The vibrations were first picked up by Rosetta's magnetometer when it was about 100 kilometers away from the planet. According to the ESA blog, the agency's scientists hypothesize that the sound might be produced by the comet as it releases neutral particles into space and becomes electrically charged. However, they still don't know the precise physical mechanism behind the oscillations.
Rosetta and Philae also took stunning images of the comet and each other. And since space travel these days is not complete without some social media sharing, here's what we got on Twitter.
Into the shadows of #67P with OSIRIS. Details & images this way: http://t.co/r99R8FLvL5 pic.twitter.com/Rouot3JYnM
— ESA Rosetta Mission (@ESA_Rosetta) November 6, 2014
Top 10 at 10 km - slideshow of my favourite close views of #67P: http://t.co/nSfju4wA0l #CometLanding pic.twitter.com/VgXU8tOIgC — ESA Rosetta Mission (@ESA_Rosetta) November 11, 2014
.@philae2014’s first postcard just after separation – it’s of me! #CometLanding Credit: ESA/Rosetta/Philae/CIVA pic.twitter.com/OXJwGunL3V — ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
I see you too @philae2014! Here you are in my OSIRIS camera - legs out! #CometLanding pic.twitter.com/hmnfe2AkN2
— ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
.@ESA_Rosetta See for yourself! ROLIS imaged #67P when we were just 3km away! Glad I can share. #CometLanding pic.twitter.com/b6mcid2fsn
— Philae Lander (@Philae2014) November 12, 2014
Now that I’m safely on the ground, here is what my new home #67P looks like from where I am. #CometLanding pic.twitter.com/gFmt8Ldvpa
— Philae Lander (@Philae2014) November 13, 2014