Outer Planets
Outer Planets
1,180 articles in this category.
Outer Planets
Titan is never the same distance from Earth twice: the gap can run from about 1.2 billion kilometres to nearly 1.65 billion depending on where both worlds sit in their orbits, stretching a signal's one-way trip from just over an hour to past ninety minutes
Outer Planets
Voyager 2 may have caught Uranus on a freak day — a 2024 reanalysis suggests the 1986 flyby that shaped four decades of understanding arrived during a compressed state estimated to occur only about 4% of the time
Outer Planets
After twelve years and more than seven billion kilometres, Voyager 2 arrived at Neptune within 100 kilometres of where it had been aimed — a margin NASA compares to sinking a golf putt 3,630 kilometres long
Outer Planets
A giant planet was hiding in plain sight in one of astronomy's most-studied star systems
Outer Planets
Europa Clipper is already in space, travelling 1.8 billion miles toward Jupiter's moon Europa, where a subsurface ocean holds more water than every ocean on Earth combined — it arrives April 2030 to ask whether anything is alive inside
Outer Planets
Titan is moving away from Saturn about 11 centimetres every year — roughly 100 times faster than scientists once believed — suggesting the moon may have begun its life much closer to the planet
Outer Planets
A Category 1 hurricane on Earth begins at 119 km/h. Neptune's fastest winds reach about 2,000 km/h — nearly 17 times faster.
Outer Planets
Europa may literally glow green, blue or white on its night side because Jupiter’s radiation energises salts frozen into its surface, and the colour of that glow could offer a new clue to what its hidden ocean is made of
Outer Planets
Cassini bounced radio waves off Titan’s three largest seas and found their open surfaces mirror-smooth, with roughness no greater than 3.3 millimetres RMS, while rougher estuaries hinted that methane-rich rivers were entering more ethane-rich seas
Outer Planets
A 2026 study modelling Europa's interior finds its seafloor is probably too quiet for the hydrothermal vents that support life in Earth's oceans, while a separate paper the same month proposes nutrients could reach its ocean anyway, carried down by sinking pockets of salty ice
Outer Planets
Voyager 2 passed Neptune's moon Triton in 1989 and photographed it erupting, a discovery scientists called the flyby's biggest surprise — dark plumes rising nearly eight kilometres and then drifting 150 kilometres downwind, on the coldest surface known
Outer Planets
NASA has approved one of its strangest missions yet: Dragonfly, a nuclear-powered drone the size of a car that will fly across Saturn's moon Titan, the one place beyond Earth with rain, rivers and seas, hunting for the chemistry that comes before life
Outer Planets
Pluto was expected to be a frozen, cratered relic, but when New Horizons flew past in 2015 it found flowing nitrogen glaciers, mountains of water ice and hints of a hidden ocean, on a world where the Sun looks like just a bright star
Outer Planets
Saturn's moon Titan has an atmosphere thicker than Earth's and seas you could sail on, and it is the one place beyond Earth where a person could stand outside without a pressure suit, though its surface sits at about minus 179 degrees Celsius
Outer Planets