Despite having still one month to go before NASA’s New Horizons spacecraft executes its historic close flyby of Pluto on July 14, and with the spacecraft currently located more than 30 million km away from its ultimate destination, Pluto has nevertheless started to slowly reveal more of its surface features in the series of latest images that have just been released from the mission’s science team.
As described in AmericaSpace’s previous mission update, New Horizons is currently in the middle of its second of three Approach Phases to the Pluto system. Covering more than 1 million km with each passing today toward reaching its target, the intrepid robotic explorer has started sending back images of Pluto and its assortage of moons at regular intervals, ever since it was awakened from its final hibernation period in early-December of last year. With anticipation and excitement running high among scientists and the general public alike, everyone has been eagerly anticipating to see what this mysterious world in the outer reaches of the Solar System actually looks like. Now, with just over five weeks remaining before the day of closest approach, New Horizons has provided our first treat of what’s to come, by returning images which reveal a tantalising set of brightness variations of very bright and dark patches across the surface of Pluto which hint at very interesting and diverse geological features on the surface of the distant world.
“Even though the latest images were made from more than 30 million miles away, they show an increasingly complex surface with clear evidence of discrete equatorial bright and dark regions—some that may also have variations in brightness,” says Dr. Alan Stern, Principal Investigator for the New Horizons mission at the Southwest Research Institute, in Boulder, Colo. “We can also see that every face of Pluto is different and that Pluto’s northern hemisphere displays substantial dark terrains, though both Pluto’s darkest and its brightest known terrain units are just south of, or on, its equator. Why this is so is an emerging puzzle.”
This latest series of raw images was taken by the New Horizon’s onboard Long Range Reconnaissance Imager, or LORRI, between May 29 and June 2, when the spacecraft was at a distance between 55 and 50 million km away from Pluto respectively. At this distance, the images had to be enlarged and extensively processed with the help of a deconvolution technique in order for the finer details to stand out, which in turn has introduced several image artifacts in the final result that make Pluto appear as having a potato-like shape instead of its real round one. Furthermore, the deconvolution technique that was used to sharpen the original raw images might have also introduced certain artifacts that could have been mistakenly interpreted as surface features on Pluto, thus requiring a more close-up, detailed imaging in order for the mission’s team to determine what is actually a real feature on the distant world and what is the product of image processing. Nevertheless, these latest images are already detailed enough for scientists to start deciphering Pluto’s surface geology.
On June 23, New Horizons will transition to Approach Phase 3, which will last until the time of closest approach of Pluto on July 14. This final approach phase prior to the long-awaited close flyby of Pluto will also mark the time when the spacecraft will be returning images of Pluto with a resolution that will be far superior to those taken with the Earth-orbiting Hubble Space Telescope and will only get better with each passing day.
“We’ve seen evidence of light and dark spots in Hubble Space Telescope images and in previous New Horizons pictures, but these new images indicate an increasingly complex and nuanced surface,” says Stern. “Now, we want to start to learn more about what these various surface units might be and what’s causing them. By early July we will have spectroscopic data to help pinpoint that.”
As these events unfold, NASA will be making sure that everyone will be along for the ride, through a multitude of media coverings that will broadcast on NASA TV and on the agency’s website and various social media pages. Contrary to popular belief, during the day of closest approach, on July 14, New Horizons will be too busy taking images that it will not communicate much with Earth, besides sending an all-too-critical signal tone that it has safely survived its close passage through the Pluto system. Being more than 4.5 billion km away from Earth at the time of closest approach, and with radio signals taking more than 4 hours to traverse interplanetary space while traveling at the speed of light, this important signal check will be received on 9:02 p.m EDT, on July 14. Most of the images of the Pluto system that New Horizons will have taken up to that point will be slowly transmitted back to Earth in the weeks and months following the day of closest approach, save for a set of black-and-white LORRI images that will be made publicly available almost in real-time. Even so, the breath-taking views of the never-before-seen planetary vistas of Pluto and Charon that will be revealed in this small set of images during closest approach are sure to keep scientists and the public engaged and fascinated enough, before the steady stream of data from New Horizons will start pouring in the weeks and months following humanity’s first historic flyby of an exciting and utterly mysterious planetary frontier.
As for what everyone will see in these images, speculation aside, in reality is anybody’s guess. “You’ll get the same answer that everybody has gotten from me for almost 20 years,” comments Stern on the subject. “I don’t make predictions, except for one: my best guess is we’re gonna find something wonderful!”
Whatever wonders Pluto may hide, we’re just one month away from finding out.
Stay with AmericaSpace for regular updates and LIVE COVERAGE of New Horizons’ approach and flyby of the Pluto system.
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