Do you love to look at the moon? 26 September is International Observe the Moon Night — the perfect time to grab a pair of binoculars and take a peek!

What is the moon?

The moon is what’s known as a “natural satellite,” meaning it’s a natural object that orbits a planet (our planet!). The moon is 4.53 billion years old. We’re not entirely sure where it comes from, but one widely accepted explanation, “the giant-impact hypothesis,” is that the moon was born from the debris made during a collision between Earth and another planet. 

When you observe the moon from Earth, you are seeing the sun’s light reflecting off its “lunar surface” — a landscape composed of “igneous rock,” a substance heavy in calcium, according to NASA. Just like our own planet, the moon has a crust, a mantle, and a core. 

What are the moon’s cycles and phases?

Humans have had their sights on the moon since the beginning of time. Ancient people used the moon as a calendar, since it travels in recurring phases and cycles. The moon travels in eight phases over the course of about a month, which is roughly the length of time it takes the moon to circle earth. From start to finish, these phases include: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter and waning crescent. The cycle recurs every 29 and a half days. Different parts of the moon are illuminated during all these phases. During the “new moon” phase you cannot see it at all.

When is the best time to observe the moon?

You might think the best phase to observe the moon is when it’s full; however, shadows are barely visible on the lunar surface during full moons, because the sun is shining directly down on it. 

In fact, the best time to observe the moon is when it’s half full. September or October, when the moon is in what’s considered “first quarter,” are the best times to take a look. This year, the moon will be in the first quarter phase tonight — September 26!

According to NASA, the best time of day to observe the moon is right when day turns into evening (the skyline during this time is dubbed “the terminator” or “twilight zone”). This is when the moon’s shadows are strongest, making it possible to see its craters. Be sure to have a pair of binoculars or a telescope ready in advance! 

Support People on the Moon

The TryEngineering lesson plan Biomimicry in Engineering teaches the concept of Biomimicry. Students learn how engineers have incorporated structures and methods from the living world in products and solutions for all industries. They then work in teams to develop a structure or system based on an example in nature that would help people living on the moon. Download this lesson plan today!