What to know before Perseverance lands on Mars

NASA's fifth Mars rover Perseverance launched in July of 2020, and is scheduled to land on Mars on Thursday, February 18th. The purpose of the rover is to look for signs of previous life on the red planet. You can follow along with NASA's streaming coverage beginning at 2:15 PM Eastern time, which will be as "live" as possible.

After six months of travel, the actual process of entry, descent and landing happens in just seven minutes. But because Mars is so far away from Earth, radio signals from Perseverance take about 11 minutes and 22 seconds to travel back to mission control. So, by the time mission control receives the signal that the rover has reached the top of Mars' atmosphere, Perseverance will have already landed—or crashed.

Scientists call that tense entry, descent and landing period the "seven minutes of terror." Not only is that period the riskiest part of the entire mission, but the delay in communication between Earth and Mars means that Perseverance has to land itself completely autonomously. "There's no joysticking that we can do," [guidance, navigation and controls operations lead Swati] Mohan says.

But before you watch the signals from Mars, and the response of the crew holding their collective breath on Earth, a bit of background will help you understand what you'll be looking at. Smithsonian catches us up on what will happen, what could go wrong, where the landing will take place and why, and what to expect from the event.