Rubbish, junk, and garbage are not words typically associated with space. Space is imagined as a vast, and impeccably clean sphere; but we are making a big mess of it, a mess that is becoming a threat. In orbit around Earth are 10 million unwanted pieces of rubbish, zooming around without a care in the Universe. We call this space junk.
32 nuclear reactors number among the varied space-junk. Among it lies Vanguard I, America’s second satellite and the oldest piece of space debris still in orbit, dating back to 1958. Not all space junk is space-worthy though, there is normal waste as well, in fact there are about 200 bags of it. Instead of carrying their refuse back down to earth with them, cosmonauts on the Russian Mir space station just threw the waste into space for its first ten years. They hoped the bags would fall to Earth and burn up in the atmosphere, a rubbish idea; especially when one considers what space junk is capable of.
Space Concerns
Space junk is more than mere clutter, it is extremely dangerous. Without any air the pieces are never slowed down by normal collisions. During the first American space walk in 1965, Astronaut Edward White managed to ‘misplace’ his glove in the vacuum of space. The glove reached 28,000 kilometres per hour, making it the most dangerous item of clothing in history. It burnt up in orbit a month later, trying to slap the Earth. Space debris of all kinds can far exceed those speeds, some containing enough devastating kinetic energy to pass straight through 50mm of steel. In other words, enough to damage any space-faring craft that dares leave Earth. In fact, this has already happened.



300,000 kilometres per second is the limit, the speed of light, nothing can exceed that speed. This is one of the most famous results of Einstein’s famous e = mc². That is nice, and convenient, except for that things can go faster than light. Why? The speed of light, the ultimate limit, is only reached in the vacuum of space, otherwise, we can slow light down, and overtake it.
Leave a jellyfish out in the sun for long enough, and it will evaporate. Over 95% water, jellyfish are ludicrously simple creatures. They have no brain, no lungs and no eyes. Assemble some tentacles, a stomach cavity, an umbrella head and you are nearly done. For respiration they just have skin thin enough to let oxygen slip through. Yet in this simplicity there is variety, and in one case, immortality.
It moves onto a surface and grips on tightly. Then it slowly becomes a blob. As a blob it performs the special process, transdifferentiation. This is the way in which some animals, like crabs, regrow their limbs. Cells become simplified, then are remade as new types of cell, giving a crab a new arm, or a starfish a new tentacle. Turritopis nutricul is unique in the animal kingdom because it does this to its entire body.
From urinating on various grains and seeing what germinated in Egyptian times to burning ribbons in the 17th Century, pregnancy tests have historically been unreliable. Then the 20th Century came, and it brought science.