On 14 January 2005, a small European probe dropped through an orange atmosphere, broke through the haze and settled onto a world nearly 1.5 billion kilometres from the Sun.
At Saturn's north pole, clouds race around a shape that looks as if it was drawn with a ruler.
The story sounds almost too neat: a spacecraft launched in 1977, a set of thrusters last used in 1980, and a team on Earth asking them to work again 37 years later.
If light has had only 13.8 billion years to travel, a universe 93 billion light-years across sounds impossible.
Four light-years sounds close only because astronomy usually deals in much larger numbers.
Mercury is a planet of extremes. At the equator during the day, its surface can become hot enough to melt lead.
Humanity has been changing the radio sky for a little over a century. Early experimental transmissions, commercial broadcasting, military radar, television, satellite links and communications with spacecraft have all sent some energy beyond Earth.
For six years one of Voyager 1's instruments had counted the same steady drizzle of low-energy particles streaming off the Sun.
The case for looking for life on Europa runs through the bottom of Earth's own ocean.
The cosmic microwave background is supposed to be directionless in the statistical sense.
From a distance, Europa looks like a frozen world. Its surface is a pale shell crossed by rust-coloured bands, ridges and fractures, with few of the impact craters that scar most old moons.
An object that looks unusually cold and faint on a map of the stars need not be a star at all.
On 28 November 2017, engineers at NASA’s Jet Propulsion Laboratory sent Voyager 1 a command to fire four thrusters that had been silent since November 1980.…
Vera Rubin did not watch individual stars race around distant galaxies in real time.
NASA's Kepler mission did not detect 300 million temperate rocky planets. It observed a narrow field of stars, found the small fraction of planets whose orbits…
The first deep images from the James Webb Space Telescope contained a population that astronomers had not expected to see.
