Does the Sun move around the Milky Way?? - NASA
Yes, the Sun - in fact, our whole solar system - orbits around the center of the Milky Way Galaxy. We are moving at an average velocity of 828,000 km/hr. But even at that high rate, it still takes …
Why does the Sun rise in the east and set in the west? - NASA
Answer: The Sun, the Moon, the planets, and the stars all rise in the east and set in the west. And that's because Earth spins -- toward the east. For a moment, let us ignore Earth's orbit around …
Why is there day and night? - NASA
Clearly, when you see the Sun shining in the sky, it is day, and when you don't it is night. So the real question is "why is the Sun in the sky at some times and not at others?" We can see that …
What does it mean for Mercury to be in retrograde? - NASA
It is not REAL in that the planet does not physically start moving backwards in its orbit. It just appears to do so because of the relative positions of the planet and Earth and how they are …
If you are on the Moon, does the Earth move in the sky? - NASA
The Moon undergoes a motion called "libration" which causes it to rock slightly back and forth relative to a line connecting the centers of the Earth and the Moon. This libration effect, as …
Why is Polaris the North Star? - NASA
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What is the orbital period of the Moon? - NASA
The Moon appears to move completely around the celestial sphere once in about 27.3 days as observed from the Earth. This is called a sidereal month. It represents the orbital period of the …
StarChild: Comets - NASA
Over time, it will completely disappear. A comet does not give off any light of its own. What seems to be light from the comet is actually a reflection of our Sun's light. Sunlight bounces off the …
What are the phases of the Moon? - NASA
It does not show which side of the Moon is lit by the Sun. The side lit by the Sun is always the side that is pointed toward the Sun, as seen in the diagram below on the left. We only see the …
StarChild: Meteoroids - NASA
A meteoroid is a piece of stony or metallic debris which travels in outer space. Meteoroids travel around the Sun in a variety of orbits and at various speeds. The fastest meteoroids move at …