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of the Moon. When you will observe the full Different meteoroids travel around the Sun at
Moon carefully, you can easily see the shadows different speeds and in different orbits. The
of hills and mountains. fastest meteoroids travel through the solar system

Asteroids at a speed of around 42 kilometers per second
The asteroids are also called the minor planets. (26 miles per second).
They are actually the debris of the solar system. Comets
This debris is found between the orbits of Mars They are popularly called ‘long haired stars’. But,
and Jupiter. These minor planets also travel they are neither stars nor hairy. They appear as
around the Sun. There are probably over a fuzzy patches of light with long tail. They revolve
million asteroids. Large asteroids are ball shaped round the Sun in elliptical orbits. When comets
and smaller ones are elongated. Ceres, the come near the Sun, they begin to slow and
largest asteroid, measures about 900 km in develop tails. Halley’s Comet, for example,
diameter. In 1937, a tiny asteroid named Hermes appears regularly every 76 years. More than 700
passed close to the Earth at a distance of less comets have so far been observed. Comets are
than twice of the Moon. Collision with asteroid probably balls of ice which vaporize when they
will be disastrous for the Earth. 65 million come close to the Sun. Therefore, a comet may
years ago, such a collision wiped out the dino- remian unseen when it next passes the Earth.
saurs. There may be other comets that return, but they
might take thousands or even millions of years to
do so.

An Asteroid

Meteors Hailley’s Comet
Meteoroids are lumps of rock or iron that orbit INDIAN ASTRONOMY
the Sun, just as planets, asteroids and comets do. Ancient India’s contributions in the field of
Meteoroids, especially the tiny particles called astronomy are well-known and well-documented.
micrometeroids, are extremely common through- The earliest references to astronomy are found in
out the solar system. They orbit the Sun among the Rig Veda, which are dated 2000 BC. During
the rocky inner planets as well as the gas giants
next 2500 years, by 500 AD, ancient Indian
that make up the outer planets. Meteoroids are
astronomy has emerged as an important part of
even found on the very edge of the solar system, Indian studies and its affect is also seen in several
in regions called the Kuiper belt and the Oort treatises of that period. In some instances,
cloud. astronomical principles were borrowed to explain

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