John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
The glowing, green interloper will become even more brilliant in coming weeks.
Vigilant observers this week might've noticed an extra star in the sky, gleaming emerald like a dragon's pupil. This is Comet Lovejoy, a luminous ball of debris and frozen gas that's appearing above cities from New York to Seattle to Cork, Ireland. Here's what it looked like this past weekend in Martos, Spain:
Lovejoy—one of a ridiculous number of comets discovered by Australian astronomer Terry Lovejoy—has taken a long, looping journey through the solar system to reach its nearest approach to Earth on Wednesday. The comet will grow even more resplendent in the next two weeks as it beats its retreat, . Explains Tony Phillips at Spaceweather:
(C/2014 Q2) continues to brighten, and it can now be seen with the naked eye even from light-polluted urban areas. Science journalist and longtime comet watcher Mariano Ribas reports from the Planetario de Buenos Aires: "Last night, I could see Comet Lovejoy with my unaided eyes in the sky of Buenos Aires. Barely, and only using averted vision. But I saw it!"...
On Jan. 7th, Comet Lovejoy was at its closest to Earth: 0.47 astronomical units (70 million km) away. Although the comet will be moving away from us for the rest of the month, it will continue to grow in brightness because it is still moving closer to the sun.
Much like with meteor showers, city dwellers can maximize their comet-spotting chances by seeking dark places like parks and times when the moon's not so prominent (the black period before moonrise is ideal). A decent pair of binoculars will add immeasurable help. The place to look is high in the celestial dome east of Orion. This nice astronomical chart outlining the comet's location in the days ahead comes from Sky & Telescope:
Tonight, you'll have about an hour of darkness before moonrise to view Comet Lovejoy C/2014 Q2. Sky & Tel chart pic.twitter.com/9GuQDWqLke— Louis Suarato (@LouisS) January 7, 2015
And if you miss it, be comforted that our mole-person descendants peering through periscopes at the irradiated skies can catch it again in about 8,000 years.