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This is the Griffith Observatory Sky Report through May 11th, 2016. Here’s what’s happening in the skies of southern California.
The giant planet Jupiter, in the constellation Leo the Lion, gleams high in the southeast sky after sunset and crosses the meridian, 64 degrees high in the south, at about 9:00 p.m. Jupiter can be seen until it sets in the west at about 3:00 a.m. Currently, Jupiter is the featured planet through Griffith Observatory’s public telescopes.
Brilliant orange planet Mars, in the constellation Scorpius the Scorpion and the golden planet Saturn, in Ophiuchus the Serpent Bearer, are both visible above the southeast horizon by 10:00 p.m. Mars appears 10 degrees to the upper right of Saturn. This separation is about the same as the angular width of your clenched fist when held at arm’s length. Below Mars is an orange star, a little fainter than Saturn. The star is Antares, the brightest star of Scorpius. The attractive trio of bright objects is highest in the south where they are best positioned for telescopic viewing at 3:00 a.m. By dawn, they will have moved to the southwest sky.
The moon is new on the 6th, and will appear waxing crescent, low in the west starting after sunset on the 7th, and sets that evening at 8:58 p.m. By Tuesday the 10th, the moon will be visible until it sets at 11:55 p.m.
The first transit of the planet Mercury since 2006 occurs during the morning of Monday, May 9th. A transit happens when Mercury, the innermost planet, passes directly between the sun and earth, and appears as a black dot, only 12 arcseconds or 1/150 the sun’s apparent diameter. The transit will have been in progress for nearly two hours by 5:56 a.m., PDT, at sunrise in Los Angeles. Mercury appears closest to the center of the sun at 7:57 a.m., Mercury takes three minutes to egress, or leave, the sun’s disc, starting at 11:39 a.m.
Remember that observing the sun is hazardous. Never, ever look at the sun directly without the proper eye protection.
Mercury appears so tiny that observation of the transit requires the same techinques and equipment used to observe sunspots, prominences, and other fine solar details, as detailed in an April 15 posting on the website Universe Today. Griffith Observatory will be closed to the public on the day of the transit, but will provide a live webcast of Mercury crossing the sun through its telescopes. The webcast, links to which are posted on the Griffith Observatory Website, will start at 6:00 a.m., and we expect to first see Mercury when it clears the San Gabriel Mountians on our local horizon, at 6:11 a.m. Weather permitting, Mt. Wilson Observatory will hold a public observing event beginning at 5:30 a.m. UCLA also will provide safe public viewing of the transit through properly equipped telescopes, located next to the Shapiro Fountain on campus, starting at 7:30 a.m. The following transit of Mercury, a portion of which will also be visible from the west coast, will happen on November 11, 2019.
The absence of bright moonlight is favorable for this year’s eta Aquariid meteor shower. The peak of the shower is expected on May 5th, but the numbers of meteors produced by the shower is not expected to change much between the mornings of the 3rd and the 6th. From the United States, about 10 eta Aquariids per hour are expected to be seen by observers far from urban light pollution on those three mornings, while up to one per minute can be seen on the same mornings from the southern hemisphere. The meteors are named for the constellation Aquarius from which they seem to stream. Eta Aquariid meteors may be observed between 3:00 a.m. and 4:25 a.m., the start of dawn. They are dust debris shed centuries ago by the famous comet Halley, and they hit our atmosphere at 40 miles per second. Comet Halley’s next visit is still 45 years away.
Free views of the sun during the day and of the moon, planets, and other celestial objects at night are available to the public in clear weather through Griffith Observatory’s telescopes from Tuesday through Sunday, before 9:30 p.m. Check our website for the schedule. The next free public star party on the grounds of Griffith Observatory, hosted by the Los Angeles Astronomical Society, the Sidewalk Astronomers, and the Planetary Society, will take place on Saturday, May 14th.
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From Griffith Observatory, I’m Anthony Cook and I can be reached at griffithobserver@gmail.com