According to the Observer’s Handbook of the Royal Astronomical Society of Canada, there are 11 meteor showers which might be thought-about to be the “principal” shows of the yr. In order to make the listing, a specific meteor bathe should produce at the least 10 meteors per hour at most.
As it seems, inside a span of solely eight days throughout mid to late December, the meteor shower on the prime of that listing and the bathe on the backside of the listing attain their peak.
Of course, there are the Geminids which is now thought-about essentially the most prolific and dependable of all of the annual meteor shows. And then, there’s the “other” December bathe that in stark distinction, hardly will get a lot discover in any respect: The Ursid meteor shower. This yr, the height of this meteor show is due throughout the pre-dawn hours of Wednesday, Dec. 22.
Related: See stunning pictures of the Geminid meteor shower of 2021
The Ursids are so named as a result of they seem to fan out from the neighborhood of the brilliant orange star Kochab, within the constellation of Ursa Minor, the Little Bear. Kochab is the brighter of the 2 outer stars within the bowl of the Little Dipper (the opposite being Pherkad), which appear to march in a circle like sentries round Polaris, the North Star.
A poor Ursid yr
The incontrovertible fact that Kochab is positioned so close to to the north pole of the sky implies that it close to by no means units for many viewers within the Northern Hemisphere. And for the reason that Ursids appear to fan out from this explicit area of the sky, means that you could search for these faint, medium-speed meteors all via the evening in case you care to.
But this yr the Ursids will likely be virtually utterly squelched below the sunshine of the brilliant waning gibbous moon. With the height of the Ursids coming just some nights after the full moon, implies that these meteors will likely be in direct competitors with what will likely be in essence an enormous celestial floodlight illuminating the sky on the primary full evening of winter.
This is certainly a really unlucky circumstance, since even when viewing circumstances are much more favorable hardly anybody ever makes an attempt remark of those meteors.
That observers have uncared for the Ursids isn’t a surprise. In distinction to the Geminids, which may produce as much as 120 meteors per hour, the standard Ursid price is however a fraction of that; usually talking, they produce about 10 or so per hour at their peak. They are literally the dusty particles shed by the periodic Comet 8P/Tuttle, which circles the sun in a 13.6-year orbit and was final seen in early 2008 and due again in August 2021.
On event, the earth has interacted with a dense, slender stream of particles shed by this comet, which has brought about temporary outbursts of Ursid meteors numbering within the dozens per hour, similar to in 1945 and 1986; counts reached 30 per hour in 2000 and once more throughout the years 2006 via 2008. Unexpected outbursts of exercise might have occurred in different years, but when they did no person apparently was round to see them. The most definitely purpose is their proximity on the calendar to the Christmas holidays, in addition to the frigidity of late December nights.
So … it seems that viewing circumstances for the Ursids in 2021 will likely be “un-BEARable!”
As Dodger followers in Brooklyn used to say: higher luck subsequent yr!
Joe Rao serves as an teacher and visitor lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers’ Almanac and different publications. Follow us on Twitter @Spacedotcom and on Facebook.
