Galileo’s TOES

Galileo’s TOES Certificate Coordinator:

Douglas Smith
6032 S. Nantac Rim Dr.
Tucson, Az 85706
(520) 396-3233


The Galilean Moons of Jupiter, Io, Europa, Ganymede, and Callisto, are aligned so well with the Earth that we are treated to events between Jupiter and the moons.  These events come in four varieties:

  1. Transits:  This is when one of the moons actually moves across the face of Jupiter.
  2. Occultations:  This is when one of the moons moves behind Jupiter from our line of sight.
  3. Eclipses:  This is when one of the moons moves into the shadow of Jupiter.
  4. Shadow Transits:  This is when the shadow of one of the moons moves across the face of Jupiter.

Each of these events has a start and a finish:

  1. Ingress:  When the event begins.
  2. Egress:  When the event ends.

Note:  All of the events do not occur during every cycle of Jupiter.

The objective of this certification is to witness all of the events; for all of the moons, and the ingress as well as the egress.  Since there are four moons, four events, and two observations each, this comes to a total of 32 observations.  Observation may be done visually at the eyepiece or through imaging

For those who are looking for a bit of a challenge, we have created this award (certificate only) to recognize those who have accomplished this significant accomplishment.

Phase 2 of Galileo’s T.O.E.S.

We have received some successful submissions for Galileo’s T.O.E.S., so it is time to Take it to the Next Phase.   Click here to get more information on the ultimate Galileo’s T.O.E.S. challenge.

Requirements and Rules

This certification is available to members of the Astronomical League, either through their local astronomical society or as members at large.  If you are not a member and would like to become one, check with your local astronomical society, search for a local society on the Astronomical League Website, or join as a Member-at-Large.

You must complete all 32 observations.  An Ingress and Egress of a specific event, for a specific moon, do not have to be done together.  They may be separate occasions.

You should document the event by logging this information for each event:

  • Moon name
  • Event type (transit, occultation, eclipse, or shadow transit)
  • Ingress or Egress
  • Date (either Local or Universal Time)
  • Time (use the same: Local or Universal Time)
  • Latitude and Longitude of the Observation
  • Equipment used
  • Filters used (if used)
  • Magnification
  • Seeing and Transparency

This certification does not count as one of the requirements for the Master Observer certification.

Submitting for Certification

This program has a certificate (only) for those who successfully complete all of the observations. Once you have made the necessary observations, either send a copy of your log to the Galileo’s TOES Award Coordinator or have it reviewed and approved by an officer of your local club. That officer should then send an email to the Galileo’s TOES Award Coordinator with the observer’s name, club, e-mail address, and mail address. Also, send the name and email address of the person to which the certificate should be sent.

Upon verification of your submission and of your active membership in the Astronomical League, your recognition (certificate, pin, etc.) will be sent to you or to the awards coordinator for your society, as you specified.  Your name will also appear in an upcoming issue of the Reflector magazine and in the Astronomical League’s online database.  Congratulations.  Good luck with your next observing challenge.

Galileo’s TOES Certificate Coordinator:

Douglas Smith
6032 S. Nantac Rim Dr.
Tucson, Az 85706
(520) 396-3233
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