If you were told that the Moon we see in our night sky isn't Earth's only one, you'd probably be a bit surprised. But some people have started to call the strange object that seems to orbit our planet, Earth's 'second moon' - and now scientists may have discovered where it came from.
In fact, there are many moon-like objects around us in space, but only a handful of the over 200,000 'near-Earth asteroids' (NEAs) have similar orbits to Earth.
One of these, named 469219 Kamo'oalewa, orbits the Sun, but moves in sync with our orbit so appears to orbit the Earth. This makes it our 'quasi-moon' or, to some, an 'Apollo asteroid.' Potentially as big as the Statue of Liberty, Kamo'oalewa is between 40 and 100m (131-328 feet) across and rotates quickly: completing one rotation every 28 minutes.
Generally, NEAs are space rocks that scientists think have come from the Main Asteroid Belt between Mars and Jupiter. But new research reveals Kamo'oalewa may be more moon than asteroid.
Published in the journal Nature Astronomy, the new study used existing analysis of Kamo'oalewa's light spectrum. This analysis revealed that it had silicates (a type of mineral) that are more common in lunar samples. In other words, Earth's 'second moon' probably came from its first.
The research team from Tsinghua University, China, used computer model simulations to test this theory. They found that Kamo'oalew...
In fact, there are many moon-like objects around us in space, but only a handful of the over 200,000 'near-Earth asteroids' (NEAs) have similar orbits to Earth.
One of these, named 469219 Kamo'oalewa, orbits the Sun, but moves in sync with our orbit so appears to orbit the Earth. This makes it our 'quasi-moon' or, to some, an 'Apollo asteroid.' Potentially as big as the Statue of Liberty, Kamo'oalewa is between 40 and 100m (131-328 feet) across and rotates quickly: completing one rotation every 28 minutes.
Generally, NEAs are space rocks that scientists think have come from the Main Asteroid Belt between Mars and Jupiter. But new research reveals Kamo'oalewa may be more moon than asteroid.
Published in the journal Nature Astronomy, the new study used existing analysis of Kamo'oalewa's light spectrum. This analysis revealed that it had silicates (a type of mineral) that are more common in lunar samples. In other words, Earth's 'second moon' probably came from its first.
The research team from Tsinghua University, China, used computer model simulations to test this theory. They found that Kamo'oalew...
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BBC Science Focus (Digital) - 1 Issue, June 2024