We are constantly scanning the skies these days for any and all threats, be they terrestrial or astronomical. Several of those surveys are looking for space rocks because, well, remember the dinosaurs? They didn’t have a planetary defense office and look what happened to them. They’re now chickens.

Last week, we told you how the ATLAS survey has now expanded to two more countries, for a total of four observatories, which can scan the entire night sky in both the northern and southern hemispheres. This next story is about a different survey telescope: Pan-STARRS1 in Hawai’i. You may recognize the name because, like ATLAS, there are quite a few Comet Pan-STARRS in the books. And just as ATLAS can find comets and asteroids, so too can Pan-STARRS.

Back in 2019, an asteroid named 2019 PR2 was discovered in the Pan-STARRS observations. Then the Catalina Sky Survey announced the discovery of a second asteroid in the same vicinity, 2019 QR6. And this week, Lowell Observatory in Arizona confirmed the two asteroids in follow-up observations and announced that they are from the same parent body. Not only that, but they only split off from that parent body, whatever it was, about 300 years ago.

If Galileo had been able to search for these asteroids, he would have only seen one, not this tiny pair, the largest of which is a mere kilometer in diameter.

One of the really interesting aspects of this discovery is that it once again involved the use of precovery data. Scientists went back through the Catalina Sky Survey data and found the pair in observations taken fourteen years ago. With that data and the more recent observations, they were able to determine very precise orbital elements, and that helped them conclude the two were once one and separated basically this morning. 

The paper on this discovery is published in the Monthly Notices of the Royal Astronomical Society, and lead author Petr Fatka notes: To have a better idea about what process caused the disruption of the parent body, we have to wait until 2033 when both objects will be within the reach of our telescopes again.

We look forward to bringing you the results of that observation when it happens.

More Information

Lowell Observatory press release

“Recent formation and likely cometary activity of near-Earth asteroid pair 2019 PR2–2019 QR6,” Petr Fatka et al., 2022 February 2, Monthly Notices of the Royal Astronomical Society