If you live north of the equator, now is the best time to see a rare bright green comet across the sky.
The last time the comet was seen was 50,000 years ago.
NASA officials said the icy visitor was first spotted in March 2022 while inside Jupiter’s orbit.
It has been visible to those in the Northern Hemisphere through binoculars for the past few weeks, but it will be closest to Earth – and brightest – on Wednesday.
“Comets are very unpredictable, but if this one continues its current trend in brightness, it will be easy to see,” NASA said on its blog earlier this month.
“It is possible that it could be visible to the unaided eye under dark skies.”
The icy celestial body – called C/2022 E3 (ZTF), a “mouthful of a name”, according to NASA – is making its closest approach to the sun on January 12 before making its closest approach to Earth the 2nd of February.
At that point it will be just about 26 million miles (42 million kilometers) away from the planet, according to the Planetary Society.
A humbling experience
Retired high school science teacher and astrophotographer Dan Bartlett is capturing images of the comet from his cabin near Yosemite National Park in California and calls it a “humanizing” experience to watch the sky.
“I’m telling you – binoculars, a dark site – you’ll see something. Bring friends and you’ll see something for a lifetime,” Mr Bartlett told the BBC.
He keeps two “spectacular scopes” on his porch in June Lake, and the clear nights and dark skies allow him to capture the amazing photos.
“Whenever you have a lake system around you, or an ocean system, it creates a smoother airflow. Smoother airflow means the stars don’t blur as much and you get more detail,” he explained.
To observers in the Northern Hemisphere without a telescope, the comet will appear as “a small greenish smudge in the sky”, while those with a telescope may see the comet’s dramatic visible tail, the Planetary Society said.
Northern Hemisphere observers will see a bright green glow in the morning sky as the comet moves northwest during January. Those in the Southern Hemisphere will be able to see it in February, NASA said.
The comet is not expected to be as “spectacular” as Comet NEOWISE 2020 – the brightest comet visible from the Northern Hemisphere since 1997, NASA said.
But it’s still “a wonderful opportunity to make a personal connection with an icy visitor from a distant solar system”, NASA said.
The comet takes about 50,000 years to orbit the sun, so “the opportunity to see it will only come once in a lifetime”, the Planetary Society said.