A missile strike Tuesday hit a private clinic in the Ukrainian city of Zaporizhzhia, killing at least four people and ...

A comet is a small icy body that orbits the sun. When it approaches the sun, the heat causes it to release a glowing atmosphere of gas and dust — called a coma — and often a spectacular tail.

A comet is a small icy body that orbits the sun. When it approaches the sun, the heat causes it to release a glowing atmosphere of gas and dust — called a coma — and often a spectacular tail. This ...