[ad_1]
Today, Pluto is known to practice five moons. His most mbadive companion, Charon, is the largest moon in the solar system relative to his parent body. This moon is so big that Pluto and Charon are clbadified as a binary planetary system. Yet, 40 years ago, scientists did not even know that Charon existed.
In 1978, James Christy used the telescope at the US Naval Observatory in Arizona to refine Pluto's orbit. On June 22, the astronomer noticed a small lump on the far side of the planet. When he looked at other pictures, he noticed that the dot was moving from one side to the other, going back and forth on Pluto's 6.39 day rotation period. He thought that Pluto possessed a natural satellite or possessed a huge mountain that rose thousands of kilometers above the surface of the planet.
Christy scanned the archives of the observatory images to measure the angle of elongation. At the same time, his colleague Robert Harrington, also at the Naval Observatory, calculated what lengthening should be if the bump was a moon. Their calculations matched, but both researchers wanted to be sure. On July 2, 1978, new images showed the lengthening right where it should be if the feature was a moon instead of a mountain. Christy and Harrington announced the discovery five days later. Decades later, the size and proximity of Charon helped send NASA's New Horizons mission to Pluto
"The importance of Charon's discovery can not really be underestimated," Alan Stern , principal investigator of New Horizons. The Southwest Research Institute in Boulder, Colorado, said in a statement.
"We, members of the New Horizons team, owe a lot to Jim Christy for his historic discovery," said Stern
Giving his wife the moon
suggesting a name to the world. International Astronomical Union (IAU). Christy wanted to name the moon after his wife. Although her full name is Charlene, friends and family call her "Char." Because he had been thinking about protons and electrons, Christy added a "-on" and submitted the new name.
Until the proposal was approved, Christy checked the dictionary. To his great surprise, he discovered that Charon was the name of the mythological smuggler who was carrying souls across the Acheron River, one of the mythical rivers surrounding Pluto's underworld. The astronomer then knew that the nickname was perfect for Pluto's mate.
"Many husbands promise their wives the moon," says Charlene Christy, "but Jim actually delivered."
Forty years after the discovery of Charon, Jim Christy holds two of the telescope images that he used to identify the largest moon of Pluto in June 1978. A close-up of the moon, captured by New Horizons, is on his computer.
Source: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute / Art Howard / GHSPi
Charon Revealed
When the New Horizons spacecraft flew to Pluto on July 14, 2015, the spacecraft revealed that Charon was an incredible world. New Horizons researchers predicted a monotonous world battered by craters. Instead, the spacecraft revealed giant mountains, vast canyons, a red polar ice cap, landslides and surface color variations.
"Even though Pluto was not there, Charon would have been a great flyover target by himself," said Will Grundy, a co-investigator of the Lowell's New Horizons science team Observatory in Flagstaff, Arizona. "It's a much more exciting world than we had imagined."
Charon is marked by a canyon four times longer than the Grand Canyon and twice as deep in several places. The faults suggest a titanic geological upheaval in the history of Charon. They also reveal clues about what goes on beneath the surface, say the researchers.
"This enormous tectonic belt tells us that Charon probably had an ocean below its surface and that the ocean froze and the ice cracked. Olkin, a scientist at the New Horizons Assistant Project of the Southwest Research Institute in Boulder, said in the statement. "This is an important discovery, especially in light of the increasing scientific interest in the oceanic worlds across the solar system."
The North Pole of Charon is colored in red. The methane gas escaping from Pluto is trapped and attracted to the pole by the gravity of the moon, where it freezes. The ultraviolet light of the sun turns methane into heavier hydrocarbons, and finally into reddish organic material known as tholins.
"Who would have thought that Pluto is a graffiti artist, painting his mate with a reddish stain that covers an area the size of New Mexico?" Grundy said:
For Jim Christy, the evolution of 40 years of our vision of Charon, from a small point attached to Pluto to a world in its own right, was amazing.
"When you get out of this little blur" You see nothing in the huge detail that New Horizons has sent back, it's amazing, "he says.
Follow Nola Taylor Redd at @NolaTRedd Facebook or Google+ Follow us on @Spacedotcom Facebook or Google+ Originally posted on Space.com
[ad_2]
Source link
