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How many Moons does the Earth have? Well, that’s easy, right? 1. Well, that certainly isn’t the case for the next few weeks. At this instant, in the depths of the cosmos, the Earth has a 2nd Moon, and it’s not going to stay for long.
How it became a Moon
There are millions and millions of asteroids in space, differing in size and shape (Read our article about asteroids for more information). Many of these asteroids orbit near the Earth. Sometimes, when there is an intersection in the course of the asteroid and the Earth’s gravitational sphere of influence, the asteroid starts orbiting the Earth. However, in most, if not all of these cases, the asteroid orbits the Earth temporarily and then continues its orbit around the Sun. This is exactly the case with asteroid 2024 PT5, which began orbiting the Earth on 29th September 2024.
The 2nd Moon
2024 PT5 (the Earth’s 2nd Moon) was discovered on 7th August 2024. It is a relatively small asteroid, only about 10 metres in diameter. It is about the size of a school bus. It takes around 1 year to complete an orbit around the Sun. Studies speculate that 2024 PT5 is actually a piece of rock broken away from our Moon by an asteroid impact a long time ago.
However, this scenario isn’t anything unusual. There are many planets in our solar system with more than 1 Moon. Mars has 2 Moons. Jupiter has 95. In fact, Saturn has 146 of them! 2024 PT5 technically does not even qualify as a Moon. This is because of its irregular and temporary orbit around the Earth. Thus, it has been classified as a quasi-satellite. This means that it does orbit the Earth, but not in the way a natural satellite like the Moon would.
A noteworthy fact about the 2nd Moon is that it is a visitor, not a colonist. 2024 PT5 will orbit the Earth for 53 days, from 29th September to 25th November. But believe it or not, this isn’t the first time this has happened. Earth got a 2nd Moon in 1981, and also more recently in 2022. But then, the 2nd Moon was too faint to be seen by the naked eye.
Will you be able to see it?
Unfortunately for us, the Earth’s 2nd Moon is too small in size to be seen by small telescopes, let alone observed by the naked eye. It can be observed using professional telescopes only, due to it being very faint to observe using small telescopes.
Will it hit the Earth?
With the help of advanced asteroid tracking technology, scientists have confirmed that the 2nd Moon does not pose any threat to the Earth, eliminating any chance of a collision. Click here to read about asteroid detection and impact mitigation technologies.
How are asteroids named?
The nomenclature of asteroids is a very interesting topic. The year of the discovery of the body is the first part of the name. To name asteroids, a month is divided into 2 halves, and the letter corresponding to the serial number of the semi-month is included in the name. Eg. If an asteroid is discovered in the second half of January 2024, it will be called 2024 B (as B is the 2nd semi-month). However, this is insufficient as several asteroids are discovered in any given month.
Thus, the letter of the alphabet corresponding to the serial number of the asteroid discovered is taken. Eg. If an asteroid is the 3rd one to be discovered in the second half of January 2024, it is named 2024 BC (as C is the letter corresponding to the number 3). However, this too proves to be futile, as the number of asteroids being discovered simply outnumbers the letters in the alphabet.
To tackle this, when we run out of all alphabets, we go back to the first alphabet and start assigning numbers. Eg. 2024 BC1, 2024 BD1… 2024 BC2 and so on.
As the 2nd Moon was discovered in the first half of August 2024, it is called 2024 PT5.
Click here to learn more about the “second Moon” of the Earth.
Conclusion
On average, the Earth gets a quasi-satellite like 2024 PT5 once every few decades. We don’t know exactly when we will experience another one of these astronomical phenomena, making it very important to acknowledge the gravity of this situation.
What are your thoughts on the “2nd Moon”? Let us know in the comments below.
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