Scientists have long sought to learn more about comets in the hopes that this could shed light on the origins of water and even life on Earth. Thanks to the Rosetta spacecraft, scientists are now gradually unveiling the secrets of these celestial objects.
Launched in 2004, the European Space Agency's (ESA) Rosetta mission aims to study up-close Comet 67P/Churyumov-Gerasimenko, a comet flying through deep space.
Data gathered by the probe reveals that the comet is stranger than what was initially believed albeit the information could help researchers learn more about the evolution of comets as data gathered from Comet 67P offer scientists improved understanding of comets in general.
In a special edition of the journal Science this week, scientists presented the initial results from seven of the 11 instruments onboard the Rosetta. The findings were based on measurements made during the spacecraft's approach to and after arrival at Comet 67P last year.
The findings are challenging scientist's concepts of a comet. Comet 67P, for instance, has surface that appears variable. There are smooth surfaces and rippled features that appear like sand dunes despite that the comet does not have robust atmosphere and high gravity.
Comet 67P has such a low gravity that if a person were to stand on its surface, he could jump high into space. There were also crumbly materials and those that look like rocks on the surface of the comet. The composition of the comet is likewise diverse.
"You might sink in into the smooth dust where we find the thick snow-field like layers, other areas might be robust enough to carry you," said OSIRIS principal investigator Holger Sierks. "The dust is dry like power."
Comets are often described as dirty snowballs but based on gathered data, Comet 67P is apt to be called a snowy dustball given its dust to gas ratio, said Rosetta's GIADA dust grain analyzer instrument principal investigator Alessandra Rotundi.
Rosetta researchers likewise found that Comet 67P harbors organic compounds, which are known to be the chemical building blocks of life with organic molecules being detected on the surface of the comet's nucleus.
As for the comet's temperature, the northern hemisphere of Comet 67P is relatively warm but the southern hemisphere is cooler suggesting that there are seasonal changes on the comet.
Researchers likewise found that the type of water present in Comet 67P/C-G is very different from water on Earth challenging the theory that comets brought water to our planet.