How many craters did the moon have

Likening the flooding lavas to the seas of Earth, astronomers call the vast plains of basalt mare singular or maria plural on the Moon. We have samples of the rock and dust that cover the surface of the Moon. Apollo astronauts with the American space program collected and returned The robotic Luna spacecraft built by the Soviet Union also collected and returned g of samples.

The Apollo samples and Luna samples were exchanged between scientists in these countries and other countries around the world so that they could begin deciphering the history of the Moon. A ratio is that there are 35x more than the km craters. Multiply this by their database, and we get only , craters on the moon larger than 1 km.

A third way is to do small test regions and then scale up to the size of the moon. You can tell that just by looking at it from Earth with your unaided eye: It has bright spots with lots of craters and dark spots with fewer craters. That amounts to only 0. Moon Mappers is using images that are about km across. In that tiny, tiny region, I counted about 5, craters that were larger than 18 pixels across roughly 10 meters. That test region amounts to just a fraction of a percent of the total surface area of the moon.

In the images we have uploaded so far, we expect there to be a few thousand craters per image. Some will have more, some will have less. Localized in places, yes. Craters give an age to the moon because once they are created, they never disappear from the lunar surface, unlike here on Earth.

On the moon, there are no plate tectonics, volcanoes, sea, wind or weather to get rid of them over time. That means that if we know how often meteors hit and count how many hits there have been, we can have a decent stab at working out how old the moon is! Based on counting lunar craters and comparing that number to the average meteor hit rate, we assume the moon to be somewhere between 4.

Incidentally, that is million years younger than previously believed! Ultimately it is the speed and angle of approach of a meteoroid which determines how big a crater it will leave behind, but the scale is impressive. An Earth-based example says that Barringer Crater, which is almost a mile wide, was caused by a lump of rock no bigger than 0. The oldest crater on the moon is believed to be Bailly , located near the moon's south-west limb. It is a lunar impact crater that, because of it condition and size, is believed to be over three billion years old.

A very characteristic crater. The different parts of a crater come into this: a raised rim, a crater wall and floor, a central peak, and materials splashed out on the ground surrounding its area. This set of features helps us to distinguish even microscopic craters.

But how do you find out how old a crater is? Older craters generally house smaller craters within them like in the picture, above so one can conclude that the age of a large crater depends on the amount of smaller craters it contains within it. By the way, if you want to see the smaller craters through your own telescope, then it's best to get yourself an inexpensive moon filter. More Videos See China launch lunar mission to collect samples from the moon Using artificial intelligence, Chinese scientists have estimated that there are more than , craters on the moon, according to a study published Tuesday in the journal Nature Communications.

That's far more than the 9, officially recognized by the International Astronomical Union and largely detected manually using elevation information and images, the study said. The scientists, using data on 7, previously identified craters and 1, dated craters, were able to apply machine learning to train a deep neural network.

With information from China's first and second lunar orbiters -- Chang'e 1 and Chang'e 2 -- the network identified , new craters.