffraction off its path from the source, and back-scattered light is reflected light. The scattering and extinction (“dimming”) of the radiation gives useful information about the dust grain sizes. When the object is many times brighter in forward-scattered visible light than in back-scattered visible light, then a significant fraction of the particles are about a micrometer in diameter. Quite a promotion: annoyance to scientific significance.
Short URL:
Space dustPosted on Tuesday, December 14, 2010 @ 13:47:42 EST in SpaceTime Associated Topics
 |
Related
)
