This week may be the last chance to snag a glimpse of a rare green comet as it zings past Mars in the night sky, potentially visible with no more than a pair of binoculars.
The comet, called C/2022 E3 (ZTF), streaked past Earth last Wednesday, the closest it has come to our planet in 50,000 years.
It is set to pass near Mars on Friday evening and through Saturday. Although the comet won’t be visible to the naked eye, a simple pair of binoculars should allow you to spot it.
Long-exposure photographs of the comet show a greenish glow around it, a short dust tail and then a long, thin ion tail stretching behind it as a line across the night sky—but through binoculars, it’s more likely to appear as a smudge in the sky next to the bright glow of Mars.
If you’re thinking of grabbing a pair of binoculars or a telescope to get a look at this cosmic traveller on Friday or Saturday, the first thing you’ll need to find in the sky is Mars.
The red planet will be visible to the naked eye in the night sky across all of Canada, provided there’s a clear sky that night.
Mars can be found by looking east in the sky, or southeast, depending on where you are in Canada, and it’ll appear as an orange dot to the right of the Orion constellation. It will be closer to the horizon for those in the western provinces, but should still be bright enough to be visible even in areas with a lot of light pollution.
The comet should be visible by binoculars or through a small telescope after the sun has gone down, with the best visibility likely in the pre-dawn hours.
The Royal Museums Greenwich recommends that any hopeful comet viewers try to find clear skies, allow their eyes to become adjusted to the darkness for at least 15 minutes before looking for anything in the night sky, and not look at your phone or any other bright lights while attempting to look for the comet.
Those in the northern hemisphere who have a telescope may be able to spot the comet past this weekend, as it will remain visible in the night sky with a telescope until the end of April, according to EarthSky.com.
Southern hemisphere viewers are unlikely to be able to see the comet, but the Virtual Telescope Project is holding a livestream of the event online, which is set to begin at 2 p.m. (EST) on Feb 11.
According to NASA, the comet was first spotted by astronomers in March 2022 using a wide-field survey at the Zwicky Transient Facility. It was initially observed as a potential asteroid before astronomers realized it had all the hallmarks of a comet.
While asteroids are largely made of rocks, comets are mostly ice and dust, with a tail of dust and gas steaming behind them
When it passed closer to Earth on Feb 1, C/2022 E3 (ZTF) was still around 100 times farther away than the moon is from us. This particular comet’s green glow comes from the breakup of dicarbon around the comet, boosted by UV radiation from the sun.
Astronomers believe this comet originated from the Oort Cloud at the edge of our solar system, where most long-period comets come from. Unlike the majority of stellar objects, which orbit on a flat disc around the sun, the Oort Cloud is formed in a spherical shell around our solar system, made up of dense space debris, including chunks of ice the size of mountains, according to NASA.
As a long-period comet, C/2022 E3 (ZTF) has a very large, loose orbit, which is why the last time it was near Earth was during the Stone Age. It’s unknown if its orbit will bring it close to Earth again in the foreseeable future, or whether it might be on its way out of our solar system for good.
