Thin Shadows and Dulled Lights
Despite a penumbral eclipse, the moon will dampen the Orionid meteors
As the sun sets Friday, the full Hunter’s Moon rises, shining all night long and reaching its highest around midnight. Like last month’s Harvest Moon, the Hunter’s Moon travels its shallowest arc along the ecliptic, rising far to the north of due east and setting far to the south. Rising so much farther to the north than other months, the Hunter’s Moon reappears just 30 minutes later from night to night, as opposed to 50 minutes normally. The effect of this is several consecutive nights bathed in moonlight from near sunset to sunrise.
As the Hunter’s Moon rises, look toward its lower edge for a slight discoloring, the telltale sign of the penumbral eclipse. Unlike a partial or total eclipse, where the moon’s surface is obscured by earth’s full, or umbral, shadow, there will be no missing bite from the lunar orb. Instead, only the earth’s outer fringe of shadow, the penumbra, will cover the south-southeastern edge, casting an eerie glow over its surface. Hereabouts the best chance to spot this penumbral shading are from the time of sunset/moonrise until maybe 8pm.
The darkness between sunset Monday and daybreak Tuesday marks the peak for the Orionid meteor shower, which competes with the still-bright Hunter’s Moon. But the Orionids tend to burn bright, so it could produce up to 12 or 15 meteors an hour. While the meteors appear to radiate from the constellation Orion, they are actually leftover from the passing of Comet Halley. Each time this year, earth crosses through the trail of debris left from Halley’s millennia orbiting through the solar system. As the bits of dust and ice carom against the atmosphere, they ignite into meteors. Earth actually crosses Halley’s orbital trail twice each year, the other time being in May, marking the Eta Aquarid meteor shower. Both the Eta Aquarids and the Orionids are fast-moving, striking the atmosphere at 41 miles a second.