"A giant of a moon appears before a giant of a planet undergoing seasonal changes in this natural color view of Titan and Saturn from NASA's Cassini spacecraft.
Titan, Saturn's largest moon, measures 3,200 miles, or 5,150 kilometers, across and is larger than the planet Mercury. Cassini scientists have been watching the moon's south pole since a vortex appeared in its atmosphere in 2012. See PIA14919 and PIA14920 to learn more about this mass of swirling gas around the pole in the atmosphere of the moon.
As the seasons have changed in the Saturnian system, and spring has come to the north and autumn to the south, the azure blue in the northern Saturnian hemisphere that greeted Cassini upon its arrival in 2004 is now fading. The southern hemisphere, in its approach to winter, is taking on a bluish hue. This change is likely due to the reduced intensity of ultraviolet light and the haze it produces in the hemisphere approaching winter, and the increasing intensity of ultraviolet light and haze production in the hemisphere approaching summer. (The presence of the ring shadow in the winter hemisphere enhances this effect.) The reduction of haze and the consequent clearing of the atmosphere makes for a bluish hue: the increased opportunity for direct scattering of sunlight by the molecules in the air makes the sky blue, as on Earth. The presence of methane, which generally absorbs in the red part of the spectrum, in a now clearer atmosphere also enhances the blue.
This view looks toward the northern, sunlit side of the rings from just above the ring plane.
This mosaic combines six images - two each of red, green and blue spectral filters - to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on May 6, 2012, at a distance of approximately 483,000 miles (778,000 kilometers) from Titan. Image scale is 29 miles (46 kilometers) per pixel on Titan.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.Source: NASA
From a finger bone, scientists have reconstructed the genetic world of an entire population of extinct human relatives called Denisovans. But questions still abound about who exactly they were.
They weren’t quite like modern humans or Neanderthals, but some other group entirely. Everything we know about the Denisovans is based on a finger bone and two teeth.
Those small remnants, found in a cave in southern Siberia, are enough to figure out a few important things about these ancient people - including that some people today share genes with them.
For the first time, scientists have sequenced the Denisovan genome, with a quality that is about as high as the genome of a person alive today. That means scientists can learn about as much genetically about a person who lived tens of thousands of years ago as they could about a living person. The findings, published this week in the journal Science, deliver a wealth of insight about ancient people who roamed the Earth tens of thousands of years ago.
Hidden behind dust in deep space are brilliant galaxies with black holes that scientists are just beginning to learn about.
NASA’s Wide-field Infrared Survey Explorer, known as WISE, has found millions of black holes and about 1,000 dust-obscured galaxies with very high temperatures, which NASA is cutely calling "hot DOGs" for short. They are believed to be the brightest known galaxies.
Hot DOGs, which have supermassive black holes at their centers, can emit more than 100 trillion times as much light as the sun, according to researchers. But they do not appear as bright in images because they are covered in dust.
“It changes our concept of how brilliant and powerful galaxies can be,” said Peter Eisenhardt, project scientist for WISE at NASA's Jet Propulsion Laboratory. “We are finding quite a few objects here that are brighter than what we knew before, and we’ve only combed through about 10% of these hot DOGs.”