British Columbia

Mars, Venus and the moon to put on astronomical dance Tuesday

Mars, Venus and the moon will be exceptionally close together on the evening of January 31, making for a great astronomical viewing party, says a Vancouver astronomer

Astronomical conjunction peaks, Jan. 31, says astronomer

In this planetary conjunction, the planets Venus (top left), and Jupiter (top right) form a triangle with the moon. On January 31, Venus and Mars will form their own triangle with the moon. (Bullit Marquez/Associated Press)

You won't have to get out your telescopes to see Mars, Venus and the moon put on a show, Jan. 31.

The three celestial objects will be exceptionally close to each other on Tuesday night in a rare celestial treat called a conjunction.

"A conjunction is when you have the apparent visibility of multiple things in one particular area of the nighttime sky," said Derek Keif, an astronomer at the HR MacMillian Space Centre.

"There's going to be a whole bunch of bright stuff in one region of our sky," he said. "You'll actually be able to see Mars, Venus and the moon really, really close together."

How close together?

Venus, Mars and the moon will form a bright and tight-knot triangle Tuesday night. Kei says the total space they'll take up is no larger than the size of your fist if you were to extend your arm.

Of course, it's all relative — they'll still be millions of kilometres apart.

But from the perspective of Earth, the conjunction marks a rare event where the objects meet in a unique dance.

"[It's] literally a dance because all of these components are moving at different speeds — our moon moves all the way around the Earth once every 29.5 days," said Kief.

"Mars and Venus are doing the same — but their time scales are much, much, much slower."

The conjunction has been going on since early January 2017. But after the 31st, Mars and Venus will begin moving away from each other.

When to watch

Kief says the best time to watch the conjunction is after sunset, starting at 8 p.m. PT.

He says to identify Venus, look for the glowing object that has a red and yellow tinge to it. Venus will shine slightly brighter than Mars, since it's closer to the Earth and has a highly reflective atmosphere that redirects light from the sun. Mars has an orange and red tinge to it.

And remember, if the celestial object you're looking at twinkles, it's probably not a planet.

"Stars twinkle in our nighttime sky because they're so far away," he said,

Planets on the other hand, are much closer.

"The atmosphere doesn't distort them as much, so you actually see them as a solid colour as opposed to the twinkling stars."

With files from CBC's North by Northwest

To listen to the full interview, click on the audio labelled: Mars, Venus and the moon to put on astronomical 'dance' on Tuesday