DAS Activities

DAS Public Nights

Public Nights
Tuesday and Thursday at
DU's Historic Chamberlin Observatory
Current start time is 8:30 pm.

Costs to the public are:
$4.00 adults, $3.00 children

To book, please click:

Public Night Reservations

Denver Observer

The Denver Observer Moves Online!

Happy New Year, and welcome to the new home of the Denver Observer, the newsletter for the Denver Astronomical Society. This page is just getting started, but the trickle of posts (or “articles,” if you want to kick it old-school) will soon become a steady stream, and you’ll find the same content here that you used to see in the Observer’s PDF and printed versions. (If you’re looking for our previous issues, they’re right here.)


We’ll do our best to help you adjust to the new format, including some quick tips for getting the most out of our new approach—those will be following soon.


In the meantime, thanks for your patience—I’m sure you’re going to love what we can do in this new medium. As always, if you have any questions, comments, or material for the new Observer, please drop me a line!


Zachary Singer

March 2019 Skies

© Zachary Singer

In March, we have a relatively quiet month for planets: Most of them are now early-morning objects, but they are at a greater angle from the Sun, allowing better observing. In the “Stars and Deep Sky” section, we’ll look at two stars in the constellation Cancer—the first is a wonderful binary, and the other, a lesser-known carbon star. …Continue reading “March 2019 Skies” »

Astro Update, March 2019

Selected Summaries of Space News

More New Horizons Results

More data has been received from the New Horizons spacecraft since its recent flyby of the Kuiper Belt object informally named Ultima Thule. One new result is that the larger of the object’s two lobes is not so much spherical, as thick-pancake-shaped. This shape was determined from examining what stars were blocked by that lobe in images taken from the object’s night side.

Both lobes display similar reflectivity and color, implying that they formed in the same way and then gently collided. …Continue reading “Astro Update, March 2019” »

President’s Message, March 2019

Passing the Gavel

This month, we have a joint message, with Ron Hranac, our outgoing president, starting off. Ed Ladner, the DAS president-elect, follows…  —Editor

February’s well-attended annual membership meeting had a packed agenda, including election of Executive Board (“E-Board”) officers and trustees to serve a one-year term beginning later this month. A tip o’ the hat to the following individuals, who will be officially seated on Denver Astronomical Society’s E-Board during our March 23rd Spring Banquet (more information about the banquet can be found HERE).


President – Ed Ladner

Vice President – Dena McClung …Continue reading “President’s Message, March 2019” »

February DAS In-Reach Cancelled

The DAS In-Reach originally scheduled for Saturday, February 23rd, 2019, has been cancelled. 

DAS News, February 2019

Lunar Eclipse Photos

DAS members were out in droves for the January 2019 full lunar eclipse, and they sent in some of their images…   Here’s a selection of their work:

Image of January 20th lunar eclipse.

This picture shows the Moon every half hour during the lunar eclipse. Each image is aligned with respect to the Earth’s shadow, so you can see the Moon passing through the shadow, as our satellite moves from west to east (from right to left). Image © Don Lynn.

…Continue reading “DAS News, February 2019” »

February Skies 2019

Image of M37, an open cluster.

Open cluster M37, by Joe Gafford.


by Zachary Singer

Some of our favorite planetary targets, Venus and Jupiter, are up in the pre-dawn sky this month, and Mercury appears in the evening, as we’ll see in “The Solar System,” below. In “Stars and Deep Sky,” we’ll take a look at two notable open clusters in Auriga, M36 and M37.

The Solar System

Mercury starts off February still lost in the solar glare, but begins to reappear after the first week of the month. It’s still difficult on the 10th, but the party is just beginning—just a few days later, on Valentine’s Day, you’ll see Mercury glowing at magnitude -1.2; look for it low in the west, …Continue reading “February Skies 2019” »

Astro Update, February 2019

Selected Summaries of Space News

by Don Lynn

Kuiper Belt Object Flyby

On December 31st, New Horizons (Pluto spacecraft) flew by the Kuiper Belt object 2014 MU69, since unofficially named Ultima Thule, at a distance of only 2200 miles, fervently taking images and other data. This was the farthest-from-Earth spacecraft encounter with any celestial body.

