The star HR 8799, about 130 light-years away from Earth, hosts a planetary system that looks like a scaled-up model of our own solar system. Three giant planetary companions have been detected so far; this image shows the star and the middle planet (marked).

The Milky Way is the galaxy which is the home of our Solar System together with at least 200 billion other stars (more recent estimates have given numbers around 400 billion) and their planets, and thousands of clusters and nebulae, including at least almost all objects of Messier's catalog which are not galaxies on their own (one might consider two globular clusters as possible exceptions, as probably they are just being, or have recently been, incorporated or imported into our Galaxy from dwarf galaxies which are currently in close encounters with the Milky Way: M54 from SagDEG, and possibly M79 from the Canis Major Dwarf). See our Messier Objects in the Milky Way page, where details are given for each object to which part of our Galaxy it is related. All the objects in the Milky Way Galaxy orbit their common center of mass, called the Galactic Center

Black holes are places where ordinary gravity has become so extreme that it overwhelms all other forces in the Universe. Once inside, nothing can escape a black hole's gravity — not even light.

Yet we know that black holes exist. We know how they are born, where they occur, and why they exist in different sizes. We even know what would happen if you fell into one. Our discoveries have revealed one of the strangest objects in the Universe, and there's still much we don't know.

The nearest black hole is many lightyears away, so we don't have to worry about threats to the Earth

From beginning to end, different stages of a star's life appear in this exciting Hubble Space Telescope picture of the environs of galactic emission nebula NGC 3603. For the beginning, eye-catching "pillars" of glowing hydrogen at the right signal newborn stars emerging from their dense, gaseous, nurseries. Less noticeable, dark clouds or "Bok globules" at the top right corner are likely part of a still earlier stage, prior to their collapse to form stars.