There is an ongoing debate about whether a huge "super-Earth" lurks in the far reaches of our solar system – but we may actually have observed it almost 40 years ago
There are good reasons to think that neutrinos have a shy cousin that could explain dark matter, but searches have so far come up empty, writes Chanda Prescod-Weinstein
After NASA’s New Horizons mission flew past Pluto in 2015, it turned around and took pictures of the dwarf planet’s back, revealing its moonlit dark side
Hints of a hefty source of gravity beyond Pluto sparked the search for a possible “Planet Nine”. Now, some astronomers think it could instead be a black hole from the big bang, offering a rare glimpse into the early universe
A massive report on priorities for the next decade of US astronomy recommends building a telescope that could one day take a picture of a habitable Earth-like planet
The microscopic organisms have previously survived exposure to the vacuum of space and are able to hibernate using just 0.01 per cent of their normal energy
We only had a skin-deep look at Jupiter before the Juno spacecraft began orbiting the planet in 2016 and the measurements the NASA mission has taken reveal unexpected information about its deep interior
Titan, Saturn’s largest moon, is slowly migrating away from the planet, which is tilting Saturn onto its side and may eventually doom the moon to orbital chaos
Apple TV’s Invasion follows various characters as they pick up on hints of alien activity. But many of them regularly make reckless, nonsensical decisions that frustratingly lead to minimal payoff, says Josh Bell
The NASA Insight lander has measured the frequency of shallow marsquakes and found they are more common when it is summer in Mars’s northern hemisphere
The very centre of the Milky Way has an unexpectedly low density of cosmic rays compared with the rest of the galaxy, which means that they are somehow being kept out
The overcrowding of low Earth orbit with commercial satellites is a problem for astronomers and the satellites – and it needs urgent international action to solve it
The dog constellations, Canis Major and Canis Minor, seem to run along faithfully behind Orion. Here's how to find them by star-hopping from Orion's belt, writes Abigail Beall
Blue Origin is one of a number of firms hoping to build a commercial space station, but it isn't clear any will be ready before the International Space Station reaches the end of its life
We are sending ever more stuff into space, and now megaconstellations of satellites risk causing light pollution on Earth and disastrous debris in orbit - but it's not too late to save our skies
Space probes will be the first to explore the furthest reaches of our solar system and beyond. To make discoveries like finding alien life, they will need to think more like humans, says NASA’s Steve Chien
The light from a distant star appears to be orbited by something that is continually changing shape and size, possibly clouds of dust from repeated collisions