There are several websites devoted to nebulae, such as the one from SEDS . They are far away. You will probably see astronauts land on Mars in your lifetime, but it will take a lot of preparation and resources. We don't know. We are not even sure that this is true.
Efforts are underway to search for life on Mars and Europa .
We might even find some sort of life on a comet . Astronomers have divided the sky into 88 constellations by drawing dotted lines on a celestial sphere. Any point in the sky is within the boundaries of a constellation. Objects that we see in it may be quite nearby or very far away. This is a question that has been asked for a very long time.