Jupiter and Saturn take prime spots in June sky

This June provides a great chance to see the solar system’s biggest planets, Jupiter and Saturn, throughout most of the evening.

Since many of the great sights of our sky are seen clearly on our sky map, I’ll use that map as our point of reference as we discuss how to find Jupiter, Saturn, the Southern Cross and Scorpius (Maui’s Fishhook).

As with all of our monthly star maps, the June map is good for 10 p.m. early in the month, 9 p.m. in the middle of the month and 8 p.m. at the end of the month. As our map shows, Jupiter and Saturn are well-placed for viewing in the mid-evening sky.

At map time, look for the bright white dot of Jupiter about halfway up in the southwestern sky. Jupiter shines much brighter than any star, so it will pop out easily. Bluish-white star Spica, about 10 degrees (the width of your palm at arm’s length) to the left of Jupiter, shines bright, but Jupiter outshines it by 20 times.

In even a small telescope, Jupiter appears as a disc with four bright dots. These dots are the “Galilean moons” that Galileo discovered with his newfangled telescope in January 1610.

In early June, Jupiter will set in the west at 2:30 a.m.; by the end of the month, it sets by 1 a.m.

Saturn is rising in the southeast at map time. The planet is about 20 degrees above the southeast horizon. Saturn has a distinctive yellow-white color; while it’s nowhere near as bright as Jupiter, Saturn does shine nicely, about 2.5 times brighter than the star Antares in the Scorpion, the first-magnitude star to the right of Saturn.

But the somewhat-dimmer Antares can be your guide to finding Saturn, because Antares is at the heart of the constellation of Scorpius. Scorpius (Maui’s Fishhook) pops out easily in the sky.

Antares is the only first-magnitude star in the Scorpion and has a distinctive orange hue. Once you’ve found Antares, look left about the width of two of your palms, and the bright yellow-white light that is somewhat brighter than Antares is Saturn.

Saturn is in opposition on June 15. When a planet is in opposition, there is a straight line between the sun, Earth in the middle, and the planet. During opposition, a planet rises at sunset, is high at midnight and sets at dawn. This is also the time when the planet is nearest to Earth (though in Saturn’s case it’s still almost a billion miles away) and shines most brightly.

In early June, Saturn will be due south by 1:30 a.m. and will work its way down the western sky in the early morning; by daybreak, Saturn will be low in the west. By the end of the month, look for Saturn due south at 11:30 p.m.; it will set in the west at 4:45 a.m., just as the first light of dawn starts to break. In these early hours, you can still use the Scorpion and Antares to find Saturn. But if you go looking for them after midnight, please note that Saturn will be above Antares, rather than to the left.

Saturn’s rings are perhaps the most beautiful telescope sight of all. Centuries after they were first spotted in a telescope, the most common comment from first-time Saturn viewers is that the “rings don’t look real.”

The rings should be more striking than usual this season. The rings are tilted 27 degrees to our line of sight this summer, the best tilt since 2003; this means that the rings are exceptionally well-angled for good telescope viewing.

Throughout June, Venus rises in the east just after 3 a.m., about a third of the way up in the east at daybreak. Venus shines at minus 4.3 magnitude, many times brighter than even Jupiter.

June constellations

In addition to featuring good views of Jupiter and Saturn, the star map shows you how to find many well-known constellations, including the Southern Cross.

On the June map, the Southern Cross is low in the south and is just about to set. To locate Crux, make sure you have a flat horizon, such as the sea, to view it. The bright stars Alpha and Beta Centauri, to the left of the cross, are just rising at map time and can be an invaluable guide. These two brilliant stars are called the “Southern Pointers.” Find them, look right, and they will point you to the top star in the Cross, Gacrux.

The map gives you a good idea of what the Cross looks like, and where to find the southern pointer stars of Alpha and Beta Centauri. That said, if you want the best shot at seeing the Southern Cross in June, I’d suggest going out about 8:15 p.m. early in the month, as darkness is just setting in. At about 8:15 p.m. in early June, Crux will be due south and at its highest point in the sky. This is still not very high — a mere 6 degrees from the bottom star to the horizon — but your odds of catching it are best when the cross is due south. Even by 8:15 p.m. in early June the Southern Pointers will have risen, so they can serve as a handy guide to finding the Southern Cross itself.

By June 15, the Cross will no longer be exactly south at 8:15 p.m., but rather a little to the right of due south; the odds of seeing it will still be better than when the Cross is about to set, as depicted on our June map.

I have seen the Cross as late in the year as July 4, under ideal weather conditions, but for all intents and purposes we lose Crux by the end of June every year in the islands. From the start of July to the end of November we can’t see it at all; the Southern Cross returns to the morning sky around Dec. 1.

Our map also shows the star Arcturus in the exact top of the sky, or the zenith. The star is known as Hokule‘a in Hawaiian, “the star of gladness.” One reason for its significance in the islands is that Hokule‘a passes almost exactly overhead as viewed from the latitude of Hawaii. You can also see the Big Dipper in the north, its cup pointing to the North Star and its handle pointing to Arcturus.

The summer triangle is just rising in the northeast by map time; the stars Vega, Altair and Deneb are pulled from three separate constellations to make a big triangle in the sky.