When we look at the Moon, we see a landscape shaped by impact craters. But scientists only discovered the true cause of crater in the last hundred years. Before that, they believed that there were many volcanoes on the Moon, and this is what caused the craters we see today.
Now we know that craters come from meteorite impacts, that still doesn’t answer the question: are there volcanoes on the Moon?
There used to be volcanoes on the Moon. The Moon is much smaller than the Earth. Although it was molten after its formation, it cooled down relatively rapidly. Scientists think that the Moon’s interior remained hot enough to produce magma for about a billion years after the Moon formed. The lava that came out of the Moon cooled quickly, and formed fine-grain, dark rocks called basalt. The Apollo astronauts sampled this material when they landed on the Moon.
When you look at the Moon, you see lighter and darker regions. The lighter regions are the mountainous highlands. The darker regions are vast “seas” of basalt lava that erupted out of the Moon billions of years ago.
Are there volcanoes on the Moon today?
There is recent evidence that there were volcanoes on the far side of the Moon much longer than on the near side. While the near side of the Moon shut down more than 3 billion years ago, there seems to be evidence that there were volcanoes on the surface of the Moon as recent as about a billion years ago.
Some researchers believe there are still vents that blast out volcanic gasses, but there are no longer active volcanoes on the Moon.
You can listen to a very interesting podcast about the formation of the Moon from Astronomy Cast, Episode 17: Where Did the Moon Come From?