This week the moon helps sky-watchers catch some celestial fish and trawl the night sky for the most distant worlds in our solar system.
Mars and Gemini Twins. At dawn on Tuesday, August 20, look for ruddy-colored Mars forming a picturesque arc formation with the bright stars Pollux and Castor from the Gemini constellation. The sky scene will repeat the next morning. Even through a telescope, the Red Planet is tiny and reveals little detail since it sits at nearly the far end of its orbit, at 218 million miles (352 million kilometers) from Earth.
The bright star to the far upper right of Mars is the largest planet in the solar system: Jupiter. Rising ever higher in the early morning sky over the coming weeks and months, views of this 530 million mile (854 million kilometer) distant gas giant will only get better. Even a small telescope will reveal its four major moons and two distinct cloud bands.
Moon Near Neptune. After nightfall on Tuesday, August 20, look for the moon to point to the 2.7 billion mile (4.4 billion kilometer) distant ice giant Neptune. The blue-tinted planet will appear only 6 degrees to the lower left of the Earth’s natural satellite. That apparent separation is a little more than the width of you three middle fingers at arm’s length.
Binoculars and telescopes are required to hunt down this tiny disk against the background of pinpoint stars in the sparsely populated constellation Aquarius.
Pisces Circlet. On the night of Thursday, August 22, the moon is positioned just below the “Circlet,” the most easily recognizable part of the constellation Pisces, or the Fishes. Marking the head of the fish that points westward, this circular pattern of seven faint stars is barely visible with the naked eye from light polluted city suburbs.
While the nearby moon will make for a convenient guidepost, its glare will require the use of binoculars to help track it down no matter how clear the skies. Look for the Circlet to span about 5 degrees across the sky.
Moon Joins Uranus. Late night on Friday, August 24 watch for the moon to hover over Uranus, the closer ice giant within the giant constellation Pisces.
Unlike the glitzy planets of the solar system like Jupiter and Saturn, Uranus presents a much blander view through backyard telescope. But it’s an easy target for binoculars even under light pollution. Shining at 5.8 magnitude amongst a sea of much fainter stars, the minuscule, green-tinged disk is barely visible with the unaided eyes from dark, pristine skies. Sky and Telescope website offers this handy finders starchart for both Uranus and Neptune.