By Mike Lynch
For the next week or so Saturn, Mars, Jupiter and Venus are all available for our perusal at both ends of the overnight Northwest sky.
Saturn and Mars have a short early evening shift in the low western sky, while Jupiter and Venus are pulling early morning duty in the high eastern heavens.
Without a doubt, Jupiter and Venus are putting on the best show in the early morning hours. They are both above the eastern horizon by 4 a.m., but are best seen around 5 to 6 a.m. when they are well above horizon and serve as the brightest starlike objects in the sky.
Venus is absolutely brilliant, but on closer inspection with a telescope or binoculars it’s not much to look at. It’s just an ovalish bright ball of light. Venus is 93 million miles from Earth, about the same distance between us and the sun but not in the same direction.
Venus and Earth are about the same size, about 8,000 miles in diameter, but that’s about the only similarity. Venus is completely overwhelmed by a thick and poisonous cloud cover that is very reflective of sunlight. That’s why it’s so bright.
Underneath those clouds made up of mainly carbon dioxide, nitrogen and carbon monoxide and laced with acid rain, there’s a runaway greenhouse effect going on.
The sun’s radiation can get to the surface of Venus, but the reradiated terrestrial heat is mostly held captive by the cloud cover. As a result its surface temperatures hit more than 800 degrees.
Jupiter, to the upper right of Venus, is a whole other world. In fact it’s the biggest world in our solar system. It’s 88,000 miles in diameter.
Jupiter is orbited by dozens and dozens of moons. and you can even see the four biggest ones with a good pair of binoculars as they circle around Jupiter in periods of 2 to 17 days. They look just like little stars hugging either side of the big guy of our solar system.
Jupiter is a huge ball of mainly hydrogen gas with cloud bands of ammonia, methane and other gases. Some of the darker clouds bands can be seen with smaller telescopes.
The winds in the cloud bands of Jupiter can exceed 200 to 300 mph. Around the Great Red Spot, a storm on Jupiter that’s been raging for hundreds of years, the winds can exceed 400 mph.
To the right of Jupiter there’s a dimmer reddish star, Aldebaran, the brightest star in the winter constellation Taurus the Bull. Above Jupiter is the best feature of Taurus, the Pleiades Star Cluster, a family of young stars that looks like a tiny version of the Little Dipper.
Just before the predawn twilight right now we get a preview of winter constellations like Orion the Hunter and others.
Mars and Saturn won’t be nearly as wonderful to look at in the low early evening western sky. Think of them as more of a visual spotting challenge. It’s really hard to see them because they are so low in the western sky and they set below the horizon not that much longer after the end of evening twilight.
You really need a low flat treeless horizon to see them because they are so low in the sky.
Toward the end of evening twilight on Wednesday look for the thin crescent moon in the very low western sky. Just to the right of the moon will be Mars. The next brightest star-ike object to the right of Mars will be the planet Saturn. The ringed planet will be about two of your fist-widths held at arm’s length to the right of Mars.
Neither Mars nor Saturn are worth trying to see with your telescope. They will both look really fuzzy since they’re really close to the horizon where Earth’s atmosphere is a lot thicker.
By the way, the red planet as has a new visitor, as you probably heard. It’s NASA’s Curiosity rover, about the size of the average automobile, taking amazing pictures and searching for life on Mars. A great website to keep up with Curiosity is www.nasa.gov/mission_pages/msl/index.html.
Mike Lynch is an astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, “Washington Starwatch,” available at bookstores. Check his website, www.lynchandthestars.com.
The Everett Astronomical Society: www.everettastro.org/.