Hook Mercury With The Crescent Moon Tonight

Look for the moon very low in the northwestern sky (about 4°), then use it to bring you to Mercury, located about 4.5° to its upper left. Distances between the moon, Mercury and Regulus are to scale. Created with Stellarium

Thank goodness for the moon otherwise few of us would find the planet Mercury tonight. The planet may hang low like the proverbial low hanging fruit, but that doesn’t work nearly as well in astronomy as it does with your apple tree. Haze, twilight and light pollution compromise any astronomical object near the horizon.

Mercury will stand only about 7° in a dusky sky for mid-northern latitude observers. Even the moon won’t be high, but it’s a lot easier to find. We’ve a brand new crescent only about 40 hours old, fragile as an eyelash low in the west-northwest. Find a place with a clear view in that direction and look about 20-30 minutes after sundown tonight. Bring binoculars. They’ll help you find the moon and from there you can hop over to Mercury. The planet sits about 4.5° to the upper left (east) of the crescent.

The best moon-planet conjunction this month happens on Friday evening, July 28 when the waxing crescent and Jupiter will be only 2.5° apart. They’ll make a striking sight at dusk. Created with Stellarium

Focus the binoculars sharply on the moon, then place the crescent off to the right side of the field of view. Higher up on the opposite side of the field, look for a tiny star. See it? That’s Mercury. It shines at magnitude +0.2, so it’s pretty bright. A little more than 1° to Mercury’s upper left, you might just see Regulus. If you do, give yourself a big pat on the back — the star’s almost a magnitude fainter.

The moon climbs higher each night and has a splendid conjunction with the planet Jupiter on Friday the 28th. Have you noticed how low Jupiter’s been getting? Earth runs along its orbit, leaving Jupiter and the spring constellations — Virgo, Leo and the rest — behind.  The planet stops for no one. Last night, I noticed that some of the early fall groups, Capricornus, Aquarius and Pegasus, are pushing up in the eastern sky, getting ready for the next season. I love the change and especially how the constellations announce it in advance.