Comet ISON's last hurrah: shooting-stars in January, hopefully
Comet ISON before its demise. (NASA handout photo)
Astronomers are still digging through the data from Comet ISON's nail-biting and ultimately fatal solar journey in November. Because ISON fell apart, we Earthlings won't have the pleasure of watching it streak through the sky this month.
But now Karl Battams, one of the astronomers tracking ISON and the man behind the twitter handle @SungrazerComets, says we may get a show out of ISON's demise after all: a shooting-star gallery in January, with any luck.
To briefly recap, ISON was a comet that originated in the Oort cloud, a deep-frozen part of the solar system, and was on track to orbit the sun. Astronomers had never witnessed that combination of factors before, which prompted a lot of excitement and guesses as to what ISON's fate would be. But ISON ultimately didn't survive grazing so close to the sun and broke up.
At its perihelion -- its closest approach to the sun -- ISON stopped emitting what's known as "Lyman-Alpha photons," Battams previously explained. The Alpha-Lyman photons are indications of sunlight reacting with hydrogen, in this case the ice. No photons = no ice = no nucleus, the icy head of the comet. ISON's nucleus appears to have been totally incinerated.
All that remains of ISON is a dusty trail.
But in mid-January, there's a chance that Earth could pass through this dusty trail. The tiny, sand-grain-sized remnants of ISON will burn up in our atmosphere, causing shooting stars to appear.
Any remaining larger chunks of the comet will continue along their original orbit, winging all the way out of the solar system.
So take heart, sky watchers! ISON might give us a show after all, albeit less spectacular than hoped.
Battams also has reassurance for the apocalyptic wingnuts who seem to be a permanent fixture when space-object stories make the mainstream news:
"We are safe, I promise! I just paid all my bills for the month. Believe me, if I thought the apocalypse was around the corner, I'd be sitting somewhere hot and sandy with a beer in my hand right now instead of blogging and reaching for another mug of mediocre coffee!"
Kate Allen is the Star's science and technology reporter. Find her on Twitter at @katecallen.