view counter

In the Absence of Light

Earth’s shadow blots out this week’s full moon

With sunrise now after 7am, perhaps you’ve seen an exceptionally bright light in the south before dawn? Looking up, did you see the constellation Orion? That’s Sirius, the brightest star in the heavens, known as the Dog Star for its place amid Canis Major. Sirius rises around 2am in the east-southeast. Close to the horizon, it pulses a dazzling rainbow of colors, its light refracted by earth’s atmosphere like that from a prism. Closer to daybreak, when Sirius is high in the south, its light cuts through less of our atmosphere and appears a brilliant, cold white. As if Sirius didn’t stand out from its brightness alone, the three belt stars of Orion point straight down to the Dog Star.
    Perhaps, though, you’re looking due east in the hour before sunrise. In that case you’re seeing Jupiter, which outshines even Sirius. The giant planet rises around 3am, and by 6am it is high in the east. Below Jupiter is the constellation Leo with its upper body looking like an inversed question mark with Regulus at the bottom.
    You’ll want to get up before dawn Wednesday to catch the total lunar eclipse of the full, Hunter’s Moon. An eclipse of the moon only occurs during full moon, when it is aligned just so with the earth and sun, which casts earth’s shadow over the lunar surface. The process begins after 4am as the moon grows darker under the outer, penumbral, shadow. A little after 5am, the full, umbral, shadow begins to take a growing bite from the moon’s left edge until it is completely over-shadowed by 6:30. Mid-eclipse is at 6:54, after which point the rising sun breaks the spell.
    At the other side of darkness, Mars and Saturn appear at sunset. Saturn is fast on the heels of the sun, low in the southwest at dusk. Night by night the ringed planet is sinking lower and inching closer to the sun until it disappears around month’s end. Mars trails Saturn by roughly 20 degrees. Normally its red hue makes it easy to spot, but you may think you’re seeing double, as Mars is less than five degrees above another red light, Antares, the heart of Scorpius, whose name means rival of Mars. Over the coming weeks Mars creeps higher while the scorpion sets from view for winter.