This is the Griffith Observatory Sky Report through July 1, 2015. Here’s what’s happening in the skies of southern California.
Blazing planet Venus and the brilliant planet Jupiter reach the climax of their eye-catching show in the western evening sky. After sunset, Jupiter appears to the upper left of Venus. The separation decreases night by night, from 3 degrees on the 24th to only 1/3 degree–less than the width of the full moon– on Tuesday night, the 30th. This close pairing, or conjunction, is the closest that Jupiter and Venus will appear to each other until the conjunction on April 30, 2023. The planets will appear to slowly drift apart from each other on nights after the 30th.
Through a telescope, Venus displays a crescent phase. Jupiter shows its clouds arranged into stripes, and its four largest moons. During the conjunction on the 30th, Venus, Jupiter, and Jupiter’s moons will fit together into the same telescope eyepiece field of view, even at 100 power! Jupiter is actually 12 times the diameter of Venus, but it is also now 12-times as far away as Venus, so the two planets appear the same size through the telescope.
The ringed planet Saturn, in Libra the Scales, is well placed for early-evening observation. It is in the southeast sky at dusk, and then moves to the south at 10:20 p.m. Saturn sets in the west-southwest at 3:30 a.m. The planet, with its beautiful rings, is currently featured, along with the moon, Venus, and Jupiter, through Griffith Observatory’s public telescopes. The moon passes close to Saturn on the 28th.
First quarter moon happens on Wednesday morning, June 24. The moon is gibbous on following nights until it becomes full on July 1. This full moon, the first of two in July, is also known as the Buck moon, from the Algonquin tradition.
The innermost planet, Mercury, appears like a bright star, 9 degrees above the east-northeast horizon at 5:15 a.m., the start of civil twilight.
A leap second will be added to the end of June. In order to reduce the accumulated difference between the slightly irregular rotation of the Earth and the precise regularity of atomic clocks, international time keeping organizations occasionally add a leap second to the last second, Universal Time, of June or December. In Pacific Daylight Time, the leap second happens on Tuesday, June 30, between 4:59 and 5:00 p.m., and so creates a 61 second-long minute. The extra second can be heard at 4:59:60 on shortwave broadcasts of the National Institute of Standards and Technology time service, stations WWV from Colorado and WWVH, from Hawaii, at frequencies of 2.5, 5. 10, 15, and 20 megahertz. Previously, the most recent leap second occurred at the end of June, 2012.
A SpaceX Falcon 9 rocket carrying a Dragon resupply capsule for the International Space Station is scheduled to take off from Cape Canaveral Florida on Sunday, June 28 at 7:21 a.m., PDT. The launch will be streamed on NASA TV and on the SpaceX web site. In addition to the orbital supply mission itself, the launch is of interest because of another planned attempt that will be made to land the first-stage booster upright on a barge floating in the Atlantic Ocean. If this succeeds, it would be an important step toward the goal of a reusable rocket system and more affordable space flight.
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 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, July 25.
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From Griffith Observatory, I’m Anthony Cook and I can be reached at email@example.com.