An international team of astronomers has identifiedon Hartley’s Comet 2, belonging to the Kuiper Belt,icy water with the same chemical composition as the Earth’s oceans. The finding supports the theory that comets brought to our planet a significant portion of the water from the oceans, which scientists estimate formed about eight million years after Earth itself.
“Thelife would not exist on Earth without liquid waterand therefore the question of how and when the oceans were formed is fundamental, “says the lead author of the study published today.Nature, Ted Bergin. “It’s a big puzzle, and these new findings are an important piece.”
The researchers reached this conclusion usingHiFi equipment, acronym in English for Heterodyne Instrument for Far Infrared,from the Herschel Space Observatory. The measurements revealed that the ice present in the commentHartley 2it has the same D / H ratio, which is the ratio of deuterium or heavy hydrogen present in water. This is the first time that ocean-like water has been detected in a comet. Astronomers suspect that Hartley 2 probably formed in the Kuiper belt, located 30 to 50 times the distance between the Earth and the Sun, and also inhabited by rocky and icy bodies such as Pluto, other dwarf planets and multiple comets.
“In the early solar system, comets and asteroids would have been moving everywhere, and it seems that some of them collided with our planet and formed the seas,” explains Geoffrey Blake, co-author of the work and professor of planetary science at the Caltech Institute. Astronomers suspect that comets’ contribution to Earth’s total water volume could be about 10 percent.
Herschel, a mission of the European Space Agency (ESA) with the participation of NASA, is an orbital telescope that allows astronomers to observe thedeep infrared wavelengths, where organic molecules and water emit their chemical signals.
