NASA's successful Mars landing will reveal yet more secrets from the red planet. But there is much we already know from Martian fragments that found their way to Earth.
Methane gas in the atmosphere is a tantalising hint suggesting that life could exists on Mars.
The Perseverance rover's landing could help reveal secrets of Mars' interior.
Plus what protesters in Belarus want to happen next. Episode 1 of The Conversation's new weekly podcast.
Martian meteorites allow scientists here on Earth to decode that planet's geology, more than a decade before the first missions are scheduled to bring rocks back home from Mars.