13) New technologies will soon allow astronomers to use X-ra… 13) New technologies will soon allow astronomers to use X-ray telescopes on Earth’s surface. Read Details
31) What do we mean by the observable Universe? 31) What do we mean by the observable Universe? Read Details
38) During the year, the Sun appears in front of different g… 38) During the year, the Sun appears in front of different groups of stars. What are these called? Read Details
16) A star near the north celestial pole, observed from the… 16) A star near the north celestial pole, observed from the northern hemisphere Read Details
15) How did Eratosthenes estimate the size of Earth around 2… 15) How did Eratosthenes estimate the size of Earth around 240 B.C.? Read Details
2) How do electrons inside an atom change energy? 2) How do electrons inside an atom change energy? Read Details
35) At the speed of light, how long would it take to reach A… 35) At the speed of light, how long would it take to reach Alpha Centauri, one of the nearest stars? Read Details
12) If all the colors (a continuous spectrum) pass through a… 12) If all the colors (a continuous spectrum) pass through a gas, what kind of spectrum do you get? Read Details
37) The apparent size of the Moon in the sky is about: 37) The apparent size of the Moon in the sky is about: Read Details
