Planets Align for the Perseid Meteor Shower

August 9, 2010:  You know it's a good night when a beautiful alignment of planets is the second best thing that's going to happen.

Thursday, August 12th, is such a night.

The show begins at sundown when Venus, Saturn, Mars and the crescent Moon pop out of the western twilight in tight conjunction. All four heavenly objects will fit within a circle about 10 degrees in diameter, beaming together through the dusky colors of sunset. No telescope is required to enjoy this naked-eye event: sky map.

A Perseid meteor photographed in Aug. 2009 by Pete Lawrence of Selsey, UK. [more]

The planets will hang together in the western sky until 10 pm or so. When they leave, following the sun below the horizon, you should stay, because that is when the Perseid meteor shower begins. From 10 pm until dawn, meteors will flit across the starry sky in a display that's even more exciting than a planetary get-together.

The Perseid meteor shower is caused by debris from Comet Swift-Tuttle. Every 133 years the huge comet swings through the inner solar system and leaves behind a trail of dust and gravel. When Earth passes through the debris, specks of comet-stuff hit the atmosphere at 140,000 mph and disintegrate in flashes of light. These meteors are called Perseids because they fly out of the constellation Perseus.

Swift-Tuttle's debris zone is so wide, Earth spends weeks inside it. Indeed, we are in the outskirts now, and sky watchers are already reporting a trickle of late-night Perseids. The trickle could turn into a torrent between August 11th and 13th when Earth passes through the heart of the debris trail.

2010 is a good year for Perseids because the Moon won't be up during the midnight-to-dawn hours of greatest activity. Lunar glare can wipe out a good meteor shower, but that won't be the case this time.

As Perseus rises and the night deepens, meteor rates will increase. For sheer numbers, the best time to look is during the darkest hours before dawn on Friday morning, Aug. 13th, when most observers will see dozens of Perseids per hour.

Looking northeast around midnight on August 12th-13th. The red dot is the Perseid radiant. Although Perseid meteors can appear in any part of the sky, all of their tails will point back to the radiant.

For best results, get away from city lights. The darkness of the countryside multiplies the visible meteor rate 3- to 10-fold. A good dark sky will even improve the planetary alignment, allowing faint Mars and Saturn to make their full contribution to the display. Many families plan camping trips to coincide with the Perseids. The Milky Way arching over a mountain campground provides the perfect backdrop for a meteor shower.

Enjoy the show!

All the other planets in our solar system nearly aligned perfectly this morning

I was out looking at the stars this morning and I noticed that currently (and for the next few weeks I guess) Jupiter is the brightest celestial object in the sky, after the moon and sun, of course. So, I came in and opened my favorite planetarium program, Stellarium, to see what else was out there, and I noticed that every planet in the solar system, plus the moon and sun were as close to perfect alignment as I've ever seen. Even some of the other objects in our solar system past Pluto were aligned (of course, Pluto was the planet farthest from alignment.) I took some screen shots:

In this image, you can see (from l to r): the Moon, Saturn, Mars, Vesta (one of those objects past Pluto), Venus, Mercury, the Sun, and Juno (another object past Pluto, quite a bit off, but in the picture). Click the image to make it larger. The planetary orbits are the red lines. I'm zoomed quite a bit out to see the big picture.

And in this image, (l to r) you can see the Sun, Jupiter and Uranus right together, Neptune, and then there's Pluto off kilter to the far right. Click the image to make it larger. In this image, I'm zoomed about the same distance but with a wider field of vision to fit the Sun in the same image with this grouping of planets.

Anyway, it was something which doesn't happen very often that I thought was cool and I wanted to share. Since they aren't perfectly aligned, I guess that's why nothing has really been written about this--that I have seen. But that's pretty dang close to perfect alignment, if you ask me!