HAI Darwin Day lectures are a unique opportunity to hear an expert speak in an accessible manner on what can often be a complex and inaccessible scientific topic


Tuesday, February 12th 2019 at 19.30


The Robert Emmet Theatre, Trinity College, Dublin
(The Theatre is in the Arts Building, which is the building you encounter immediately upon entering the campus from Nassau Street)


Dr. Ian Sanders of Trinity College on Meteorites and the Birth of the Solar System



Charles Darwin’s birthday, February 12th, is marked among humanists as a celebration of the rational. Darwin’s theory of Evolution by Natural Selection is, some humanists would argue, the greatest idea ever. It shows that organisms can improve in tiny steps by blind evolution without any higher purpose or higher cause. It changed completely humanity’s view of ourselves and establishes humans firmly as part of nature as a whole.

The Humanist Association of Ireland has, for many years, marked the occasion with a public lecture by a distinguished scientist who will bring information and insights about important developments to a general audience.

On Tuesday February 12th 2019, at 19.30 at the Robert Emmett Theatre in Trinity College, Dr. Ian Sanders (Trinity College) will give a talk entitled Meteorites and the Birth of the Solar System.

There will be a chance to handle meteorites!! i.e. to touch pieces of asteroids.



In the early nineteenth century, with the recognition that the Earth had taken shape over an unimaginably long period of time, geology was a new and exciting branch of science. Among its enthusiastic followers was the young Charles Darwin. As a student at Cambridge, while nominally training to become a clergyman, he spent his time as a disciple of Adam Sedgwick, the Woodwardian Professor of Geology. Soon afterwards, as Captain Fitzroy’s travelling companion on the Beagle, he was amassing a wealth of new geological evidence for the slow development of the planet’s landscape and life.

Meteorites are rocks from space. A few of them are pieces of once-molten metal, and some are made of basalt, but most of them are aggregates of various kinds of rocky and metallic ‘bits’ compacted together into hard rock – a kind of cosmic sandstone. Meteorites turn out to be fragments of baby planets called planetesimals that formed from 4567 until about 4562 million years ago out of a huge disk of gas and dust that surrounded the infant Sun. Most planetesimals are thought to have merged together to make the planets we know today, but a few survive, battered and broken, in the asteroid belt between the orbits of Mars and Jupiter, and it is these remnants, the asteroids, that supply us with meteorites.

The talk will address questions about this view of the Solar System’s origin. What was the nature of the dust in the disk? Where did the dust come from? Did it include the seeds of life? How do we know precisely when planetesimals formed? Why did some planetesimals melt while others did not? The talk will also report on developments in astronomy which, with new high-resolution images of young stars with dusty disks and new planets, corroborate the story from meteorites.



Ian Sanders grew up in rural Leicestershire but spent his later childhood in southeast London where he attended Colfe’s Grammar School and was influenced by some hugely inspirational teachers. He spent six years at St. John’s College in Cambridge where he read Natural Sciences and specialized in mineralogy and petrology. Since then he has enjoyed teaching and research in the Department of Geology at TCD. He has just finished teaching the annual cohort of ever-keen and happy Senior Freshman students for the 47th year. His current research involves the study of meteorites.