Objects in Space

•A comet is a celestial body, observed only in that part of its orbit that is relatively close to the sun, having a head consisting of a solid nucleus surrounded by a nebulous coma up to 2.4 million kilometers (1.5 million miles) in diameter and an elongated curved vapor tail arising from the coma when sufficiently close to the sun. Comets are thought to consist chiefly of ammonia, methane, carbon dioxide, and water.

•Comets were once believed to be omens, and their appearances in the sky were greatly feared or welcomed.

•The most famous comet, Comet Halley (or Halley's comet), passes close to the Earth roughly every seventy-six years, most recently in 1986.

Asteroids
Asteroids are gaint rocks in space that could not be classifyed as a planet. There is a asteroid belt between mars and jupiter. I call them space junk.

Meteroids
Meteroids are the things that hit earth. Most of them burn up in the atmosphere. Some do hit earth and the cause big craters. One of the theores is that a meteor hit earth and created so much dust that it killed off all the dinosaurs. Meteors are smaller than asteroid. Meteors are shooting stars.

Black Hole
A black Hole is an area where gravity is so powerful that not even light can escape from it. In every galaxy there is a Black Hole in the middle. A Black Hole has such a large gravitaional pull that it makes all the stars around it orbit it. That is why a Black Hole makes a galaxy. If 2 galaxies were to get too close to one another the bigger Black Hole would Over power the smaller one and they would merge into one big one. There are galaxies that have done this.