A new “mini-moon” has been captured in Earth’s orbit.

A “mini-moon” is a small asteroid or object temporarily captured by Earth’s gravity, causing it to orbit the planet for a short period before escaping back into space. Unlike the Moon, which is a permanent satellite of Earth, these objects are transient, often staying in orbit for a few months to a few years.

Mini-moons usually enter Earth’s orbit when they pass close enough for Earth’s gravity to influence them. Eventually, they either drift away or burn up in the atmosphere. Mini-moons are rare and often difficult to detect because of their small size, but they are interesting to scientists for studying near-Earth objects (NEOs) and asteroid dynamics. One example of a mini-moon was “2020 CD3”, discovered in 2020, which orbited Earth for about three years before leaving.

Can we see it?

Most mini-moons are “very small”, often only a few meters across, so they are usually “too tiny to see with the naked eye”. Even with telescopes, they are hard to spot because they’re not very bright and don’t stay in orbit for long. Scientists need special equipment to detect and track them. A mini-moon is like a guest in Earth’s neighborhood, but it’s so small and quick that we usually can’t see it without an advanced telescope.

Earth has caught a ‘second moon,’ scientists say

Recently, Earth has temporarily captured a small asteroid, designated 2024 PT5, which some scientists are referring to as a “mini-moon”. This space rock, about 33-37 feet (10-12 meters) in diameter, was drawn into Earth’s orbit in late September 2024. Unlike our regular moon, this second moon won’t stay for long; it’s expected to circle Earth for about two months before continuing its orbit around the Sun. Events like this are relatively common, though they often go unnoticed by the general public.

Although it won’t be visible to the naked eye due to its small size, astronomers are tracking its trajectory using advanced telescopes. These temporary moons are fascinating but short-lived, highlighting the dynamic nature of Earth’s relationship with near-Earth objects.

Wait, What’s All This About a Temporary Second ‘Moon’ the Size of a City Bus?

The buzz about a temporary second “moon” refers to asteroid 2024 PT5, which has been temporarily captured by Earth’s gravity. It’s about the size of a city bus, measuring around 33 to 37 feet in diameter. These temporary moons, or “mini-moons,” occur when small asteroids get pulled into Earth’s orbit for a short period before they continue on their path around the Sun.

Unlike Earth’s actual moon, this mini-moon won’t be here for long—it’s expected to remain in orbit for just a few months before being flung back into space. Its small size also makes it difficult to observe without professional equipment, so amateur stargazers won’t likely be able to spot it.

This phenomenon is part of a rare but known occurrence, as similar objects have been briefly captured in the past, though they are usually too small to notice. It’s not a permanent moon, but rather a temporary visitor.

Earth will get another moon this month — but not for long!

Yes, Earth will briefly have another “moon” this month, but it’s a temporary visitor! The object in question, asteroid 2024 PT5, was captured by Earth’s gravity in late September. This small space rock, about the size of a city bus, will remain in orbit for a couple of months. Unlike Earth’s permanent moon, this mini-moon will only stay for a short period before returning to its solar orbit.

These kinds of “mini-moons” are rare but not unheard of. They are typically small asteroids that are temporarily captured by Earth’s gravity, making a few orbits before being ejected back into space. Because of its small size, the 2024 PT5 won’t be visible to the naked eye, and only advanced telescopes will be able to track it.

So, while it’s fun to imagine Earth with two moons, this new one will quickly make its way back into the solar system.

Earth’s moon to get a new friend tomorrow! How and where to see the second moon?

Earth’s moon will get a temporary companion tomorrow in the form of asteroid 2024 PT5, a small object temporarily captured by Earth’s gravity. This “mini-moon” will orbit Earth for just a few months before being flung back into space. While it’s not a true second moon, it’s a fascinating cosmic event.

To catch a glimpse of this phenomenon, unfortunately, it won’t be possible with the naked eye due to the asteroid’s small size (about 33-37 feet wide). However, professional astronomers using powerful telescopes can observe its brief stay in Earth’s orbit. If you’re interested in watching, keeping track of sky-watching events from observatories or online space platforms like NASA might offer real-time updates and imagery.

Online platforms or astronomy groups could also livestream the event, allowing enthusiasts to follow along virtually.

Scientific Significance of Mini Moons

1. Why Scientists Study Mini Moons 

Scientists study mini-moons for several key reasons, as these temporary natural satellites can offer unique insights into both Earth’s gravitational influence and the nature of near-Earth objects (NEOs):

2. Understanding Earth’s Gravitational Reach

Mini moons are captured by Earth’s gravity, allowing scientists to study how our planet interacts with small objects in space. This helps refine models of Earth’s gravitational field and its ability to capture asteroids temporarily, providing a clearer understanding of near-Earth space dynamics.

Insight into Near-Earth Objects (NEOs):

Mini moons are often asteroids or fragments of larger objects. By studying their composition and behavior, scientists can gain insights into the larger population of NEOs, some of which could pose potential threats to Earth. This knowledge aids in planetary defense strategies.

Space Exploration and Resource Utilization:

Mini moons represent potential targets for future space missions. These small objects are more easily accessible than larger celestial bodies, making them ideal for scientific missions or resource extraction (e.g., mining for water or metals). They could provide test cases for missions aimed at capturing asteroids or learning more about deep space exploration.

Orbital Mechanics and Cosmic Dynamics:

Observing mini-moons helps scientists refine their understanding of orbital mechanics—how objects move in space under the influence of gravity. Each mini-moon captured by Earth offers real-world data to verify and enhance existing theoretical models.

Planetary Formation and Solar System History:

  Mini moons can provide clues about the formation of the solar system, particularly when their material composition is analyzed. Scientists can compare the makeup of mini-moons with other asteroids and planetary bodies, furthering knowledge of early solar system conditions and processes.

Developing Early Warning Systems:

Studying mini-moons also supports the development of detection systems for incoming asteroids, which could one day help avert potential collisions with Earth. Tracking these objects as they orbit Earth provides a testing ground for improving detection and response technologies.

By studying mini-moons, scientists can improve their understanding of Earth’s environment, asteroid behavior, and potential future opportunities for space exploration.