The Sky This Month – July 2012
Posted by Brian Ventrudo
Venus is back and this time it has company. After transiting the Sun’s face last month, the bright planet now takes its place as the “morning star”, glittering brightly in the pre-dawn sky along with Jupiter and two famous star clusters. This ensemble makes for lovely viewing if you’re up really early (or if you’ve stayed up really late). Also this month, you’ll have a chance to see two shadows cast simultaneously onto Jupiter by its moons Io and Europa, and observers in Europe will see the Moon pass in front of the planet Jupiter in the pre-dawn hours. Here’s what to look for in the sky this month…
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1 July. From today through July 6, the Pleiades star cluster, Jupiter, Venus, the star Aldebaran, and the Hyades star cluster arrange themselves into a straight line over the eastern horizon about one hour before sunrise. This alignment makes for excellent viewing with the unaided eye or with binoculars. It also makes for a good photographic opportunity (to learn more about how to easily take images of the night sky with off-the-shelf cameras, click here…)
Venus, Jupiter, the Pleiades, and Aldebaran as seen from 45N latitude before dawn on July 1, 2012 (click to enlarge)
4 July. Full Moon, 18:52 UT. (This full Moon is often called the “Full Buck Moon”)
4 July. Mars crosses the celestial moving south. The Red Planet and Saturn shine brightly in the southwestern sky (northwestern sky as seen from the Southern Hemisphere). Mars and Saturn draw closer during the month and lie just 8º apart by month’s end.
5 July. The Earth reaches its maximum distance from the Sun, also called “aphelion”, at 03:00 UT.
11 July. Last Quarter Moon, 1:48 UT.
14 July. The slender waning crescent Moon lies close to the Pleiades and the planet Jupiter about 45 minutes before dawn.
15 July. Another good photo-op! A very thin Moon lies at one point of a small quadrangle, a quadrangle which is completed by Venus, Jupiter, and the bright-orange star Aldebaran. Watch for this alignment just before sunrise. Observers in Europe and Asia can see the Moon occult (pass in front of) Jupiter just before sunrise.
15 July. Saturn reaches quadrature and lies 90º east of the Sun. This makes for stunning lighting and shadows of the rings on the planet, rendering a “3D”effect. Observe the planet with a telescope if you can!
19 July. New Moon, 4:24 UT.
26 July. First Quarter Moon, 1:48 UT.
28 July. Observers in western North America can wake early to see two shadows cast simultaneously on the planet Jupiter, one by the frozen water-world of Europa and the other by the hellish, volcanic moon Io. The shadows are visible from 4:46 to 5:33 a.m. Pacific Daylight Time.
