I don’t get to see many sunrises, but an early morning photo shoot presented a rare opportunity to watch the orange ball rise over the planet’s rim. I like my sunrises in peaceful places generally, but found myself off a freeway exit instead. It was quick and offered an elevated view. Nearly as enjoyable as the sun were its multitude reflections off the windows of homes perched on the hillside above downtown Duluth. Sunbeams were everywhere.
If you’re used to staying up and watching the stars rise, culminate in the southern sky and drop down in the west, the sun seems like just another star in the nightly progression of celestial sights from dusk until dawn. Its rising, while a spectacle, is expected, natural and woven into the flow of things as much as Sirius, Vega and the Big Dipper are.
The moon is now in gibbous or 3/4 phase, that time between first quarter and full. Need light to ski at night? Let the moon be your spotlight. Well to the east of the moon, Orion the Hunter climbs the southeastern sky and is easily seen around 9:30 and later.
There’s no better guide to navigating your way to new stars and constellations than Orion’s distinctive “three stars in a row” or Belt. Shoot a line through the Belt upward and you’ll run into the pinkish Aldebaran, the “alpha” or brightest star in Taurus the Bull. Shoot a line in the opposite direction and you’ll spear Sirius, the alpha star in Canis Major the Greater Dog. Perpendicular to the Belt are Orion’s two brightest stars: Betelgeuse and Rigel. If you’re not familiar with these stars, this is a perfect time to get acquainted. They’re bright enough to be unaffected by moonlight or moderate light pollution. Knowing where they are in the sky will help down the road as we explore sights – naked eye, binocular and telescope – in the upcoming winter season. You’ll also get a kick out of Sirius (SEER-ee-us), which sparkles like no other star. Its low elevation coupled with its extreme brightness makes it more obviously affected by turbulent air than stars higher up. Look closely and you’ll see that Sirius both flickers and changes color rapidly – all atmospheric effects.
I thought you’d appreciate a truly unearthly solar system landscape in this photo of Mars’ south polar region shot recently by the eagle-eyed Mars Reconnaissance Orbiter. At center is a 2 1/2 mile diameter depression near the edge of the south polar cap that could be an impact crater. All the white areas around the feature are covered in bitter cold carbon dioxide frost. The areas at upper right and strung along the left are called “swiss cheese terrain” because of their rounded, holey contours. Contrary to first impressions, these white areas are large slabs of dry ice (frozen carbon dioxide) from 10 to 30 feet thick that stand higher than the surrounding terrain. As the sun warms the surface, ice vaporizes directly into a gas, opening up dark “islands” of surface rock. During the Martian fall season, as temperatures drop, the carbon dioxide re-condenses out of the atmosphere, returning to the surface as ice.