We here on Earth don't often get a chance to view celestial bodies that land from space. So, needless to say when the European Space Agency's Rosetta mission began orbiting Comet 67P/Churyumov-Gerasimenko earlier this summer, researchers and astronomers alike had lots of questions about the distant comet, and what others like it from our solar system's outer rim were like.
The Rosetta mission began setting records earlier this summer with the first successful orbit of a flying comet, and while it's Philae Lander may have fumbled on its way to the surface of the comet, researchers have been able to collect invaluable amounts of data describing exactly what the comet is like and what's likely to happen as it comes closer in its orbit to the sun.
Early images of Comet 67P/Churyumov-Gerasimenko described the topography of the space rock, and gave researchers a unique view of the rocky surface. But what ESA astronomers on the Rosetta space team were not expecting was that early black & white images may also be conveying the comet's truer colors.
Created by sequential snapshots of the comet, while Rosetta mission's cameras filter red, blue, and green wavelengths, a new image released this week on the ESA's mission blog reveals that the comet is even more dark and gray than they expected ever before.
"As it turns out, 67P/C-G looks dark grey, in reality almost as black as coal," mission scientist Holger Sierks of the Max Planck Institute says.
And Sierks even pointed out false images previously released in which the comet had a distinct reddish air about it. ESA researchers confirm that comet is in fact gray and dark, though explains that the red tint of the image is caused by natural phenomena that were not originally taken into consideration when compiling the image.
"This [red tint] is a well-known phenomenon observed at many other small bodies in the solar system and is due to the small size of the surface grains," the ESA spokesperson says. "That does not, however, mean that the comet would look red to the human eye.Natural sunlight has its peak intensity in the yellow part of the spectrum and the response of the human eye is similarly matched."
"Thus, overall, the comet would look rather grey to the human eye, as seen here."
While the imaging was captured up close and personal with comet 67P, ground-based telescopes have confirmed that the comet is indeed gray in color, which they discovered some weeks before the Rosetta spacecraft even intercepted the comet. And researchers now are hopeful that other hypotheses formed regarding the comet may also be proven true by Rosetta's work and the discoveries to come.
