Astroblog: Venus and Jupiter Meet in the Twilight (27, 28 August 2016)

Thursday, August 25, 2016

Venus and Jupiter Meet in the Twilight (27, 28 August 2016)


Western evening sky on Saturday August 27 looking west at 40 minutes after sunset. Jupiter and Venus are around a lunar diameter apart with Mercury nearby. Similar views will be seen throughout Australia at the equivalent local time. (click to embiggen).	Western evening sky on Sunday August 28 looking west at 40 minutes after sunset. Jupiter is spectacularly close to Venus with Mercury nearby. Similar views will be seen throughout Australia at the equivalent local time. (click to embiggen).	Simulated telescopic view of Jupiter and its Moons, Venus and the star Zavijava. The field of view of a 24mm eyepiece in a 114 mm Newtonian refractor is simulated. Click to embiggen.

If you have been watching the western twilight over the past week or so you will have seen two bright dots coming closer together. These are Venus and Jupiter, and on Saturday and Sunday they meet in the most awesome event of the current Planet Dance.

With speedy Mercury nearby, the planetary pair form a long pointy triangle. On Saturday and Sunday Venus and Jupiter will be around a lunar diameter apart (33 arc minute and 28 arc minutes respectively, if you want to get technical). That's about half a finger-width (when you hold your finger out at arms length).

That means not only will they be together in binocular fields (and Mercury, just), but they will be together in wide field telescope eyepieces. You should be able to see the bands on Jupiter (just) and the Galilean Moons together with Venus. Venus will be painfully bright in a telescope eyepiece, and is featureless gibbous shape, but seeing the two planets together will be great. The second brightest star in Virgo, Zavijava, should also be visible in telescope eyepieces.

While the three planets are visible in the western sky from half an hour after local sunset to at least and hour and a half after sunset, the best time to look is between 40 minutes to an hour after local sunset. This is when the sky is dark enough to see all three easily, but there is still plenty of twilight colour to make the sky dramatic and the planets are hight enough above the horizon that most normal horizon clutter doesn't get in the way.

Venus and Jupiter are the brightest objects in the sky once the sun has set, and Mercury is the third brightest object above the western horizon just near Venus and Jupiter, so spotting the trio should be easy.


40 minutes after sunset Venus, Jupiter and Mercury gleam above the twilight colours (25 gust). Click to embigen	An hour after sunset sunset Venus, Jupiter and Mercury are brilliant above the horizon (24 August). Venus's light forms a path in the sea. Click to embigen