New Images Offer An Never-Before-Seen Look At A Comet

New detailed images of the Rosetta spacecraft's host comet shows dune-like ripples and gas jets rising from pits on the surface.

The photographs were released Thursday by the European Space Agency (ESA) and Rosetta's initial observations of Comet 67P/Churyumov-Gerasimenko are outlined in a series of articles published in a special issue of the journal Science.

Last August, Rosetta became the first spacecraft to rendezvous with a comet, after a 10-year journey. Over the next year, the spacecraft will hang with the comet as it travels around the sun.

In November, a probe named Philae was deployed onto the comet's surface. Due to a slight hiccup during landing, however, the probe bounced off in the wrong direction when it landed. Researchers at the ESA have a pretty good idea of where Philae is, but because of how the probe landed, it wasn't able to recharge it's batteries using sunlight and died after a few days.

The results published this week are based on measurements from Rosetta while approaching the comet and shortly after she arrived in August 2014.

Comet 67P has two lobes. Here's a section of the smaller lobe taken in October from a distance of about 8 kilometres (5 miles) to the surface. Each pixel represents 15 centimetres.

Scientists identified 19 regions on Comet 67P/Churyumov-Gerasimenks, which are separated by distinct boundaries. The regions are named after Egyptian gods. The regions are grouped into five basic types of terrain: dust-covered (Ma'at, Ash, and Babi); brittle materials with pits and circular structures (Seth); large-scale depressions (Hatmehit, Nut, and Aten); smooth terrains (Hapi, Imhotep, and Anubis); exposed, rock-like surfaces (Maftet, Bastet, Serqet, Hathor, Anuket, Khepry, Aker, Atum, and Apis).

Comets are made of ice, dust, rock. When comets get close to the sun, the heat causes the ice to vaporise. The gas that escapes tends to drag dust across the surface, creating "dune-like ripples" (left image). On the right, boulders have stopped the direction of the gas flow, creating "wind tails" (right image), or streaks of material downwind from it, the ESA explains.

Rosetta also spotted pits in the comet's Seth region from which gas appears to rise.

An enhanced contrast image of the same active pits shows fine structures in the pit's shadows. Scientists interpret these as "jet-like features rising from the pit."

A bright patch indicates a small patch of ice in a larger, dust-covered area.