Scientists believe that lunar maria formed from lava flows caused when the surface of the moon was disrupted by the impacts of gigantic meteors and comets. Maria is the plural of "mare," which is Latin for sea. One of the most famous of the lunar maria is the Sea of Tranquility, which was the site of the first moon landing.
If a large enough object struck the moon, it may have actually cracked the surface, causing magma to bubble up from the mantle and spread out into the surrounding moonscape and into the impact crater itself, then cooling into a volcanic rock called basalt. The objects that impacted the moon had to be very large. Some maria on the moon are over 621 miles across; scientists believe that it takes an object about one-tenth that size to create such a large feature.
Maria are often darker than the surrounding landscape, and the youngest ones are smooth and nearly devoid of impact craters. Meteors and other debris that struck the moon were common when the moon and the solar system were first forming, but as the solar system aged and became more settled, the number of impacts decreased. The rocks found in the lunar maria are estimated to be about 3.8 billion years old.Learn More
The moon appears to shine because its surface reflects sunlight. Light from the sun travels through space to reach the Earth-moon system just over eight minutes after it is emitted. Some of this light falls on the surface of the moon where, according to Universe Today, 12 percent of it is reflected back into space.Full Answer >
Sunlight reflects off the moon's surface, and it is seen at different angles from the Earth as the moon moves in orbit around the planet. These changes are known as lunar phases, which occur in a cycle that repeats every 29.5 days.Full Answer >
It takes light from the moon's surface approximately 1.3 seconds to reach the Earth. This is also the amount of time it takes for sound to travel from the Earth to the moon. That means that communication from the Earth to an astronaut on the moon has a 2.6-second delay.Full Answer >
The lunar highlands are elevated areas on the moon that were created by material that accumulated in layers from the ejecta of craters. The highlands are riddled with craters and the rocks found there are thought to be between 3.84 and 4.48 billion years old. These craters were formed by the intense bombardment on the moon in the early days of its existence.Full Answer >