Two big pieces of space junk 'could' collide tonight at 7:56.

If they do hit each other, it will take place 616 miles above the South Atlantic Ocean, just off the coast of Antarctica, according to space.com.

LeoLabs, a company that tracks space debris, says the probability of a collision is more than 10% — which is rather high --- considering that the combined weight of the objects is over three tons. Oh, and they'll be speeding towards each other at nearly 33,000 mph.

So what is this 'junk?' It's a retired navigation satellite that was launched in 1989, and the ChangZheng-4C Y4 third stage rocket that was sent up in 2009. (photos below)

If they DO collide, what will happen here on Earth? Nothing ON Earth, but above us, the collision would create a lot more space debris. 

As of Wednesday, LeoLabs said their models show that the satellites will miss each other by less than 82 feet.

Despite all the 'junk' orbiting our planet, there's relatively few collisions. National Geographic says that in 2009, nearly 500 miles above Siberia, two satellites (one from Russia, the other from the U.S.) collided at around 22,300 mph, bursting into a cloud of thousands of pieces of debris. This collision was the first documented case that two satellites collided in space

As of October 2019, the US Space Surveillance Network reported nearly 20,000 artificial objects in orbit above the Earth --- but these are just the objects large enough to be tracked.

As of January 2019, there's more than 128 million pieces of debris smaller than 1/2" about 900,000 pieces of debris less than 4" and around 34,000 of pieces larger than 4" were estimated to be in orbit around the Earth.

While there is over 2,600 active satellites currently orbiting Earth, there are also 3,000 dead ones out there.