The '7 Minutes of Terror' Are Nearly Upon Us

NASA is bracing itself for "seven minutes of terror" Thursday afternoon. Its Perseverance rover is set to touchdown on Mars around 3:55pm ET, but that it'll do so in one piece is no sure thing. Perseverance will essentially have that short period to go from traveling in excess of 12,000mph to landing—the seven minutes is how much time will elapse between it entering Mars' atmosphere until landing, and it'll have to manage that landing on its own. That's because it takes 11 minutes for a signal to get to us from Mars, so if the rover runs into trouble, NASA won't know until it's too late. "The only question is whether the rover will end up in one piece, ready to begin its mission, or smashed into many pieces," reports the New York Times. More:

• USA Today has a great visual explanation of the various steps Perseverance will take during those 7 minutes, including when it will deploy a supersonic parachute that will help slow the rover's descent.
• If it makes it, Perseverance will have some company. Spacecraft from the United Arab Emirates and China reached Mars' orbit last week, with the AP explaining that all three missions began in July to take advantage of a fortuitously close alignment of Earth and Mars. The US is the only country to have ever landed a rover on Mars. Perseverance, if successful, will be No. 9 to make it. Only one previous attempt, in 1999, failed.

• The rover is headed for what the AP calls "NASA's smallest and trickiest target yet: a 5-by-4-mile strip on an ancient river delta full of pits, cliffs, and fields of rock." Once in the Jezero Crater, which USA Today explains once contained about the same amount of water as Lake Tahoe, the plan is for Perseverance to drill down and retrieve rock samples that might reveal signs of billions-of-years-old life on the planet. They would ideally get back to us by 2031.
• NASA is up front about the difficulty: "The Mars sample return project is probably the most challenging thing we’ve ever attempted within NASA," said planetary science director Lori Glaze.
• If it makes it, the hunt for life will begin. At NBC News, Seth Shostak of the SETI Institute explains: "Unlike the Viking landers, the new Perseverance rover isn’t looking for chemical signs of metabolism" but, rather, sediments that "could contain clues to organisms that pitched and swirled in long-vanished seas. The rationale is simple: If Mars ever had life, the dead will surely outnumber the living, and are therefore more likely to be found."
• We can't actually see the landing, but you can follow it via NASA's commentary, which will begin Thursday at 2:15pm ET here.

(More Mars stories.)