A powerful solar flare on January 7 launched a barrage of plasm our way, which has the chance of producing auroras at much lower latitudes than usual. Scientists expect the activity to begin before dawn Thursday, January 9, which is too late to help given this issue’s release that day. But solar astronomers don’t rule out more blasts to come, as this solar flare, technically called a coronal mass ejection, was caused by an eruption from a massive and very active sunspot, AR1944, which is facing earth head-on. The sunspot, “as wide as seven earths,” NASA reported, is “one of the largest sunspots seen in the last 10 years.”
Called aurora borealis when seen north of the equator and corona borealis to the south, these displays are the result of powerful bursts of radiation from the sun. Earth’s atmosphere blocks that harmful radiation, or these would be lethal events, but as the charged particles collide with earth’s own magnetically charged atmosphere, they produce a vivid and eerie light show. While these aurora are harmless to life, they can wreak havoc on our satellites, disrupting GPS, cellular reception and radio and television transmissions. The flare has already forced private space company Orbital Sciences to delay the launch of an unmanned cargo craft to the International Space Station.
Any chance to see the so-called Northern Lights as far south as the Chesapeake is well worth keeping an eye on the sky over the next few nights.
The moon is also busy this week. It visits over the weekend, to the left of the moon Friday night, look for the Pleiades star cluster. At first glance the Pleiades appear as a fuzzy patch of light in the constellation Taurus. But closer examination on a clear night reveals six stars shaped like a miniature dipper.
Saturday the Pleiades are above the moon, while below the moon is Aldebaran, the red eye of the bull, and the Hyades star cluster.
On Tuesday, the near-full moon is five degrees south of Jupiter. Tuesday, January 7, marked the anniversary of Galileo Galilei’s 1610 discovery of Jupiter’s largest three moons, Io, Europa and Ganymede (he discovered Callisto a few days later). Today, a good pair of binoculars will reveal more of mighty Jove’s orbiting satellite’s than the great astronomer’s first telescope.
Wednesday the 15th marks January’s full Wolf Moon, which also reaches apogee, its farthest point in orbit from earth, making this full moon the smallest of the year.
Venus reaches inferior conjunction, Saturday, passing between the earth and sun, leaving our morning skies only to reappear as the Evening Star thereafter. Unlike the transit of Venus in 2012, this time Venus will pass five degrees north of the sun — still far too close to watch without a solar filter. Viewed with telescope or binoculars and the proper eye protection, our sister planet appears as a wide but razor-thin crescent.