Two years ago, KJZZ  News reported that Kamo'oalewa — a space rock co-orbiting the sun with the Earth — likely came from the moon, rather than zooming in from a ring of asteroids beyond Mars, as is typical.

“This asteroid is actually orbiting the sun, but it's in this peculiar orbit that so that, from the vantage point of the Earth, it looks like it's orbiting the Earth,” said co-author Renu Malhotra of the University of Arizona Lunar and Planetary Laboratory.

Now, scientists have published a paper in the Nature journal Communications Earth & Environment that explains how this surprising event might have occurred.

A chunk of rock knocked off the moon by a collision should fall back to the lunar surface or end up orbiting, or falling onto, the Earth — not circling the sun alongside our blue planet in an orbit that is seemingly stable over millions of years.

But that’s exactly what Kamo'oalewa did, thanks to the bank-shot to end all bank-shots.

As in real estate, it largely came down to three things: location, location, location.

“Launches from some parts of the moon are more favorable than other parts,” said Malhotra. “So, the most favorable we found is from the trailing hemisphere of the moon. That’s the hemisphere that’s opposite to the moon’s orbital motion.”

The balance of forces involved was so delicate that another type of location also exerted its influence: The arrangement of the solar system’s other planets.

“The gravity of the other planets, even though it's very small, can nudge things in just the right way to end up keeping the exit orbit very close to the Earth's orbit,” said Malhotra.

She and her team are now studying those conditions.

“And that will also help us narrow down when this object left the moon, and exactly where on the moon,” she said.

The team has already ballparked the area of the impact, which they calculate blasted Kamo'oalewa spaceward at just above escape velocity.

In fact, Malhotra said she’s confident the team can pin down the actual crater made by the event.

“That's not been done to my knowledge,” she said. “Typically, it's not something that we are able to do, so that's really exciting.”

Addy Graham/University of Arizona.

An artist's conception of the quasi-satellite Kamo'oalewa.