What Is A Quasi Moon? I Oxford Open Learning

    Quasi moons

    What Is A Quasi Moon?

    … And Does Earth Have Any?

    A quasi-moon, also known as a quasi-satellite, is a celestial body that temporarily orbits a planet, but is not gravitationally bound to it in the same way as a natural moon. Instead, a quasi-moon follows a complicated and often irregular path around the planet, sometimes staying in orbit for a considerable amount of time before being ejected into space or drawn into a different orbit.


    Perhaps the most well-known quasi-moon has, until recently, been Zoozve. This is an asteroid that appears to be in orbit around Venus. A closer inspection of its celestial journey, however, reveals clearly that it is not gravitationally bound to the planet. Rather, Zoozve goes around Venus and the Sun in a complex and unstable orbit which means it will be ejected from this quasi-satellite orbit or get drawn into another orbit.

    Far Away And Close To Home

    What’s fascinating about Quasi-moons is that although astrophysicists as far back as 1913 had predicted their existence, the theory was not confirmed until 2002 when Brian Skiff (of the Lowell Observatory) discovered Zoovze. Since this discovery, 8 more quasi-moons have been found; one associated with Neptune and 7 others that are orbiting alongside Earth. Neptune’s quasi-satellite doesn’t have a name but is referred to as 2007 RW 10 and has been in this state for around 12,500 years. It is believed that it will remain the same for just as many more.

    The 7 confirmed current quasi-satellites of Earth are 469219 Kamoʻoalewa and (164207) 2004 GU9, as well as (277810) 2006 FV35, 2014 OL339, 2013 LX28, 2020 PP1, and 2023 FW13, which is the most recently discovered.

    Quasi Moon 2023FW13

    The new-found quasi-moon 2023 FW13 was first noticed last year on March 28 by the Pan-STARRS observatory and was confirmed by 3 other observatories before being officially revealed on the 1st of April. Experts believe that it has been orbiting the earth since 100 BC and will do so for another 1,500 years. Perhaps reassuringly, tt is thought to be the most stable earth-associated, quasi-satellite ever discovered!


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    I am a practising HR consultant working with several start-ups on an ongoing and ad-hoc basis in the London and M4 area, and am a Chartered Member of the Chartered Institute of Personnel and Development or CIPD. I am the Director of thecareercafe.co.uk; thecareercafe.co.uk is a resource for start-ups and small business. It includes a blog containing career advice, small business advice articles, HR software reviews, and contains great resources such as HR Productivity Apps.