Is it a (very fiery) bird? Is it a (very slow moving) plane? Perhaps you’ve pondered the nature of that really bright point of light currently appearing in the western sky before sunset and remaining prominent in the night sky?

It’s the planet Venus, the brightest celestial object in the night sky excepting the moon.

Venus is sometimes referred to as the evening star but its steady glow gives away its identity as a planet. Stars twinkle but planets do not. Twinkling, which scientists refer to as “stellar scintillation” because their mothers never taught them nursery rhymes, is the end result of the light from far away stars being battered about by our planet’s atmosphere. As the light passes through the different densities found in the upper atmosphere it distorts in a way that we perceive as twinkling. Planets do not twinkle because the light, while much less intense than that emitted by a star, is far closer to us. Think of a planet being like your neighbour’s porch light and a star like the headlights on a jet cruising overhead. The jet’s lights are considerably brighter but the dinky little 40-watt porch light will appear much more stable to you.

So a distinct inability to twinkle is a good sign you are looking at a planet. If it doesn’t twinkle and looks a little orange it’s probably Mars. Speaking of Mars, there’s an email that makes the rounds every year or so proclaiming that Mars will soon look as large as the moon in the night sky. It’s not true. Ain’t gonna happen. And that’s a good thing because the only time Mars would ever appear to be that large is right before it smashed into us.

Mars, Venus, Jupiter and Saturn are the only planets that are really visible to the naked eye and Saturn is just barely there. I once saw Mars, Jupiter and Saturn in the same part of the sky while camped out beside a lake far from civilization and the light pollution that comes with it. Venus and Jupiter were both easy to spot, as was the slightly reddish light from Mars. It took four of us about half an hour to come to a consensus that the tiny little pin prick of light that we could kind of see if we didn’t really look straight at it was Saturn. And that was with a diagram telling us where to look.

So if you’ve always wanted to know what a planet looks like or just want to impress your friends with your astrophysical expertise, look for the first star-like object to appear in the sky. It’ll be right near where the sun is setting. If you live in Rutland or the Mission, just look towards the bridge. You can’t miss it. If you really want to impress your friends you can point out that it was Copernicus’ study of the phases of Venus that led to his theory of heliocentricity – the notion that the planets orbit the sun. Galileo later used a new gadget called the telescope to prove the theory.

The Royal Astronomical Society of Canada Okanagan Centre often set up telescopes at public spots in and around Kelowna. I got a terrific glimpse of Jupiter and several of it’s moons last summer. You can check their web page at http://www.ocrasc.ca/ for upcoming viewing events.