Sunday: Is your favorite astronomy-loving relative asking for a telescope this Christmas? Before reaching for your credit card, read this guide to choosing your first telescope, available at http://goo.gl/5oXmGj. If cost is an issue, look no further than this article about low cost telescopes https://goo.gl/8yyddy. These are not cheap telescopes. They are simple, low-cost, easy to use telescopes that your future astronomer will still use for quick observing sessions long after she has purchased a much larger instrument for richer viewing. If you want to give a gag astronomy gift to someone who really bugs you, give them a copy of this column. After such a dud “gift”, you’ll never hear from them again. And that may be the best gift of all.
Monday: Jupiter and Saturn will be close together in the southwestern sky all week. Bright Jupiter is one and a half fists above the south-southwest horizon at 5:00 p.m. Saturn is less than a half a fist to the upper left of Jupiter.
Tuesday: Mars is five fists above due south at 8:00 p.m. As seen through small telescopes on Earth, Mars looks like a reddish circle. During the Martian winter, you might be able to see the Martian polar ice cap. But not much else. Up close, Mars has a very interesting topography. The southern hemisphere of Mars is many kilometers higher, on average, than the northern hemisphere. Some scientists think this may be due to a collision between Mars and another planet in the early solar system. There is a color-coded image of the Martian surface at https://stardate.org/astro-guide/gallery/martian-dichotomy.
Wednesday: The earliest sunset of the year in Ellensburg occurs today and tomorrow: 4:12 p.m. This seems odd because the shortest day of the year, the winter solstice, isn’t for about two more weeks. The Sun is at its southernmost point with respect to the background stars on the day of the winter solstice. This means the Sun spends the least amount of time above the horizon on that day. But, the sunrise and sunset times depend on more than the Sun’s apparent southward motion in the sky. It also depends on where the Sun is on the analemma, that skinny figure-8 you see on globes and world maps. During the second week in December, the Sun is not quite to the bottom of the analemma. But, it is on the leading edge of the analemma, the first section to go below the horizon. For a slightly better explanation of this, including a diagram, go to https://go.shr.lc/2NOMOQC. Or just go watch the sunset. But don’t stare at the Sun.
Thursday: It’s getting too cold to see frogs in the wild. Some people see them on their dinner plate. But this is a great time to see frogs in the sky. Ancient Arabs referred to the stars that we now call Fomalhaut and Diphda as Ad-difdi al-awwal and Ad-difda at-tani. This means the first frog and the second frog, respectively. Both frogs are low in the southern sky at 5:30 p.m. Fomalhaut is nearly one and a half fists above due south. The slightly dimmer Diphda is two fists above the south-southeast horizon.
Friday: Venus and the Moon rise together tomorrow morning just after 5:00 a.m. By 7:00 a.m., they are a little more than a fist above the southeastern horizon. Venus is about a third of a fist to the lower left of the Moon.
The positional information in this column about stars and planets is typically
accurate for the entire week. For up to date information about the night sky,
go to https://nightsky.jpl.nasa.gov/planner.cfm.
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