A planet smorgasbord flies overhead
From sunset to sunrise this week you have a chance to view all of our companion planets in the solar system with the naked eye. Mercury, Saturn, Jupiter, Mars and Venus will be super easy to find.
The two planets you want to look for early in the evening are Mercury and Saturn.
In fact, you have to start looking for Mercury very low in the west-northwest sky even before the end of evening twilight. It will be barely above the horizon so you have to be in a high spot with a very flat treeless horizon to see it. A hilltop location usually works the best.
Find Mercury as soon as you can because it sets below the horizon just about an hour after sunset. It won’t come anywhere close to blowing you away with its brilliance, but it will be the brightest starlike object in that part of the sky.
Since Mercury is the closest planet to our sun at only 36 million miles away, it never strays that far from the sun in our sky as it orbits our home star every 88 days. That’s why we either see it in the very early evening like we do now or the very early morning.
Most of the time when you see Mercury it’s backlit in twilight. Through a telescope there’s honestly not much to see. It’s a small planet and because we’re forced to try and see it through so much of our Earth’s atmosphere near the horizon it’s really, really fuzzy.
What you may see, though, is that Mercury has the shape of a half moon. Planets that lie within the Earth’s orbit like Mercury and Venus go through phase changes just like our moon.
Next in our evening parade of planets is my favorite, the ringed wonder Saturn. It’s a little higher in the sky than Mercury at the start of the evening at about 20 degrees or two widths of your fist at arm’s length above the western horizon.
It’s also really easy to spot right now because it has a twin just to its right. Look for a “double star” in the low western sky.
Saturn’s companion is the star Porrima, the second brightest star in the faint constellation Virgo the Virgin. It’s much farther from us than Saturn at over 239 trillion miles away.
Saturn is always a fine target for even the smallest of telescopes, although it’s also low in the sky at the end of evening twilight and getting a little fuzzy like Mercury. It’s also getting far away. Saturn is more than 910 million miles away, nearly at its maximum distance from the Earth in 2011.
Nonetheless you should easily see the 130,000 miles-plus diameter ring system and maybe even some of its many moons that look like tiny stars swarming Saturn.
One of its moons is much bigger and brighter than the rest. That’s Titan, which, in fact, is even larger than the planet Mercury. Titan’s diameter is 3,200 miles and Mercury’s is only a little more than 3000 miles.
After you’ve visually bagged Saturn and Mercury, you can choose between other celestial treasures until Jupiter comes up in the low eastern sky around one o’clock in the morning, or you can get your beauty rest and instead set your alarm for about an hour and half before sunrise.
Whatever you choose to do Jupiter will easily be the brightest starlike object you see before twilight in the eastern sky. It’s the largest planet in our solar system with a diameter of 88,000 miles, more than 10 times the girth of Earth.
Presently Jupiter is a little more than 455 million miles away but by the end of October, when it reaches what astronomers call opposition, the Earth and Jupiter will be at their closest approach to each other with the Jovian giant less than 360 million miles from our world.
Just like Saturn, there’s much to see on Jupiter through even a small telescope. On the planet itself you should be able to see some of its cloud bands of ammonia, methane and other gases that stripe the planet, nearly in a horizontal orientation from our present view in the early morning.
What really stands out, though, are four of Jupiter’s largest moons, dubbed the Galilean moons in honor of Galileo, who was first on record to discover them. They look like little stars that flank the great planet on either side. Now you may not be able to see all four moons on any given morning because they dance around Jupiter in orbits of two to 17 days.
Every time you aim your telescope toward Jupiter the number of moons visible and their arrangement will be at least a little or sometimes a lot different. This coming Saturday morning there will be some really nice eye candy in the sky as the waning gibbous moon will be placed just above Jupiter. You’ll like what you see!
The next planet to look for in the early morning eastern sky is Mars, which unfortunately is not nearly as much fun to look at as Jupiter. In fact, you might even have a hard time spotting it with the naked eye.
About 90 minutes before sunrise, a little before morning twilight, begin looking for it in the very low eastern sky on the lower left side of the constellation Taurus the Bull, which somewhat resembles an arrow pointing to the upper right.
On the lower left hand side of that arrow is Taurus’s brightest star Aldebaran, which has a slightly reddish hue to it. Just a little to the lower left of Aldebaran you’ll hopefully see Mars, also with a reddish tint but not nearly as bright.
Mars is tough to spot right now because it’s much smaller than Earth at a little over 4,200 miles in diameter and presently it’s nearly 200 million miles away.
About every two years or so Mars and Earth get close up and personal with each other.
Distance varies in these oppositions but in all cases Mars is a lot brighter than it is now. Early next March Mars and the Earth will be a lot closer to each other and through a telescope you should see at least a little detail on our Martian neighbor as it will be just under 63 million miles away.
Right now through a telescope about all Mars will look like is a tiny red dot.
To close out the morning see if you can spot the planet Venus rising just ahead of the sun in the east. Because of its very reflective but poison atmosphere, Venus is a very bright planet, but it may be overwhelmed by the oncoming sunlight as day begins.
Enjoy the overnight planet parade!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, “Pennsylvania Starwatch,” available at bookstores and at www.lynchandthestars.com.
