Jimmy Westlake: June sky highlights
June 1, 2010
Warm June evenings are perfect for stargazing, and the upcoming month offers plenty of celestial events to keep you busy looking up. Whether you are camping out under the stars or viewing from your back porch, you won't want to miss any of the action.
June opens with the red planet Mars rapidly closing in on Leo's brightest star, Regulus. The two are closest together on the evening of June 6, when they shine less than 1 degree apart.
You barely will be able to fit your finger at arm's length between the two. Start watching several nights before June 6 to appreciate Mars' orbital motion relative to the background stars.
The color contrast between ruddy Mars and icy-blue Regulus should be striking. Although they look close together, it is merely a line-of-sight illusion — Regulus is 78 light-years away while Mars is only 12 light-minutes away. Look for the pair between 9:30 and 10 p.m. high in the western sky, not far from the dazzling planet Venus.
And speaking of Venus, on June 19 the Evening Star has a close encounter of its own with the naked-eye star cluster called the Beehive.
Bright moonlight will hamper the view, so use binoculars to enhance the twinkling stars in the Beehive, less than 1 degree to the left of Venus at 10 p.m. low in the western sky. In the case of cloudy weather, Venus will appear close to the Beehive for a couple of days on either side of June 19.
When the full Hay Moon rises at sunset June 25, it will just look like any other gorgeous full moon, but beginning at 4:17 a.m. the next morning, the northern half of the moon will pass into the Earth's dark shadow, creating a partial eclipse of the moon.
The dark "bite" out of the lunar "cookie" will be greatest at 5:39 a.m., just as the moon sets in the southwest and the sun breaks the horizon in the northeast.
From Colorado, most of this eclipse will be seen during morning twilight. It isn't every day that you get to see an eclipsed moon in a colorful predawn sky.
This one is just a warmup for the spectacular total eclipse of the moon that we will be treated to this coming December.
The world is waiting to see just how bright newly discovered comet McNaught will become in late June. Comets are notoriously unpredictable in how bright they will appear to us as they round the sun and begin to boil away and grow their tails.
I'm going to go out on a limb and predict that Australian comet-hunter Rob McNaught's recent discovery, Comet McNaught 2009 R1, will put on a nice show for us after sunset June 20 and again the next morning before sunrise June 21. The comet could be faintly visible with the unaided eye as it passes less than 2 degrees from the very bright star Capella in the constellation Auriga. Binoculars will enhance the view considerably.
Look very low in the northwest after sunset on June 20 for the bright star Capella and then low in the northeast between 3 and 4 a.m. June 21.
Comet McNaught will appear very close to Capella. If I am right, this could be an unforgettable view and our best chance to see a naked-eye comet this year.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. Check out Jimmy's astrophotography website at http://www.jwestlake.com.