by Kim Malville
January 1: In the first week of January, the planet Mercury can be seen low in the southwestern 5:40pm sky. To the left of Mercury are the two brightest stars of Capricornus with Alpha on top and Beta below.
January 2: The Earth is closest to the sun for the year, at a distance of 91.4 million miles. The reason for the seasons is not the small variation in the Earth-Sun distance of only 3%. Our seasons are caused by the tilt of the Earth’s axis of 23.5°.
In mid evening (8pm), the gorgeous winter evening stars are on full display. The lowest and brightest star is Sirius, marking the head of the Big Dog. Orion’s belt of three stars in a row points down and left to Sirius. Above and to the left of Sirius is Procyon, marking the head of the Little Dog. Orion’s belt points right and up to the orange star Aldebaran. Sirius, Procyon, the two brightest stars of Orion and Aldebaran form a tilted “W” in the southeastern sky.
January 3, 4: The Quadrantids is an above average shower, with up to 40 meteors per hour at its peak. It is produced by dust grains left behind by an extinct comet known as 2003 EH1, which was discovered in 2003. The shower runs annually from January 1-5. It peaks this year on the night of the 3rd and morning of the 4th. The second quarter moon will block out all but the brightest meteors this year, but it could still be a good show if you are patient and warmly dressed. Best viewing will be after midnight. Meteors will radiate from the constellation Bootes, but they can appear anywhere in the sky.
January 7: A slender crescent moon is low in the southeastern 6am sky with Saturn and Venus above and to the right. On the morning of January 9, brilliant Venus and bright Saturn will be only half a degree apart (one moon’s width).
January 11: The crescent moon can be seen in the Southwest, setting two hours after sunset. The evening moon grows to half full on January 16th. The planet Jupiter rises in the East and is easily viewed in the last hour of the evening.
January 12 through 18: Jupiter’s moon Callisto is a good distance to the West of Jupiter and easily spotted with binoculars above Jupiter in the late evening. Venus in late January is rising about two hours before sunrise. In the Southeast, below and to the left of Venus is the planet Mercury. Look for these two planets about 6 a.m. Saturn is now far to the right and higher. Mars, rising before 1:30am, is high in the south at dawn. Jupiter is in the southwestern dawn. Thus all five bright planets can be seen at dawn in late January.
January 23: The moon grows to full in Cancer. This full moon was known by early Native Americans as the Full Wolf Moon because this was the time of year when hungry wolf packs howled outside their camps. In the early evening Castor and Pollux of Gemini will point downward at the moon. This full moon will have a high path across the night sky. When the sun is low, the full moon, which is always opposite the sun, is high in the midnight sky.
January 27: The moon shines below Jupiter in the late evening eastern sky.
January 31: The moon will appear half full in the southern dawn.
Season’s Greetings from Pluto
It appears that New Horizons has given Earth a gift that keeps on giving. As you all know, the spacecraft flew past Pluto on July 14, taking detailed photos and measurements of the dwarf planet and then stored them away in its own memory. Because of the great distances involved as it moved further and further away from Earth, as well as the low-power antenna of the spacecraft, some of the best photographs are reaching Earth only now, and will continue to splash in.
In early December New Horizons returned the best pictures we Earthlings have yet seen or perhaps will ever see in our lifetimes. The newest images cover areas 50 miles wide and have an amazing resolution of some 250 feet. The first shows a “shoreline” between hard ice mountains on the left and soft plains of nitrogen ice on the right. These al-Idrisi Mountains, made of water ice, are up to 1.5 miles (2.4 km) high. They appear to float like towering ice bergs on the nitrogen ice. The smooth, icy plane of Pluto’s heart is informally named Tombaugh Regio, after Clyde Tombaugh who discovered Pluto at the Lowell Observatory in Flagstaff Arizona.
The jumbled rubble consists of giant blocks of water ice as much as one and a half mile high at the base of the mountains. They could be Pluto’s version of glacial moraines, produced as these mountains flow forward. Notice how the rubble is encroaching on the smooth plains of ice. In two places it is moving into the boundaries between polygonal features. Thermal convection in the several-mile-sthick layer of nitrogen ice produces its huge, 25-mile-wide, polygonal features. These are similar to what you see in a bubbling pan of Maltomeal in the morning. Polygonal patterns are also present in permafrost of the arctic.
The second image of the center of Pluto’s “heart” shows a close-up of intricate pits on the nitrogen ice, taken just as New Horizon skimmed 9,550 miles above the surface of Pluto. Because there are only a few impact craters on top of the pits, it appears that the indentations, which are hundreds of yards across and tens of yards deep, formed relatively recently. They may have been produced by liquids flowing across the area that developed puddles, turned to ice, fractured the ground and then evaporated. There are two rings which could be ancient craters. Note the lines of pits, which look like ripples in the flow or perhaps, even, the results of winds blowing across its frigid surface. For me, as well, I hope, for you too, the great thrill of these latest pictures is that we are sharing the discovery of something truly alien, something never before seen by human eyes.