NASA has beefed up a process of traffic monitoring, communication and maneuver planning to ensure that Mars orbiters do not approach each other too closely. Last year's addition of two new spacecraft orbiting Mars brought the census of active Mars orbiters to five, the most ever.
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.
