Massive amounts of water discovered in pre-stellar cloud

            Water is a ubiquitous substance in the universe, not only appearing as a liquid on Earth but also frozen ice on distant planets, comets, and in the depths of interstellar space.  How much water is present during the formation of star systems, however, is a question left unanswered due to challenges of measuring vapor content in regions of energetic, often violent star birth.  However, by directing their observations toward a much calmer, nebulous area of star formation, a team lead by Professor Paola Caselli of the University of Leeds has recently determined the quantity of water to be on the order of 2,000 times the volume of Earth’s oceans.

            Caselli’s team studied a cloud, dubbed Lynds 1544 in the constellation Taurus, which is a pre-stellar core, or a collection of gas and dust on the verge of collapsing into an infant star.  Using the Herschel Space Observatory, a powerful telescope orbiting the earth, Caselli and her team were able to directly observe water vapor to determine its combined mass.  Their results indicate that there is far more water in early star systems than previously expected, a significant finding which helps shape our understanding of juvenile solar systems.

            “I am passionate about understanding our origins, which is why I have been studying for many years dark clouds, where stars and planets form,” said Prof. Caselli of the University of Leeds in West Yorkshire, England.  “These particular clouds are the ideal objects where to focus our attention if we want to unveil the initial conditions of the whole process of star and planet formation.”

            Unlike young star systems which are subject to solar winds, stellar jets, and other astounding displays of energy, Lynds 1544 is a relatively peaceful gas cloud with the potential to collapse into a Sun-like star.  Already, the drift of the water vapor as observed by the Hershel Observatory indicates that the cloud is gradually undergoing gravitational collapse, in which material is slowly flowing toward the center where a star is likely to be born.

            While the water in pre-stellar cores is typically frozen in ice, which makes it hard to detect, the water content in L1544 is excited by passing cosmic rays, or bands of energetic particles which, when absorbed by hydrogen molecules, can help evaporate ice crystals.  In this case the water is made observable in the form of energized vapor.  “This is an important result because it is the first time that we have been able to measure water vapor in a pre-stellar core,” Caselli commented.  “We now know the initial reservoir, or budget of water, at the dawn of a new solar-type system.”

Water is a crucial ingredient in the formation and preservation of life as we know it on Earth.  Therefore, knowing how much water is present during the formation of stars and planets is key to understanding the processes which made life possible in our solar system.  The team’s next step is to perform similar observations on other nebulous clouds in the galaxy to study how different environments affect the chemistry of water, as understanding these dynamics may unveil clues as to the origins of our own solar system or even the planet Earth itself.

“I only hope that people will wonder a little bit more about our wonderful Universe,” said Caselli, “and how lucky we are to be here.”