SpaceX has been trying, but not succeeding, to land its Falcon 9 rocket upright at sea. Then, last month it succeeded on land. Soon, another sea-going attempt!
At 26 million light-years from Earth, NGC 5195 has one of the nearest supermassive black holes to Earth that's currently undergoing such violent outbursts.
As water piles up before a ship, so material stacks up ahead of high-mass stars moving fast through space. These cosmic bows shocks revealed the runaway stars.
Astronomers have said globular clusters might not foster planets, and only one such planet is known. Here are new arguments on why they might exist, after all.