Astrophysicists from Trinity College Dublin offered the public a unique opportunity to observe and learn about the 2016 Mercury transit, when our solar system’s smallest planet became visible moving across the Sun on Monday May 9.
The hundreds of people who attended the event in Trinity’s Front Square saw Mercury against the backdrop of the Sun through high-tech telescopes, and witnessed footage of the rare event streamed to a plasma TV from NASA’s Solar Dynamics Observatory.
Visitors also chatted to scientists about the physics of our Sun, the science of planetary transits, and about new and exciting missions we are involved in.
There are only about 13 Mercury transits that are visible from Earth every century. The next ones are in 2019 and 2032, but these will not be visible from Ireland and it will be many more years before the next opportunity arises on our shores.
Mercury first became visible against the Sun shortly after 12 noon, and it remained so until just after 7:30 pm.
Professor in Physics at Trinity, Peter Gallagher, said: “Mercury is too small to see without magnification, but our telescopes allowed people see it against the vast face of our Sun."
"There were also plenty of experts on hand from our Astrophysics Research Group to chat about this exciting event, and to help everyone view the transit safely – we hope everyone had a great day!”
Planetary transits were hugely important throughout science history. They were pivotal in proving Kepler's then-revolutionary idea that all the planets moved around the Sun in elliptical orbits, and also provided estimates of the distance from the Earth to the Sun.
The 2016 Mercury transit comes 100 years after the transit of Venus helped Eddington to verify Einstein’s laws of gravity in his General Theory of Relativity. The Irish connection was that the tracking mirror used for this famous expedition was made on Observatory Lane in Rathmines, Dublin.