The most easily viewed planets parade at dusk and dawn as November slides into December in 2019.
I should correct myself just as I get started. Earth is the most easily viewed planet. Unless of course your are stargazing on a moonless night from a wonderfully dark site, free of neighbor’s lights, passing headlights and street lamps. Then you may need a flashlight to see the Earth beneath your feet! The Earth on which we ride eclipses stars below your horizon, making a contrast with the starry firmament in the sky.
From our home planet, take a look the next clear evening about 45 minutes after sunset. Low in the glow along the southwestern horizon is the planet Jupiter, with the planet Venus shining even brighter nearby but to the upper left. Venus glows at magnitude -3.9; Jupiter, at -1.8.
As seen this weekend, Nov. 30 to Dec. 1, the planet Saturn is found further to the upper left of Venus, approximately twice the span as you see between Jupiter and Venus.
Saturn is a lot dimmer, magnitude +0.6, but readily visible and appearing like a steady, yellowish “star.”
Each evening this week, you can observe how the planets shift; the orientation and span between the planets change, as the Earth keeps moving away from them and the planets themselves, move on their orbits.
Remember, Venus is closer to the sun than we are, and Jupiter, followed by Saturn, are a lot further away. Venus is nearly the same size as Earth, both planets being much smaller than Jupiter and Saturn. Yet Venus looks so much brighter. That’s because Venus is closer to the sun and to Earth, and also is a good reflector of sunlight, being shrouded in white clouds.
You are not likely to see the planets “twinkle.” The brighter stars, especially when seen low in the sky, typically seem to rapidly fluctuate in brightness. The stars are so far away they are essentially points of light. We are looking through more layers of Earth’s atmosphere near the horizon; a beam of starlight becomes bent, or refracted, back and forth as it heads to your eyes.
The planets don’t seem to twinkle because they are so much closer, they appear as tiny but easily discernible discs in a telescope, unlike the stars. Sunlight reflects back to us off the planet from an infinite number of points, and the combined effect of refraction tends to cancel out before reaching out eyes.
The atmosphere seen at a low angle also breaks the light into component colors, and the red part of the light’s spectrum reaches our eyes more readily. Not only does this make the setting and rising sun and moon red and dimmed, stars and planets will be reddened and less bright.
After a full night of seeing stars, watch for morning twilight. About 45 minutes before sunrise, look low in the east-southeast for planets Mercury and Mars. Mercury its very low, and about magnitude -0.6.
Reddish planet Mars is much dimmer, magnitude +1.8, and is to the upper right of Mercury. Extend the line further to the upper right to find the bright white star Spica.
Planets Uranus and Neptune are in good position after dark. With a detailed finder chart and some experience, along with binoculars, it isn’t hard to find Uranus. Neptune is a lot fainter but within view in most binoculars. One of many online places to find charts to locate these distant worlds is www.skyandtelescope.com.
The waxing crescent Moon also draws our attention this weekend, leading up to first quarter phase on Dec. 4. Look for the “earthshine,” the dim reflection of sunlight from off the Earth, illuminating the portion of the moon within the bright crescent. The view with binoculars will be stunning.
Keep looking up!
Peter Becker is managing editor at The News Eagle in Hawley, Pennsylvania. Notes are welcome at email@example.com. Please mention in what newspaper or website you read this column.