Bright Evening Planet Lineup
By Chuck McPartlin
Between now and the end of July, all five of the brightest planets can be spotted in Santa Barbara's evening skies, with the Moon acting as a convenient guidepost to help you find them. I've also included an image of each of them at the same scale from NASA's solar system page. You can see how small the rocky planets are compared to the gas giants.
The first pairing will be the hardest to spot, especially if there is haze, but it's worth the effort. Not many people have seen Mercury, the innermost planet in our solar system. As the Sun sets on Saturday, July 14, look for a very slim crescent Moon in the west. Just below it will be Mercury. You may need the help of binoculars to spot both of them. They'll be about 15 degrees down and right of brilliant Venus. Your fist at arm's length spans about ten degrees.
Mercury is the smallest of the eight major planets, with a diameter of about 3,000 miles, and will be about 74 million miles away.
Venus will have a beautiful pairing with a thicker crescent Moon on the next evening. This will be a great photo opportunity.
Venus is just a skosh smaller than Earth, with a diameter of 7,500 miles, and it will be about 88 million miles away. Binoculars or a telescope will show that it is in half-Venus phase. Over the next two months, as it approaches us, its phase will shrink into a thin crescent, but it will grow even brighter.
On Friday, July 20, a just past first quarter Moon will be sitting above and slightly left Jupiter. (see above photo)
Jupiter is the biggest planet in our solar system, with a diameter of 88,800 miles, and it will be about 468 million miles away. If it were hollow, it would hold about 1,300 Earths. It's got 69 moons (at last count), and four of them are large enough to see in binoculars.
On July 24, the fat waxing gibbous Moon will be sitting just above the planet Saturn.
Saturn is the most photogenic planet in our solar system, with a diameter of 75,000 miles, and it will be about 852 million miles away. If it were hollow, the ball of Saturn would hold about 750 Earths, but it's less dense than water. The rings span 200,000 miles, but are only about 30 feet thick. They're tilted very face-on to Earth right now, but you'll need a small telescope to see them.
And finally, on the nights of July 26 and 27, the full Moon will bracket bright orange Mars.
Mars is rather small, with a diameter of 4,200 miles, and it will be at a distance of about 36 million miles, the closest it's been for 15 years. It'll be especially bright, because there's also currently a huge dust storm enshrouding it. Unfortunately, that means we won't get much in the way of telescopic views of surface features.
If you'd like a live view through a telescope of our fellow wanderers of the solar system, just drop by at one of the free public star parties hosted by the Astronomical Unit. You can find our schedule of events on the SBAU web page below.
References for a Cloudy Evening