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According to astronomers, a new 'minimoon' has appeared on Earth.
The asteroid '2026 QQ8' was first observed by Hungarian astronomer Christian Charnetsky in August, but was officially reported to the Minor Planet Center under the International Astronomical Union (IAU) only last month.
This asteroid is very small, only about 1 to 2 meters in diameter, and is located more than 500,000 km (323,000 miles) away from Earth, farther than the moon.
A minimoon is a small asteroid that is captured by the Earth's gravity and temporarily orbits the Earth.
Astronomers believe that 2026 QQ8 was captured by Earth's gravity in April and will leave its orbit within the next couple of months.
But the minimoon isn't Earth's only temporary celestial companion.
subsatellite
Earth's quasi-satellites get their name because, from our vantage point on Earth, they appear to orbit the Earth like the Moon. But if you look closely, these are actually asteroids that orbit the sun parallel to the Earth.
One recent example is the asteroid '2025 PN7', discovered in August last year, which has been moving almost in lockstep with Earth for several decades.
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“Subsatellites are interesting in that they don’t actually orbit our planet like the Moon orbits the Earth, but rather just stay close to us,” explains astronomer Dr. Jennifer Millard.
The length of 2025 PN7 is approximately 20 meters.
"It's not huge, it's about the size of a small office building," Dr Millard told the BBC. "Based on its current orbit, it has been around the Earth for about 60 years and is likely to remain there for another 60 years."
But none of these temporary 'satellites' can rival Earth's only true satellite, the Moon.
He explains, "As they orbit the sun, they move along a very similar path in space as the Earth. The difference is that they move very close to us, sometimes leading and sometimes falling behind, so it appears as if they are orbiting around us, but they are not actually bound by Earth's gravity."
However, while these asteroids move along their orbits, they are slightly influenced by Earth's gravity and are pulled a little closer.
All of Earth's quasi-satellites known so far are temporary, and their orbits can last from several decades to over 100 years.
mini moon
On the other hand, a minimoon is actually a celestial body orbiting a planet.
Earth's minimoons are small asteroids temporarily captured by our planet's gravity, possibly remnants from the formation of the solar system or other space debris, and usually remain in orbit for less than a year.
They are very small and difficult to capture. According to the Planetary Society, a non-profit space exploration organization, only four examples of 2026 QQ8 had been observed before its discovery, and none are currently orbiting Earth.
The last minimoon observed before 2026 QQ8 was discovered in August 2024. Known as '2024 PT5', the asteroid was about 10 meters long. This asteroid is believed to have come from the 'Arjuna asteroid belt', a group of space rocks that orbit the sun in a similar orbit to Earth.
However, further analysis of its chemical composition raised the possibility that 2024 PT5 may actually be a part of our moon that was broken off by an asteroid impact long ago.
The asteroid spent just a few months near Earth before returning to deep space. Some astronomers estimate that this asteroid will pass close to Earth again in 2055.
ghost satellite
Ghost satellites, as their name suggests, are the most mysterious of the three types.
They are thought to be swirling dust clouds that share Earth's orbit and stay in front or behind the Earth as it orbits the Sun, but there is still no widespread scientific consensus as to whether they actually exist.
But Dr. Millard believes this concept has credibility.
"There's a lot of dust in space," he says. "There are interplanetary dust particles, so I wouldn't be surprised if some of it was trapped in the gravitational stability point around Earth's orbit."
Are subsatellites or minimoons dangerous?
Despite their close distance from an astronomical perspective, these celestial bodies do not approach close enough to pose a risk.
Even when it gets closest, it remains several times farther away than the moon. By cosmic standards, it's close, but in reality, there's nothing to worry about.
“It’s not something that comes roaring out of the dark,” explains Dr. Millard.
“Even if it does come towards us, it will be moving very slowly, giving us ample warning time to see it coming and react.”
Do other planets also have quasi-satellites?
It is only in recent decades that telescopes have become sensitive enough to detect these faint and elusive asteroids.
These exist at the limit of what current technology can detect in terms of brightness.
These advances, along with improvements in computing power, have made it possible to model their movements and confirm that these mysterious objects are in fact quasi-satellites.
"It's not a rare phenomenon, it's just very difficult to detect," says Dr Millard. "If it's difficult to detect near Earth, you can imagine how difficult it would be to find it elsewhere in the solar system."
So far, quasi-satellites have been observed around Jupiter, Venus, Saturn, Neptune, and Pluto, and more may be discovered in the future.
"The solar system is still a very vibrant and dynamic place," Millard said. "It's not dead or stagnant; everything is constantly in motion."
