Philae is packed with all kinds of sensors and experiments to learn as much as possible about the comet's nucleus. One of these is CASSE – the Cometary Acoustic Surface Sounding Experiment, which was described by Martin Knapmeyer of the DLR Institute of Planetary Research in Berlin. Each of Philae's three feet has two pads, or soles. CASSE's sensors are in these feet: one sole of each foot contains a transmitter, and the other a receiver. Signals sent from the transmitter will be picked up and the change in the received signal will be interpreted to learn more about the surface near the lander.

As well as determining the properties of the ground when sitting on the surface, the CASSE team are hopeful that the instrument will be operating during Philae's landing itself. To prepare for this, they conducted simulated landings to see how the instrument and lander respond to landing on different types of surfaces. Having calibrated the test data thoroughly, information from CASSE on the lander will allow the reconstruction of Philae's first contact with the comet nucleus, including any bounces and measurements of the acceleration levels that each leg experiences. No matter how thoroughly the nucleus's surface will be analyzed from Rosetta and Philae, direct measurements such as those of CASSE will be needed to provide as full an understanding as possible of what a comet's surface is really like.

One of the instruments on the main Rosetta spacecraft is COSIMA – the Cometary Secondary Ion Mass Analyzer, which will measure the characteristics of the dust thrown into space around the nucleus. Martin Hilchenbach of Germany's Max Planck Institute for Solar System Research described how the instrument has already provided some surprises.

Part of COSIMA is a microscope to take high resolution images of cometary dust grains. A few tiny particles are in the instrument already, and there was an expectation that, if anything, there'd be a few more by the time Rosetta reaches its target. However, two dust particles actually disappeared from under the microscope during the spacecraft's asteroid Lutetia encounter in 2010! Hilchebach explained that COSIMA hasn't detected anything that wasn't already present in the instrument on the ground, so it hasn't been contaminated and will provide pristine observations at the comet.

There were many more presentations on various aspects of Rosetta, and the science that’s being done on its target and many other comets.

In the 1980s, cometary science underwent a revolution through the combined coordinated observations of Comet Halley and direct sampling and imaging of the comet by an international flotilla of spacecraft. Thanks to Rosetta, it's very likely that we're on the verge of another revolution in cometary science, where it's not the basic questions about comets that are answered, but rather the difficult ones.