www2.jpl.nasa.gov

Zpm1a TIL that, according to NASA, huge asteroid impacts (around the size of the Chicxulub asteroid, which is the one that killed off the dinosaurs) occur about every 50-100 million years. Chicxulub hit earth 66 million years ago.
E1JVx TIL In 1996, a group of scientists claimed to have found evidence of microscopic fossils formed by Martian primitive life billions of years ago on a meteorite discovered in Antarctica.
nYNW TIL the Soviet Union named a crater on Venus after Christa McAuliffe, the teacher astronaut who died during the Challenger space shuttle disaster.