Heads UP! for August 2010
One blazing planet and three or four dimmer planets are low, but seeable, in the twilight soon after sunset. But they are upstaged by the rise of the King of the Planets, Jupiter. Also, around the middle of the month, tiny pieces from the distant comet Swift-Tuttle give us the Perseid meteor show. It’s a good year for viewing these fast-moving, bright meteors.
Stay out after sunset
Four planets are conveniently located in the western twilight sky an hour after sunset. Venus gets our attention at once. It’s beyond dazzling, but you’ll need a clear view of the western horizon. Look low in the part of the sky where the sun just set.
Venus has good company this month. If you watch the sky each night, you’ll notice that it looks like Venus is going to run over much fainter Mars and Saturn. They are fainter, but readily visible with some patience. Over several nights, Saturn (as bright as one of the brighter stars) appears to sidestep the on-rushing Venus, passing just above Venus around the 7th . Mars (a little brighter than Saturn) appears to slow down as it lingers in the vicinity of Venus all month. For the first half of the month, you can cover all three planets with your outstretched fist. Our gang of three are closest together for our WAA Observing Night on the 7th. Our fourth early evening guest, Mercury, is way down to the lower right of Venus, for the second and third week of August. The crescent Moon drives by on the 12th and makes a striking line-up after dark on the 13th.
So follow Venus this month as it brightens a bit but sinks lower toward the horizon. On September 1st, Venus will make a small group with Mars and the bright star Spica. It will be an especially cool sight in binoculars. Just aim at Venus and move a little to the right.
A Rain of Stars
Do you tilt your umbrella forward when you run in the rain? That’s a classic demonstration of why we see more meteors on the morning side of midnight than during the ‘prime time’ evening hours. In the morning, our side of the planet is in ‘front’, that is, in Earth’s direction of travel, as we move around the sun. That’s why we advise sky watchers to get up early in the morning for the most meteors. This year, the Perseid meteor shower has two features that may encourage those who are disheartened at getting up at 0200 (i.e., oh-too-early in the morning for me). First, the shower is predicted to peak around 9pm EDT on August 12th. Second, the Perseids is a display with many bright meteors. If your goal is to see some bright meteors, you should be just fine with whichever of the evenings near the 12th will be clear. Stay out after the sky gets dark (10pm or later) and lay out so you can see a large part of the sky comfortably, preferably with a sleeping bag to protect you from the mosquitoes and the dew, and you should get your share of ‘OMG, did you see that?’ meteors.
The Reign of a Planet
Jupiter is called the king of planets, when it (he?) rises after 10 o’clock early in the month you’ll know why. Brighter than anything except the Sun, Moon and Venus (as we saw earlier in the evening), it’s hard to miss his entrance. To view Jupiter and his retinue of 4 bright moons, you’ll need to stay out late or get up before dawn so you can get a good view in the morning sky. Use a telescope or steadily-held binoculars to see the moons and I think you’ll agree it worth the wait. The Moon comes by on the 26th.
Be a Beach Bum
You need a really dark location to see the Milky Way. So, it’s a great time to visit someone’s beach house. If you can get away from the lights, the Milky Way looks like a stream of high, thin clouds in a band soaring high into clearer skies away from the murky horizon. But also look low in the south- can you see the group of stars that looks like a teapot, low in the southern sky? If you look carefully, the Milky Way looks like ‘steam’ from the teapot. This area around the constellation Sagittarius is a wonderful visual playground for an observer with binoculars or a small telescope.
What’s that Bright Star Overhead?
Overhead, the sky and your imagination can transport you millions of miles or tens of light-years away. Vega is that bright star almost overhead on these August nights. Vega’s north pole points nearly at Earth, so the Sun (a dim, but visible star at Vega’s 25 light year distance) could be the pole star for Vega’s possible planets. Nearby, the top of the Northern Cross points like an arrow to a spot 7 degrees away that would mark the pole star – if you were on Mars. So look straight up and you can imagine being someone else’s pole star; and what it would be like standing on the north pole of Mars!
For a great sky scene that you can’t see from Earth, go to NASA’s Solar System Simulator this month and ask it to give you a view of Venus as seen from Mars. Start with a 60 degree field of view. Earth is part of a striking scene with Venus and Jupiter. Mercury joins the scene about mid-month. I wonder if they’ll try to get a photo of this scene from one of the rovers.
The Moon is a great sight with binoculars or telescope. For August:
Last Quarter 8/3 New Moon 8/9 First Quarter 8/16 Full Moon 8/24
You can see lots of detailed craters and mountain ranges, especially from the 15th through the 18th.
The International Space Station
The ISS makes overflights of our area in the dawn skies from August 4th though 24th and in the evening skies from August 23rd through September 15th. Check nasa.gov, spaceweather.com or heavens-above.com for times when you can see the ISS and many other bright satellites for your location. The ISS is often as bright as Venus, so it’s easy to spot as it appears to lazily drift over us while orbiting the Earth at 18,000 miles per hour.
Have a telescope? Want to see how to use it?
Come to Pound Ward Ridge Park on Saturday evening, August 8th, members of the Westchester Astronomers will be there to help you use your telescope. Check the August WAA newsletter at http://www.westchesterastronomers.org/ for updates.