Space: It's a Weird Place

Telegraph UK: Mysterious force holds back Nasa probe in deep space

Researchers say Pioneer 10, which took the first close-up pictures of Jupiter before leaving our solar system in 1983, is being pulled back to the sun by an unknown force. The effect shows no sign of getting weaker as the spacecraft travels deeper into space, and scientists are considering the possibility that the probe has revealed a new force of nature.

Another reason why the aliens ain't showed up: the universe pushes back if you try to leave home!

-The Gneech