What is Mercury Made of?
The first European mission to explore Mercury, the smallest and least explored terrestrial planet, is being launched into space on Saturday.
The European Space Agency and Japanese Aerospace Exploration Agency have each contributed a probe to study the planet.
Space scientist, Dr Suzie Imber, from the University of Leicester, explains how this small strange planet is unique, how the mission could improve our mobile phone and internet networks and why Mercury might hold the secret to how our solar system was formed.
Mars landing 2021: How far away is Mars?
There are three missions to Mars happening in 2021.
The United Arab Emirate's Hope satellite has entered the planet's orbit while Nasa's Mars Perseverance has landed on the surface.
China's Tianwen-1 is due to land a rover on the red planet in May.
But how far away is Mars? And why is landing on Mars known as the "seven minutes of terror"?
Here BBC Science Correspondent Laura Foster explains how long it takes to get there and why it's so difficult.
Video by Laura Foster, Megan Fisher and Terry Saunders.