Stars Is it true that there are more stars in the universe than there are grains of sand on Earth? How could one calculate such figures?
Robotic Spaceflight Why can’t the recently launched Herschel Space Telescope produce sharper images than the Spitzer Space Telescope?
Observing, Telescopes and Equipment I have an 8-inch telescope but can see only Mars as orange instead of red. All other planets appear colorless. Why?
