Oklahomans Treated To Spectacular Sight In Twilight Sky


Thursday, June 25th 2015, 10:00 am
By: Richard Clark


The two brightest planets in the night sky are putting on a spectacular show in the twilight sky over Oklahoma for the next week.

Venus and Jupiter have been drawing closer together in the western sky in the evening this month. The experts at Sky & Telescope say you can't miss them because after the Sun and Moon, they're the brightest objects in the sky.

On June 1st, they were 20° apart in the sky, about twice the width of your fist held at arm's length. As the month passed, Jupiter and the stars behind it gradually moved lower in the evening twilight. Venus, due to its rapid orbital motion around the Sun, has stayed high up. Until now.

The two planets were very close to each other, from the Earth's perspective, on the evenings of June 19th and 20th, 2015. 

Beginning on June 27, 2015, the two planets will spend eight evenings within 2° of each other. That's about a thumb's width at arm's length. They'll be that close through July 4th.

On the evening of June 30th, Venus and Jupiter will appear so close together -- just 1/3° apart -- that they'll look like a brilliant double star in the evening sky, according to Sky & Telescope. 

Astronomers refer to this event as a conjunction. 

"Planetary conjunctions have no effect on Earth or human affairs," notes Sky & Telescope Senior Editor Alan MacRobert, "except for one: they can lift our attention away from our own little world into the enormous things beyond. That's what amateur astronomers do all the time. A spectacular conjunction like this often gets people started in the hobby. Once you start, there's no end to how far you can go."

Sky & Telescope says these close pairings of Venus and Jupiter are not particularly rare. They appeared slightly closer together before dawn on August 18, 2014, and they'll be separated by about 1° before dawn on the morning of October 26th.

Sky & Telescope Contributing Editor Fred Schaaf points out that this current trio of Venus-Jupiter conjunctions closely resembles a similar series in 3-2 BC that has been suggested as the Star of Bethlehem. 

"As has been the case in 2014–15, the first two conjunctions back then were extremely close, the last one separated by about 1°, all three occurred not far from Regulus, and all were similarly high up in the sky," Schaaf said.

Although they'll appear near one another, they're not. The Moon is just 247,000 miles away. Venus is 56 million miles from Earth while Jupiter is just over 550 million miles.

For more information, visit Sky & Telescope's web site.