This past week, the major media carried headlines about a lineup of planets. They urged everyone to watch the sky just before dawn.
Except they all got it wrong. It seems no one knowledgeable about astronomy fact-checked it. Sure, in theory, all five naked-eye planets formed a long line. In actuality, only four were visible. You see, Mercury always starts its morning sky apparitions at its dimmest, and very low. But no one on Earth can glimpse a second-magnitude “star” buried in thick low horizon air, especially while the glow of dawn paints the sky. Nobody saw it. Experienced astronomers using binoculars or a small telescope might have found that innermost planet, but no one else.
That changes this week. Mercury is steadily growing higher up while brightening explosively. It’s the only planet that undergoes a thousandfold change in its brightness. Now it’s there and now you can easily find it, and now is when that “string of pearls” is visible.
Such an alignment of all five planets happens every so often, but this time it’s between 6:30 and 6:45 a.m. during the statistically coldest time of year. Also, two of the planets are low in the east, which requires a flat horizon. Some folks perched on hilltops do have such an eastern vista, but most of us don’t.
In truth, a similar lineup of all the planets will unfold in the middle of this coming August. That may possibly be a bit warmer than now. Better still, it will then occur in the evening, at a convenient hour. So you won’t be blamed for deciding to sit this one out.
Okay, with all of that legal disclaimer type stuff out of the way, let’s say you really want to observe this predawn display, which will last for the next week. Step outdoors at 6:30 a.m., and get to a place with a perfectly flat view of the east, just as the first traces of dawn touch the eastern sky. Dazzling Venus is just over the eastern horizon. Mercury, far less luminous, dangles below Venus. Brilliant Jupiter frames the right side of this alignment, all the way in the southwest. Going leftward from Jupiter takes you first to Mars and then Saturn. There’s also a couple of bright stars sprinkled below the line: blue Spica and orange Antares. They add nice color, but could confuse beginners trying to pick out the planets.
One trick is that if you close one eye and extend a finger at arm’s length to block out the object, a star blinks out abruptly, while a planet gets extinguished a bit more slowly. Also, planets tend not to twinkle.
Extra guidance arrives with the Moon. It will hover just above Mars on February 1, above Saturn on February 3 and forms a stunning triangle with Mercury and Venus on February 6: a true don’t-miss event just before dawn. That’s the ace number-one primo morning to perform this exercise.
It’s all very cool. See you out there – maybe.
Want to know more? To read Bob’s previous “Night Sky” columns, visit our Almanac Weekly website at HudsonValleyAlmanacWeekly.com.