Astronomy news for the week starting Friday, February 9, 2001.

The Moon, now past full, fades from the evening sky. At first waning through its gibbous phase, it passes third quarter the night of Wednesday the 14th shortly before Moonrise in the Americas, and then enters its waning crescent phase. The morning of Thursday the 15th finds the Moon just to the north of Mars, the pair just short of encountering the three-star head of Scorpius.

Mercury and Uranus make an odd pair this week, as both go through conjunction with the Sun, Uranus on Friday the 9th, Mercury on Monday the 12th. The two could not be more different. Mercury, an "inferior planet," one closer to the Sun than we are, passes its "inferior conjunction" as it goes roughly between us and the Sun. Half an orbit later (as viewed from Earth) it will pass its "superior" conjunction," when it is on the other side of the Sun from us. Uranus, on the other hand is a distant "superior planet" that is outside the Earth's orbit. Its conjunction is always on the other side of the Sun. When the Earth swings through half an orbit (as viewed from Uranus), Uranus will then pass opposition with the Sun, when the two are opposite each other in the sky. Though both are in solar conjunction, Mercury is moving westward against the stars, retrograde, whereas Uranus is moving in its normal direction, eastward. They could hardly be more different physically, either: Mercury is less than 40 percent the size of the Earth, cloudless, and made of iron and rock; Uranus is four times Earth's size, 15 times its mass, is covered with methane clouds and haze, and is made of hydrogen, helium, water, and other light stuff. Unfortunately, the solar glare will make viewing them impossible.

We CAN, however, easily view brilliant Venus, high in the southwestern sky at twilight, and still brightening, as well as the still-close pairing of giant Jupiter (the brighter) and Saturn, high to the south in early evening, both still set within the confines of Taurus (not to mention the morning appearance of Mars, which is now rising around 1:30 AM).

The polar sky begins to turn our thoughts toward spring. At 8 PM, Perseus is nearly overhead or to the north for most in North America. While Cassiopeia falls to the northwest, and the Little Dipper rides beneath the pole below Polaris, the Big Dipper in Ursa Major begins its majestic rise in the northeast, led by the four- star "Bowl." Watch as it climbs ever higher as the Earth rounds the Sun and the seasons advance. To the south, Orion the Hunter still dominates, below him a distorted box that makes Lepus the Hare, and below that the small flat triangle of Columba, the Dove.
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