Here comes summer in the night skies
The summer of 2019 begins next Friday at 10:54 in the morning, at least astronomically. Astronomers call it the summer solstice, and it’s the longest day of the year. Friday’s the day that the sun reaches its highest height in our Marshall sky. It all has to do with the inclination or tilt of Earth’s axis as it orbits the sun. On the day of the summer solstice the Northern Hemisphere is tilted to the maximum toward the sun’s most direct rays. At noon the sun shines directly overhead along the Tropic of Cancer at a latitude of 23.5 degrees north of the equator. Here in Marshall at 44.5 degrees latitude our noontime sun won’t be quite at the zenith, but it’ll be close at nearly 70 degrees above the southern horizon.
On Friday, the sun will take a very long and very high arc across the sky. It will rise in the northeast at 5:39 a.m. and set in the northwest at 9:11 p.m., giving us 15 hours and 22 minutes of daylight. As a bonus, morning and evening twilight lasts a lot longer than it does in winter.
The longest days of the year of course make for the shortest nights, and with the late sunsets and extended twilight stargazing becomes a late-night adventure. You have to become a night owl! Summer stargazing can also be a little more challenging because additional moisture in the air this time of year can muddy up even clear skies a bit. Without a doubt, though, the warmer weather more than makes up for the late hours and the humidity, even if you live in areas prone to mosquitoes. There’s bug juice for that and in most places the mosquitoes ease off biting an hour or two after sunset.
A really fun thing to do this time of year is to spend an entire night under the stars. It’s certainly doable now with the shortest nights of the year. I’ve done it many times and I find it really good for the soul. If you a have a telescopes or binoculars it’s a lot of fun to search for targets like planets, the moon, star clusters, nebulas, and more. But I also just like to sit in silence, lying back in a lawn chair with or without a star map or smart phone stargazing app. Roll your eyes all around the celestial dome!
If you have time and you’re not too tired, stay awake long enough to take in morning twilight. Sit back and face the northeast about an hour before sunrise and take in all the sights and sounds. Turn off your cell phone and get rid of any other distractions. You’ll see, hear, and even smell the wonder of another day breaking. You don’t have to be off in some exotic location either. Your own neighborhood is just fine, be it urban or rural.
As nice as it is, I don’t recommend that you set off on your “all nighter” star watching adventure for the next week to 10 days because we have a full moon. As lovely as any full moon is, it’s murder on stargazing as our lunar neighbor really washes out the celestial dome with its second hand reflected sunshine.
You can’t help but notice that the full moon this time of year takes a short and low track from east to west across the southern sky. The sun takes this same low arc around the winter solstice, the first day of winter. This makes sense because any full moon is always on the opposite end of the sky from the sun, so this time of year while the sun takes its high arc across the sky the full moon is a low rider. Around the winter solstice in late December there’s a flip-flop. The sun takes its low trajectory in the southern sky and the full moon is a high rider around Christmas.
By the way, if you have clear enough skies and can stay up late enough this Sunday night, you’ll notice that the full moon has a bright companion as it rises in the southeast. Just to the upper right of the moon you’ll see a super bright “star.” That’s no star, it’s the great planet Jupiter, at its closest approach to Earth this year. I’ll have more on the big guy of our solar system in next week’s Starwatch.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net.