Playing Peekaboo with Mars
Posted January 3, 2025
Day after day we watch the sun rise and set: east to west…east to west…east to west. We watch the stars, planets, and moon rise and set: east to west…east to west…east to west. We see the sky this way because the Earth spins on its axis once per day in the opposite direction: west to east. Imagine driving from Raton to Clayton: when you come up over 19-mile hill you see Capulin Volcano appear on the eastern horizon. Then as you drive past it, the volcano recedes to the west—east to west—because you are driving west to east.
But over the course of a month, season, or year, the planets, our Moon, and our Sun actually appear to cross the sky from west to east: the opposite of what we see in a single day and night. From above, objects in our solar system orbit the sun in a counter-clockwise motion, and over long periods of time the steps of that cosmic dance come into focus.
This is easiest to notice with the moon. In the first week of this new year you may have seen the crescent moon and bright planet Venus close together right after sunset. Every night after that the moon moves further and further to the east of Venus, rising about 50 minutes later every day. On January 13th the full moon will rise at the same time the sun sets, and then 50 minutes later the next day, and the next…moving further east until it rises just before the morning sun as New Moon approaches on January 29th.
But there is a special event in this first month of 2025. The west-to-east motion of the moon will be on full display as it appears to go right over the top of Mars. This visibly red planet will disappear behind one side of the moon and then reemerge on the other exactly one hour later…peek-a-boo!
If it’s a clear sky on Monday, January 13th, go outside at 6:45 pm. You’ll see Mars (bright and noticeably orange) extremely close below the full moon. You can easily watch with your eyes alone, or pull out some binoculars or a small telescope for an even better view. The moon will get closer and closer to Mars until it “gobbles up” the planet at 6:54 pm. Mars will peek into view again on the moon’s opposite side at 7:54 pm. Watch for a while longer and you’ll see the moon continue its eastward orbit as it moves further and further past Mars.
This event—one celestial object appearing to move in front of another—is called an “occultation.” It’s relatively uncommon for the moon to occult another planet, and this time will be extra spectacular because Mars will also be as close to Earth as it gets. If you do have a telescope, you may even be able to see Mars’ icy north pole: a bright white cap against its rusty orange landscape. What a sight! Let’s hope for good clear skies!
Other things to watch for this month:
- Close pairing (conjunction) of Venus and Saturn January 16 – 19.
- Though the shower’s peak is between January 2 – 3, we’ll continue to see Quadrantid Meteors through January 16th.
- The sun will be at peak activity through 2025 and more aroura (northern lights) events are possible in our area. Up to the minute aurora forecasts can be found at www.swpc.noaa.gov/products/aurora-30-minute-forecast and many Aurora Forecast apps are available for smart phones.
A New Constellation?
Posted December 14, 2024
When days are short and temps are low it’s hard to step away from the fireplace, put down the steaming cup of cocoa, pull on a coat, hat, and gloves, and go outside. It’s even harder to do all that when it’s dark. But as we approach another Winter Solstice it’s worth remembering actress Mae West’s encouraging words, “I never said it would be easy, I only said it would be worth it.” So let’s don that winter gear and head out to enjoy the stars…you can even bring that steaming cup of cocoa if you want.
One good thing about winter’s long nights is you don’t have to stay up late to enjoy a beautiful starry sky. With late December sunsets around 4:45 PM, you can even squeeze in some stargazing before dinner. This month we have two bright planets to look for right after sunset: Venus is impossible to miss in the southwest while Jupiter, only slightly dimmer, is rising in the east. If you have a telescope or good pair of binoculars, zoom in on Jupiter to see four of its moons stretched out in a line beside it. As twilight deepens, you’ll notice a reddish star appear to the right of Jupiter. This is Aldebaran, an old red-giant, whose name means “The Follower” in Arabic. What is Aldebaran following? To find out, you’ll have to let it get a bit darker…might be a good time to refresh that cocoa.
When I was a kid, we were driving to see my grandparents in North Dakota. It was a late night in Montana’s Big Sky Country and I was mesmerized by the uncountable number of stars I could see out my window. A fuzzy patch of light caught my eye. When I looked right at it, the fuzziness instantly resolved into a cluster of 6 tiny stars. Fascinating! The only patterns of stars I knew at that time were the Big Dipper, and Orion’s Belt. This new bunch of stars reminded me a lot of the Dipper, but much, MUCH smaller. Certain that I had discovered a new constellation, I named it the “Itsy-bitsy-teeny-weenie-yellow-polka-dot-bikini Dipper.” Cheer if you still remember that song!
Years later, I learned that “my constellation” was in fact a group of stars that has been much admired all over the world and carries many names. Have you ever wondered about Subaru’s starry logo? Subaru means “unity” in Japanese and is what my Itsy-Bitsy Dipper is called in Japan. In Hawaii the stars are Makaliʻi (Little Eyes). In Wales: Tŵr Tewdws (Heap of Stars). The Berbers in the northern Sahara call them Cat iheḍ (Daughters of the Night). Many indigenous cultures around the world tell stories of women turned to stars after being chased by animals or dishonorable men, and in Greek mythology, these “Seven Sisters” are still fleeing from Orion the hunter.
In astronomical nomenclature this little group of stars is called the “Pleiades Cluster.” They are young: barely toddlers at about 100-million years old. Born together in a vast cloud of gas and dust, they drift through the galaxy and slowly separate over time as gravity and orbital dynamics lure them apart. In deep-sky photos you’ll see them surrounded by whisps of nebulosity that reflect and scatter their light in alluring shades of blue. This month (around 6:00 pm) you’ll see them hovering in the east above Jupiter and Aldebaran: the “Follower” star. If you’ve still got your binoculars handy, zoom in on that Itsy-bitsy “Dipper” and you’ll see that Aldebaran is following not “Seven Sisters,” but several dozen!
Stay warm fellow stargazers!
Other cool late-December stuff:
- Winter Solstice (longest night): December 21st
- Saturn: visible high in the south about an hour after sunset
- Mars: from Raton, look for it in the east above Johnson Mesa around 8:30 pm—very red/orange
- Milky Way: arcing high overhead from west to east (brightest in the west)
- Quadrantid Meteor Shower: start watching during the last week of December. Peak = January 2 – 3. Meteors appear to radiate from an area near the handle of the Big Dipper, but can be seen anywhere in the sky. Rate: about 120 per hour.
Included photo file: “Pleiades Star Cluster.” Public Domain. Credit: NASA, ESA, AURA/Caltech, Palomar Observatory