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Frequently Asked Questions

About the Observatory

Why did the City decide to build an observatory?

The City Council saw an opportunity to grow the Rancho Mirage Library campus and further enhance the Library’s mission of lifelong learning. The Rancho Mirage Library has evolved over the years from just a library to an educational and cultural center for valley residents and visitors. The Observatory will offer educational programming and opportunities for all ages and levels of expertise from the young to the young at heart, from the amateur to the expert. The Observatory is free and open to the public and brings the Library’s mission of lifelong learning to an even higher level. The sky’s the limit!

How much did it cost?

The total cost of the Observatory Project, which includes all exploratory costs, specialized surveys, construction and all equipment was $4.2 million. The Observatory Project was funded with non-City trust fund monies that would have been returned to the state if not spent locally. The ongoing operations and maintenance of the observatory are being funded with restricted library funds.

Who can use it?

The Observatory is a regional scientific asset. Like the Library, it is available and free of charge to all valley residents and visitors.

When can you use it?

The Observatory is open for two tours each day, Tuesday through Saturday. These tours begin at 3:00pm. Additionally, the Observatory will be open for programs, stargazing parties, and other events regularly. Specific events, dates, and times can be found at The Library & Observatory Website and on the calendar of events for more details.

We refer to the Observatory as research grade because the facility is capable of conducting research-level work similar to other research-focused observatories.

Is there a program schedule?

As with the Library Programming, we will continue to schedule on a quarterly basis. Please check our Program Guide for information and updates.
• Astronomy Programming
• Original programming developed by Eric McLaughlin, City Astronomer.
• Introduction and discussion of films and videos important to Astronomy.
• Lectures and conversations with other Astronomy and science professionals from Jet Propulsion Lab, NASA and many other organizations.
• Stargazing Events

Do I need to bring my own telescope to stargazing events?

• You do not need your own telescope to participate in the stargazing parties.
• In addition to the main Planewave Telescope, The Library & Observatory has 4 telescopes for everyone to enjoy the facility to the fullest.
• If you do have your own telescope and telescope camera, please feel free to bring it and connect to one of our 4 telescope pads.

Is there a tour schedule?

There are no tours scheduled at this time.

What does the weather station do?

The weather station at RMO is a very important component of the overall function of the observatory. High speed winds, rain, and other inclement weather can potentially reduce the lifetime of the sensitive equipment inside the dome. The weather station not only informs us about sky conditions, it also automatically protects the observatory systems. It both prevents the opening of the dome in poor conditions and automatically shuts the system down and protects it in the event of deteriorating conditions.

What makes it unique?

Have you ever been to a public observatory at a public library? The Rancho Mirage Observatory is a public education center built specifically for the public. From planning through construction and into programming, this Observatory was intended as a place dedicated to astronomy for the public.

Why did the City hire a full-time astronomer?

The Rancho Mirage Library and Observatory is dedicated to inspiring and enabling lifelong learning. With this in mind, the position of astronomer was created to do more than just guide observations and stargazing events. The astronomer will also continuously be building an entire suite of programs, events, and guest presentations. Also, the astronomer is working to establish links to schools, community groups, and even research institutions. Moreover, as a learning resource for the public, the astronomer is required to have and be able to communicate both a breadth and depth of knowledge in astronomy and a variety of other technical fields. In other words, to produce, maintain, and expand the quality of programming expected at the Rancho Mirage Library and Observatory, adding a full-time astronomer position to facilitate the region’s entrance into this exciting new venture was required.

Construction Facts

Concrete and Rebar

1,400,000 pounds of concrete and 4.5 miles of rebar reinforcement were used to construct the observatory.

Concrete Footings

The observatory building is designed with round concrete footings that go at least 20 feet into the earth.

Building Materials

The main exterior materials used for construction of the Observatory were chosen for their durability; concrete, steel and wood. Particularly interesting is the wood decking and wood siding on the viewing deck. The wood material is commonly called ipe and is known as one of the world's most dense wood types (it doesn’t float!).

Telescope Foundation, Isolation

The telescope sits on a 16 foot high concrete pedestal that is anchored to a 120,000-pound concrete footing, which is completely isolated from the rest of the building. In essence, the building was constructed around the telescope pedestal. This minimizes the transfer of vibrations from the building to the telescope.

Temperature Control, Weather Systems

The telescope room has its own air conditioning system. It might be cool or warm in the telescope room as the air conditioning system works to keep the telescope mirror close to outside ambient air temperature.

360 Degree Dome

The dome roof automatically spins and opens to the night sky with a touch of a button (or screen). The dome can spin 360 degrees in either direction without stopping.

The glass windows from the telescope room to the cosmic office have instantaneous tinting capabilities. Suspended Particle Display (SPD) glass allows the astronomer to dim the windows just like you dim a light. By keeping the windows dark the astronomer keeps light from trespassing into the telescope room while the telescope is in operation.

To keep light pollution down and maintain a safe level of light for nighttime use the entire building is equipped with futuristic red lighting, which doesn't have the same light polluting effect as regular white light.

