Thanks to a close encounter with Venus , skywatchers the next few nights get a chance to easily glimpse the 7th planet from the Sun – the green giant Uranus.
While the pair of planets will be visible together within the field of view of any standard 7×50 binocular until Feb.15th, Venus and Uranus will have their closest encounter for 2012 on the 10th at 2:oo UT (9 pm EST) making it well positioned for North American observers in the evening of Feb.9th. The two worlds will only be separated by 0.3 degrees - less than the width of the moon’s disk in the sky.
Shining at magnitude 5.9, Uranus is technically visible to the naked eye as a superfaint bluish star, but that’s really only possible from very dark skies far from city lights. So what this means for most of us is that we need at least binoculars to catch sight of it. Through a small telescope under medium to high magnification it really looks distinctively like a bonafide planet with its tiny blue-green disk. By the way, it’s the absorption of red light by methane in its atmosphere that gives Uranus it’s cool cyan coloring.
Start your hunt by facing the west-southwest horizon at local dusk and zero-in on beacon like Venus – the brightest starlike object in the evening sky. Then with your binoculars or a small telescope look for a tiny, faint blue-green dot to the left of Venus.
And remember if you do get clouded for the main show on the 9th then you can still catch the pair for a few days after as Venus quickly leaves behind the green planet , rising higher in the western sky.
First spotted in 1781, Uranus was the first new planet discovered since ancient times however it wasn’t until NASA’s Voyager 2 flew by in 1986 that we got an up close view at the third largest planet in the solar system – 4 times the width of Earth.
It’s so far away from the Sun that if you were a Uranian – you would be lucky to celebrate your first birthday. A single year on this planet, the time it takes to make one orbit around the Sun, lasts just about a human lifespan – 84 years.
Sitting at a whopping 3.1 billion km from Earth, Uranus’ great distance means that it takes the sun light reflecting off its upper cloud deck 2 hours and 52 minutes to reach your eye. Just a little something to think about when gazing at that tiny green dot in the sky!
Skywatching Extra: After about 9 pm local time on Feb.9th face the eastern horizon and watch the waning gibbous moon hang lower right of orange colored Mars. The cosmic duo will be 10 degrees apart - equal to the width of your fist held at arm’s length.
Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.