Could ET be real? 2023 has seen moon landings, asteroid samples, comets and crashes. But some think it might be a watershed year in the search for alien life.
Aliens, asteroids and atoms: 2023 in space
Waterworld: Jupiter’s moon Europa has a saltwater ocean 10 times deeper than Earth’s. Glossary
Meteor showers - A celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky.
SpaceX - Founded in 2002 by South African entrepreneur Elon Musk, SpaceX's mission is to reduce the cost of space transportation to make possible the colonisation of Mars.
Richard Branson - His businesses have included Virgin Records, Virgin Trains and the space-tourism company Virgin Galactic.
Orbit - Proxima b's orbit lasts 11.2 Earth days.
Nasa - The National Aeronautics and Space Administration, responsible for the US space programme.
Asteroid - A small body in space, made of metal and rock material. Asteroids usually orbit the sun, but if knocked off course they can be drawn into Earth’s gravity and fall towards it.
Europa - Many astrobiologists consider Jupiter's smallest moon to be the most likely place to find extraterrestrial life. An enormous ocean may lie beneath its water-ice crust, with underwater volcanoes creating thermal vents.
Solar tornado - When the Sun emits huge bursts of energy in the form of solar flares.
Light years - A unit of measurement equal to the distance that light travels in one year, which is 9.4607 times 1012 km. That's nearly 6 million million miles!
Cosmic - Relating to the universe or cosmos.
Astronomer - A scientist that studies the universe and space.
Cosmos - The universe, especially when it is understood as an ordered system.
Organic - Relating to or derived from living matter.
Unprecedented - Never been seen before.