Four Auxilary Telescope Workstations

The four telescope workstations on the viewing deck are equipped with power and data links to a mini IT Rack housed in the Cosmic Office. Images taken from the workstations can be viewed inside the cosmic office or in the Library's Community Room.

Digital Storage and Delivery Systems

The main IT racks in the Cosmic Office have ten terabytes of storage and have a ten gigabit per second connection to the Library, via fiber optic line. The Library has another ten terabytes of storage dedicated for the observatory programs.

Telescope Facts

How far can the telescope see?

Our PlaneWave Instruments CDK 700 telescope can observe objects over 50 million light-years distant. (What is a light-year) In other words, our telescope can observe objects that are further than 3 trillion times the distance between the Earth and the Sun. Bode's Galaxy, recently captured by our telescope, is approximately 11.8 million light-years from Earth. By way of example, the center of the Milky Way ranges from 24-28 thousand light-years from Earth.

How do the quality of our images compare to other observatories?

The quality of an astronomical observatory and the images it takes is often related to what is called seeing. Seeing is a way of describing the amount of atmospheric disturbance in an image and relates to the best possible angular resolution of a telescope system at the time of observing. As part of the construction of the Observatory, Paul Gardner of Observatory Systems conducted a series of tests with the Rancho Mirage Observatory. His tests were able to measure a seeing value of 1.035 arcseconds (or less than one thousandth of a degree) with our telescope. This shows that RMO's systems and location can produce phenomenal images for both educational and research purposes.

What does "research level/grade" mean?

We refer to the Observatory as research grade because the facility is capable of conducting research-level work similar to other research-focused observatories.

What kind of telescope do you have?

Our main telescope is a PlaneWave Instruments CDK 700. This telescope uses a Corrected Dall-Kirkham optical system. This recently developed system uses an ellipsoidal primary mirror, a spherical secondary mirror, and a series of correcting lenses to collect light so that it can either enter a camera or eyepiece. For more information on the specifics of CDK optical systems, click here.

How big is the telescope?

The primary mirror is 700 mm in diameter (or 27.56 inches). This is the most critical dimension of a telescope because telescopes need to collect as much light as possible to view very faint objects. A larger primary mirror results in a better ability to collect light.

Can you use it during the day?

While we may be able to view a few objects in the Solar System near dusk and dawn, in general, we will not be able to use the telescope during the day.

Can you use it during the Summer?

While there are more hours of daylight in the months surrounding the summer solstice, there is still plenty of time during the night for observing the sky.

Fun Facts

What will the telescope be able to see?

• We will be able to see details on planets such as Mars and Jupiter.

• We will see nebulae, enormous clouds of gas and dust spread over vast regions of space.

• Large clusters of stars.

• Distant galaxies.

How far away is the Moon?

The distance to the Moon has been measured very precisely using lasers and reflectors placed on the Moon during the Apollo Program and several other missions. This distance varies by over 10,000 kilometers as the Moon revolves around the Earth, but the average distance from the Earth to the Moon is around 384 ,000 kilometers or approximately 239,000 miles.

How far away is the Sun?

It takes light from the Sun a little more than eight minutes to reach the Earth. That translates to approximately 150 million kilometers or 93 million miles. This distance is the basis for the Astronomical Unit (au). Thus, the distance to the Sun is about 1 au.

How far away is the nearest star?

Besides the Sun, the nearest star is Proxima Centauri. It is approximately 4.2 light-years distant. It has one known planet. Unfortunately, we cannot see this star from Rancho Mirage because you must be located south of a latitude of about 27°N to have any chance to see it.

How far away is the center of the Milky Way Galaxy?

The center of the Milky Way Galaxy ranges 24 -28 thousand light-years away in the constellation of Sagittarius. At the center of the Milky Way is a supermassive black hole that is around four million times the mass of the Sun.

What is a light-year?

A light-year is the distance light travels in one Earth year. In a vacuum, light travels at about 300,000 kilometers per second (or about 186,000 miles per second). At this speed, light travels from the Earth to the Moon in about 1.3 seconds! Thus, over one year, light travels about 9.46 trillion kilometers (about 5.88 trillion miles).

Getting Involved

Become A Docent

If you're interested in becoming a docent at the Observatory, please take a look at the Observatory Docent Volunteer job description, and if interested, please:

Download, Print & Sign the VOLUNTEER Application Form

Please return your application back to the library to Eric McLaughlin's attention.

An Observatory for the public!

The City of Rancho Mirage Observatory, which officially opened on March 25, 2018, is a teaching and learning tool for all ages, intended to further public understanding of our night skies while offering new programming opportunities in astronomy. The Observatory plays an integral role in the growth of the Rancho Mirage Library’s campus. Constructed adjacent to the Library’s western entrance, the addition of this research level facility underscores the Library’s commitment to lifelong learning, education for all ages, and a focus on the sciences. In addition to onsite tours, telescope viewing and group stargazing with individually owned telescopes, the Observatory will be able to transmit images into locations within the Library, creating limitless possibilities for educational programming and activities for all ages and levels of expertise.

All of our programs are funded by the Rancho Mirage Library and Observatory Foundation

For more information, please call (760) 341-7323, extension 605.