There is jubilation at NASA this morning after the safe landing of its Mars rover, Perseverance. Now one of the great science projects can start in earnest, trying to understand whether life ever existed beyond earth.
Congratulations have poured in to the space agency from all over the world after its spectacular success in nailing the daunting technical feat of landing a robot the size of a large car on Mars despite the ultra-thin atmosphere of the red planet.
Soon after its arrival, low-resolution images were beamed back to Earth to confirm that it survived the massive deceleration and the series of elaborate, automated manoeuvres that NASA scientists call the "Seven Minutes of Terror".
On Monday we should be in for a real treat. That's when the mission scientists will have downloaded the high-resolution video and imagery from Perseverance's journey through the Martian atmosphere.
And they have an extra bonus in store for us: the sound of Mars. Aboard the rover are two microphones that are being used to pick up the surrounding audio.
So we may hear a recording of the capsule roaring though the atmosphere, the deployment of the huge parachute, the retro-rockets firing to bring the descent stage under control, and the crunch as the rover was lowered by tether onto the Martian surface.
Scientists will be checking out the systems aboard the rover for the next several days.
Then the science can begin. At the heart of the project is the search for signs of ancient microbial life. The location of Perseverance is a spectacular bonus for planetary geologists.
The rover is in the Jezero Crater - which billions of years ago was a river delta, a prime candidate for having once hosted life on Mars.
It is unlikely that the rover itself has the tools to detects signs of life. So a key capability of the mission is to collect and store samples with the aim of returning rocks and soil samples to Earth for study in labs back here, although that will take two future missions and so is at least a decade away.
But the hard part is behind NASA - landing the rover. The relief is palpable. So too is the excitement of what lies ahead.