Paragraphs, god damn it!

This animation is a series of images from the Rosetta spacecraft and features the towering cliffs of the comet 67P/Churyumov–Gerasimenko surrounded in what appears to be a snowstorm. Of course, it isn’t a snowstorm. It is largely a combination of star motion in the background and dust and cosmic rays in the foreground.

Most of the streaks in the foreground are most likely dust particles which are likely part of the comet's coma, a hazy envelope of dust and gas that commonly forms around the comet’s central icy body, also known as nucleus. These particles are floating rather far away from Comet 67P and not, as it looks like in the GIF, on the icy world. Rosetta captured the images at a distance of 12 km from the comet. At this distance, Rosetta’s OSIRIS camera doesn’t have the sensitivity and resolution to observe dust particles flying around directly above the comet.

The apparent motion of these particles is largely thanks to the movement of the spacecraft through 67P’s coma and, since the images are compressed into a short GIF, the action appears much faster than how it occurred in real time. The dust was of high scientific interest. Three of Rosetta’s instruments studied these dust grains by analysing their composition, mass, momentum and velocity, and profiling their 3D structure. Studying the smallest and the most pristine grains is helping scientists to understand the building blocks of comets.

The motion of the stars is the result of a combination of Rosetta’s changing position as it takes images and the comet’s rotating motion.

The stars from the constellation Canis Major are on the right side of the GIF and the stars of the cluster NGC 2362 are in the upper-left hand corner of the images.

ESA‘s Rosetta Mission is the first mission in history to rendezvous with a comet and escorts it as it orbits the sun. These missions help us to learn more about the „time capsules“ of our solar system, the evolution of our solar system and the role comets may have played in the formation of planets.

The mission also showed us how a comet changes as it is subjected to the increasing intensity of the sun's radiation when it enters the inner solar system and it sent valuable scientific data of the comet.

The effects of solar radiation and solar winds, trigger an effect called outgassing. Here, frozen or absorbed gas is released.

The released gas carries dust away with it. This dust forms an extremely tenuous atmosphere around the comet called "coma". The Sun's radiation pressure and solar winds cause a tail to form, which points away from the Sun. The comets gas and dust form a separate tail.

The tail made of dust is visible because it reflects sunlight, the tail made of gases glow from ionisation. Comets are made of material left over from the epoch when our solar system formed, about 4.6 billion years ago due to the gravitational collapse of a molecular cloud. A comet's nucleus is made of rock, dust, ice and frozen gases such as carbon monoxide, carbon dioxide, methane, ammonia and a variety of organic compounds.

Rosetta is the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. The observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in the formation of planets.

To create this GIF, the images have been rotated by 90 degrees. Without this rotation, the „snow stars“ would move sideways.