Crescent Venus

July begins with Venus and Saturn low in the west just after sunset. On July 1, the two planets appear very close together, as seen from our vantage point on Earth. Each night after that, they drift apart from each other. Watch on July 16, when a thin crescent Moon appears between the two planets.

Every night through July, Venus sets a little bit earlier. By the end of the month it will set before the sky is completely dark after sunset. If you have a telescope, keep watch! You’ll see the bright planet change phases from just past first quarter to a thin crescent.

Around the middle of August, Venus will reach a ‘new’ phase, situated almost directly between Earth and the Sun. By then it will be so close to the Sun in the sky, we won’t be able to see it!

Sadly, no matter what phase Venus is in, you never see much detail on the planet itself. The thick atmosphere reflects so much of the Sun’s light that it appears white in color, and practically featureless. Actually, it is possible to see some vague features in the clouds, but it takes calm, still, cloudless skies, a quality telescope, and the right filters to cut down on the planet’s distracting glare. Determination, practice, and patience are also essential.

If you’ve ever seen dramatic pictures of Venus where it looks like a mottled, technicolor orange, be careful! You’re seeing a false-color view of the planet’s rocky surface. The same thick atmosphere that makes Venus so bright in our sky also blocks any chance of seeing Venus’ surface in visible light.

The Magellan spacecraft arrived at Venus in 1990 and used sensitive radar to peer through the clouds and create a detailed, three-dimensional map of the surface we will never otherwise see. The bright colors were added to black and white images to highlight geologic features. It’s a fascinating view of the second planet from the Sun, but it’s not what it really looks like from space.

Lots More to See

As we say good-bye to Venus this month, we bid farewell to Saturn as well. If you have a good western horizon, this is your last chance to catch a close-up of those beautiful rings before they too are lost in the glare of sunset.

Meanwhile, bright Jupiter rules the skies to the south. It should be easy to find near the red star Antares, marking the heart of Scorpius the Scorpion. With just a good pair of binoculars you can see four of Jupiter’s moons.

While you’re scanning that part of the sky, don’t just stop at Jupiter! If you’re reasonably far away from light pollution, you’ll be able to see a wide variety of fuzzy patches in the southern summer sky, mostly in the region around Scorpius and its next-door neighbor Sagittarius the Archer. This is because you’re looking in the direction of the center of our Milky Way galaxy. Here, you’ll find plenty of star clusters and nebulae, distant clouds of dust and gas. Through binoculars and small telescopes most just look like blurry stars. Larger telescopes can reveal more detail.

Early birds may catch a glimpse of Mars, high in the east before sunrise, but Mars is moving quickly through the sky. As July begins the unmistakably red planet is near Aries the Ram, but as the month ends, it lies close to the Pleiades, a bright star cluster in Taurus the Bull. Don’t like to get up early? Mars will return to evening skies this autumn and will be especially bright at the end of the year.

Summer Star Party

Join us and members of the Barnard-Seyfert Astronomical Society (BSAS) for the Perseid Meteor Shower! The next FREE public star party is scheduled for Saturday, August 11, 2007 from 8:30 - 10:30 pm at Edwin Warner Park. Weather permitting, this should be a good one - there’s no moon up, so the skies will be dark. Jupiter will also be visible.

This star party will be at a different location than usual. We’ll be at Ridgefield, accessed behind picnic shelter #4 in the park. Future star parties will be back at the Special Events Field, once improvements there are finished. Click here for directions to the Ridgefield site.