Earth officially has two moons now

Earth Officially Captures Second Moon, Transforming Asteroid 2024 PT5 into a Temporary Mini-Moon

TL;DR

Earth has officially captured a new temporary moon, the small asteroid 2024 PT5, on September 29, 2024. This intriguing mini-moon will orbit our planet for a limited time before escaping back into space, highlighting the dynamic nature of our solar system. Mini-moons like 2024 PT5 provide a unique opportunity for scientists to study near-Earth objects and enhance our understanding of cosmic events. Although too small to see with the naked eye, its presence serves as a reminder of the fleeting visitors that occasionally accompany our planet.

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In recent weeks, you may have heard the buzz about Earth acquiring a second moon. Well, it’s now confirmed that Earth officially has two moons after capturing the asteroid 2024 PT5.

On Sunday, September 29, our planet captured the small asteroid known as 2024 PT5, transforming it into a temporary mini-moon.

This fascinating occurrence was first observed by astronomers at the Complutense University of Madrid. Richard Binzel, an astronomer at the Massachusetts Institute of Technology (MIT), provided some insights about these cosmic visitors.

“These events happen with some frequency, but we rarely detect them because they are quite small and difficult to spot,” Binzel stated. “Only recently has our surveying technology improved enough to identify them routinely.”

Using a powerful telescope in Sutherland, South Africa, the team from Complutense University discovered the tiny space rock back in August.

What are mini-moons?

What exactly are mini-moons, and how often do they come by?

Mini-moons like 2024 PT5 are small asteroids that Earth’s gravity temporarily captures, allowing them to orbit our planet before moving on.

These small asteroids usually orbit the sun like others, but when they get close enough to Earth, our gravitational pull can draw them into a temporary orbit.

They don’t remain for long — they may linger for several weeks or months before escaping and continuing their journey around the sun.

Scientists find mini-moons particularly intriguing as they provide a unique opportunity to study near-Earth objects up close and enhance our understanding of our solar system.

Journey of 2024 PT5

According to data from NASA’s Jet Propulsion Laboratory Horizons system, the stay of this mini-moon will be short-lived.

The temporary capture began at 3:54 p.m. EDT on September 29, 2024, and is set to end at 11:43 a.m. EDT on November 25, 2024.

So, where did this little visitor originate?

2024 PT5 is part of the Arjuna asteroid belt — a collection of space rocks that have orbits similar to Earth’s, situated about 93 million miles from the sun.

Some objects from the Arjuna asteroid belt can approach Earth at a distance of approximately 2.8 million miles and at relatively low speeds of under 2,200 miles per hour.

“Asteroid 2024 PT5 will not complete a full orbit around Earth. You could say that if a true satellite is like a customer purchasing items in a store, objects like 2024 PT5 are merely window shoppers,” explained Carlos de la Fuente Marcos, a professor and mini-moon expert from the Complutense University, to Space.com.

Carlos has authored a scientific paper titled “A Two-month Mini-moon: 2024 PT5 Captured by Earth from September to November,” which was recently published by the American Astronomical Society in the journal IOPscience.

How common are captures like 2024 PT5?

Though it might seem remarkable for Earth to gain a second moon, these gravitational captures are more frequent than one might think.

Scientists have documented two prior “short captures,” which last around a week and are estimated to occur several times per decade. Additionally, there have been two rarer “long-capture” events.

After its brief stay, 2024 PT5 will continue its orbit around the sun as part of the Arjuna family of asteroids.

It won’t remain for billions of years like our primary moon, but its transient presence serves as a reminder of the dynamic nature of our cosmic environment.

Not currently visible

You might be wondering if you can see this mini-moon in the night sky. Unfortunately, it’s too small and dim for most people to observe.

The object is too faint and small for typical amateur telescopes and binoculars. However, it falls within the brightness range of the telescopes used by professional astronomers.

To observe this object, a telescope with a diameter of at least 30 inches along with a CCD or CMOS detector is necessary; simply using a 30-inch telescope with the naked eye will not suffice.

Comparing 2024 PT5 to our moon

To provide some perspective, our moon has a diameter of about 2,159 miles, while 2024 PT5 is estimated to be only 37 feet wide. This means our moon is over 300,000 times wider than this tiny asteroid!

Even though we can’t observe it directly, knowing it exists up there is quite exciting. It’s akin to having an invisible guest sharing our orbit for a little while.

These mini-moons may be small, but they present significant opportunities for scientists to learn more about near-Earth objects. They can offer insights into asteroid composition and the dynamics of our solar system.

“These temporary captures serve as natural cosmic laboratories,” Binzel remarked. “They enhance our understanding of the small bodies that approach Earth and could be crucial for future space missions.”

What happens next?

As 2024 PT5 continues its journey, we’ll keep our eyes — and telescopes — focused on the skies. After all, who knows when the next mini-moon might pay us a visit?

Perhaps advancements in technology will enable us to study these fleeting visitors in greater detail. One day, we may even launch missions to them to collect samples or test new spacecraft.

For the next few weeks, Earth will have a tiny companion orbiting around it. While it’s here, let’s take a moment to appreciate the wonders of our ever-evolving universe and the surprises it has in store for us.

The full study was published in the journal IOPscience.