Why didn't the Apollo astronauts return with pictures of stars and galaxies taken from the Moon's surface? Are stars visible from the surface of the moon?

We stand nowhere in our universe. It's actually impossible to tell that how many stars and galaxies exist in the non visible universe. It is difficult to learn about the...

It's very rare but a star can be created outside a galaxy. I don't have any examples but they exist and it's rare.

I assume that your 1010 means $10^10$. Then the number of stars is simply $10^10*10^10=10^20$.

There are a ton of extremely powerful telescopes both here on Earth and in space that is capable of looking billions of light years far. And we can see a...

Many galaxies are members of groups or clusters. Since groups and clusters contain so many galaxies relatively close together, it should not be surprising that galaxies sometimes collide with each...

Stars tend to exist in a binary setup. That is, two stars orbiting about each other. Our star, , is an exception although there is discussion that maybe a long...

Galaxies early on in their lives are actively forming hot, new stars and appear more bluish. Older galaxies are forming fewer new stars and their constituent stars are older on...

While the Hubble never takes pictures of the sun, , and all do, as well as a number of ground based telescopes. Usually they use a variety of...

Phoenix communicate to earth through Mars Reconnaissance Orbiter which in orbit around Mars. Light travels through vacuum at speed of 300,000 kilometer/second. 1 AU=149000000 kilometers. so aproximately 12 minutes...

From recent discoveries of astronomers, they have found out that dark matter is responsible for , and dark energy fuels the dark matter. But dark matter and dark energy are...