The astronomical event, which overlaps with the Winter Solstice, is often overlooked because of the winter chill.

© Ian Webster and Peter Jenniskens

For his next trick, your cosmic correspondent for the past quarter-century will (try to) retire.

© Jim Wilson/The New York Times

China said two of its astronauts spent nine hours outside the Tiangong Space Station. The longest previous spacewalk, by Americans, was eight hours and 56 minutes.

© China Central Television, via Reuters

China said two of its astronauts spent nine hours outside the Tiangong Space Station. The longest previous spacewalk, by Americans, was eight hours and 56 minutes.

Lunar exploration in the 21st century offers a unique opportunity to unite us.

No shockwave. No mushroom cloud. But a space nuke would change life on Earth forever.

Readers discuss what one calls a “boom-or-bust precipitation cycle.” Also: Pete Hegseth’s mother’s accusation; what opera needs; Elon Musk and Mars.