Western Slope Skies

Do you know when the Earth is nearest the sun?  It’s January 4th, during what is typically the coldest part of our winter.   Seasons are caused by the tilt of the Earth’s rotation axis, not by our distance from the sun.

When the northern hemisphere is tilted away from the sun in late December and January we experience deep winter, while the southern hemisphere is tilted toward the sun and experiencing summer. 

December 21st marks the year’s longest night and shortest day, with daylight lasting only 9 hours and 20 minutes on the Western Slope.  This is our winter solstice, the first official day of winter.

This month marks an anniversary for Western Slope Skies. Our first broadcast was in November of 2011 and Jupiter was the topic. Once again this year, Jupiter will be the brightest object in the night sky. It rises in the east during evening twilight in late November.

Autumn is a wonderful time to observe our Western Slope Skies.   While the temperatures are not bitter cold, the nights are getting longer.

During these late October evenings, a bright moon rises in the east as sunlight and twilight fade. The full moon that occurs nearest the first day of fall is known as the Harvest Moon. The next full moon after that is known as the Hunter’s Moon. This year, there is a Hunter’s moon on October 29th.      

One summer, when I was growing up, it was common to hear about sightings of the “northern lights” over Grand Mesa. Most of the stories came from high school kids staying out too late on dates. At the time, I scoffed at those stories, but have since learned that that summer happened to be during a particularly active sun cycle.

Albireo is a beautiful double star in the constellation Cygnus, the Swan.  If you heard the previous edition of Western Slope Skies, you learned about the Summer Triangle, which includes Deneb, the tail of Cygnus.  Albireo is the head of Cygnus and is dimmer than Deneb. 

Many stars have Arabic names dating back hundreds of years.  For example, Deneb means ‘tail.’  Because of the history involving several languages, the current name Albireo, while appearing to be Arabic, is actually meaningless.

As these early fall days grow shorter, our western slope skies are still dark at 6:00 AM.  So, this is a great time to see a celestial spectacle in the morning without having to get up too early.  From September 29 through October 7 the brilliant planet, Venus, often called the morning star, will be moving past Regulus, the brightest star in the constellation Leo.   

The Summer Triangle dominates the summer sky. It crosses the hazy band of the Milky Way, which is split into two by a large dust cloud near the star Deneb.

The points of the triangle are three of the brightest stars in the summer sky, and each is the brightest star in its own constellation. The brightest is Vega, in Lyra; second is Altair, in Aquila; and third is Deneb, in Cygnus. Even city-dwellers with glowing, light-polluted skies can find the Summer Triangle.

On  clear August nights,  the Milky Way extends brilliantly from our southern  horizon, creating a beautiful vision of stars,  reflected light, nebulae, gas and dust.   As darkness falls, and you step outside, it first appears as a band of clouds reaching across the sky. These "clouds" are actually stars that cannot be distinguished from one another with the unaided eye.  In the southern portion you will be able to pick out constellations like Sagittarius, the Archer, more commonly known as “the teapot”, and Scorpius, the scorpion, pinchers reaching upward, tail trailing.