Tonight – July 8, 2016 – and tomorrow night, look westward, the sunset direction, for the waxing crescent moon in evening twilight. As night falls, a bright planet – Jupiter – will pop into view, close to the moon. They’ll be a beautiful sight as dusk gives way to darkness.
The moon and Jupiter will be close together at nightfall on July 9, too – especially as seen from Australia.
These two worlds aren’t close in space, of course. The moon lies only about 1.3 light-seconds from Earth, while Jupiter lies well over 2,000 times farther away, at nearly 49 light-minutes.
For reference, one light-second = 186,242 miles (299,792 km).
One light-minute = 11,176,944 miles (17,987,547 km).
If Jupiter were at the moon’s distance from Earth, its disk in our sky would appear about 1,600 times larger than the lunar disk. Wow!
There are three other planets in the evening sky right now, two of which are easy to spot – and one that is not.
The two easy ones are Mars and Saturn. They form a noticeable triangle with the bright star Antares. From the Northern Hemisphere, look southward – and from the Southern Hemisphere, look overhead – as darkness falls.
Here’s how to tell Mars from Saturn and Antares. Mars is the brightest of the three. Antares twinkles the most. Mars and Antares are reddish, while Saturn exhibits a golden hue. If you have difficulty discerning these objects’ colors, try using binoculars.
The fourth evening planet – Venus – is not easy to see at present. It’s very low in the west after sunset now and soon follows the sun below the horizon. But Venus is getting farther from the sunset each each now, and many are already reporting seeing it with optical aid, or even with the eye alone.
Venus is the brightest planet. If you’re able to spot it, it might surprise you with its brightness, even amidst such a bright twilight background.
Given crystal-clear skies and an unobstructed horizon, try to spot Venus near the sunset point on the horizon around 30 minutes after sunset.
Binoculars will be helpful! Also, notice that the bright portion of the crescent moon points toward Venus. On these nights when Jupiter is near the moon, a line between this planet and the moon points to Venus, too.
Night by night, Venus – the brightest planet – will climb away from the sunset glare, while Jupiter – the second-brightest planet – will be sinking towards it. These dazzling two worlds will pass each other, on our sky’s dome, in August!
Their rendezvous will be on August 27, 2016. It’ll be the closest conjunction of two planets for all of 2016.
Bottom line: Use the moon to locate Jupiter on July 8 and 9, 2016.