Photo of yellow crocuses in the snow

Groundhog Day

Feb. 2, 2022

It’s Groundhog Day! Punxsutawney Phil can’t really predict the weather, but he can confirm his holiday has roots in ancient astronomy. February 2 is a cross-quarter day, meaning it's half way between the winter solstice & the spring equinox.

Photo of the updated installment of the scale-model solar system. Photo credit: James Negus

Sky & Telescope's Stargazer’s Corner: A New Scale-Model Solar System

Jan. 20, 2022

From Sky & Telescope magazine: The University of Colorado, Boulder, has unveiled a 1:10 billion scale-model solar system with an interactive sound experience. Have you ever longed to experience a planetary voyage through the solar system? Or to travel from the Sun from Jupiter? The University of Colorado, Boulder (CU...

Photo of the full moon from NASA with the two craters Tycho and Copernicus labeled along with the more prominent mare

First full Moon of 2022

Jan. 17, 2022

Enjoy watching the first full Moon of 2022 tonight! Can you spot the bright craters Tycho & Copernicus with your unaided eye? Look for the dark, smooth mare too. Mare means seas in Latin, but we now know mare are ancient lava flows. It's amazing what we can see from...

Photo of Sirius by Akira Fujii


Jan. 10, 2022

Have you seen Sirius—the brightest star visible from Earth? Use Orion’s belt to draw a line to the lower left to spot the brilliant Dog Star in Canis Major. Sirius is 8.6 LYs away (a mere 51 trillion miles) and one of our nearest stellar neighbors.

Photo from NASA Earth Observatory - shows four photos of earth in black and white demonstrating the changes of the seasons, related to the position of sunlight on the planet, are captured in this view from Earth orbit by the Meteosat instrument

Shortest Day of the Year + Longest Night

Dec. 21, 2021

Welcome to the shortest day of the year - the winter solstice! Avid observers, bundle up and enjoy the longest night of the year. Earth’s axial tilt causes the Sun to be at its farthest south (lowest) in the sky today for Northern Hemisphere dwellers. The Southern Hemisphere receives the...

Photo of a full moon in the early evening with birds flying in the sky Credit: NASA/Aubrey Gemignani

Last Full Moon of 2021

Dec. 18, 2021

Enjoy the last full Moon of 2021 tonight! You’ll find the Frost or Winter Moon in between the horns of Taurus, the Bull. Does it appear slightly smaller than average? The Moon is at apogee, meaning at its furthest point in orbit from the Earth — making it a mini-moon...

Graphic from Sky & Telescope magazine showing the eastern horizon with the constellation of Gemini above the horizon and the radiant of the meteor shower

Geminid Meteor Shower

Dec. 13, 2021

Meteor shower alert! Fingers crossed for clear skies tonight & into tomorrow morning. The Geminid meteor shower will be at its best after the Moon sets through sunrise. For those living under dark skies, expect to observe 2-3 per minute. City dwellers can expect to see 1 per minute. Bundle...

Graphic from Stellarium showing the eastern sky on December 7 at 9pm shows winter constellations rising

The Winter Sky

Dec. 7, 2021

The wonders of the winter sky have arrived! Look to the east for a magnificent display of very bright stars — more than any other season. The iconic constellation Orion is fully above the horizon by 9pm. His companions Canis Major and Canis Minor are not far behind. The twins...

A glass block marks Saturn's spot in the solar system in a new scale model on the CU Boulder campus. (Credit: CU Boulder)

Hear planets sing as you ‘walk’ through space in new solar system model

Dec. 7, 2021

Have you ever wanted to travel to Neptune? Thanks to an updated solar system model on campus, you can “visit” the planet as you stroll from the Fiske Planetarium north to Colorado Avenue—just a few minutes if you hustle. You can also catch the sounds of Neptune and other planets...

Graphic from Stellarium showing the glow of sunset along the southwest horizon with Jupiter, Saturn and Venus along the ecliptic

Three Planets in a Row

Dec. 4, 2021

Check out Saturn tonight in the southwestern sky! The ringed-planet appears half way between Jupiter to the upper left and crazy-bright Venus down to the lower right. The three planets help us trace out the ecliptic (the imaginary line in our sky which marks the Sun’s path, plus this is...