Researchers at NASA analyzing scientific data collected by the Hubble Space Telescope have confirmed Thursday that under the frozen surface of Ganymede, one of Jupiter's moons, is an impressive ocean, Reuters informs.
According to American scientists, confirmation of this ocean of Ganymede contribute to increasing the chances of discovery of alien life forms.
The discovery also led to decipher a mystery that enveloped the largest natural satellite in the Solar System, after Galileo space probe launched by NASA, US researchers provided a number of indications that Ganymede would have a subsurface ocean to freeze. Galileo probe conducted an exploratory mission to Jupiter and its satellites from 1995 to 2003.
Scientists at NASA have revealed in a conference that had still needs a little "detective work" to be able to confirm this finding.
Like Earth, Ganymede has a core of liquid iron generates a magnetic field, but the field of Ganymede is embedded in the magnetic field of Jupiter. This detail creates a special dynamic that lead to spectacular visual phenomena - twin rings of bright auroras around the two poles of Ganymede. As Jupiter rotates, its magnetic field reverses, causing auroras on Ganymede to "swing". Scientists have measured the motion and found that it is not as broad as it should have been. Using computer models of computation, American scientists have concluded that an ocean saltwater conductor of electricity, under the surface of the moon, counteracts the magnetic attraction exerted by Jupiter.
"Jupiter is like a lighthouse, whose magnetic field reverses rotation with the headlamp. Influences aurora on Ganymede," said Joachim Saur, professor of geophysics at the University of Cologne, Germany. "The existence of that ocean, swaying auroras on Ganymede is reduced considerably," he said.
Scientists have run over 100 computer models to see whether other factors could have the same impact on auroras on Ganymede. They repeated the analyzes of data collected in the ultraviolet spectrum for seven hours of Hubble and analyzed data from both auroras.
"These additional checks give us confidence in our measurement result," said Professor Saur.
Jim Green, director of the Planetary Science Division of NASA says that this discovery is "an extraordinary".
"My colleagues have created a new approach to look inside a planetary body with a telescope," said Jim Green.
Ganymede thus joined a list that includes satellites in the solar system containing water beneath their surfaces. Wednesday, scientists announced that Enceladus, a moon of Saturn, has hot water springs under bark covered with ice. Other bodies in the solar system containing water are two satellites of Jupiter - Europa and Callisto.
Scientists believe that the ocean on Ganymede has a maximum depth of 100 km, making it 10 times deeper oceans on Earth, and is hidden under a crust composed mainly of ice, which has a thickness of 150 kilometers .
"The discovery is a step forward in finding habitable celestial bodies rich in water, located in the solar system," said astronomer Heidi Hammel, a member of the University Association for Research in Astronomy, whose headquarters is in Washington.
source : http://www.mediafax.ro/