Moon sees red as Mercury, Earth catch up in orbital race
The sky could get pretty red in April, as Mars makes its best showing of the year and the moon undergoes a total eclipse.
On the 8th, Earth finally catches up to Mars in the orbital race. At that moment the sun, Earth and the Red Planet will be lined up and Mars will appear opposite the sun in the sky, a position called opposition.
Mars is slightly farther than its average distance from Earth during oppositions, but it’s still bright enough to be well worth a look. It’ll rise in the east around sunset and stay up all night, traversing the sky with the bright star Spica, in Virgo.
“Opposite the sun” is also the position occupied by the full moon, and one week later, a round moon visits Mars and Spica. Just after midnight on the 15th, the moon begins a total lunar eclipse that may turn its usually pearly face red as light from Earth’s sunsets and sunrises bends into Earth’s shadow. The moon begins to enter the dark inner shadow, or umbra, at 12:58 a.m. and is totally engulfed by 2:06 a.m. Totality lasts 79 minutes, and at 3:25 a.m., the moon starts to emerge from the umbra. The show ends at 4:33 a.m. Lunar eclipses generally occur twice a year, although not all are visible from our part of the world.
Saturn also has an opposition coming up. It rises three hours after sunset on the 1st, but cuts that interval to just half an hour by month’s end. To find it, look for the next bright object to the east of Mars and Spica. If you go out a couple of hours after midnight, you may catch Mars and Spica in the south or west, Saturn east of them, and just southeast of Saturn, the S-shaped form of Scorpius rising. The brightest star in Scorpius is the gigantic red star Antares, another reason to designate red as the color of the month.
In April the constellation Leo, the lion, reaches its highest point in the south during peak evening viewing hours. Look for the Sickle, a backward question mark of stars anchored by bright Regulus, the lion’s heart, and a triangle of stars to the east that designates the hindquarters and tail. Framing the lion are brilliant Jupiter, to the west, and Mars to the southeast.
Venus still greets early risers, even as it heads into its next trip behind the sun. Look for it in the east about an hour before sunrise. On the 25th and 26th, a thinning crescent moon accentuates the beauty of our sister planet.
The night of April 30 is an old Celtic holiday based on astronomy. Called Beltane, it was the last night of freedom for the evil spirits that had been let loose on Halloween. Beltane became the feast of May Day; both it and Halloween are cross-quarter days, which fall midway between an equinox and a solstice.
The University of Minnesota offers public viewings of the night sky at its Morris, Duluth, and Twin Cities campuses. For more information and viewing schedules in Duluth, visit the Marshall W. Alworth Planetarium at www.d.