In this first half of February, we get superb chances to see lunar crescents of extraordinary thinness and beauty. In addition, the slender moon poses at several dusks with the participants in another wonderful show: a rare, tight pairing of the planets Mercury and Mars.
Close meeting of Mercury and Mars: What is better than a bright planet shining in the delicate and slowly fading glow of evening twilight? Two planets, of course. And that is what we get for the next two weeks with Mars and the elusive planet Mercury.
I say that Mercury is elusive because it is the planet nearest to the sun in space and only for a few weeks each year pulls far enough away from the sun in our sky for us to see it relatively easily. Now is such a time, when the bright little world remains visible low, above where the sun went down for up to an hour and a half after sunset. We’re really fortunate that one of these limited good periods of visibility for Mercury happens just as it is passing Mars in our sky.
Make sure you have a clear view almost all the way to the west-southwest horizon. About 30 minutes after sunset, you should catch your first glimpse of Mercury’s point of light. After another 15 minutes, the currently much dimmer Mars may come into view. Binoculars will help you locate and observe Mars much more easily.
Of course, the proximity of Mercury to Mars will make the latter a lot easier to find.
Through Thursday, Mars appears to the upper left of Mercury. The gap closes dramatically. Tonight you can probably fit your thumb at arm’s length between the two planets, but on Thursday they are separated by only about half the width of your little finger at arm’s length.
The closest approach of the two to each other takes place after sunset Friday. By that time, Mars has moved to just lower left of Mercury and the two are almost twice as tight a pair as the night before.
If you have a telescope, this is a rare chance to see the little globes of both worlds together in a fairly high magnification field of view.
During the following week, Mars slowly moves farther away from Mercury. But by marvelous coincidence, Mars stays almost exactly straight below Mercury as seen from the latitude of New Jersey.
Days of the silver moons: As mentioned at the start of this column, Mercury and Mars get joined on a few nights by a lovely thin lunar crescent.
The first slender moons to look for, however, come before dawn late this week. If you have a clear view low in the east-southeast, you should have no trouble spotting the moon there about 40 minutes before sunrise Friday.
The real challenge comes Saturday, when an astonishingly thin moon is only just coming above the horizon 40 minutes before sunrise. At that time that day, the moon is only about 20 hours short of reaching new moon phase, when it is unviewable.
On Sunday, the time to look is about 30 minutes after sunset, when yet another thin lunar crescent is potentially visible — this time, low in the western sky.
It is well to the lower right of the Mercury-Mars pair that night. The next night, a thicker lunar crescent is easily visible well to the pair’s upper right.
Winter’s brilliant constellations at their highest: These next two weeks the moon is not only thin but also not visible for long in the night sky.
That is good for all of us who want to avoid bright moonlight and get the darkest possible skies to see the glory of the winter constellations.
Look to the south between about 8 p.m. and 10 p.m. to see Orion, Gemini, Taurus and the other sparkling patterns of wonder. To help identification, you can go to www.skyandtelescope.com and register to use their interactive sky chart.
Fred Schaaf is a local author and astronomer. He can be reached at: firstname.lastname@example.org