Star Parties

Great Conjunction of Jupiter and Saturn

Did you miss it?  Here is a link to the recording:

Recording of Great Conjunction Star Party

On Monday December 21, 2020 we will host an online remote viewing of the great conjunction of Jupiter and Saturn.  We will go live over Zoom at starting at 5 pm on December 21 and follow it until the planets set sometime about 6:30 pm.

For more information on connecting to virtual Star Parties over zoom please see “Connecting to Virtual Star Parties” below.

The Star Party will feature views through the 14-inch telescope at the UIS Campus Observatory, fun facts, and answering live questions.  If weather interferes we will still have the event and share pictures from another night.

A conjunction is when two objects in the sky draw close to each other and appear in the same field of view.  Normally we can just see one planet in the telescope at a time.  But during a conjunction they can get close enough that we can see both planets at once in the same telescope field of view.  This conjunction between Jupiter and Saturn is considered “great” because the planets will be so close.  At closest, Saturn will appear about 6 Jupiter-diameters away from Jupiter.  There hasn’t been a conjunction that close between Jupiter and Saturn in many hundreds of years.

Bird's eye view of the solar system for the Great Conjunction.
Where the Earth, Jupiter, Saturn and Sun are relative to each other for the Great Conjunction on December 21, 2020.

Keep in mind that even though we see them close together in the sky that Jupiter and Saturn will still be very far apart.  During the conjunction our line of sight to the two planets converge so that Saturn appears to be near to Jupiter along the line of sight but it is actually very far behind Jupiter.  Kind of similar to what happens when the Moon passes near a bright star, we know the Moon is a lot closer than the bright star, but the lines of sight to them converge.

Here is a brief video explanation of the conjunction and some facts about Jupiter and Saturn:

Video Introduction to the Great Conjunction of Jupiter and Saturn

Here is a photo take of the last conjunction of Jupiter and Saturn in 1981 that is featured on the wall of the Campus Observatory.  The conjunction this year is going to bring the planets even closer together.

Conjunction of Jupiter and Saturn in Spring 1981
A picture taken with the Campus Observatory 14-inch telescope of the conjunction of Jupiter and Saturn in Spring, 1981


Our regular Star Party schedule for Fall 2020 has concluded.  We learned a lot doing these virtually this fall.  And that has led us to consider doing a few virtually this winter.  Normally winter is just too cold for most people in person, but from the comfort of your own home may work.  We know now we can do that.  Stay tuned for information about those events.


The recordings of the virtual events this fall are linked in below.  They will be available for up to 180 days after the date of the event.

Connecting to Virtual Star Parties

Star parties on Friday nights this fall (September and October) will be 8-9 p.m. CDT at the link below.

Direct Zoom Link:

We have sometimes experienced technical difficulties with Zoom where the link above will not connect you and you will be asked for a password.  Many of those issues are resolved by re-installing or updating your Zoom app.  Make sure you are running the most current version of Zoom.  Another quick solution to the problem is to manually enter the meeting ID and password give below directly into your Zoom app.

Meeting ID: 970 0930 5382

Password: stars

Star Parties in the Era of COVID

Like everyone else, our plans have been interrupted by the COVID-19 pandemic.  We plan to follow the direction of the government and advice of public health professionals to decide what we cancel.  It is very important to us also that our volunteers feel comfortable helping with the event.  Out of an abundance of caution and to comply with University policies for visitors on campus this semester, we are going to replace in-person star parties with virtual events.

There is a silver lining to this.  A virtual Star Party lets us share things with you that we could not for an in person Star Party.  We are planning to go live for many of them from the research observatory.  When the weather cooperates we will share views with cameras through the 20-inch telescope and of the dark night sky.

When the weather does not cooperate… well no problem.  This is another advantage of the virtual Star Party: we will do it whether clear or cloudy.

So please plan on joining us virtually on Friday nights this fall between 8 – 9 pm central time.

Fundraising for a New Deck

Someday we hope to resume in-person Star Parties We are currently raising money to replace the deck used for Star Parties.

For information about our efforts to renovate the UIS Campus Observatory used for Star Parties, please follow this link.

Friday Star Parties For 2020.

In Fall 2020 Star Parties will be virtual and on Friday nights in September and October.

The scheduled dates are:

September:  4, 11, 18, & 25

October: 2, 9, 16, 23, & 30

Virtual Star parties are 8-9 p.m. on the Fridays.  They are free and open for everyone.  Come as you are anytime between 8-9 p.m.

For virtual Star Parties the “weather permitting” caveat is lifted.  We will host you on zoom between 8-9 p.m. every Friday in September and October in Fall 2020.

What is a Star Party?

Since 1980, thousands of people of all ages have come to the UIS observatory for Friday Night Star Parties, as well as for special astronomical events such as lunar and solar eclipses and comets.

At a typical Star Party, vImage taken from hubblesite.orgisitors learn about galaxies, the sun, stars,
and stellar evolution, as well as star and constellation identification
prior to using the telescopes. These discussions take place in the stairway
gallery of astronomical pictures on the way to the rooftop observation
deck atop Brookens Library. Then, the observatory director and qualified
volunteers help visitors use each of the telescopes.

Over the years, stargazers have seen many celestial objects, including the moon and planets, deep-sky objects such as the Orion Nebula and other fascinating star systems, the beautiful yellow-blue double star Albireo, and the open star cluster called the Pleiades.

The Astronomy Program also offers Sunday Night Star Parties for the disabled and their friends and families.

How do I get more information?

For general questions about Friday Night Star Parties call 217-206-8342.

What do you do if it is cloudy?

This is NOT a thing for virtual Star Parties in Fall 2020.  For virtual Star Parties we will do them regardless of clouds in the sky.

When we are back to in person Star Parties, in order to learn if the weather is suitable for viewing, please call 217-206-8342 after 7:00 PM on the night of the Star Party.

Or you can get information on when the observatory is open from our twitter feed.

Is there elevator access to the Campus Observatory for a Friday Night Star Parties?

Again, not an issue for virtual Star Parties in Fall 2020.

For in person Star Parties at the campus observatory: No. Not during a Friday Night Star Party. Visitors to a Friday Night Star Party must be able to climb up and down four flights of stairs AND climb a short 5 ft ladder up to the main telescope dome. If you or a loved one that wants to attend a Star Party has trouble with stairs or ladders you should call 217-206-8342 and ask about our Sunday Night Star Parties for people with disabilities. Those Star Parties are fully accessible and require no stair or ladder climbing.

Are regular Friday Star Parties accessible in 2020?

Sorry but accessible Star Parties are canceled until the University lifts restrictions in place for COVID.

But if you are interested and you want to attend an accessible Star Party sometime in the future you are encouraged to express your interest.  Please contact John Martin (217-206-83442) about Sunday Night accessible Star Parties.

Where is the UIS Campus Observatory?

The Campus observatory will be closed until the University lifts restrictions in place for COVID.

The Campus observatory is on the roof of Brookens Library. The door for the observatory is on the southeast corner of the library (side opposite the UIS fountain) and the door is marked “Observatory.” You have got to go all the way round the corner to see the observatory door. The observatory is through that door and up five flights of stairs to the roof. We appologize for the deplorable lack of signage. We are working on it. On that map below the library is building #7 and the door for the observatory is on the lower right corner of the outline of the building. Map to Campus Observatory