Astronomers locate universe’s ‘missing’ matter

June 17, 2025 12:45 PM

Astronomers locate universe’s ‘missing’ matter

The universe has two kinds of matter. There is invisible dark matter, known only because of its gravitational effects on a grand scale. And there is ordinary matter such as gas, dust, stars, planets and earthly things like cookie dough and canoes. Scientists estimate that ordinary matter makes up only about 15% of all matter, but have long struggled to document where all of it is located, with about half unaccounted for. With the help of powerful bursts of radio waves emanating from 69 location...

Two galaxies seen in a ‘joust’ preceding a cosmic mega-merger

May 22, 2025 6:18 PM

Two galaxies seen in a ‘joust’ preceding a cosmic mega-merger

Astronomers have observed two distant galaxies - both possessing roughly as many stars as our Milky Way - careening toward each other before their inevitable merger at a time when the universe was about a fifth its current age, a scene resembling two knights charging in a joust. The galaxies, observed using two Chile-based telescopes, were seen as they existed about 11.4 billion years ago, approximately 2.4 billion years after the Big Bang event that initiated the universe. At the heart of one...