Oceans from the Stars


Prof. Fiorangela La Forgia

University of Padova

DATE: 30th July 2020 (GMT +8)
TIME: 6:00 – 7:00 pm (Time in China)

Where does Earth’s oceans come from? In the first moments after the Big Bang, the universe was extremely hot and dense. As the universe cooled, conditions became just right to give rise to the building blocks of matter: the quarks and electrons. A few millionths of a second later, quarks aggregated to produce protons and neutrons and within minutes protons and neutrons combined into nuclei. As the universe continued to expand and cool, things began to happen much more slowly. It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms. 1.6 million years later, gravity began to form stars and galaxies from clouds of gas. Water molecule formation in the gas phase is not efficient, therefore pristine water has to be formed and grown directly as water ice on the surface of icy dust grains. When Earth formed it was too hot for water ice to be stable and most of its original ice has been lost by sublimation. Earth’s liquid water has to be come from elsewhere later on. Water is currently widespread in the ice form in the Solar System, but can it be present also in liquid form? Understanding Earth’s water origin is essential to contrain the presence of life in the Solar System and in the Universe. Are we unique and alone in the Universe?

Fiorangela La Forgia obatined her PhD in Astronomy in 2014 at the University of Padova and she currently works at the Center for Space Activities “Bepi Colombo” in Padova. Her research field is Planetary Science and in particular she works on spectrophotometry of comets and asteroids. She is “Associate Scientist” of OSIRIS instrument onboard Rosetta (ESA) space mission which for the first time succeded in chasing a comet, landing a module on its surface and follow the comet along its orbit around the Sun. She worked in the USA at University of Maryland on data from space mission EPOXI on comet Hartley 2 and is actually involved in Hera mission to binary asteroid Didymos. She in part of the european project NEOROCKS to study hazardous asteroids and is involved in various observative campaign dedicated to asteroids and comets at the biggest telescopes from Earth (TNG-Canarias, ESO-VLT-Chile, ALMA etc.)

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Harmon, J. K; Slade, M. A.; Rice, M.; 2011, Radar imagery of Mercury’s putative polar ice: 1999-2005 Arecibo results, Icarus 211, 37-50

Bockelee-Morvan, D.; Calmonte, U.; Charnley, S. et al. 2015. Cometary Isotopic Measurements. Space Science Reviews, 197, Issue 1-4, pp 47-83

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