Saturday Seminar – Recent Discoveries in the Outer Solar System and their Implications for the System’s Origin

Tutor/Facilitator Andrew Prentice

Date: on/from Sat 18 Nov 2023 to Sat 18 Nov 2023
Frequency: Single Event
Class time: 2:30-3:30

Delivered ZOOM

Other information

To watch the seminar click here on the day at 2:20pm for a 2:30 start.

In this seminar to mark the 20th anniversary of the founding of the Port Philip U3A, Dr Prentice will discuss various new discoveries about our Solar system that have been made since 2013, when he gave the 10th anniversary seminar. The discoveries have come about as a result of NASA’s New Horizons spacecraft flybys of Pluto and its family of moons, and of the tiny Kuiper Belt object Arrokoth. Until those flybys, very little was known about Pluto or its moons. Nothing was known about Arrokoth. The flybys provided a unique opportunity for the speaker to test his Modern Laplacian Theory of Solar system origin. This theory successfully predicted that Pluto’s crust was made mostly of methane ice and that Pluto’s largest moon Charon was once an ocean world. Dr Prentice also correctly predicted that Arrokoth’s surface would be smooth and crater-free and have no water ice. In this illustrated talk, he will explain the workings of the theory and why it does such a good job predicting the Solar system’s physical and chemical makeup.

The speaker is Dr Andrew Prentice from the School of Physics & Astronomy, Monash University.  Dr Prentice gave the very first U3A Port Phillip Saturday Seminar, then the Saturday Seminar for our 10th anniversary and, now, the Saturday Seminar for our 20th anniversary.

Over the past 50 years, Dr Andrew Prentice has developed a new theory for how our Solar system was formed.

Andrew has spent most of his academic life at Monash University. He is presently an affiliate of the Monash School of Physics and Astronomy. He is an honorary lifetime member of the Astronomical Society of Victoria and a fellow of the Astronomical Society of Australia.

Although his ‘Modern Laplacian Theory’ theory sits outside mainstream thought, he has used it to make many successful predictions regarding the physical structure and chemical makeup of our Solar system.  The opportunity to test these predictions has come about through NASA’s program of interplanetary spacecraft exploration, including most recently the New Horizons spacecraft visit to the Pluto system and to the Kuiper Belt object Arrokoth.

Heather Wheat is the seminar facilitator.  She also was a founding member of U3APP and organised the inaugural seminar.

To view the beautiful flyer created by Margaret Byron, click here.

This seminar is open to all U3A Port Phillip members and subscribers and to the general public.

As there are limited numbers, please book in below.

This is an online live seminar, presented as a webinar on Zoom.

If you have not yet used Zoom, you will need to download Zoom onto your device in advance- click here for instructions.

Enrolments / Bookings

U3APP members must log in, and members of the public must register, to make a booking.
U3APP Members, please login.

Login with your email address and password. If you haven't used the system before, your password is also set to your email address. If you've changed it but forgotten what you changed it to, send an email to and we will reset your password for you.

Members of the public, please register to attend a Public Event open to non-members (listed on our Public Events page).

To enrol in a course, you must be a financial member of U3A Port Phillip. If you are financial and still unable to book, it means bookings have not yet opened.


How to Enrol

On-line: after bookings have opened

On-line enrolments are preferred as this significantly reduces the amount of back-office work for our volunteers.

  • Login to the website.
  • Go to the Courses & Enrolling page.
  • Scroll down to find the course that you are interested in.
  • Does the course have spaces available?
    • Click on the course name to go to the booking page.
    • Click on “Book for this course or event”.
    • You will receive a confirmation email.  Please check your Junk/Spam folders as these automatically-generated emails often finish up there.
  • OR is the course shown as FULL?
    • Click on WAITLIST.

Paper Enrolment Form: before bookings open for First Semester

  • Obtain a paper Enrolment Form either from the Office or by printing an online copy available here.
  • Complete the paper Enrolment Form and submit it to the Office.

The start date for acceptance of paper Enrolment Forms for first semester is published on the U3APP website and in the e-Bulletin. Enrolment Forms received before this date are treated as though they had been received on the start date (ie there is no advantage to be gained by submitting early). On the start date and thereafter, paper Enrolment Forms are numbered in order of receipt.  Paper Enrolment forms are processed by U3APP volunteers on the same day as on-line bookings.

If your enrolment is successful, you will receive a confirmation email.  Please check your Junk/Spam folders as these automatically-generated emails often finish up there.

If your enrolment is unsuccessful,  you will receive an email telling you that you have been waitlisted.

Via the Office: after bookings have opened

  • Contact the office in person, or by email or phone.