Asteroids and comets – and the meteors that sometimes come from them – are leftovers from the formation of our solar system 4.6 billion years ago.
The History of Halley's Comet Until the time of English astronomer Edmond Halley (1656-1742), comets were believed to make only one pass through the solar system. But in 1705, Halley used Isaac Newton's theories of gravitation and planetary motions to compute the orbits of several comets.
The planetary system we call home is located in an outer spiral arm of the Milky Way galaxy. Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids. Beyond our own solar system, there ...
The Kuiper Belt should not be confused with the Oort Cloud, which is a thousand times more distant. In 1950, astronomer Jan Oort proposed that certain comets come from a vast, extremely distant spherical shell of icy bodies surrounding the solar system. This giant swarm of objects, now named the Oort Cloud, occupies space at a distance between 5,000 and 100,000 astronomical units. No objects ...
Many comets crash into the Sun or the planets. Those that have close encounters with Jupiter tend to be ripped apart or tossed out of the solar system entirely. The other source of comets is the Oort Cloud, where most long-period comets on highly tilted orbits come from.
When comets come around the Sun, they leave a dusty trail behind them. Every year Earth passes through these debris trails, which allows the bits to collide with our atmosphere and disintegrate to create fiery and colorful streaks in the sky.