Ken Croswell

1 week ago | sciencenews.org | Ken Croswell

Bad news, earthlings. Computer simulations of the solar system’s future reveal a new risk facing us all: The gravitational tug of a passing star could either cause another planet to smack into Earth or else fling our planet into the sun or far away from it, where any inhabitants would freeze. Blame Mercury. Astronomers have long known that the innermost planet’s orbit, which is fairly oval-shaped, can become even more elliptical due to gravitational jiggles from Jupiter.

1 month ago | sciencenews.org | Ken Croswell |Liz Kruesi

For the first time, astronomers have confirmed the existence of a lone black hole — one with no star orbiting it. It’s “the only one so far,” says Kailash Sahu, an astronomer at the Space Telescope Science Institute in Baltimore. In 2022, Sahu and his colleagues discovered the dark object coursing through the constellation Sagittarius. A second team disputed the claim, saying the body might instead be a neutron star.

2 months ago | sciencenews.org | Ken Croswell

Uranus emits more energy than it gets from the sun, two new studies report — a discovery that contradicts findings from the venerable Voyager spacecraft. When Voyager 2 sped past Uranus on January 24, 1986, the spacecraft detected no significant excess heat from the planet, making it seemingly unique among the sun’s giant worlds.

Feb 28, 2025 | sciencenews.org | Ken Croswell

Alpha Centauri, the nearest star system to the sun, is probably shedding comets and asteroids into our solar system — and even producing a few meteors in our sky. Located just 4.3 light-years from Earth, Alpha Centauri consists of three stars that revolve around one another.

Nov 1, 2024 | sciencenews.org | Ken Croswell

The first-ever sighting of starlight from a galaxy hosting one of the most distant quasars known has revealed an astronomical oddity. Quasars — blazingly bright galactic cores — owe their brilliance to the intense heat that results as gas whirls around a big black hole. The black hole powering a quasar 13 billion light-years from Earth is half as massive as all the stars around it — a record high ratio for a quasar host galaxy, astronomers report in a paper submitted October 14 to arXiv.org.