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Star Trak: August 2020

For immediate release: August 1, 2020

BLOOMINGTON, Ind. -- The annual Perseid meteor shower will peak on the night of Aug. 11-12. The Perseid shower is one of the most popular every year because it happens on warm summer nights, when gazing at the starry sky is always enjoyable. This year the moon will accompany the shower's peak, adding a lot of light to the sky and washing out the fainter meteors. But in a dark sky as many as 100 meteors per hour may be visible.>/p>

The Perseids will perform for most of August, though there will be fewer meteors to see the farther from the peak date you watch. If the peak is hidden by clouds, look for the bright streaks again as soon as the night sky is clear. To minimize the effect of local light pollution, try to avoid artificial lights.

Face east if you have a clear view in that direction, and use a building or tree to block the moon. Look about halfway up the sky from the horizon. You won't need binoculars or a telescope, because the meteors move much too fast for those devices. The Perseids produce more of the extremely bright meteors called fireballs than any other shower. The chances of seeing a fireball will be greatest near dawn.

The Perseids may appear anywhere in the sky, but they will seem to originate from a point called the radiant in the constellation Perseus, which gives these "shooting stars" their name. The higher the radiant is above the northeastern horizon, the more meteors will be visible. Perseus is just north of the W-shaped constellation Cassiopeia in the Milky Way. Meteors near the radiant will have short trails because we see them nearly straight on, while those far from the radiant will look longer because they are seen from the side.

Most meteor showers happen when Earth crosses the orbit of a comet, and the Perseids come from Comet Swift-Tuttle. The meteors are caused by particles released from the comet's nucleus and left behind in space. As Earth plows through this stream of debris, ranging in size from sand grains to pebbles, each particle slams into our atmosphere at a speed of more than 30 miles per second and burns up almost instantly from friction with air molecules. The resulting heat momentarily creates a streak of glowing air that we see as a meteor. All of this happens about 60 miles above the ground, regardless of how close some meteors may appear.

Planets

Jupiter and Saturn will shine 20 degrees high in the southeast an hour after sunset during the first week of August. They will start the month 8 degrees apart with brighter Jupiter on the right (south) and slowly move away from each other as the month passes. Saturn's famous rings will be tilted 22 degrees to our line of sight. Saturn's brightest moon, Titan, will be due north of the planet on Aug. 1 and 17 and due south on Aug. 9 and 25.

Mars will rise three hours after sunset at the beginning of August and an hour earlier by month's end. The Red Planet will brighten significantly as the month passes. The best views with a telescope will usually come when it is highest in the south.

Venus will rise at almost the same time all month for observers at mid-northern latitudes, clearing the eastern horizon around 2:45 a.m. local time. The brilliant white planet will reach its greatest elongation on Aug. 12, when it will be 46 degrees from the sun.

Mercury will be very low in the dawn sky at the start of August before it passes out of sight behind the sun.

Light pollution

CassiopeiaCassiopeia
Photo Credit: VegaStar Carpentier

If you look at the constellation Cassiopeia in the northeast on a clear summer night and can't see the Milky Way sprawling high across the sky from the northern to the southern horizon, it means your sky has significant light pollution. This is the case for about two-thirds of the world's population. The dimming of the night sky is caused by excessive artificial lighting, much of which is wasted. See the International Dark-Sky Association website for more information.

Moon phases

The moon will be full on Aug. 3, at third quarter on Aug. 11, new on Aug. 18 and at first quarter on Aug. 25.

Author: Hal Kibbey Email: hkibbey [at] gmail.com

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