Comet 67P/Churyumov-Gerasimenko: Data from Rosina.

Mosaic of 4 images, gas and dust from comet can clearly be seen from the center. Courtesy: European Space Agency (ESA).

While anxiously waiting for data from the COSAC (Cometary Sampling and Composition Experiment) aboard the Philae lander, we turn to some of the information that has already been sent by the Rosetta’s Rosina (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instrument.  While sampling the comet’s coma they have found carbon dioxide in nearly the same proportions as water. Rosina has the ability to measure the ratio of hydrogen to deuterium in water.  Deuterium is believed to have been created in the Big Bang 13.8 billion years ago.  Since deuterium accounts for approximately 0.0156% of all hydrogen found on earth, this data may shed light on the origin of our water.

So far the following compounds have been detected by Rosina:

Water, Carbon monoxide, Carbon dioxide, Ammonia, Methane, Methanol, Formaldehyde, Hydrogen sulfide, Hydrogen cyanide, Sulphur dioxide, Carbon disulfide and ethanol.

The ‘Perfume’ of 67P/C-G