When we think of space, we think big and empty but when it comes to Earth's orbit, it's cluttered with millions of pieces of garbage that we call space junk.

The junk—or space debris—is made up of uncontrollable human-made items that remain in orbit long after they've served their original purpose. The scale of debris ranges from the very large including discarded stages from rocket and satellite launches, through to smaller metal pieces such as nuts and bolts, all the way down to particles such as paint flakes.

At its smallest, the space junk may only be one millimeter in size, but there are thousands of pieces bigger than a pizza box causing problems.

According to the latest European Space Agency statistical modeling, there are approximately 34,000 objects greater than 10 centimeters in orbit, but up to 128 million items between one millimeter and one centimeter floating around.

The search for life beyond Earth typically focuses on first looking for water, the basis for life as we know it. Whether the water is a gas, liquid, or solid, its presence and composition can tell researchers a lot about the planet, moon, comet, or asteroid on which it is detected and whether it could support life.

Because interstellar space is so cold and is primarily a vacuum, the water we detect from Earth is usually in the form of amorphous ice, meaning its atomic structure is not arranged neatly into a crystalline lattice like ice on Earth. How the transition between the crystalline and amorphous ice phases occurs on icy bodies like Europa or on Kuiper Belt Objects beyond Pluto, is difficult to study—unless you can mimic the cold, dark vacuum of outer space, under intense radiation, in a laboratory.