August 12 2010 conjunction of Venus, Mars, Saturn, with Moon and Mercury

I don’t usually blog about things going on in the sky, unless those goings on are things we witness through telescopes or robotic space probes—things that can’t be seen with the unaided eye. I thought I’d make an exception in this case.

Mark your calendars for August 12th—and cross your fingers that the weather is clear that evening. Then, plan to be in a spot where you can have an unobstructed view of the western horizon. Check your calendar frequently to remind yourself, and when the date draws near, set your alarm clock….

Okay, what I’m going on about here is an upcoming “conjunction” of objects that will be at its stunning best on this evening. The players: Venus, Mars, Saturn, Mercury, and our own Moon, performing together as an ensemble for a limited engagement, on the stage of the western horizon.

Right now (as of mid June), Saturn (high in the south in Virgo), Mars (in the southwest in Leo, near the bright star Regulus), and Venus (that really stupendously bright thing that will give you second-hand sunburn if you’re not careful–low on the western horizon, next to the twin stars of Castor and Pollux, in Gemini) are all strung out in a long, well-spaced line, as if queuing up for some great performance. But, as time goes forward, these three will gradually move closer and closer to each other, gathering toward the western twilight.

Around early to mid August, these three will be in a quite compact little group, at one point forming a nice little triangle. But on August 12, not only will they be in about their tightest grouping of this conjunction, they will be joined by the thin crescent of the Moon, just past the New phase, and that Mercurial planet—what else? Mercury—in one amazing gathering of luminaries.

It’s not the end of the world, or a time of great change—at least, not a time of great change CAUSED by the conjunction–but it is a rare and beautiful alignment of celestial bodies that we don’t get to see more than once every few years. Hence, I’m blogging about it so you don’t miss it!

If this celestial stage act were not reward enough for those who find beauty in nature’s rare and wondrous events, August 12th is also the peak of the Perseid Meteor Shower, the most reliable of the annual meteor showers.

So, no excuses: make a plan, put together a nocturnal picnic, search a spot from where you can view the western horizon, and, if you can one, that’s away from city lights as much as possible (to make it easier to see those meteors).


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A Night to be Out Under the Stars…and Planets…and Moon…and Meteors…. 12 June,2013Ben Burress


Ben Burress

Benjamin Burress has been a staff astronomer at Chabot Space & Science Center since July 1999. He graduated from Sonoma State University in 1985 with a bachelor’s degree in physics (and minor in astronomy), after which he signed on for a two-year stint in the Peace Corps, where he taught physics and mathematics in the African nation of Cameroon. From 1989-96 he served on the crew of NASA’s Kuiper Airborne Observatory at Ames Research Center in Mountain View, CA. From 1996-99, he was Head Observer at the Naval Prototype Optical Interferometer program at Lowell Observatory in Flagstaff, AZ.

Read his previous contributions to QUEST, a project dedicated to exploring the Science of Sustainability.

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