The Solar System Essay
Our solar system was born when, in a spiral arm of the Milky Way galaxy, a giant rotating cloud of
dust and gasses began to collapse. Gravity compressed the dust and gasses and the cloud got
increasingly hotter and began to spin faster. During the following one hundred million years, the
gasses compressed until the center was so hot that nuclear fusion occurred giving off tremendous
energy, combining charged atoms of hydrogen to form helium. This process gave birth to a star, our
Sun (Our Solar System, n.d.). Scientists have a good deal of data documenting the solar system's
history for about the last 3.9 billion years, but it was actually formed approximately 4.6 million
years ago. The first 700 million years are somewhat of a...show more content...
After the invention of the telescope, three more planets in the solar system were discovered: Uranus,
Neptune, and Pluto. However, in 2006 Pluto's classification was changed to dwarf planet (Our Solar
System, n.d.). The eighth planet is, of course, Earth. In addition, there are 165 moons gravitationally
attached to the eight planets; three dwarf planets, Pluto, Eris, and Ceres, and their four moons; and
billions of other small bodies (Solar System, n.d.). Mercury, Venus, Earth, and Mars are the inner
planets and are called terrestrial (meaning earth from the Latin terra) planets because of their
similarities to Earth. The outer planets, Jupiter, Saturn, Uranus, and Neptune are Jovian planets
and are so called because of their resemblance to Jupiter. Jovian planets have gaseous outer layers.
The planet closest to the Sun is Mercury and is a small planet with a rocky surface. Mercury's
diameter is 4,880 kilometers or 3,032 miles. Because its orbit around the Sun is oval shaped, its
distance from the Sun ranges from 45.9 million kilometers (28.5 million miles) to 69.7 million
kilometers (43.3 million miles) and takes 88 days to complete its orbit. Mercury has no
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