Photograph by NASA/JPL-Caltech 
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This high-resolution mosaic view of Mars was constructed from Viking Orbiter images and showcases the largest canyon in the solar system, Vallis Marineris. This week skywatchers get a chance to glimpse Mars in the dawn sky.  

Photograph by NASA/JPL-Caltech 

This Week's Night Sky: Mars Lines Up With Stellar Twins

Before the stars Castor and Pollux lead the way to the red planet, a Green Giant will pair up with the moon.

Meteors Ramp Up.  The best meteor shower of the year, the Perseids, begins to trickle in this week as it heads for a peak on August 12 and 13. By the end of the week, sky-watchers in dark countryside locations will see perhaps a half dozen shooting stars per hour in the overnight period.  

Green Giant.  Near midnight on Tuesday look for the planet Uranus beside the waning gibbous moon as it rises in the east.  

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Look for the moon to point the way to planet Uranus as the pair sits in the eastern sky near midnight on Tuesday. 

The two worlds will be separated by only 3 degrees—less than the width of your three middle fingers held at arm’s length. The planet’s close proximity to the moon will make it easy to locate the magnitude-5.8 ice giant. Because of the lunar glare, however, binoculars will be needed to see the planet’s distinct greenish hue.

Gemini Lineup. As dawn approaches on Friday look toward the low eastern sky for a striking lineup between the Gemini constellation’s bright stars Pollux and Castor and the planet Mars below.

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On Friday at dawn, look for a cosmic straight line formed by Gemini’s two brightest stars and Mars low in the east. 

Mars should be an easy naked-eye target, but the 240-million-mile-distant red planet will be even easier to spot by scanning the quickly brightening sky with binoculars.

Lunar Triad. Early risers on Saturday, get treated to a pretty conjunction of the moon with the orange giant star Aldebaran and the Pleiades star cluster.  

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This skychart shows the crescent moon forming a triad in the constellation Taurus with 66 light year distant Aldebaran and the Pleiades star cluster, which is 400 light years away.

Just before local dawn begins to wash out the sky, look high in the east for the waning crescent moon to form a celestial triangle with bright Aldebaran to its lower left and the Pleiades to its upper left. To counteract the brightening sky and lunar glare, use binoculars to spot the 400-light-year-distant star cluster.

Clear skies!

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