QUICK TAKES

SMASHING RECORDS

The Dark Energy Spectroscopic Instrument (DESI) is just seven months into a five-year mission to map the cosmos in 3D. It has already surpassed every previous 3D galaxy survey combined, cataloging more than

7.5 million galaxies.

LUNAR OCEAN

A new discovery points to Saturn’s smallest moon, Mimas, as hiding an ocean beneath its ice. Previously, scientists thought the world was frozen solid, but on closer examination found it has a slight rotational wobble usually indicative of an internal ocean.

CLOSE CALLS

The Tiangong space station avoided two close encounters with SpaceX satellites, according to a Chinese document submitted to the United Nations Office for Outer Space Affairs. On both July 1 and Oct. 21, Tiangong performed evasive maneuvers to avoid a Starlink satellite.

DYING BREATH

For the first time, astronomers have caught the end of a red supergiant’s life in real time. The doomed star was first spotted in the summer of 2020 and was observed for its final 130 days before it exploded in a supernova.

GALACTIC WEIGH-IN Determining the mass of the Milky Way is tricky, but it’s an important number to know. Using new data from Gaia and next-generation modeling methods, astronomers are now moving our galaxy to a lower weight class: 500 billion to

800 billion solar masses.

ALIEN MOONS ABOUND?

An exomoon may have been spotted orbiting Kepler 1708 b, a Jupiter-sized planet 5,500 light-years from Earth. The large satellite is only the second to be reported — though neither it nor the first one are confirmed.