How Many Moons Does Earth Have?

It seems like there is an obvious answer to the question of how many moons does Earth have. We all know that Earth has one moon. Many years ago, we even named our satellite “Moon” since we thought it was the only natural occurrence of an object orbiting a planet.

But you might be surprised that the Moon is not the only object pulled into Earth’s orbit. Over centuries of exploring the cosmos, astronomers now know that hundreds of moons exist in the solar system. And Earth’s Moon is one of numerous temporary satellites that circle our planet.

The number of moons Earth holds over time ranges from none that humans recognized to one to multiple natural satellites. Let’s explore Earth’s Moon.

How Did The Moon Form?

Moons, or natural satellites, form in many types, shapes, and sizes. They usually have solid formations, and some larger moons even have their own atmospheres. Scientists think most moons formed from the gas and dust discs that orbited around planets during the early solar system.

After the planets formed, the remaining debris circled them. Some of it coalesced into natural satellites orbiting the world. But that’s not what astronomers believe happened with our Moon. Instead, they think Earth collided with a Mars-sized celestial object. The collision broke off a piece of our planet and created a massive dust and rock field. 

That space debris formed the Moon around 4.5 billion years ago. You might wonder if we can gain more moons from other space debris around our planet. So, let’s keep diving into how many moons does Earth have.

How many moons does earth have?
Image Credit: NASA, LRO and Jatan Mehta

Near Earth Objects: Asteroids

In 2006, Arizona’s Catalina Sky Survey observers found something orbiting Earth. They first thought it was a spent rocket stage since its spectrum was similar to NASA’s titanium white paint. Rocket stages often wind up in heliocentric orbits.

But as astronomers looked more closely, they realized the object was a tiny asteroid about the size of a school bus. They called the natural satellite 2006 RH120. However, less than a year after they found the asteroid, it unexpectedly left Earth’s orbit for its next destination.

By 2011, Cornell astrophysicists suggested that Earth’s temporary second moon wasn’t an anomaly; instead, its presence is the norm for our home planet. So, how many moons does Earth have? 

Scientists say that temporary natural satellites come into Earth’s orbit because of the gravitational pull between the Moon and Earth. These near-Earth objects (NEOs) are asteroids and comets that get pushed around by the outer planets. Then, their orbits bring them into Earth’s celestial neighborhood.

The Cornell team found that the gravitational system between Earth and the Moon frequently captures near-Earth objects. They think at least one NEO is orbiting Earth at any given time. The objects revolve around our world about three times in ten or so months before heading to another celestial body.

Asteroid illustration
Asteroid Illustration Credit: NASA, JPL-Caltech, and ASU

2009 BD

Another near-Earth Asteroid (NEA) is 2009 BD. It and 2006 RH120 are two of the 1,400 identified NEAs. But NASA says more than 12,800 NEAs orbit Earth. And if they are closer than the asteroid belt, studying these closer objects may shed light on the early solar system formation.

So, let’s back up. Just how many moons does Earth have? Are there 12,800 natural satellites? The answer isn’t as simple as that. 

Earth has one Moon. However, it also has small objects coming and going in its orbit. These near-Earth asteroids and objects usually spend less than a year before moving on.

How Many Moons Does Earth Have?

Our Moon is the most significant and brightest object in the night sky. Our lives wouldn’t be the same without the Moon’s presence since humanity relies on the lunar-caused ocean tides. The natural satellite helps stabilize Earth as it rotates on its axis. And that gives us a relatively predictable climate over thousands of years.

We call Moon-related things “lunar” after the Latin name “Luna.” We even live by a lunar calendar. For example, one month is the time it takes the Moon to complete a rotation around Earth.

Image Credit: NASA and JPL-Caltech

Earth has one Moon. And it dictates much of our daily lives. The fishing industry is one example of humanity’s dependence on the lunar tides. Some anglers even believe fishing conditions thrive under a Full Moon when fish feed heavily at night. While no evidence proves this theory, anglers still credit lunar cycles for their catch (and blame them when they strike out.)

We have one Moon, but near-Earth objects often come into our world’s orbit for a short time.