After a journey of almost 300 million miles, NASA is about to attempt to land its InSight probe on the surface of Mars.

What’s happening: InSight launched May 5, and scientists at NASA’s Jet Propulsion Laboratory are now making the final course adjustments before the landing on Monday, November 26. It is due to land at about noon US Pacific time (8 p.m. GMT).
Nerve-wracking: This is going to be a white-knuckle ride. The probe will experience the so-called “seven minutes of terror” that you might remember from Curiosity’s successful landing six years ago. InSight will streak through Mars’s thin atmosphere at 12,300 miles per hour and then have to scream to an almost halt of just 5 miles per hour. All this, in less than seven minutes. The probe is borrowing its landing technology from the successful 2008 Phoenix mission. It will use a parachute to slow down before it fires its 12 thrusters just before landing on its three shock-absorbing legs. It’s aiming to land on a flat area known as Elysium Planitia.
Will it work? Maybe. Plenty might go wrong. In fact, more than half of all Mars missions have failed. A European landing attempt by the Schiaparelli probe ended in calamity in 2016 when a computer error sent it into an uncontrollable spin and it crash-landed into the Martian surface, leaving a crater. (Some failures could have been avoided. The infamous Mars Climate Orbiter failed because some engineers were using metric, and others were using imperial…)
Why it matters: Unlike other rovers on the planet, InSight is there to dig down beneath its red surface. Once it’s safely in position, its robot arm will place science experiments on the ground. One, HP3, will delve up to 16 feet beneath the surface to take Mars’s temperature. The other experiment is a seismometer that will look for signs of marsquakes. Together they will provide scientists with precious information about how rocky planets like Mars and Earth form, find out how tectonically active Mars is, and gauge how often it is hit by meteorites.
All the gang: That’s not all. Two tiny CubeSats are flying in formation behind InSight as part of the Mars Cube One mission. They will help relay data from InSight back to mission control at JPL.
Party time: You can watch what’s happening live here. And if you’re really into it, parties are planned across the world to celebrate. You can find the nearest one to you here. We might know right away that it made it—or we might have to wait a few nail-biting hours.