Jezero Crater: Close observation of the landing site of the "Perseverance" rover.

Jezero crater may be the main ideal location for Martian microbiota. The persistent goal is to find out whether there are any Martian fossils on Mars.

Billions of years ago, a huge space rock hit Mars and dug a crater 750 miles (1200 km) wide, which is now called the Isis impact basin. But the cosmic impact is not over yet. Another small impact in the basin later produced an embedded crater, which was later called Jezero crater. This overlapping influence has uniquely changed the rocks in this area and helped to create a special landscape, which scientists believe may be suitable for life.

Gezero crater: diverse landscapes

According to the image of the spacecraft, researchers believe that the Gezero crater was once the site of a lush river delta. Rivers inject sediments into relatively calm large water bodies, such as lakes and oceans, thus forming deltas. The deposition process has created many different environments.

When Mars was young and wet, life might have just taken root on the earth. Jezero crater is the birthplace of 1600 feet (500 meters) deep lake. Scientists believe that there may be a series of rivers flowing in here, which is the best place for life evolution on Mars.

This is why NASA chose to explore. The idea of continuing wetlands on Mars is enough to convince astronomers to choose Jezero crater as the landing site for NASA's persistent rover and its companion original helicopter.

Jezero crater, named after the Bosnian town of Jezero, is about 28 miles (45 kilometers) in diameter, giving the rover enough roaming space. (More than ten years ago, the International Astronomical Union, which is responsible for naming planets, decided to name some craters on Mars with towns around the earth. )

Perseverance is a car-sized rover, which aims to describe the geological characteristics of Mars and study its ancient climate. In this process, it will look for signs of ancient alien life-especially microbial life-and collect soil and rock samples, which will eventually be sent back to Earth for further research in world-class laboratories.

Jezero crater provides an ideal and persistent place to collect a series of promising samples.

The long journey to land in Jezero.

In 1976, NASA's Viking Lander landed on Mars only a few months apart. They roamed the surface of Mars without wheels, but these tasks still changed astronomers' views on Mars.

The Viking lander found clear signs of river valleys, wet weather and erosion. In addition, soil experiments carried out on Viking even found preliminary evidence of microbial life. Scientists later decided that this was a wrong detection, but on the whole, the discovery of Viking brought excitement to better understand the ancient climate of Mars. This excitement inspired further exploration.

In the next few decades, based on these discoveries, the National Aeronautics and Space Administration (NASA) of the United States launched several probe cars to Mars. One is more complicated than the other.

The latest robotic rover before NASA's Curious Rover Perseverance landed on 20 12, with the goal of determining whether Mars can support microbial life. The robot has traveled more than ten miles in Gale Crater, which used to be a lake bed, providing people with new insights into the ancient climate, current geology and past water resources of Mars.

This will help stimulate astronomers' interest in exploring other ancient places on Mars where there used to be water. Therefore, in order to prepare for the trip of Perseverance, astronomers considered about 60 candidate landing sites within a few years. Different research groups have their own ideas about which site is the best, and the debate about landing sites is often controversial. However, with the development of the situation, it is becoming more and more obvious that Gezero crater was once a vast wetland.

Flowing river delta

In 20 15, a study published in the Journal of Geophysical Research: Planets showed that the now-dried Jezero crater was once the water source of Mars twice.

Scientists used satellite observation data to conduct what geologists call "from source to sink" analysis. They traced the upstream sources of various minerals in the Mars basin. Interestingly, the team's analysis shows that Jezero crater became an active watershed in two different time periods before the water dried up about 3.5 billion years ago. Once it stands firm, it increases the chances of life on Mars. The water level may be so high that it overflows the crater wall. Since then, many papers have supported these findings.

Astronomers now imagine that the Gezero crater is a dynamic system, and water will flow in and out for a long time. NASA is happy to take samples in the center of the delta, where the water may be the deepest. Mud deposits there may have kept records of organic matter, just like similar rocks on earth. Perhaps the most interesting possibility is that Jezero crater may be home to microbial communities, just like scum formed on the edge of a lake. Some minerals may have preserved the scum in the pond and formed what scientists call stromatolites-layered rocks that are essentially fossils.

The "indomitable" rover will pay close attention to this fossil deposit on Mars. Moreover, when it pokes and samples the soil, the rocks in Jezero crater will provide new clues to help us understand whether there was life in the early wet period of Mars.

Reference: