The photos that came from NASA’s Pluto space explorer are still fuzzy, but they show a striking fact about the unexplored ice world: it has a different color than its satellite in orbit, Charon.
Images from New Horizons, which are currently 15 million miles from their target, demonstrate that Pluto is orange-beige and Charon is gray.
“Scientists are thinking about what this can mean,” said Lisa Hardway, camera manager for New Horizons, director of Discovery News. "They expected the two objects to have the same composition, but this was not the case."
Even before the difference in color, it was known that some scientists suggested that Charon collected garbage from space, which was formed after a collision with Pluto. A similar event is considered to be the cause of the formation of the Moon - the Earth satellite.
Charon, which was discovered in 1978, has half the size of Pluto and has enough mass to be in the same orbit with a partner, and this is the only known pair in the Solar System. Like the moon, one side of Charon is constantly confronted with the parent organism, a configuration known as tidal blockage. But Charon does not rise in the sky above Pluto, appearing in the same place.
Like the gas giant Uranus, Pluto and Charon rotate slightly tilted to one side with respect to the sun, and this is possible evidence of a massive impact.
Among the secrets that New Horizons must decide is the following: does Pluto’s atmosphere reach Charon and surround it?
Computer models, beginning in the late 1980s, show that particles emanating from Pluto’s atmosphere must orbit Charon. This was announced by lead researcher Alan Stern of the Southwest Research Institute in Boulder, Colorado.
"Charon's gravity could pull some of these atmospheric gases into orbit around it, or even to the surface of Charon, where a secondary atmosphere was created," said Stern. "We watch it very closely."
"It would be great if we found something like this," he added. "Never in the history of the exploration of the planets did we see two bodies with a general atmosphere, as we can see in the Pluto system. It can be quite wonderful." The images published on Monday show a clear and inexplicable dark area at the north pole of Charon.
"Both bodies have different dark and light spots on their surface, which indicates a variety of landscapes. Bright fringe on Pluto, for example, may be an area where cold is formed from the polar cap that evaporates now, during summer on Pluto," Jeff Moore, a scientist at NASA Ames Research Center in California.
New Horizon scientists will see Pluto and Charon in infrared light for the first time this week. On July 14, the spacecraft, which has been flying in the solar system for more than nine years, plans to go quite close to Pluto and its surroundings from the moons.
