Conjunction Alert: Jupiter Meets Venus at Dusk

Jupiter and Venus
Invasion of the naked eye planets... shining a laser at Jupiter and Venus. Credit: Dave Dickinson

Get ready: The conjunction queries are inbound. “Did you see those two bright things in the sky last night?” Says a well-meaning family member/friend/coworker/random person on Twitter who knows you’re into astronomy. “They were HUGE!”

Continue reading “Conjunction Alert: Jupiter Meets Venus at Dusk”

Catch a Fine Lunar Planetary Grouping This Weekend

Image Credit: Andrew Symes (@FailedProtostar).

Phew! Our eyes and thoughts have been cast so far out into the outer reaches of the solar system following New Horizons and Pluto this week, that we’re just now getting to the astronomical action going on in our own backyard.

You’ll recall that Venus and Jupiter have made a fine pairing in the evening sky since their close approach on July 1st. Despite some of the incredulous ‘Star of Bethlehem’ claims that this was a conjunction that happens ‘once every two thousand years,’ this sort of pairing is actually quite common. In fact, Venus and Jupiter are set to meet up again in the dawn sky later this year on October 25th. Continue reading “Catch a Fine Lunar Planetary Grouping This Weekend”

Catch Jupiter Homing in on Venus Through June

Getting closer... Venus, Jupiter, the Moon and an iridium flare on the night of May 26th, 2015. Image credit and copyright: Chris Lyons

Are you ready to hear an upswing in queries from friends/family and/or strangers on Twitter asking “what are those two bright stars in the evening sky?”

It’s time to arm yourself with knowledge against the well-meaning astronomical onslaught. The month of June sees the celestial action heat up come sundown, as the planet Jupiter closes in on Venus in the dusk sky. Both are already brilliant beacons at magnitudes -1.5 and -4 respectively, and it’s always great to catch a meeting of the two brightest planets in the sky.

June 5th
Looking west on the evening of June 5th from latitude 30 degrees north… Image credit: Stellarium

Be sure to follow Venus and Jupiter through June, as they close in on each other at a rate of over ½ a degree—that’s more than the diameter of a Full Moon—per day.

June 20th
…and looking west on the evening of June 20th…

Venus starts June at 20 degrees from Jupiter on the first week of the month, and closes to less than 10 degrees separation by mid-month before going on to a final closing of less than one degree on the last day of the June. Th climax comes on July 1st, when Venus and Jupiter sit just over 20’ apart—2/3rds the diameter of a Full Moon—on July 1st at 3:00 UT or 11:00 PM EDT (on June 30th). This translates to a closest approach on the evening of June 30th for North America.

July 1st
… and finally, looking westward on the evening of July 1st.

Venus starts the first week of June forming a straight line equally spaced with the bright stars Castor and Pollux in the astronomical constellation Gemini. On June 12-13, Venus actually nicks the Beehive cluster M44 in the constellation Cancer, a fine sight through binoculars.

Credit: Starry night Education software
The apparent paths of Venus versus Jupiter through the month of June. Credit: Starry Night Education software

Jupiter and Venus will then be joined by the Moon on the evening of June 20th to form a skewed ‘smiley face’ emoticon pairing. Not only is the pairing of Venus and the crescent Moon represented on many national flags, But the evening of June 20th will also be a great time to try your hand at daytime planet spotting before sunset, using the nearby crescent Moon as a guide.

The daytime view of Venus, the Moon and Jupiter of the evening of June 20th. Image Credit: Stellarium
The daytime view of Venus, the Moon and Jupiter of the evening of June 20th. Image Credit: Stellarium

The Moon will actually occult Venus three times in 2015: On July 19th as seen from the South Pacific, on October 8th as seen from Australia and New Zealand, and finally, on December 7th as seen from North America in the daytime.

This conjunction of Venus and Jupiter occurs just across the border in the astronomical constellation of Leo. As Venus can always be found in the dawn or dusk sky, Jupiter must come to it, and conjunctions of the two planets occur roughly once every calendar year. A wider dawn pass of the two planets occurs this year on October 25th, and in 2019 Jupiter again meets up with Venus twice, once in January and once in November. The last close conjunction of Venus and Jupiter occurred on August 18th, 2014, and an extremely close (4’) conjunction of Venus and Jupiter is on tap for next year on August 27th. Check out our nifty list of conjunctions of Venus and Jupiter for the remainder of the decade from last year’s post.

The view through the telescope on the evenings June 30th and July 1st will be stunning, as it’ll be possible to fit a 34% illuminated 32” crescent Venus and a 32” Jupiter plus its four major moons all in the same low power field of view. Jupiter sits 6 astronomical units (AU) from Earth, and Venus is 0.5 AU away on July 1st.

30 FoV
Looking at Jupiter and Venus on July 1st using a 30 arc minute filed of view. Image credit: Starry Night Education Software

And just think of what the view from Jupiter would be like, as Venus and Earth sit less than 3 arc minutes apart:

View from jupiter
The view from Jupiter on July 1st looking at the Earth. Image credit: Starry Night Education software

Venus reaches solar conjunction this summer on August 15th, and Jupiter follows suit on August 26th. Both enter the field of view of the European Space Agency’s Solar Heliospheric Observatory (SOHO) LASCO C3 camera in mid-August, and are visible in the same for the remainder of the month before they pass into the dawn sky.

But beyond just inspiring inquires, close conjunctions of bright planets can actually raise political tensions as well. In 2012, Indian army sentries reported bright lights along India’s mountainous northern border with China. Thought to be reconnaissance spy drones, astronomers later identified the lights as Venus and Jupiter, seen on repeated evenings. We can see how they got there; back in the U.S. Air Force, we’ve seen Venus looking like a ‘mock F-16 fighter’ in the desert dusk sky as we recovered aircraft in Kuwait. Luckily, cooler heads prevailed during the India-China incident and no shots were exchanged, which could well have led to a wider conflict…

Remember:  Scientific ignorance can be harmful, and astronomical knowledge of things in the sky can save lives!