The Rosetta mission is to find a regular model of different blue and red tones of the comet 67P when it travels close to and then far from the sun. The space ship of the European space agency-ES Rosetta was the first to orbit the comet when it circled the comet 67p/ Churymov-Gerasimenko from 2014 to 2016. The glimpse from a near distance of 67 by Rosetta, gave an unprecedented chance to scientists to get to know what are those small, ice realms. A team of explorers unlocked one of the secrets of the comet. While the comet was getting near around the sun, clouds of gas and dust were curving and settling, surrounds the comet in a fog of changing colors, visible only for the telescopes.
Different parts of the comet are prone to reflect different colors and light, depending on where the comet is. In its orbit, the explorers found out that the season-cycles of dust and ice on the comet causing those changes in color. The astronomers representing their new discoveries in the article, published on Wednesday in “Nature”.
Comet changing’s colors.
A team of explorers, lead by Janarico Filcachone from the National Institut of Astrophysics (INAF), in Italy, analyzing the observation of comet 67P from the instrument VIRTIS by Rosetta. VIRTIS measuring the light, that the comet reflects in different colors, allowing the scientist to understand what chemical compounds are inside.
The explorers examined more than a year of VIRTIS data and concluded that the size of the wave or colors of the light, reflected by the comet, is changing when the comet is getting closer to the sun. When the comet gets closer to the nearest point of the sun, the atmosphere or coma of the comet getting bright red color, the coma of the comet looked bluer, while the core became redder. The cycle of Ice and dut: With detailed analysis and computer simulations the explorers decided that the change of the color is cast down to dust and ice. Water ice has the tendencies to reflect brighter light, while the dust grains, made from carbon and organic compounds, reflect more reddish light.
When the comet gets closer to the sun’s orbit, the sunbeams heating the comet and lifts a lot of sand grains from the surface of the comet’s coma. That makes the comet looks more reddish, while the removal of the dust from the core, reveals more ice on the surface, which makes it look bluer. The process reversed when the comet was in the part of its orbit when it moves away from the sun: the dust settled back on the core, which makes the core look redder. The particles, lifted and the core in this part of the orbit, usually are richer in water ice, which makes the coma bluer. The capture of those simultaneous changes as in the coma, as in the core of the Comet 67P would no be possible with an observation from the Eath, says Filkanchinoe in the email. But sending a spaceship to the point of view in the orbit of the comet, the scientist gathered clear picture of this ice world than it ever been.