Discovering the lunar landscape
Saturday was all about the Moon on our final Discovery Day of the academic year.
Our source material was the old and the new, a copy of Galileo’s Siderius Nuncius (published in 1610) and Luna Cognita, three volumes of probably the most comprehensive guidebook to the Moon ever, written by Robert A. Garfinkle and published in 2020.
Our understanding of the Moon has clearly advanced in the past 410 years. We had a lunar globe and various artefacts for our explorations, including an Ordnance Survey map of the Apollo 11 landing site - a must have for the more adventurous rambler!
We started with a look at the formation and geological history of the moon (the term geology has replaced selenography) and early observations of the Moon by Galileo and Thomas Harriott. We then headed outdoors to embark on an experiment to replicate the creation of lunar craters.
We now know that the moon is made not of cheese but of sand, flour and chocolate powder (!), so these were our ingredients to create our lunar surface. For additional authenticity, we had real meteorites, a NWA Stone Meteorite and one of the famous Campo del Cielo Iron Meteorites (this has a fascinating back story from 1576 - a topic for a future Discovery Day perhaps).
Our experiment involved launching our meteorites down a tube at varying angles and analysing the impact craters. This worked surprising well, creating in one case an excellent example of ejecta - lunar rays that we can see on the Moon today.
Back indoors we used imagery to explore “seas", mountains and other geological features taken by the humanities teacher from his back garden and from NASA’s Lunar Reconnaissance Orbiter, which, it has to be admitted, were of slightly superior quality. We also had a small piece of the Moon itself to examine.
This led us to the topic of lunar exploration and returning outdoors we contemplated the distance to the Moon. On the scale of our 12 inch globe, space starts just several millimetres above the surface. The International Space Station and Hubble Space Station were all within two centimetres. On this (very rough) scale, the Moon was just over 12 metres away, and the sun almost 5 km away. This clearly illustrated the challenge of getting to the Moon.
But humans did make it to the Moon and we watched footage of the Apollo 11 landing and the naming of craters and celebration of some amazing astronomers and scientists. We focussed on Copernicus, in keeping with our historical theme of heliocentricity, Tycho Brahe, the man who lost his nose in a dual to ascertain his prowess in mathematics and Eugene Shoemaker, who remains the only human to have his ashes scattered on the Moon (in a crater that now bears his name, right at the south lunar pole).
From here our attention turned to other moons. A simulation of the Galilean moons orbiting Jupiter prompted discussion on the impact of heliocentricity theory on the early 17th century. We moved on to Saturn and watched NASA footage of Huygens landing on Titan in 2004. And finally, exomoons, the recently discovered Kepler 1625bi, a moon orbiting a planet orbiting distant star some 8000 light years away.
This was a great conclusion to our lunar morning, with fantastic contributions and engagement from our students and guests. We look forward to the next one.