To pick one example, before the landing it was discovered that the gas jets emitted by the comet interact with the solar wind to produce a unique signal: http:/

To pick one example, before the landing it was discovered that the gas jets emitted by the comet interact with the solar wind to produce a unique signal: http://www.abc.net.au/science/articles/2014/11/12/4126840.htm http://www.abc.net.au/science/articles/2014/11/12/4126840.ht... The detailed dynamics are yet to be determined, but since the comet has an orbit that takes it from as close to the sun as Earth and as far away as Jupiter, this signal should change as it travels. Or maybe it doesn't, and if so, that would be a mystery worth investigating. This is a completely unexpected discovery that enables us to study a comet's magnetic field, and how it interacts with the solar wind. Here are some possible benefits just from this one discovery: 1) The instruments necessary to even detect this signal are very impressive by themselves, developing them has probably improved a number of instrumentation technologies on Earth already. 2) The lander's instruments cannot penetrate the surface very far. The fact that this comet even has a magnetic field (however weak) is interesting. It could mean that a significant portion of the comet's interior is composed of iron, nickel, cobalt, or rare earth metals, which would be useful knowledge for people like these: http://www.cbsnews.com/news/asteroid-mining-venture-backed-by-james-cameron-google-ceo-larry-page/ http://www.cbsnews.com/news/asteroid-mining-venture-backed-b... 3) If future missions to comets find a different type of signal, which in turn leads to a different type of internal composition, the differences in a comet's magnetic field could be used to infer the composition of its interior from a distance, without sending any probes to the surface at all.