Astronomers Discover Previously Unknown Quasi-Moon Near Earth (cnn.com)
- Reference: 0179446648
- News link: https://science.slashdot.org/story/25/09/22/0034204/astronomers-discover-previously-unknown-quasi-moon-near-earth
- Source link: https://www.cnn.com/2025/09/16/science/earth-quasi-moon-2025-pn7
> The newly discovered celestial object, named 2025 PN7, is a type of near-Earth asteroid that orbits the sun but sticks close to our planet. Like our world, 2025 PN7 takes one year to complete an orbit around the sun...
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> The newly found 2025 PN7 is just one of a handful of known quasi-moons with orbits near our planet, including [2]Kamo'oalewa , which is also thought to be an ancient lunar fragment. Kamo'oalewa is one of the destinations of China's Tianwen-2 mission launched in May, which aims to collect and return samples from the space rock in 2027. The Pan-STARRS observatory located on the Haleakala volcano in Hawaii captured observations of 2025 PN7 on August 29. Archival data revealed that the object has been in an Earth-like orbit for decades.
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> The quasi-moon managed to escape the notice of astronomers for so long because it is small and faint, said Carlos de la Fuente Marcos, a researcher on the faculty of mathematical sciences at the Complutense University of Madrid who recently authored a paper about the space rock. The paper was published on September 2 in the journal [3] Research Notes of the American Astronomical Society , which is for timely non-peer-reviewed astronomical observations. The space rock swings within 186,000 miles (299,337 kilometers) of us during its closest pass of our planet, de la Fuente Marcos said.... "It can only be detected by currently available telescopes when it gets close to our planet as it did this summer," de la Fuente Marcos explained. "Its visibility windows are few and far between. It is a challenging object...."
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> Astronomers are still trying to figure out 2025 PN7's size. About 98 feet (30 meters) across is a reasonable estimate, de la Fuente Marcos said. It also has the potential to be 62 feet (19 meters) in diameter, [4]according to EarthSky . The space rock is currently the smallest-known quasi-moon to have orbited near Earth, de la Fuente Marcos said.
[1] https://www.cnn.com/2025/09/16/science/earth-quasi-moon-2025-pn7
[2] https://www.cnn.com/2024/05/01/world/lunar-crater-asteroid-scn/index.html
[3] https://iopscience.iop.org/article/10.3847/2515-5172/ae028f
[4] https://earthsky.org/space/earth-quasi-moon-2025-pn7/?mc_cid=305c0b2c14&mc_eid=be2a1ee2ac
Small enough to be interesting (Score:2)
It's small enough a nation or some billionaires could bring it close to earth and mine it.
Re: Small enough to be interesting (Score:2)
Just install a tow hitch and drag it home for everyone to look at? Sure buddy
So 100 feet is quasi-moon, then promote Pluto (Score:2)
Promote Pluto back to a full planet.
Obligatory (Score:2)
That's no moon.
What's with the "moon" term? (Score:2)
It's just a small rock/asteroid in a fleeting orbit. Calling it a quasi-satellite would seem much more appropriate. I get the feeling someone wanted to sex up the story.
Re: (Score:2)
Per [1]the actual discussion identifying the object, [groups.io] it is a quasi-satellite. I think the moon related naming comes from the general public thinking of satellites as being man-made objects in Earth's orbit. However, plenty of publications have referred to such objects as being quasi-moons, including writers for The Planetary Society.
[2]https://www.planetary.org/arti... [planetary.org]
> Quasi-moons
> Earth’s quasi-moons get their name because, from a certain vantage point, they appear to act like moons. But from a wider perspective, it becomes obvious that they aren’t actually moons at all — they’re asteroids.
[1] https://groups.io/g/mpml/topic/2025_pn7/114980804
[2] https://www.planetary.org/articles/the-quasi-moons-of-earth
Random bright object in the sky? Probably ISS. (Score:2)
That's no moon. It's a space station. :-D
Too little (Score:2)
19 meters in diameter? Nah, not worth naming it
GatGPT5:
Short answer: a 19-meter asteroid is “Chelyabinsk-class.” It almost certainly explodes high in the atmosphere (an airburst) rather than making a crater. Think spectacular fireball, a very loud shock wave, lots of broken windows—and mostly local damage.
Re: Too little (Score:3)
How about Rocky?