Astro Bob: Moon swings by Mercury then departs dawn sky
The five bright planets will still shine at dawn for the next week or two, but Monday morning, June 27, will be our last chance to see the moon in the lineup.
DULUTH — It's been an exciting week. We experienced the longest day of the year at the summer solstice, the northern lights made a couple "quiet" appearances on June 23 and June 25, and of course, the moon and planets aligned at dawn. More auroras may be in store Tuesday night, June 28, when the periphery of a explosive solar blast is expected to reach Earth.
Monday morning, June 27, will be the last time we'll see the moon take part in the grand planet lineup. New phase occurs the following day, then the moon moves back to the evening sky for two weeks. By the time it rejoins the planets, Mercury will have left the scene. Before it goes, it does us a favor by pointing the way to Mercury. For the Americas, the super-thin crescent will shine about 3° to the upper left (northeast) of the planet 45 minutes to one hour before local sunrise Monday.
Mercury's played hard to get throughout the planet alignment because it hangs out near the horizon where the bright glow of twilight easily masks it from view. That's finally changing as it gains a bit of altitude and brightens. Now at magnitude -0.5, it's nearly as bright as Canopus, the second brightest nighttime star after Sirius.
To get a look at both the moon and planet, find a location with an unobstructed view to the east-northeast. Although the moon rises about 90 minutes before sunrise, most of us will have to wait 10-30 minutes for Mercury to clear distant trees or hills.
Assuming a straight shot, you should see it well enough about an hour before sunrise. With binoculars, look for a pinpoint of light several degrees to the moon's lower right. Luckily, they're close enough that both will fit in the same field of view. Once seen with optical aid try to find the planet without assistance with just the naked eye.
If you can't see Mercury on the first try, wait till it rises higher, but watch the time! Twilight catches up to it in a hurry. If you wait until less than 40 minutes before sunrise it may be lost in the glare. When you do spot it, lower the binoculars and gaze at the panoply of planets, from innermost Mercury to distant Saturn.
Take a moment to relish your accomplishment — seeing every bright planet in one sweep! Your perception of the solar system has deepened as well. You now have a visceral sense of its emptiness, punctuated by pinpoints of light orbiting the sun. Though distant from one another, these tiny orbs are still part of a close-knit family.
Beings on one those specks have the privilege of wondering about such things.
"Astro" Bob King is a freelance writer for the Duluth News Tribune.