Public observatory · Prairie Ridge, Illinois

Look up. The universe is waiting.

Nightfall Observatory opens its domes to everyone. Join a stargazing night, tour the planets, and learn to read the sky with us.

Tour the planets Plan a visit

01 · The tour

Tour the Solar System

Five worlds you can see through our telescopes, with the numbers that make each one remarkable.

  • Third from the Sun

    Earth

    Home. The only world we know that hosts liquid oceans, a breathable atmosphere, and life. Every observation we make starts here.

    Distance from Sun
    149.6 million km
    Length of day
    23.9 hours
    Moons
    1
    Diameter
    12,742 km
    Illustration of Earth with blue oceans, green continents and white clouds

  • The red planet

    Mars

    Rust-colored deserts, polar ice caps, and Olympus Mons, the tallest volcano in the solar system at roughly 22 km high.

    Distance from Sun
    227.9 million km
    Length of day
    24.6 hours
    Moons
    2
    Diameter
    6,779 km
    Illustration of Mars with rust-colored terrain and a white polar cap

  • King of the planets

    Jupiter

    A gas giant more than twice as massive as every other planet combined. The Great Red Spot is a storm wider than Earth that has raged for centuries.

    Distance from Sun
    778.5 million km
    Length of day
    9.9 hours
    Moons
    95+
    Diameter
    139,820 km
    Illustration of Jupiter with swirling cream and brown bands and the Great Red Spot

  • Jewel of the night sky

    Saturn

    Its rings are made mostly of water ice and span about 280,000 km, yet they average only around ten meters thick. Saturn is the crowd favorite on every public night.

    Distance from Sun
    1.43 billion km
    Length of day
    10.7 hours
    Moons
    140+
    Diameter
    116,460 km
    Illustration of Saturn with its pale gold bands and wide rings

  • The windy blue giant

    Neptune

    The most distant planet, home to the fastest winds in the solar system at more than 2,000 km/h. One trip around the Sun takes 165 years.

    Distance from Sun
    4.5 billion km
    Length of day
    16.1 hours
    Moons
    16
    Diameter
    49,244 km
    Illustration of Neptune, a deep blue planet with a dark storm and thin white clouds

02 · Programs

Programs for every curious mind

Whether it is your first look through an eyepiece or your hundredth night of imaging, there is a program for you.

Public Stargazing Nights

Every clear Friday and Saturday night, our 24-inch reflector and lawn telescopes are open to everyone. Volunteers guide you from the Moon's craters to galaxies millions of light-years away.

Fri & Sat · Free

Telescope Workshops

Bring your own telescope or borrow one of ours. Learn how to align, focus, and star-hop in a hands-on evening that ends under the real sky.

Tuesdays · Free

Astrophotography Lab

From phone-through-eyepiece snapshots to tracked deep-sky imaging, learn stacking, calibration frames, and processing with free software.

Monthly · $15

School Field Trips

Half-day visits for grades 3 through 12 with a planetarium show, safe solar viewing through filtered scopes, and a scale-model walk of the solar system.

Weekdays · By booking

Junior Astronomers

A club for ages 8 to 14 that meets twice a month to build spectroscopes, track the International Space Station, and earn observing badges.

Ages 8–14 · $40 per season

Dark-Sky Advocacy

We work with the county on responsible outdoor lighting so the Milky Way stays visible from the prairie for the next generation.

Volunteer · Free

“We are made of star-stuff.”

Carl Sagan
Reserve a night

03 · Events

Upcoming events

Reserve a spot or just show up. Open any event for the full details.

Oct 2

Saturn at Opposition

8:00 PM Main Dome

Saturn reaches opposition this week, its closest and brightest for the year. Come see the rings through the 24-inch.

Oct 21

Orionid Meteor Campout

10:00 PM Dark-Sky Meadow

Camp under the peak of the Orionids, dust left behind by Halley's Comet, with hot cocoa and a guided constellation tour.

Nov 14

Intro to Astrophotography

6:00 PM Learning Lab

Go from phone-through-eyepiece snapshots to your first stacked image of the Orion Nebula in a single evening.

04 · Time-lapse

The night sky, in motion

Aurora over the east lawn, from dusk until the curtains fade.

Rendered time-lapse of the northern lights above Prairie Ridge.

When the lights come south

A few times a decade, a strong geomagnetic storm pushes the northern lights all the way down to central Illinois. This clip shows what such a night looks like from our east lawn: curtains of green drifting above the tree line while the stars wheel behind them.

  • Look north, away from town lights.
  • Watch the Kp index. A Kp of 7 or higher can reach Illinois.
  • Give your eyes twenty minutes to adapt to the dark.

05 · Visit

Plan your visit

Admission is always free. Clear skies are not guaranteed, but good company is.

  • Address

    4100 Prairie Ridge Road
    Urbana, IL 61802

  • Hours

    Fri & Sat, 8 PM to midnight
    Tue workshops, 6 to 9 PM

  • Admission

    Free for everyone.
    Donations keep the domes open.

  • Contact

    (217) 555-0142
    hello@nightfall.example

Clear-sky alerts

One email a week, only when the forecast looks good.

You are on the list. See you under the stars.

Friday, October 2, 2026 · 8:00 to 11:00 PM

Saturn at Opposition

Once a year Earth passes directly between Saturn and the Sun. For a few nights the ringed planet rises at sunset, stays up all night, and shows its finest detail in the eyepiece. Our volunteers will keep the 24-inch reflector and six lawn telescopes on Saturn all evening, with Jupiter joining the show after 10 PM.

Cloudy forecast? Call the clear-sky line after 5 PM. If skies are overcast we run an indoor planetarium talk instead, and the rings will still be there next week.

Where
Main Dome and East Lawn
Cost
Free, donations welcome
Bring
Warm layers, a red flashlight, a lawn chair
Accessibility
Dome is wheelchair accessible; lawn scopes sit on level gravel

Wednesday, October 21, 2026 · 10:00 PM to 4:00 AM

Orionid Meteor Campout

The Orionids peak in the small hours of October 22, when Earth crosses the debris trail left by Halley's Comet. Under a dark sky you can expect 15 to 20 meteors an hour, many leaving glowing trains. We open the meadow for tents at 8 PM, run a constellation tour at 10 PM, and keep the cocoa hot until dawn.

Where
Dark-Sky Meadow, north of the domes
Cost
$10 per tent, registration required
Bring
Tent, sleeping bag, a reclining chair or blanket. No white lights, please.
Capacity
60 campers, first come first served

Saturday, November 14, 2026 · 6:00 to 9:00 PM

Intro to Astrophotography

This hands-on workshop starts with the basics: exposure, ISO, focus, and steady mounts. Weather permitting, we head to the lawn to capture the Moon and the Orion Nebula with a tracked camera and phone adapters, then come back inside to stack and process the frames with free software you can take home.

Where
Learning Lab, ground floor
Cost
$15 materials fee
Bring
A DSLR, mirrorless camera, or phone; a laptop if you have one
Seats
12, ages 14 and up