The mother of all comets is on it’s way in from the outer limits of the Solar System, and it’s a big one! In fact, it’s the biggest comet astronomers have ever observed, with a predicted diameter of 160 kilometers (100 miles). In comparison, Comet Hale-Bopp (1997) had a diameter of 40-80 km (25-50 miles), and Halley’s Comet (1986) measured 8-15 km.
The new comet, designated 2014 UN271 [the 271 is written as subscript, but my device doesn’t sport that function], originated in the Oort cloud, between 1,000 and 100,000 AU from the sun. An AU (astronomical unit) is defined as 150 million kilometres (93 million miles) or approximately the distance between Earth and the Sun. The comet is about 20 AU from the Sun now, even as I type this.
Comet 2014 UN271 was discovered by computers programmed to search the massive database gathered by the Dark Energy Survey from August 2013 until early 2019. With this information, the comet’s orbit was calculated and made public June 19, 2021 through the publication Minor Planet Electronic Circular. At an inclination of 95°, the highly eccentric trajectory is nearly perpendicular to the orbital plane of Earth and the other planets in our system. The giant comet will reach perihelion (closest point in its orbit to the Sun) on January 23, 2031. However, that point will be approximately 10.95 AU from the sun, or slightly farther out than the orbit of Saturn. In comparison, Halley’s Comet reached perihelion at 0.586 AU, and Hale-Bopp checked in at 0.914 AU.
Given this great distance from the Sun we might conclude that comet 2014 UN271 might not be as impressive a sight in 2031 as Hale-Bopp or Halley’s Comet were, in which case this is not the SMOD you’re looking for. Looking at it from the sunny side, though, the comet is 20 AU out and already has a coma, or tail. Also, it’s humongous, so it might be extra bright. I’m going to be optimistic, and hope for a terrific show. And if they’re looking for a better name than 2014 UN271, I submit ‘Comet Godzilla’, because, why not?
Question Of The Night: Did you see Halley’s Comet in ’86, or Hale Bopp in ’97? If you saw both, which left a greater impression on you?
