Thursday, April 17, 2014
By Bernie Reim
The month of February is named after the Latin Februum, which are rites of purification. Braving the long, cold nights of February to enjoy just a glimpse of the beauty and wonder of the sky can be very purifying and humbling.
SKY GUIDE: This chart represents the sky as it appears over Maine during February. The stars are shown as they appear at 9:30 p.m. early in the month, at 8:30 p.m. at midmonth and at 7:30 p.m. at month’s end. Jupiter is shown in its midmonth position. To use the map, hold it vertically and turn it so that the direction you are facing is at the bottom.
Sky chart prepared by George Ayers
Jupiter is slowly getting a little dimmer and smaller since it’s already a month past its opposition. The king of the planets still rules the night sky, rising several hours before sunset. At minus 2.5 magnitude, it is still about eight times brighter than Mars. Notice that Jupiter is slowly moving westward, or in retrograde motion through Gemini toward the constellation of Taurus. That will end March 6, when it will again take up its normal, prograde or eastward motion with respect to the fixed background of stars for the next eight months before it starts its next four-month-long retrograde loop.
Look for its four unique Galilean moons through a pair of binoculars, or look for good detail in its cloud bands through a telescope while Jupiter is still brighter and closer than usual. The nearly full moon will pass close to Jupiter on the 10th and 11th.
The biggest asteroid, Ceres, and the brightest one, Vesta, will be less than 4 degrees apart, making looping paths through Virgo just to the left of Mars. They will be less than one degree apart on July 1. An unseen third body is orbiting between them. NASA’s Dawn spacecraft will encounter Ceres exactly one year from now.
Mars will join Jupiter in the evening sky as it begins the month rising by 11 p.m. in the constellation of Virgo and ends the month rising around 9:30 p.m. The red planet nearly doubles in brightness during the month, and it will be close enough to detect some of its surface features in a telescope by the end of the month. But its northern hemisphere will experience its summer solstice on the 15th, which means its north polar ice cap may be too small to detect. Mars will nearly double in size by the time it reaches its opposition April 8. Watch as the waning gibbous moon will pass near Mars one hour before sunrise in the morning sky on the 19th and 20th.
Saturn starts the month rising around 1:30 a.m. in the constellation of Libra and will end the month by rising before midnight in the same constellation. This beautiful ringed planet glows with a soft golden light that is 15 times fainter than Jupiter. Through a telescope, you will see that its marvelous ring system is now tilted open nearly 23 degrees, which is close to its maximum and offers a dramatic view of its thousands of incredible rings. These rings are paper-thin at only about 25 feet thick. That is fully 16 million times smaller than the diameter of Saturn, which is about 10 times that of our earth.
Saturn reaches western quadrature, which means it will be exactly 90 degrees west of the sun, on Feb. 11. This is when the shadow of its globe on its rings will be the most prominent for the year. You may also be able to see up to four or five of Saturn’s 63 moons through a good amateur telescope. Saturn is approaching its own opposition May 10, which is just one month after Mars will reach opposition this year. The many resonances established within its ephemeral and quaking ring system and its moons are perfect examples of pure mathematics and physics at work.
Venus has returned to the morning sky after a long evening apparition just ended in January. Look for brilliant Venus about a half-hour before sunrise low in the eastern sky in Sagittarius. Our sister planet will still be at its maximum brilliancy for the year, at about 10 times brighter than Jupiter and fully 150 times brighter than Saturn. Venus will then be getting smaller and fainter again, but it will go from a very thin waxing crescent to 36 percent lit by the end of the month. Look for a thin waning crescent moon near Venus on the morning of the 26th. The next morning, the slightly thinner crescent moon will be just above Mercury, which will be hard to spot so low in the twilight, even with binoculars. Our first planet will make a good evening apparition during the first few days of the month. Look for Mercury low in the West-Southwestern sky 45 minutes after sunset just below the slender waxing crescent moon during the first two evenings of the month.
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