Satellites orbit the earth, we all know that, but how and what causes them to fall? How do they get up into space anyway? Some satellites fall due to decay and lack of maintenance, but there are many other reasons satellites fall. Sometimes orbits decay and satellites can’t stay up in space anymore, maybe the satellite was orbiting too low or too high and was pushed back to earth or lost in space.
There are tons of satellites orbiting earth, but what is an orbit and how do objects stay in orbit? An orbit is when an object, like a meteor, shoots past an object with a much larger mass, like a planet, and is pulled in to the planet’s atmosphere, and instead of continuing on it starts to move around the planet using it own momentum. This is caused because of the perfect balance between the forward motion of a body and the pull of gravity from another body in space. The forward motion of the orbiting object will keep it orbiting from millions of years.
Satellites start an orbit different than a moon, and it stays in orbit for a different reason. Satellites get up into space using a rocket and is than dropped off in one exact spot and it starts drifting off until the suction of space and the gravity of earth keep it moving around earth for as long as it needs or its orbit decays or something like that. That’s how a low earth altitude satellite starts an orbit, a high earth altitude starts the same way but doesn’t orbit it stays in one exact spot, and can last millions of years.
We all know that there are a lot of satellites orbiting earth, but how many are there? Right now there are over 3,000 satellites orbiting around earth each with a different reason, but there are over 8,000 man-made objects orbiting earth. There are so many satellites it may be hard to believe but there has been only one collision of satellites in 1996. A French satellite collided with debris from a satellite they launched. If any collisions happen, they happen in low earth altitude earth orbits. In High earth altitude orbits satellites orbit one spot and stay in that spot, so it is very unlikely for a collision in high earth orbits.
Orbits can be destroyed but how does it happen? It’s called orbital decay and there are three different forms of it: gravitational radiation, tidal effects and atmospheric drag. Gravitational Radiation happens when two objects orbit each other the combined effect of the space time curvature of the moving objects produces gravitational waves which carry away orbital energy. Tidal effects happen when an object is large enough to cause a tidal bulge on the body it is orbiting this takes momentum from the orbiting object thus lowering the object until frictional effects come into play. Atmospheric drag happens during solar maxima (The greatest solar activity of the solar cycle) this causes drag up, to the earth's atmosphere, to a hundred kilometers higher that the solar minima, this causes satellites to be lower than normal so they may start descend back to earth.
Earth has so many satellites and other stuff orbiting earth and some of it is just junk from satellites. We are running out of space in space. Some of the satellites aren't even in use. Every new satellite we send into space increases chances of satellites colliding. Our atmosphere is now so crowded we can’t afford to send anything else into space, it too risky now. We should just hope nothing will go wrong before we are ready.
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