An instrument of the National Aeronautics and Space Administration (NASA) on board the Rosetta orbiter has finally sent the first batch of scientific data from the comet 67P/Churyumov-Gerasimenko.
Rosetta was launched by the European Space Agency, or ESA, in March 2004 to conduct a detailed study of comet 67P, which could provide scientists better insights on the origin of the solar system and the contributions that comets may have made in providing water and even life to planet Earth.
On Thursday, NASA revealed that the data that Alice has sent showed surprising facts about the comet. It turned out that Rosetta's target comet is not covered in ice nor did it appear bright and reflective. The team behind Alice, which started to map the surface of the comet last month recording its first far-ultraviolet light spectra, said that the comet is actually darker than coal when it is viewed in ultraviolet wavelengths.
"We're a bit surprised at just how unreflective the comet's surface is and how little evidence of exposed water-ice it shows," said Alice principal investigator Alan Stern, from the Southwest Research Institute in Boulder, Colorado.
Among the primary objectives of Rosetta's deployment is to perform a detailed study of comet 67P's environment and Alice has also already detected oxygen and hydrogen in the coma of the comet, or its atmosphere.
The Alice team has also found that the surface of the comet does not show large water-ice patches so far which is contrary to what the team expected to see because the planet is too distant from the sun for the heat to turn the comet's water into vapor. The absence of ice in the comet's surface suggests that comet 67P at one point in its journey in space had been close to the solar system's sun or another star.
Comet 67P is over 500 million kilometers away from the sun and is only visible using large professional telescopes such as the Very Large Telescope, or VLT, of the European Southern Observatory in Chile. Rosetta is equipped to measure the way Comet 67P changes and this could help scientists learn more about the origins of comets and even of the solar system.
So far, Rosetta has already determined that the surface temperature on the comet is about 70°C on average, which is actually 20 to 30°C warmer than expected for the comet given its location.