Why is the internet so chock-full of stories about asteroids on a collision course with Earth? At this rate, we should have been obliterated many times over already. Here comes the newest scare story: asteroid 2007 FT3. No, it won't hit us, either.

Loki, the largest volcano on Jupiter's moon Io, erupts on a more or less regular schedule. Planetary scientists are predicting an eruption this month. Here's what we know.

Cassini data suggested that Saturn's rings were only 10 to 100 million years old. A new study suggests that a "ring rain" onto Saturn makes the rings look younger than they really are, and that in fact Saturn's rings date back billions of years.

What is ULX-4 - a mystery green blob of X-ray light that appeared in the Fireworks Galaxy - and then soon disappeared again? A black hole or neutron star are 2 possibilities.

"We have never seen anything like this in the 24 years we have studied the supermassive black hole. It’s usually a pretty quiet, wimpy black hole on a diet. We don’t know what is driving this big feast."

It was exciting last week when scientists announced water vapor in a super-Earth's atmosphere. But, even as the announcement came, other scientists were cautioning that the planet - K2-18b - is probably less like a super-Earth and more like a mini-Neptune.

Astronomers now call recently-discovered flares from supermassive black holes in distant galaxies quasi-periodic eruptions. "Giant black holes regularly flicker like a candle but the rapid, repeating changes seen in GSN 069 from December onwards are something completely new," said one scientist.

Astronomers think the object they've labeled C/2019 Q4 - discovered August 30 - came from a place far, far away. If confirmed, it's only the 2nd interstellar object ever detected, after 'Oumuamua in 2017.

It's a huge bipolar gas structure, hundreds of light-years across, centered on our galaxy's center and near the galaxy's central supermassive black hole. Astronomers found it with the new, supersensitive MeerKAT telescope in South Africa.

It's a first-ever detection of water vapor in a super-Earth's atmosphere, orbiting in the habitable zone of its star, 110 light-years away. The discovery supports the possibility that our galaxy contains many such habitable worlds.