The “evening star” nuzzles the lion the next few nights. Venus will pass quite close to Regulus, Leo’s brightest star. At their closest, they’ll be just one degree apart – the width of a pencil held at arm’s length.

Despite their proximity in the sky, Venus and Regulus are nowhere close to each other in reality – they’re separated by many trillions of miles.

Venus is a planet in our own solar system. Right now, it’s 92 million miles away. That’s about the average distance to the Sun – a distance known as the astronomical unit. It’s the basic “yardstick” for measuring the solar system. It’s a lot more convenient than miles or kilometers – a lot fewer zeroes to worry about.

But it’s not a great yardstick for measuring the distances between stars. Regulus, for example, is more than five million astronomical units from us – five million times farther than Venus. Yet it’s one of our closer neighbors.

So there are two other units for measuring those distances. The most common is the light-year – the distance light travels in one year – almost six trillion miles. And astronomers generally use parsecs; one parsec is three and a quarter light-years. So Regulus is about 24 parsecs from Earth.

Regulus is close to the upper left of Venus at nightfall this evening. Venus will slide past the star over the next two nights. They’ll be closest together on Wednesday – but close only in appearance.

Script by Damond Benningfield