What’s in the Sky
Here we are already in the second half of 2020, July and our nation’s birthday!
In addition to wishing friends and families a “Happy 4th, try wishing them a “Happy Aphelion Day”. Whatever is that, you say? July 4 this year marks when we are farthest from the Sun in our elliptical orbit, called “Aphelion”. Yes, in warm July we’re farther from the Sun than any other time of year! Our orbit is only slightly elliptical. We’ll be about 94,500,000 miles from the Sun, above our average distance of about 93 million miles. So happy Aphelion day to all on July 4!
But wait, there is more, as those late-night TV ads say. July 4 will also feature the month’s full Moon, and a lunar eclipse. But before you get too excited, that eclipse will hardly be noticeable. It will be a “penumbral” eclipse, where only some of the Sun’s light is blocked from reaching the Moon. There will be a small area of the Moon that is slightly less bright from Moonrise until about 10:30pm. As you look at the Moon, the upper-left part of the globe will be very slightly eclipsed.
July brings the bright, giant planets Jupiter and Saturn into the evening sky. They will both be low in the southeast and southern sky after sunset, to the left of the Milky Way. They will be very low in early July, and higher in the sky later in the month, but still low in sky. They will be easy to spot, as both will be brighter than stars in the area. On July 4th, they’ll be just to the left of the full Moon. They will both move slightly to the west during July, closer to the Milky Way, and the “Teapot” of the constellation Sagittarius. Both will make their closest approaches to Earth for 2020 in the month of July, Jupiter on the 14th, and Saturn on the 20th.
Venus is now the “morning star”, visible in the east before sunrise, all month. Look for it near the waning crescent Moon on July 16 and 17. In the latter half of the month, look for Mercury below and to the left of Venus.
Mars is still an object to see in the morning sky, but will be moving into the evening sky next month. Look for the red planet near the Moon in the early morning of July 11.
The binocular object for July is one of those bright planets – Jupiter! Train your binoculars on the solar system’s giant and see if you can detect little pinpoints of light near Jupiter, sometimes appearing to be in a line. Those pinpoints are the planet’s 4 largest moons, Io, Europa, Callisto, and Ganymede. You can watch them change positions as they orbit Jupiter. At times, such as July 10, all 4 will be on one side of the planet. Other times, such as July 9, two will be on one side, and two on the other. Watch them for a couple of nights and see if you can detect the change in positions. Over 400 years ago, Galileo used the newly-invented telescope to observe the moons, and concluded that they orbited Jupiter, a huge discovery at the time. If you cannot see the moons, you may need binoculars that gather more light. Those with front lenses that are 50mm in diameter or larger will help.
The skies begin to darken a bit earlier in July, and you’ll not have to wait up quite as long to see the celestial delights. Sunset comes at about 9pm in early July, dropping back to about 8:35 at the end of the month. The constellations we see continue to change as we orbit the Sun too. You’ll see Leo the lion sinking in the west at sunset, and summer constellations rising higher in the east. In the south, look for Scorpius the scorpion, with its bright, reddish star Antares. To its left, find the “Teapot” of Sagittarius the archer, in the Milky Way. Nights should be warmer, allowing for pleasant viewing. Enjoy the night skies of July!
What’s in the Sky
Welcome to June, warmer weather, and the start of summer. Our nights may be shorter, with darkness coming later, but the beauty of our night skies makes the wait worthwhile.
Summer begins for us on June 20, the summer solstice. On that date, the Sun will be as far north as it gets in our sky, and will be directly overhead at the Tropic of Cancer. We’ll have about 15 hours and 45 minutes of daylight, with the Sun rising at about 5:15am, and not setting until about 9pm.
Last month I mentioned that Mercury was in good position to view, late in the month. That continues in June. In fact, June 4 will be the best, when the solar system’s innermost planet is at its greatest elongation from the Sun, and highest in our evening sky. After the 4th, it will drop lower in the sky as we see it, closer to the Sun and more difficult to view.
At the start of June we will have a bright, waxing gibbous Moon in the constellation Virgo, just above the bright star Spica. Full Moon will follow on June 5, with our natural satellite located just above the bright star Antares in the constellation Sagittarius. On June 9 and 10 the Moon will join the bright planets Jupiter and Saturn, low in the south before sunrise. On the 12th and 13th the Moon will serve as a beacon for nearby Mars in the southeastern morning sky. New Moon will be on June 20. On the 28th and 29th, the Moon will be back near Spica, in the southern evening sky.
If staying up late is not your thing, try finding the faint crescent Moon just after new Moon, on June 22. You’ll need a fairly good view of the western horizon. At sunset (about 9pm), the Moon will be about 12 degrees above the horizon, in the west-northwest. How high is 12 degrees? If you extend your arm and make a fist, your fist covers about 10 degrees, so think of it as a bit more than a fist-width above the horizon. Binoculars may help locate it in the still bright sky. June 23 will be easier, with the Moon now some 20 degrees high.
And yes, speaking of binoculars, I have a binocular object for June. Look for the bright star Mizar, in the handle of the Big Dipper (part of the constellation Ursa Major). Find the Big Dipper, and locate Mizar as the middle star in the handle. Mizar is bright, so you don’t need to wait until total darkness to see it well, helpful in this month of short nights. If you look very close, with your naked eye, you may detect a faint star right next to Mizar. That companion is Alcor. Train your binoculars on Mizar, and you will see that it is really 2 closely-spaced stars. Alcor will also be visible, as a nearby bright star. And there are even more stars in the system, although you cannot see them – Mizar and its near companion are part of a set of 4 stars orbiting each other, and Alcor has a faint companion as well. So there are a total of 6 stars in the gravitationally-bound system.
The bright planets are still absent from the evening sky. Venus, which has been visible in the western evening sky, will pass between Earth and the Sun in early June. After about mid-month, you will be able to see it low in the east, now in the morning. On the 19th it will be near the thin crescent Moon, low in the northeast at sunrise.
Jupiter and Saturn remain best visible before sunrise in the south, but they both will be peeking above the horizon in the evening too, after about 11pm, late in the month. More about them next month, as they move into our evening sky. Mars remains a morning-sky object; it is growing closer to us, and will be at its closest this year in October.
Summer constellations are beginning to enter our night skies. Cygnus, the Swan, nestled in the summer Milky Way, is above the eastern horizon by 10pm. Just above Cygnus is the bright star Vega, in the little constellation Lyra. They will loom higher in the sky later in the summer. Spring constellations, such as Leo the Lion, are now low in the west. It is fun to watch the march of stars across our night skies as the seasons change.
Enjoy the experience of June’s night skies!