The waning moon Tuesday morning brushes up against a red pine. Photo: Bob King
Nice to walk out the door this morning and see the crescent moon in the south before sunrise. I find the crescent the most eye-catching lunar phase. Don’t forget — tonight we have a fine pass of the International Space Station beginning at 6:14 p.m. just under the planet Venus in the southwestern sky. This would make a good photo opportunity for an enterprising photographer.
You can use brilliant Venus to help you find the outer planet Uranus from Jan. 20-23. The map is drawn for around 6:30 p.m. each night, and the black circle represents a typical binocular field of view. Uranus is moving too, but much more slowly, so it will stay in the same place during the interval. Illustration created using SkyMap software by Chris Marriott.
Venus will be our guide the next few nights to finding the planet Uranus. It’s a fortunate thing that all the planets travel in nearly the same plane of the solar system. They’re like runners on a track. The faster ones closer to the sun lap the further ones. That makes for lots of cool lineups called conjunctions. This week, Venus will be passing near the outer planet Uranus. If you’ve never seen Uranus before, destiny is knocking on your door.
Uranus is barely visible with the unaided eye from a dark sky location, but it’s easy to see in binoculars. Since the planet looks just like a star, the problem is distinguishing it from all the other stars in the vicinity. Venus gets you close enough to make this task easier. The map above is about one binocular field of view wide. The little unmarked dots are stars, all of which are bright enough to be seen in most binoculars.
The planet Uranus is shown in true comparison size to Venus. Even though Uranus is four times the diameter of Venus, it’s so much further away that it looks like a star in binoculars and a minute disk through a telescope. Illustration: Bob King
First, print out a copy of the map, grab a red or dim flashlight and go outside. Point your binoculars at Venus and set it off to one side of your binocular field. Try not to stare it! The glare will make dimmer Uranus harder to find. Now compare the map to the real view in the binoculars, and "star hop" your way from Venus to Uranus. If you find it, you deserve a big congratulations. Let us know via the comments links how it went.
I’ll be out there the next clear night to try it myself and will update the blog with more tips if needed. Good luck!