What moon of neptune orbits in a retrograde direction?
What is the constant called that is the average flux of the suns energy arriving at the earth?
This powerful telescope weighs about 11 tons, has a primary mirror 7.9 feet in diameter, and orbits about 380 miles above the earth?
What are the only two planets to rotate from east to west?
What do astronomers call the point in the sky that is directly overhead?
How is venus different to earth?
How many types of galaxies are there?
How many black holes exist?
When did solar system come into existence? What is the expected life of solar system?
Which was the vehicle used for the first landing on the moon?
According to keplers third law, plotting the squares of the periods of the planet against the cubes of the semi- major axes of their orbits will result in what sort of graph?
Do galaxies interact?
What is the name for the celestial body of interstellar gas and dust where stars are sometimes born?