The Rosetta mission team is celebrating its first anniversary of the spacecraft's August 6 arrival at Comet 67P/Churyumov-Gerasimenko.
Among Rosetta's wealth of information is the discovery that the water vapor around the comet reveals a different chemical makeup than that seen on Earth. This finding could be important to understanding how our solar system formed. Many astrophysicists and chemists believe water may have been delivered to Earth soon after its formation by comets. This new finding, however, does not support that theory.
Molecular nitrogen, rarely seen in the solar system today, was more common during the formation of our family of worlds. This material – which only becomes trapped in ice under exceedingly cold conditions – was found in the tenuous atmosphere of the comet. This suggests that the class of objects formed far from the sun, in the distant Kuiper Belt.
"This mission is about scientific discovery and every day, there is something new to wonder at and try to understand. A year of observations near to the comet has provided us with a wealth of information about it, and we're looking forward to another year of exploration," said Nicolas Altobelli, acting Rosetta project scientist at the European Space Agency (ESA).
One of the strangest discoveries is the odd shape of Comet 67/P: it resembles a duck. Most astronomers believe it was formed this way, from the merging of a pair of cometary pieces. It is possible that the two bodies were originally part of a larger object, which was torn asunder. Later, the two pieces likely came back into contact with each other.
Rosetta mission engineers also determined that there does not appear to be any large-scale magnetic field surrounding the comet. Some organic chemicals have, however, been detected surrounding the frozen body.
The comet is due to make its closest approach to the sun on August 13 — accompanied by the Rosetta orbiter and the Philae lander, which has remained mum since a rough landing. On that date, the comet and vehicles will be just over 116 million miles from the sun — 23 million miles farther away than our own home world. That's roughly three times closer to the sun than where the comet was upon Rosetta's arrival.
The highlight of the mission will come when the robotic observatory makes its closest approach to the sun. Researchers hope the extra energy will awaken the Philae, still sitting silently on the surface of the comet.
