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August 6: Mercury moves south of Pollux
The Moon passes 5° north of Uranus in Taurus at 1 P.M. EDT. The pair is visible earlier in the morning, with the Moon rising shortly before midnight on the 6th along with the Pleiades star cluster (M45).
In fact, the Moon crosses in front of the Pleiades starting around midnight EST in an event called an occultation, visible largely to observers along the U.S. East Coast shortly after moonrise, although the region will be quite low. For the best view, get to a location with a clear, dark eastern horizon, ideally at an altitude above your surroundings. Even then the greater amount of air we must look through at the horizon may muddy the view early on.
For those in the western two-thirds of the U.S., the occultation will either be underway (in the Midwest) or over by the time the Moon rises, although you can still watch our satellite pull away, bit by bit, from the bright star cluster.
For those with a view of the event, it begins just minutes after midnight EST on the 6th (so, a few minutes into the 7th), as the crescent Moon plows through the northern region of the cluster. Our satellite will temporarily block stars that may include Electra, Celaeno, Taygeta, Maia, and Sterope — exactly which stars will be blotted out depends on your location. The timing is also heavily location dependent — you can find a table of occultation timings for 40 cities in North America on the website of the International Occultation Timing Association here. If your location will see the occultation, it will be listed by date. The duration of each occultation also depends on location, but will generally last a little less than an hour before a given star reappears at the trailing dark limb of the Moon.
Later in the morning, an hour or two before sunrise, turn your attention to finding Uranus, some 6.2° southeast of the Pleiades and 2° southeast of magnitude 4.4 37 Tauri. You’ll need binoculars or a telescope to spot the planet, whose grayish disk spans 4” on the sky.
Sunrise: 6:04 A.M.
Sunset: 8:07 P.M.
Moonrise: 12:09 A.M.
Moonset: 3:59 P.M.
Moon Phase: Waning crescent (28%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.
Alison Klesman is senior editor of Astronomy magazine. She holds a Ph.D. in astronomy and has studied a variety of topics, from minor planets to supermassive black holes.
