Step outside anytime this month just before the stroke of midnight and you’ll be able to see three bright naked-eye planets. Jupiter and Saturn are near their highest point in the southern sky, while Mars begins to ascend the eastern sky. If you’re an early riser and head out about an hour before sunrise during the first week of August you’ll have a chance at seeing five bright planets at the same time: Mercury, low in the east-northeast; brilliant Venus, higher up to the upper right of Mercury; Mars high and almost due south, while Jupiter and Saturn approach their setting in the west-southwest.
Mercury will disappear by the second week of August.
A telescope will reveal the cloud bands on Jupiter as well as its four big moons, Saturn’s beautiful rings, the disk of Mars which will appear to slowly swell as it continues to approach Earth and Venus goes from a crescent to gibbous phase, appearing like a half moon at midmonth.
In our schedule, remember that when measuring the angular separation between two celestial objects, your clenched fist held at arm’s length measures roughly 10-degrees. Here, we present a schedule below which provides some of the best planet viewing times as well directing you as to where to look to see them.
Mercury
Mercury – is still visible before sunrise as August begins, but it quickly drops of sight and reaches superior conjunction with the sun on August 17th.
Venus
Venus – rises about the same time all August: around 2:40 a.m. local daylight time. It accomplishes this by racing eastward against the westward seasonal progression of the constellations, starting the month 2° from Zeta Tauri and ending in eastern Gemini near Cancer. On the morning of August 12th, Perseid watchers will find Venus is at greatest elongation, 46° from the sun, and it will be fascinating to observe in a telescope within a few days of this date, appearing exactly half-lit in telescopes – though not necessarily on the 12th itself. Venus glows less than 4° to the lower right of a slender crescent moon on the morning of the 15th.
Mars
Mars – is rising earlier every week and becoming dazzling! At the beginning of August, it comes up soon after 11 p.m. local daylight time, and by the 31st it rises around 9:30 p.m. Mars is gradually slowing in its nightly eastward progression in the southeast corner of Pisces the Fishes. Drawing ever nearer, Mars doubles in brightness during August, surpassing Sirius on August 21st and reaching magnitude -1.8 by month’s end. By the end of August its disk will have swelled to about 40% of Jupiter’s, which may still look pretty small in a telescope but is enormous compared to how Mars usually appears. Set your alarm clock so you can be out about 4:30 a.m. local daylight time. Mars is best during the first light of dawn when it is high in the south. On August 8th, in the hour before midnight, you’ll see the waning gibbous moon ascending the eastern sky, accompanied by brilliant Mars situated about 2½° to the moon’s upper left. As the night wears on, watch how the moon appears to draw closer to the red planet. They will appear closest during the predawn hours, separated then by about a degree.
Jupiter
Jupiter – shines in eastern Sagittarius and was at opposition on July 14th, so in August it’s already visible in the southeast at dusk and sets before dawn. This giant world still glares at magnitude -2.7. Its large disk is best observed when the planet is highest in the sky: around 11:30 p.m. local daylight time at the start of August, and 9:30 p.m. by month’s end. On the evening of August 1st, Jupiter can be readily found about 3° to the upper right of the moon. The moon has a second encounter with Jupiter this month, passing about 2° below it as darkness falls on the evening of the 28th.
Saturn
Saturn – shines in the south-southeast during evening hours and like Jupiter, is also in eastern Sagittarius. And with all due respect to Venus, Mars and Jupiter, many would say unequivocally that Saturn is also the most beautiful planet. It never fails to elicit a gasp from someone shown it for the first time through a reasonably good telescope. The ringed-planet design has so thoroughly imbued our popular culture that many people are amazed to see that such an object actually exists! The famous rings are now tilted 21½° from edge on, a value that will gradually close to zero by 2025. A cloud belt or two may be detectable on the ball of Saturn itself, and possibly an elusive bit of detail if you have a high-resolution telescope and some luck. And any telescope that shows Saturn’s rings will also show Titan, its largest satellite. Titan always appears within four ring-lengths of the planet. It’s that far west of Saturn on August 13th and 29th, and about the same distance east on the 5th and 21st. On August 1st, Saturn is 6° to the moon’s upper left. Then, the moon will slide past Saturn during the midday hours on the 29th. By that evening, you’ll find the ringed world 5° to the moon’s upper right.
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Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications in New York's lower Hudson Valley. Follow us on Twitter @Spacedotcom and on Facebook.