Ultima Thule turns out to be a contact binary, that is, two roughly spherical bodies barely in contact with each other. The larger, “Ultima,” is about 12 miles across, while the smaller, “Thule,” is about nine. It’s thought that the two bodies came together early in the history of the solar system. The “crash” must have occurred at the speed of a walk, in order for them to have stuck with little damage.

The object is probably mostly water ice, though the surface is fairly dark (about as dark as our Moon’s dark markings) and reddish …Continue reading “Astro Update, February 2019” »

President’s Message, February 2019

Getting Involved

by Ron Hranac

Denver Astronomical Society is a volunteer-based organization that has been serving Colorado’s Front Range for nearly 70 years. Indeed, we wouldn’t exist if it weren’t for the countless people who have made and continue to make DAS what it is today.

A couple questions that come up from time to time are “How can I become more active in DAS?” and “How can I volunteer?” …Continue reading “President’s Message, February 2019” »

January 26th In-Reach CANCELLED

Please note that the DAS In-Reach originally scheduled for this evening, Saturday, January 26th, has been cancelled. (Separately, we have some good news about our In-Reach program, and we’ll post that soon.)

Lunar Eclipse Party Update

We’ve been fielding questions these last few days about whether the DAS is hosting any activities for the upcoming Sunday, January 20th lunar eclipse. (Click here for an explanation of the eclipse and its timing.)

While DAS is not having an event, Mile High Astronomy, run by our own Sorin, is—they’re roping off their parking lot, and bringing out their telescopes (including some of their newest models), and eyepieces, too. You can also bring your own ‘scope—just let them know.

They’ll be there from 8:00 PM – 12 midnight.

Mile High Astrononomy is located at 9797 West Colfax Ave. #3VV, Lakewood 80215; 1-877-279-5280.

Directions on Google Maps


Click here to sign up (RSVP) on Facebook.



January Skies 2019

by Zachary Singer


We start the first month of the New Year off with a splash—a total lunar eclipse on the night of January 20th. Along with that, we have planets and two targets in Eridanus—one is an important multiple-star system, and the other a striking planetary nebula.

Lunar eclipses happen when the Earth, Moon, and Sun align so that the Earth is between the other two bodies, preventing the Sun from shining onto the Moon. A total lunar eclipse occurs when all of the Sun’s direct rays are blocked; these are mesmerizing phenomena to observe, and while a telescope or binoculars would be great to have, you’ll be riveted even with your naked eyes. (Unlike solar eclipses, …Continue reading “January Skies 2019” »

January General Meeting

Join us on January 18th, 2019, at 7:30 PM, for our monthly General Meeting. We’ll have a call for Executive Board Nominations, and a presentation by Dr. Graham Lau on “THE CRAZIEST CREATURES ON EARTH: What the world’s wackiest organisms can tell us about life in the cosmos.”

For a full description of the presentation and directions to the meeting, click here.

Astro Update, January 2019

Selected Summaries of Space News

by Don Lynn

Phobos Grooves Explained

Since the first close-up images were taken of the Martian moon Phobos decades ago, scientists have argued about why there are long grooves on its surface. Leading theories were that the moon cracked from an impact or from tidal forces. But there were problems applying any of the theories to the observed grooves. A new computer simulation of an impact on Phobos suggests that the grooves were formed by boulders rolling across the surface after they were thrown out by the impact that formed the largest crater on that moon.

Sun’s Sibling Found

Stars generally form in a cluster, then scatter over time. Astronomers would like to find the stars that formed in a cluster with our Sun, though they may now be spread around our galaxy. So a team of astronomers searched archived observations for stars that are both the same age as the Sun, and that have spectra showing the same distribution of elements.

As it happens, out of hundreds of thousands of stars, only one …Continue reading “Astro Update, January 2019” »

President’s Message, January 2019

State of the Society

By Ron Hranac

You may recall that we hit a major membership milestone in 2017, passing the 500 mark for the first time ever. As of December 26, 2018, the count was a record 563, up from 502 at the same time in 2017, 457 at the end of 2016, 428 in 2015 and the high 300s in 2014. We introduced a new category of membership called dual/family, too. A tip o’ the hat to all of you who support DAS and its many programs!

Given the significant membership growth, …Continue reading “President’s Message, January 2019” »