It’s been a great summer for the planetarium.

We installed a Digistar 4 full-dome video system in the Watumull Planetarium this summer, ahead of our other renovations, and got full use of the system. We presented 14 full-dome planetarium showings on Transit of Venus Day (June 5) to about 1,000 of the 2,100 people who attended the museum’s overall Transit of Venus Festival.

Later in the summer, we gave equal time to the Red Planet. On Aug. 5, 420 people attended "Invasion of Mars," a special evening Bishop Museum event centered on the landing of the Curiosity rover on Mars. We ran the webcast of the landing at three locations on campus, filled all three rooms to overflowing, cheering crowds, and were rewarded with the first images of Mars from Curiosity shortly after the landing. Nearly all of the attendees got to one of our six Mars planetarium shows that night. With the new digital system, we were able to fly to Mars, pass over Gale Crater (Curiosity’s landing site), and even view the same Martian sky that shone down on Curiosity on the night of its landing.

It’s been quite the debut summer for our new system, but now it’s time to finish the renovations. We are going to close the planetarium on Sept. 10 for 10 weeks. During the closure, we’ll install a new interior dome, a new Goto Chronos II star machine, new seats, lights, carpet and sound. We plan to reopen on Dec. 1.

September planets

Jupiter and Venus, the brightest dots in the sky, blaze away in the early-morning hours throughout September.

Throughout the month, look east from 3:30 a.m. till daybreak, which starts around 5:15 a.m. this time of year. Venus is the brilliant light lower in the eastern sky. Throughout the month, Venus rises by 3:30 a.m., shining at minus 4.3 magnitude and is brighter than any other dot in the heavens.

Look for Jupiter high above Venus, shining at minus 2.3 magnitude. This is several times brighter than the brightest star, but still nowhere near as bright as Venus. At the start of September, Jupiter rises at midnight and is nearly halfway up in the east when Venus rises at 3:30 a.m. By the end of the month, Jupiter rises by 10:20 p.m. and is about two-thirds of the way up in the east by the time Venus rises at 3:30 a.m.

This combination of the two brightest planets takes place in front of some of the brightest and most distinctive stars in the heavens. All month long, the starry cluster of the Pleiades shines above Jupiter, while Orion the Hunter shines below Jupiter and above Venus. At the start of September, Venus and the brightest star, Sirius, rise at almost exactly the same time, around 3:30 a.m.; Sirius is to the right of Venus. Brilliant as Sirius is at 1.47 magnitude, Venus to its left is 15 times as bright. By the end of the month Sirius rises at 1:30 a.m., about two hours earlier than Venus.

From Sept. 8 to 11, you can mark the path of the moon against this eastern gathering of bright planets and stars. On Sept. 8, in the predawn sky, look for the third-quarter moon next to Jupiter.

The morning of Sept. 12 should be particularly lovely. Look east for a slender waning crescent moon just to the right of Venus. Then, look to the left of Venus and try to spot the Beehive Cluster, which is in the heart of Cancer the Crab. This cluster of stars will be about as far to the left of Venus as the crescent moon is to the right of Venus. The cluster shines at 4th magnitude, and it helps to have binoculars to spot it. You can search for this Beehive/Venus/Moon trifecta from 3:30 a.m. (when Venus and the moon and the Beehive all rise) until dawn.

You may notice that Mars, Saturn and the star Spica form a distinctive triangle in August’s evening sky. If you look west around 8 p.m. in early September you can still see them as a long, skinny triangle. Spica is nearest the horizon and slightly blue; Saturn is about 4 degrees above Spica (or two fingers held at arm’s length) and slightly yellow; and Mars is well off to the left of the two other dots. Spica and Saturn are close in brightness. Spica shines at 0.96 and Saturn at 0.77. Mars is dimmer at 1.2 magnitude, and slightly orange. Mars will be about a palm’s distance to the left of Saturn on Sept. 1.

This triangle, so eye-catching in August, falls apart pretty quickly as the month goes on. Saturn and Spica will appear a little lower at dusk each night; by the end of the month, Spica will be gone and Saturn will set a half-hour after dusk. Meanwhile, Mars will hold its own in the west as the other two plunge into the twilight. At the end of September, Mars will be about 20 degrees (two palms) above the western horizon at dusk, and will set around 9:30 p.m. The Red Planet is fading fast in brightness, so it helps to have a guide to find it. Look for the waxing crescent moon just below Mars on Sept. 18 and just above Mars on Sept. 19.

Mercury makes a brief appearance at the end of September, but you will need ideal circumstances to see it; it will be extremely low in the west (2 degrees above the horizon) at 6:45 p.m. on Sept. 30, and will set by 7 p.m. On the other hand, it will be very bright, at minus 0.4 magnitude, so you might just be able to catch it in this narrow 15-minute window if you are, for example, looking west over the sea at dusk at the end of the month.

———
Mike Shanahan is director of Education, Exhibits and Planetarium. For more information, go to www.bishopmuseum.org/planetarium/planetarium.html