The moon might look like a perfect circle to us here on Earth, but scientists say it's shaped less like a perfect orb and more like a citrus fruit. (Via Getty Images)
A study published this week in the journal Nature explains the moon is actually slightly squashed and has two large bulges, kind of like a lemon.
Scientists have known the moon's shape was irregular but until now have not been able to pin down what that shape is and why it's like that. (Via Getty Images)
The study says the deformation likely happened early in the moon's history when it was very hot and vulnerable to the Earth's gravitational pull. Researchers believe the Earth's pull could have stretched out the moon's crust, causing it to thicken in the middle and thin at the poles.
Scientists also say as the moon cooled down and moved away from Earth, it was likely frozen in its current form.
To discover all this, Gizmodo reports the researchers used a laser altimeter to map out and study the moon's surface.
The Verge says these were the first scientists to "get a clear picture of the moon's real shape — other scientists who have attempted the same in the past have been foiled by the sheer number of craters pockmarking the planetoid's exterior."
And according to the BBC, they were able to get past all of those craters on the moon by solving complicated math problems. Study researcher Ian Garrick-Bethell said, "We did a lot of work to estimate the uncertainties in the analysis that result from those gaps [in the data]."
So be sure to check out the moon on the next clear night and see if you notice its lumpy shape.