Mysterious circles appear, grow on comet
Rosetta spacecraft spotted five round depressions in June, early July
![comet circles](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/09/092415_cc_cometcircles_free.jpg?fit=860%2C460&ssl=1)
SEE SPOT GROW The first of five growing circles on comet 67P appears in a June 5 image from Rosetta (left). By June 23, two spots were spreading across the surface (center). They were joined by a third on July 2 (right).
MPS for OSIRIS Team/Rosetta/ESA, MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA