2017 Week 3: (January 15-21)

The third week of January this year has a few naked eye sights that may be of interest to the casual observer.  The weather seems to be getting warmer and possibly with few clouds.  Venus is getting brighter each night and makes for a great sight.  I was able to see Venus before the Sun went below the horizon this evening.  The table of upcoming events is shown below.

Date	Event
Jan 17	Vesta Opposition
Jan 18	Jupiter 3°S of Moon
Jan 19	Mercury at Greatest Elongation West (24°)
Jan 19	Last Quarter
Jan 20	Jupiter 4°N of Spica
Jan 21	Moon at Apogee

The first event this week will be the asteroid Vesta at opposition.  When an object is at opposition it means it is on the opposite side of the sky as the sun.  This is the point in its orbit where it is typically the brightest and the largest as seen from Earth.  It will be magnitude 6.2 which is easily achievable in the smallest of binoculars.  Castor and Pollux, the Alpha and Beta stars of Gemini, point directly to it on January 17, 2017 with the sky chart for 21:30 is provided below.

Location of Vesta at 21:30 January 17, 2017

Vesta is the second largest object in the asteroid belt comprising nearly 10% of the belt's total mass.  It is covered in craters similar to our Moon and troughs far deeper than the Grand Canyon.  If the weather is good I will try to find Vesta in my telescope and take some pictures but it will look like a tiny dot of light.  The image below is from the spacecraft Dawn that orbited the asteroid from 2011-2012.

Vesta

There will be two minor conjunctions between celestial objects this week.  Jupiter will be in the same binocular field as the Moon on January 18, 2017 and in the same field as Spica on January 20, 2017.  The Moon will also be at Last Quarter on Thursday, making it a very good target for a telescope if you can stay up late.

The most interesting event will be Mercury at its Greatest Elongation West.  This means it is at the furthest point from the sun in its current orbital cycle.  It is one of the best times to view the planet in the early morning before the sun rises.  If I can find a vantage point to view the eastern sky I may give Mercury a shot but it will be cold and early.  I have still yet to find a good observation point for the eastern sky near my home without looking like a creep in the middle of a park at 4am in the morning.