NASA's Mars Perseverance has alighted on the red planet.
Perseverance, the most advanced astro biology laboratory ever sent to another world, streaked through the Martian atmosphere on Thursday and landed safely on the floor of a vast crater, its first stop on a search for traces of ancient microbial life on the Red Planet.
The robotic vehicle sailed through space for nearly seven months, covering 293 million miles (472 million km) before piercing the Martian atmosphere at 12,000 miles per hour (19,000 km per hour) to begin its descent to the planet’s surface.
Moments after touchdown, Perseverance beamed back its first black-and-white images from the Martian surface, one of them showing the rover’s shadow cast on the desolate, rocky landing site.
"Hello, world. My first look at my forever home," it wrote. The second photo showed its a look behind it - on the Jezero Crater.
Why this specific landing spot? NASA on its own website explains why it chose Jezero Crater as the landing site for the Perseverance rover. Scientists believe the area was once flooded with water and was home to an ancient river delta. The process of landing site selection involved a combination of mission team members and scientists from around the world, who carefully examined more than 60 candidate locations on the Red Planet. After the exhaustive five-year study of potential sites, each with its own unique characteristics and appeal, Jezero rose to the top.
Jezero Crater tells a story of the on-again, off-again nature of the wet past of Mars. More than 3.5 billion years ago, river channels spilled over the crater wall and created a lake. Scientists see evidence that water carried clay minerals from the surrounding area into the crater lake. Conceivably, microbial life could have lived in Jezero during one or more of these wet times. If so, signs of their remains might be found in lakebed or shoreline sediments. Scientists will study how the region formed and evolved, seek signs of past life, and collect samples of Mars rock and soil that might preserve these signs.
What is the Jezero Crater?
Jezero Crater is 28 miles (45 kilometers) wide, and is located on the western edge of a flat plain called Isidis Planitia, which lies just north of the Martian equator. The landing site is about 2,300 miles (3,700 kilometers) from Curiosity’s landing site in Gale Crater.
Jezero Crater sits within the Isidis Planitia region of Mars, where an ancient meteorite impact left behind a large crater some 750 miles (1,200 kilometers) across. This event is known as Isidis impact, and it forever changed the rock at the base of the crater. A later, smaller meteorite impact created the Jezero Crater within the Isidis impact basin. Scientists believe that these events likely created environments friendly to life. There is evidence of ancient river flow into Jezero, forming a delta that has long since been dry.
Jezero Crater is thus likely to have been habitable in the distant past. The Mars Reconnaissance Orbiter's CRISM instrument has revealed that the crater contains clays, which only form in the presence of water. On Earth, scientists have found such clays in the Mississippi river delta, where microbial life has been found embedded in the rock itself. This makes Jezero Crater a great place to fulfill the Mars 2020 mission's science goal of studying a potentially habitable environment that may still preserve signs of past life.
At Jezero Crater, Perseverance should be able to access rocks that are as old as 3.6 billion years.