Mercury Spices Up The Evening As The Heavenly Palace Glides By

Mercury will be low in the northwestern sky over the next couple weeks. The picture shows the view tonight about 30 minutes after sunset. The stars shown are for reference and may or may not be visible because of a bright sky. Maps created with Stellarium

Sure it’s not Venus but at least the western sky won’t be planetless this month. Mercury has returned to the evening twilight stage. It’s bright but low. Go out about a half hour to 40 minutes after sunset and look northwest to the left of the sunset point to find it. The speedy planet is about 6 degrees above the horizon 30 minutes after sunset tonight. In the coming week, it will get easier to spot  – especially for northern observers with our long twilights – as it departs the sun’s glare and gains altitude.

Meanwhile, Venus has moved to the other side of the sun and is now in the morning sky though still too close to see with the naked eye. By late June it will pop up in the east in morning twilight, and in mid-July will gather with Jupiter, the star Aldebaran and the blade-thin moon for a spectacular dawn conjunction.

A pass of the International Space Station below the Big Dipper back in April this year. Photo: Bob King

I know some of you saw the space station pass by a couple times last night. I was out between 10:30 and 10:40 p.m. and saw both the station and the Chinese Tiangong 1 (Heavenly Palace 1) satellite at the same time buzzing along different paths in the sky.

The Chinese space laboratory module, a precursor to a full-blown Chinese space station, was sent into orbit for rendezvous and docking exercises with the manned Shenzhou spacecraft. Although Heavens Above indicated it would appear as a bright 1st magnitude star, the ship was much dimmer at 4th magnitude. If you’d like to see it, click on the link, log in and select your city, then click on the Tiangong 1 link. Don’t be surprised if it’s fainter than predicted.

A ring of 1st and second magnitude stars in the constellations (from left) Gemini, Auriga, Perseus and Cassiopeia ornament the northwestern horizon at nightfall.

We’ve had a few partly clear nights lately, so I’ve been enjoying watching the ring of bright fall-winter stars arrayed along the west and north horizons.  From left to right as you face to the northwest they are: Pollux and Castor in Gemini, Mirfak in Perseus, Menkalinan and Capella in Auriga and the W of Cassiopeia with Schedar and Caph nearly equal in brightness. For some of you living in the southern U.S. one of more of these luminaries may have already been gobbled up by your local horizon.  Taken together, the bunch look like guards stationed at distant outposts around the western terminus of the sky.