Venus, Jupiter and Saturn! The Brightest Planets of June

What a great weekend for the Summer Solstice celebration, even the heavens is going to give us a show!

Make plans for sky-watching June 30th! Jupiter and Venus are drawing closer together and will end up amazingly close!


The sky is gearing up for a very cool event: On June 30 and July 1, Venus and Jupiter will pass extremely close together in the sky, less than a third of a degree apart!

That’s close. The full Moon is a half degree across, so this will be very pretty. And it plays out over several days, so you’ll have plenty of chances to see it.

The planets orbit the Sun more or less in the same plane. We’re in that plane, too, so we see the solar system from the inside, and edge-on. That means that as the planets move around the Sun we see them moving along the same line in the sky, which we call the ecliptic.

In reality the planets’ orbits are all tilted slightly with respect to one another, so they don’t follow the exact same line. This means that, from Earth, we see them pass by each other in the sky, sometimes closer than other times. Usually they miss each other by a few degrees—and remember, this is just a perspective effect. In reality the planets are hundreds of millions of kilometers apart.

 Venus orbits the Sun closer than Earth does, and Jupiter well outside. Right now, Venus is “rounding the corner” of its orbit, on the near side of the Sun and starting to overtake us. Jupiter is headed for superior conjunction, when it’s on the other side of the Sun from us. All these motions combined means Venus and Jupiter are approaching each other in the sky, getting closer every night.

If you go outside just after sunset (even before the sky is totally dark) and look to the west, you won’t miss them; Venus and Jupiter are the third and fourth brightest natural objects in the sky. It’s been pretty rainy where I am, but the other night we had clear skies and I saw them about 10° apart. They’re already making a striking pair.


They get closest together around 03:00 UTC on July 1 (which is in the evening in the U.S. on June 30). At that point they’ll be about 17 arcminutes apart (there are 60 arcminutes to a degree, so the Moon is 30 arcminutes in size). Through a telescope they’ll be amazing. They should both fit easily under low power. Jupiter’s disk will show stripes, the moons will be visible, and Venus will shine in a waning crescent phase.

This is the closest the pair have been for a while … but just wait until next year. They’ll get an incredible 4 arcminutes apart on Aug. 27! That’s during the day here in the U.S., but should be visible with binoculars or a telescope. So think of this month as a warmup.

On June 14, Mars will begin its trip behind the sun, so prepare to say farewell to the Red Planet until it becomes visible again in August. Other planetary treats include Jupiter and Saturn shining bright in the night sky. With that in mind, here’s a look at some of the must-see planet events in theJune night sky. Remember, when measuring the angular separation between two celestial objects, your clenched fist held at arm’s length measures roughly 10 degrees.

June 6: Venus dominates the west after sunset for another month. It reaches greatest elongation (45 degrees east of the sun) this evening. By pure geometry we would expect the planet’s disk to look half-lit (called dichotomy), like the first quarter moon. But in a small telescope (at an evening apparition) this usually happens about a week or so before the elongation date. During the rest of June, look for very subtle shadings in the cloudy crescent of Venus as it noticeably thins and lengthens. Venus is also beginning to decline in the twilight, so skywatchers at 40 degrees north latitude saw the planet shining about 25 degrees above the western horizon an hour after sunset on June 1, but by June 30 Venus will only be 15 degrees above the horizon an hour after sunset and will set less than 30 minutes after the end of twilight. These are all signs that Venus is swinging toward us along its orbit, on its way to passing between the Earth and sun in August.

June 12 and 13: Use binoculars or a wide-field telescope these evenings to enjoy the fine sight of Venus on the north edge of the sparkling Beehive star cluster.

June 14: Mars in conjunction with the sun and is invisible this month. In fact, we’ll have to wait until late in August to see Mars again as the Red Planet emerges from the glare of the rising sun as a morning object.


June 19: This evening, take note of the 3 1/2-day old crescent moon hovering well below the planets Venus and Jupiter in the west-northwest sky.


June 20: Take note on how the moon has shifted its position since last evening relative to Venus and Jupiter. The trio now resembles a broad obtuse triangle; the obtuse angle is at Jupiter. The moon appears to Jupiter’s lower left while Venus is 7 degrees to Jupiter’s lower right.

Jupiter is still prominent in the west in the June twilight; next to Venus it’s the second brightest evening “star.” Throughout June, Jupiter will be closing in on Venus from the upper left. Telescope users will do best to observe Jupiter early in the month and early in twilight. Even though Jupiter is on the far side of the Sun and about as small as it ever appears, in a telescope it still shows the largest disk of any planet (although by month’s end Venus will appear just a trifle smaller). In the first half of June this giant planet is still at least 30 degrees high (three fist-widths at arm’s length above horizontal) as seen from mid-northern latitudes 45 minutes after sundown. Look for Regulus, only about a twentieth as bright, to Jupiter’s upper left. Jupiter, in Cancer, is trekking slowly eastward against the stars toward Regulus; it reaches the Cancer-Leo border on June 9.


June 24: After passing through inferior conjunction on May 30, Mercury reaches its greatest elongation from the sun in the dawn sky. This is not a very high apparition of Mercury for mid-northern latitudes, but you can try catching it low in the east-northeast about an hour to 45 minutes before sunrise during the second half of this month. Also this morning, Mercury appears 2 degrees above and to the left of the orange star Aldebaran. This pair of 1st-magnitude objects might be spied with binoculars very low near the east-northeast horizon except perhaps from far-northern states, where they might simply be too low to pick out against the brightening dawn

June 28: Saturn and the moon pair off for a second, closer meeting this month. This evening Saturn will sit a couple of degrees to the moon’s lower right.

June 30: Venus and Jupiter make their closest approach to each other this evening, forming a stunning “double planet,” Jupiter appearing above Venus and separated by just over 0.3 degrees. Jupiter shines at magnitude -1.8 and yet as brilliant as it is, it’s still only 1/11th as bright as Venus.


In the meantime, get out and watch! It’s fun to go out every night and see them get closer. If the weather holds up, you can bet I’ll be outside, and looking through my own ‘scope, too.



Source : space .com , slate .com