Name the part of the sun that we can see without any instruments?
Which star is called the polaris?
Describe how are clouds formed?
How have some stars had time to die since the universe began?
What is the distance between two galaxies?
How many moons does saturn have?
What moon of neptune orbits in a retrograde direction?
The work of this harvard college observatory scientist made possible the first accurate determination of extragalactic distances by what is often called henriettas law?
Which is the first unmanned space vehicle which landed on the moon?
Do galaxies interact?
Who were the ancient indian astronomers?
In the doppler effect, what is the correct term for the change in the color of light when an object that is emitting light is moving toward the observer?
Explain how old is our earth?