noun
COLLOCATIONS FROM CORPUS
■ ADJECTIVE
carbonaceous
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Therefore a carbonaceous asteroid , although unlikely, can not be ruled out as an explanation of the Tunguska event.
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These appear to be pieces of carbonaceous asteroids .
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Comets and carbonaceous asteroids of the appropriate energy disrupt too high, whereas typical iron objects reach and crater the terrestrial surface.
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Phobos and Deimos are small, irregularly shaped bodies, generally similar to carbonaceous asteroids in color, reflectivity, and density.
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The solid residue left after baking the volatiles out of carbonaceous asteroid materials is of considerable interest in its own right.
large
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Two large asteroids have passed alarmingly close to Earth in the past few years.
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The first and largest asteroid discovered, Ceres, was found on the night of January 1, 1801.
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The new data shows that many stars are rich in iron, having gobbled up large numbers of asteroids and comets.
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Within the main belt are several distinct orbital families of large asteroids , each family named for its most prominent member.
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Such ease of access means that very large masses of asteroid materials can be returned to the vicinity of Earth.
small
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Almost 1,000 small asteroids crossing our orbit are now known, 300 of them found last year alone.
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But we have so far concentrated exclusively on the small minority of asteroids that have orbits bringing them close to Earth.
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These results affect assessments of the hazard posed by impacts of small comets and asteroids .
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In 1976 a small asteroid , 2062 Aten, was discovered in an orbit that actually circles the Sun faster than Earth.
stony
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Even if the comets had strengths comparable to that of stony asteroids , they still could not fit the Tunguska observations.
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Similarly, granting a carbonaceous object the strength of a stony asteroid would allow it to penetrate to comparable altitudes.
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Figure 2 shows the effect of impact angle on the explosion of stony asteroids .
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Values of much less than 30° seem to be inconsistent with an explanation of the Tunguska object as a stony asteroid .
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FIG. 2 Airburst altitudes for four 15-Mton stony asteroids with different incidence angles.
■ NOUN
belt
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Almost all of the moving objects seen are slow-moving belt asteroids , out between the orbits of Mars and Jupiter.
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Spacewatch has been discovering as many as 20, 000 new belt asteroids per year.
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Spacewatch discovers hundreds of new kilometer-sized belt asteroids with every observing run.
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The wealth of materials available in the belt asteroids , revealed by the study of meteorites, staggers the imagination.
impact
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The effects of comet and asteroid impacts are potentially damaging to life in general, and to human civilization in particular.
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Thus the four terrestrial planets are all affected in important but very different ways by comet and asteroid impacts .
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Much water has been lost for ever from Mars, blasted into space by comet and asteroid impacts .
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Clearly, the iron-nickel metal on the surface of the Moon is contributed by asteroid impacts .
■ VERB
find
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Say we find three S asteroids of that brightness for every C type.
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Generally, it is very difficult to find asteroids smaller than about 1 kilometer in diameter using photographic techniques.
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It is clearly important to find out what asteroids are made of.
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It has also found two Centaur family asteroids in orbits that cross the orbits of several of the Jovian planets.
EXAMPLES FROM CORPUS
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Astronomers had accidentally caught a comet in the act of turning into an asteroid .
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Comets and asteroids are subjects for Chapter 14.
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Extraction of helium-3 from the surfaces of asteroids is not likely to compare with that from the Moon.
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Finally, the total exposed surface area of the asteroids is less than the surface area of the Moon.
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For example, Vesta, the fourth-largest asteroid , reflects light in a unique way: some 50 meteorites match it closely.
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These asteroids with Earth-crossing orbits and orbital periods greater than one Earth year constitute the Apollo family.
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Two large asteroids have passed alarmingly close to Earth in the past few years.
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We do it now on a small scale to bring the rocks into Earth orbit from the asteroid belt.