Arcturus, the brightest star in the constellation Botes and one of the brightest stars in the night sky. Arcturus is a giant orange-colored star with a diameter about 25 times that of the sun. The surface temperature of Arcturus is only 7,000 F. (3,870 C.), some 3,000 F. (1,670 C.) less than the sun's surface temperature. Because of its size, however, Arcturus gives off more than 100 times as much light and heat as the sun. Arcturus is approximately 36 light-years from the earth. It has an apparent magnitude of -0.1 and an absolute magnitude of -0.3.
After Viking 1 captured images of what looked like a face on Mars, the public began to speculate. Had Martians carved a colossus, or was there another answer?
It wasn't so long ago that astronomers thought the universe contained normal matter, or baryonic matter, the base unit of which is the atom. But when it comes to the cosmos, there's always more than meets the eye. What else is hanging out in space?