Noachian

The Noachian refers to an early time period on Mars. During this time, meteorite and asteroid impacts were common, and there might have been a lot of surface water. This period happened around 4100 to 3700 million years ago. Big impact basins formed on both the Moon and Mars.

Scientists think that during the Noachian, Mars had a thicker atmosphere. The climate may have been warm enough sometimes to allow rain.

Noachian areas on Mars are good places for spacecraft to look for fossil signs of life. At that time, large lakes and rivers existed in the southern part of Mars, and an ocean may have covered the northern plains. Lots of volcanism built up the Tharsis region. This released gases into the air and made clay minerals that could support tiny life.

Today, Mars is a cold, dry desert. This makes the Noachian period very interesting for scientists studying Mars's past climate. While there is strong evidence for water on early Mars, how and when this water was there is still being debated. Some researchers think the climate was mostly cold and icy with short warm periods. Others think there were occasional rainy periods warmed by special conditions in the air. Either way, the Noachian climate was not always warm and wet. Much of the river and lake activity happened toward the end of this period.

Description and name origin

The Noachian System and Period is named after Noachis Terra, which means "Land of Noah". It is a heavily cratered area west of the Hellas basin on Mars. The Noachian surfaces are very hilly and rugged. They look similar to the lunar highlands. These areas have many old craters and are covered with materials thrown out by impacts. Large impacts also lifted parts of the ground, creating mountains.

Noachian-aged units cover much of Mars, mostly in the southern highlands. They are also found in places like Tempe and Xanthe Terrae, Acheron Fossae, and near the Isidis basin (Libya Montes). This period had many large impacts, making the surface very cratered.

Noachian chronology and stratigraphy

Martian time periods are found by looking at the planet's surface using pictures from spacecraft. Scientists study things like texture, color, and land shapes to sort areas into groups. These groups help experts learn the order of events in Mars' history.

The Noachian is one of these time periods on Mars. It is known for many crashes from space rocks and maybe a lot of water on the surface long ago. Experts do not know exactly when the Noachian happened, but it was likely between 4100 to 3700 million years ago. This was a busy time for impacts, making many large craters and basins on Mars.

Mars during the Noachian Period

The Noachian Period on Mars was a time of big changes. Mars had many crashes from space, like rocks from space hitting the planet. These crashes helped shape the surface of Mars.

During this time, Mars also had lots of wear and tear. Many places show signs of valleys that look like rivers on Earth. This suggests that water may have flowed on Mars long ago. These valleys are mostly in older areas, which hints that Mars might have been wetter and warmer in the past. There is also evidence that big lakes and maybe even oceans existed, especially in low areas. This makes us think that water may have been more common on Mars back then.