Catch the Stellar Summer Show
Rest up in the afternoon so you can be nice and fresh to take in some divine summer stargazing this month. It's not truly dark enough until after 10:30 pm, but there's a wonderful show going on in the western sky much earlier than that in the later stages of evening twilight.
There's a spectacular conjunction, or what I called a celestial hugging, between the very bright planets Jupiter and Venus. You can't miss them. They are the brightest star-like objects in the evening sky, popping out in the west even before the end of evening twilight. Early this week they're practically touching, less than a half a degree apart. That's less than the width of the full moon in the sky. It will look like a pair of eyes poking out at you. Venus is the brighter of the two. Even though the planets look like they're touching, they are actually separated by hundreds of millions of miles. Venus is around 45 million miles away and Jupiter is more than 550 million miles distant.
Through even a small telescope you should be able to see both planets in the same field of view. With Jupiter you can easily see up to four of Jupiter's largest moons and maybe some of Jupiter's brighter cloud bands. Venus looks like a tiny half moon. Since Venus's orbit lies inside of Earth's orbit, it goes through phases just like our moon. Later in the week Jupiter and Venus will begin their gradual separation, although most of this month they'll be hanging pretty close to each other.
Meanwhile, in the low southeastern sky all this month, the planet Saturn is on the rise near the constellation Scorpius the Scorpion. Saturn is the brightest star-like object in that part of the sky, and is wonderful to take in through a small telescope. You can easily see it's famous ring system that spans over 136,000 miles in diameter, but is only 50 feet thick. Keeping Saturn company in the low southeast sky this week will be a full moon on the rise, taking low arc across the sky this time of the year.
The brightest actual star in the sky this month is Arcturus, the brightest star of the summer sky. At twilight's end Arcturus is perched high in the western sky at the tail of a giant kite. That kite is more formally known as the constellation Bootes, the hunting farmer. How the kite is supposed to be a hunting farmer is anyone's guess. Arcturus is a giant star, more than 22 million miles in diameter and more than 36 light-years distant, with one light-year equivalent to about 6 trillion miles.
In the eastern heavens, you'll see the prime stars of summer on the rise. As we move through July they'll be a little higher at the start of each night as the Earth in its solar orbit passes in their direction. The best way to find your way around the summer stars is to locate the "Summer Triangle" made up of a three bright stars, the brightest in each of their respective constellations. You can't miss them. They're the brightest stars in the east right now.
The highest and brightest star is Vega, the bright star in a small faint constellation called Lyra the harp. The second brightest star on the lower right is Altair, the brightest in Aquila the Eagle. Altair is on the corner of a diamond that outlines the wingspan of the great bird. The third brightest at the left corner of the summer triangle is Deneb, a star possibly over 1800 light-years away. It's also the bright star in at the tail of Cygnus the Swan. Cygnus is also known as the "Northern Cross" because that's what it really looks like. Deneb is at the head of the Northern Cross that is presently laying on its side as it rises in the east.
In the northern sky look for the Big Dipper hanging from its handle in the northwest, along with the fainter Little Dipper standing on its handle. The moderately bright star Polaris, otherwise known as the North Star, is at the end of the Little Dipper's handle. Every single thing in the sky, including the sun and the moon, appear to revolve around Polaris every 24 hours.
Enjoy the short but starry nights in July!