Even though man has studied the heavens for thousands of years, we still know very little about the Universe we live in. And as we continue to learn more, we are consistently amazed, and sometimes confused, by what we learn. Here is a collection of amazing, interesting, and strange astronomy facts, in no particular order.
* Scientists believe that we can only see about 5% of the matter in the Universe. The rest is made up of invisible matter (called Dark Matter) and a mysterious form of energy known as Dark Energy.
* Neutron stars are so dense, that a soup can full of neutron star material would have more mass than the Moon.
* The Sun produces so much energy, that every second the core releases the equivalent of 100 billion nuclear bombs.
* Galileo Galilei is often incorrectly credited with the invention of the telescope. Instead, historians now believe the Dutch eyeglass maker Johannes Lippershey as its creator. Galileo was, however, probably the first to use the device to study the heavens.
* Black Holes are so dense, and produce such intense gravity, that even light can not escape. Theoretical physicists predict that there are situations under which light can escape (which is called Hawking radiation).
* Light from distant stars and galaxies takes so long to reach us, that we are actually seeing objects as they appeared hundreds, thousands or even millions of years ago. So, as we look up at the sky, we are really looking back in time.
* The Crab Nebula was produced by a supernova explosion in 1054 A.D. The Chinese and Arab astronomers at the time noted that the explosion was so bright, that it was visible during the day, and lit up the night sky for months.
* Shooting stars are usually just tiny dust particles falling through our atmosphere. Comets sometimes pass through Earth’s orbit, leaving trails of dust behind. Then as Earth plows through the dust in its path, the particles heat up, creating the streaks in the night sky.
* Even though Mercury is the closest planet to the Sun, temperatures can reach -280 degrees F. Why? Since Mercury has almost no atmosphere, there is nothing to trap heat near the surface. So, the dark side of Mercury (the side facing away from the Sun) is very cold.
* Venus is considerably hotter than Mercury, even though it is further away from the Sun. The thickness of Venus’ atmosphere traps heat near the surface of the planet.
source:http://space.about.com/od/humor/a/AstronomyFacts.htm
