Starwatch: A super moon in the east and a little lamb in the west

February 16, 2019

I’ve been accused of being a curmudgeon and killjoy when for saying that the “supermoon” full moon is not all that much bigger in the sky than the average full moon. The full “supermoon” rising in the eastern sky early this week is only about 7 percent larger than average and only 14 percent brighter than normal.

The reason for the “super moon” is because the moon is in the right place at the right time. The moon’s 27.3-day orbit around our Earth is not quite a perfect circle. It’s a slight ellipse. That causes moon’s distance from us to vary over 30,000 miles in the course of its orbit. Its farthest distance, called apogee, is 252,000 miles. Its closest approach, called perigee, is a little over 220,000 miles. It just so happens that this month’s full moon is occurring when the moon is close to perigee, at about 222,000 miles away.

No matter what you call it, every full moon does the best job it can whitewashing the night sky with its second-hand reflected sunlight. It’s difficult to see fainter stars or constellations, even if you’re in the countryside. Despite the lunar whitewashing this week, you can still spot a small but distinct constellation hanging in the western sky opposite the moon.

It’s the constellation Aries the Ram, hanging in the low early evening western sky. This year it’s easier to spot Aries because it’s just to the upper right of the fairly bright planet Mars, the brightest star-like object in that part of the sky. About all there really is to Aries are two moderately bright stars and a dim star. The three stars resemble the horn of ram. To me it resembles the horn on the side of the Minnesota Vikings helmet.

The two brighter stars are Hamel and Sheratan, and the dimmer star off to the lower right is Mesarthim. Hamel is a giant star in our Milky Way galaxy, over 850 trillion miles or 66 light-years, away from Earth. It’s 37 times larger than our own sun and more than 426 times as bright.

Even though Aries the Ram is a tiny, diminutive constellation, it has a big story, at least according to Greek mythology. It’s a sweet tale as well. Zeus, the king of the gods, had a pet ram that he named Aries. He was a grand ram with a coat made of golden fleece. Aries also had wings so he could soar the skies above Mount Olympus.

One day, Zeus and one of his many lady friends were having a picnic in a lush valley at the foot of Olympus when out of the distance he could hear Apollo, the god of the sun, shouting at him from high in the sky. The god of the sun had noticed that two small children about a couple miles away were about to be eaten by a lion. The kids slipped away from their mother at a marketplace and were being hungrily eyed by a mighty lion lurking in the bushes. The very cruel and selfish Zeus wouldn’t have given this a second thought, but wanted to win the heart of his picnic companion. He summoned his faithful pet ram and pointed Aries in the right direction, sending him flying off on a rescue mission.

The lion was within 20 feet of attacking the kids when out of the blue Aries swooped from the sky like a cruise missile. He scooped up the children on his back and flew them off to safety. Aries winged his way back to the local marketplace and reunited the kids with their greatly relieved mother.

All the rest of his life, Aries went on missions of mercy and rescue. When Aries died, Zeus rewarded his little ram by transforming his body into stars and placing him into the heavens to become the wee constellation we see today.

For extra credit, see if you can spot the very faint planet Uranus just to the lower right of Mars. You will need at least a small telescope to spot it. Don’t feel too bad if you can’t see it — it’s over 1.8 billion miles away!