Science Almost all “Reader gallery” pictures seem to be four or more long exposures. Are these pictures combined, and if so, how?
Science How can the Hubble Space Telescope (HST) take pictures of objects light-years away but not get a good picture of Pluto?
Science How many spacecraft have landed on neighboring Venus, and is there anything left of them by now?
Science Occasionally, especially on cold winter nights, I see a large ring around the Moon. What causes this?
