







NASA's Upper Atmosphere Research Satellite (UARS) is headed towards Earth. But don't fear, it's still unlikely anyone will be hit.

The space agency now says the U.S. is back as a possible "landing site" for the satellite. As it gets closer to impact, NASA now says the 6.5-ton behemoth will fall to earth sometime Friday or Saturday ET.

"The satellite orientation or configuration apparently has changed, and that is now slowing its descent," NASA says, explaining why the space agency's prediction the satellite would fall to Earth Wednesday has been revised, and why the U.S. is now back in the running as a possible, albeit unlikely target.

The agency still can't pinpoint exactly when the spacecraft will reenter the atmosphere, writing on its website, "It is still too early to predict the time and location of re-entry with any certainty, but predictions will become more refined in the next 12 to 18 hours."

Should we be afraid? In a word, no. Even though NASA says about a half a ton's worth of spacecraft pieces — that's about 26 hunks of space junk — will fall to earth, it says most (if not all) of the debris will probably land in an ocean. If you want to know the odds of your own survival, Orbital Debris and Meteoroid Consultant Don Kessler calculated the chances of any one person being hit by any of that debris is less than one in 10 trillion.

But that's not stopping people from creating some humorous tweets: