Betelgeuse, a bright reddish star in the constellation Orion. It is about 495 light-years from the earth, though some measurements put it at about 640 light-years away. Its color indicates a relatively low surface temperature of about 5,000° F. (2,800° C.), about half that of the sun. Betelgeuse is a variable star that fluctuates irregularly in size and brightness. At its smallest, Betelgeuse has a diameter some 300 times that of the sun; its greatest diameter is about one-third larger than this. Betelgeuse is classified in the group of largest known stars, the supergiants.
Long, long ago, our sun began its life as a mere twinkle in the universe's eye. How did it become the ruler of our solar system?
Since the 1960s, we've been captivated by our planetary neighbor. How different is the planet next door, and what have we learned about it so far, compliments of the Phoenix Mars Lander and other spacecraft?