creators home
creators.com lifestyle web
Dennis Mammana

Recently

Listen to the Moon Week of April 26 — May 2, 2015 There's an old joke that astronomers love to tell. An elementary school teacher was presenting a lesson about the moon and asked the children which was more important — the sun or the moon — figuring …Read more. Enjoy the Lyrids Meteor Shower Week of April 19-25, 2015 A few days ago, I had just begun one of my popular outdoor night sky presentations when my guests erupted with gasps and cheers. I wanted to believe that it was my witty and captivating repartee that produced their excited …Read more. Celestial Water Snake Week of April 12-18, 2015 Here's a trivia question for you. Which is the largest of all constellations? If you answered Hydra, you know more about the night sky than you admit. At this time of year we can find Hydra, the water snake, low in the …Read more. Star Patterns Made Easy Week of April 5-11, 2015 I recall many years ago standing under the stars trying to understand why the constellations looked nothing like the elaborate drawings I'd seen in star maps and books. I mean, why could I never find a great bear among the …Read more.
more articles

Spotting Mercury, the Messenger

Comment

Week of May 3-9, 2015

In Roman times, it was known as the god of commerce, travel and thievery. The Greeks called it Hermes, the messenger of the Gods, when it appeared at dusk and Apollo when they saw it at dawn.

Today we know it as Mercury — the nearest planet to the sun — and it's back in our evening sky this week for all to enjoy.

If you've never seen Mercury, you're certainly not alone. Many stargazers have never spotted it, including the great 16th-century Polish astronomer Nicolaus Copernicus. But, since this week marks the year's best opportunity for Northern Hemisphere stargazers, now's the time to check out this elusive planet.

I call Mercury "elusive" because it whips around the sun in only 88 days and, as a result, it never stays in our sky for long, and never strays far from the sun's glare. Even under the most ideal conditions, we can never see Mercury more than 28 degrees from the sun, which means it cannot ever appear in a completely dark sky.

This week, however, you can find the planet as long as clear weather extends all the way to the horizon at dusk.

Shortly after sunset, you'll see a brilliant light midway up in the western sky. It's been there for a few months already; that's the planet Venus. Now, with your eyes or binoculars, scan below and to its right low Mercury will appear as a much fainter star-like object in that part of the sky, and will be shining with a distinctly yellowish cast.

And don't be surprised if it twinkles; the thick column of air through which its light must pass will do that even to a planet, despite what we might have learned in school.

Mercury is a world quite different than all others in our solar system. Spacecraft photos of this dry, cratered world look remarkably like those of the moon. Because it's much too small and close to the sun to have an atmosphere, temperatures on its daytime side soar to hundreds of degrees, and on its nighttime side plunge to hundreds of degrees below zero.

Now, while it's true that Mercury is the closest planet to the sun, it isn't the hottest of our planetary family. That honor belongs to Venus; even though it lies twice as far from the sun as Mercury, its thick cloud cover acts as a blanket and holds the planet's temperature at a toasty 900F — hot enough to melt lead.

If the western sky is clear at dusk this week, try aiming a small telescope in the direction of these two planets, but don't expect to see much.

Venus, of course, is a good place to start; it will appear significantly larger than Mercury and, this week, will appear nearly in a quarter phase.

Mercury is relatively small, some two and a half times smaller than the Earth, and its light will be significantly distorted by air turbulence near the horizon. But if you're fortunate enough to see a steady image, might notice that Mercury appears not round but rather in a thick crescent phase.

Visit Dennis Mammana at www.dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

COPYRIGHT 2015 CREATORS.COM




Comments

0 Comments | Post Comment
Already have an account? Log in.
New Account  
Your Name:
Your E-mail:
Your Password:
Confirm Your Password:

Please allow a few minutes for your comment to be posted.

Enter the numbers to the right:  
Creators.com comments policy
More
Dennis Mammana
Apr. `15
Su Mo Tu We Th Fr Sa
29 30 31 1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 1 2
About the author About the author
Write the author Write the author
Printer friendly format Printer friendly format
Email to friend Email to friend
View by Month