Looking at these two neighbouring planets now it’s hard to believe that once upona time Mars could have been mistaken for Earth’s smaller twin. Instead of the rusty red surface that we see today, Mars was once covered in water, and maybe even life. This was billions of years ago, of course, and as well as oceans across the surface, Mars also had a thick atmosphere that kept it warm enough for the water to stay in liquid form. Today, this water is gone, although ice does remain in polar caps and beneath the red planet’s surface.

Roving robots

Much of the information we have about Mars is thanks to the robots who were sent there to explore and retrieve data. Because Mars is our closest neighbour (only 64 million kilometres away!) it’s the most robotically explored planet beyond Earth.

Missing magnet

Earth is surrounded by a protective magnetic field that acts like a force field. Unlike Earth, Mars is missing this force field, which means that the Sun has stripped away most of the planet’s atmosphere and left the frozen surface. Without this force field the Sun’s heat easily escapes, leaving a burnt but chilly planet behind. Mars did once have a magnetic field of its own, but what happened to it remains a mystery.

Mission to mars

Robots have set foot on Mars, and hopefully one day humans will join them! NASA is already planning Moon landing missions in preparation for a history-making journey to Mars. Elon Musk, the founder and CEO of SpaceX, has also declared his intentions to send humans to Mars, and is building a massive spacecraft called Starship to make the journey. 

More extreme

Mars is a planet with mountains, valleys and volcanoes. While Mars looks pretty similar to Earth on the surface, things are far more extreme on the red planet. Olympus Mons, the largest volcano on Mars, is three times the height of Mount Everest at an epic 22 kilometres. It’s also super wide, stretching 624 kilometres across – Olympus Mons is so big that its slope curves with the surface of the planet!

Mars is also home to the Valles Marineris canyon system. These amazing valleys span over 4000 kilometres and are 7 kilometres deep – that’s four times deeper and five times longer than the Grand Canyon!