The Sky This Week, 2017 January 3 - 10
|Last Moon of the year, 2016 December 30
imaged from Mollusk, Virginia with a Canon EOS Rebel T2i DSLR
The Moon waxes in the evening sky this week, passing the First Quarter phase on the 5th at 2:47 pm Eastern Standard Time. Luna begins the week to the northeast of ruddy Mars, then embarks on a trek through the dim autumnal constellations. By the end of the week she passes the bright star Aldebaran.
The Earth reaches perihelion, its closest point to the Sun, on the 4th at 9:18 am EST. At this time the distance between the center of our planet and that of the Sun will be just over 147 million kilometers (91,404,000 miles). We’ll reach our most distant point from Old Sol on July 3rd.
The first lunation of the year provides an excellent target for those of you who may have received a telescope as a holiday gift. The Moon is the easiest object in the sky to observe, and it is also probably the most rewarding. Suddenly that object that you’ve grown accustomed to as a thing in the sky becomes an actual place, a world of countless topographic forms that present a different view on each successive night. This is a great time to get to know your telescope and its accessories. The Moon makes it easy to align the finder scope, and you can explore the different magnifying powers of the telescope’s different eyepieces. Start your lunar tour with the lowest power eyepiece, which will have the largest focal length (i.e. 25 mm) etched on its collar. Once you’ve become familiar with the general view and the tracking ability of your instrument, use shorter focal length eyepieces to increase the magnification. The amount of detail that you see will be dependent on your telescope’s aperture, but even small aperture telescopes will do quite well with Luna as a target. Once you are familiar with the Moon’s general appearance, download a lunar map or a lunar atlas app and get to know the more prominent features. With a little patience you’ll learn to find your way around our only natural satellite, and you’ll be able to spend many hours over the future years continually finding new features to explore. We often say that the Moon is "looked over, then overlooked" by amateur astronomers, but even after 50 years of viewing I have yet to grow tired of peering at Luna’s stark and beautiful landscapes.
Venus will probably be your next target. She is impossible to miss in the early evening sky, blazing away in the southwest in the deepening evening twilight. Through the telescope she presents a dazzling white disc that currently resembles a slightly gibbous Moon. Over the course of the next two months her apparent size will grow as her phase becomes more of a crescent shape.
Mars may be found a bit higher in the sky northeast of Venus and will be the brightest object in the southwest after the dazzling planet. The red planet is now moving through the dim constellation of Aquarius and can be easily identified by his colorful tint. Through the telescope Mars is a tiny pink-orange dot; don’t expect to see much detail, even in a large-aperture telescope.
Most of the planetary action takes place in the morning sky this week. Giant Jupiter rises at around 1:00 am EST, but he’s best placed for a telescopic view in the hours before sunrise. Jupiter and the four moons first recorded by Galileo are visible in any decent telescope, and the moons’ positions will change from night to night. Telescopes of four inches or more aperture will begin to reveal details on the planet itself.
You’ll find Saturn lurking about 10 degrees above the southeast horizon in the gathering morning twilight about 45 minutes before sunrise. You might catch a quick glimpse of him before the sky becomes too bright, but he’ll provide much more rewarding views during the summer months.