In order to be selected by NASA to go to space, an astronaut must be in almost perfect health, free of any known chronic conditions, and able to undergo rigorous physical training over the course of years.
But even though astronauts may be at the peak of fitness, they’re only human. Despite NASA’s excellent screening practices, no person is immune from medical issues. And even the most extensive amounts of preparation and training can’t prevent every single type of medical emergency that could occur in lower Earth orbit.
The supermassive black hole is 40 million times as massive as the sun and powers a quasar that existed 700 million years after the Big Bang.
The asteroid zoomed by Earth at a perfectly safe distance of around 1.8 million miles (2.9 kilometers).
Images show surprise changes to the spacecraft as it interacted with the atmosphere.
