Last night I got to go observing for the first time! We used telescopes to look at three different astronomical objects, but my favorite thing to look at was the Moon. It was in the waxing gibbous phase, but it was so close to being full that it looked like a perfect circle (see the picture above). It was so cool to see it up close, that I just had to write a blog post about it!
How did the Moon come to be? Astronomers think that our moon is the result of a giant impact. A large, Mars-sized planetesimal likely collided with a molten Earth, sending the outer layers flying into space. These pieces then clumped together into orbit around Earth, creating the Moon! The composition of the Moon is very similar to that of Earth’s outer layers, supporting this formation theory.
What is the surface of the Moon like? The Moon is a rocky, heavily cratered place. Most of the impact craters are a result of heavy bombardment, which occurred during the first few hundred million years of our solar system’s history. There are two distinct areas on the Moon’s surface. The lunar highlands have so many craters that they are almost on top of each other. The younger lunar maria consist of few craters (this is the darker surface on the Moon). The relatively smooth surface is a result of past volcanic activity that covered up many of the impact craters. The Moon is now a geologically dead place, and it has been since the maria formed. Its small size means it has lost all of the internal heat it gained from accretion and differentiation, so no geological activity is able to occur. The only ongoing change to its surface is sandblasting, in which sand-sized particles from space create the powdery lunar soil on the surface. This means that footprints left by astronauts will remain on the surface of the Moon for millions of years!
Maddy Pollard Blog 