Why were asteroids not discovered until the 19th century?
A.although asteroids are the same size as the planets, they are completely covered with dark dusty material, which means they reflect almost no light
B.several asteroids collided with each other in early 1801, calling them to the attention of astronomers
C.in their long looping orbits, it was not until the 19th century that an asteroid came close enough to the Earth to be detectable
D.only after Halley's work did astronomers think to look for the tails which allow us to spot an asteroid
E.asteroids are generally small compared to planets and require a
good telescope and patient searching to spot them
I'm almost postive it's A.
If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt?
2007-03-05
07:43:43
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5 answers
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asked by
Anonymous