With NASA’s New Horizons spacecraft being just over 80 hours away from its historic rendezvous with Pluto, the intrepid robotic explorer has started to return its first detailed views of the dwarf planet’s fascinating geology. Meanwhile, a host of other planetary probes and space observatories that are situated across the Solar System will be weighing in the ongoing study of the distant world in the following weeks and months as well, providing important long-range observations that will complement the treasure trove of data that New Horizons will be beaming back during its brief close-up visit of the Pluto system.
The latest black-and-white image that was released by the New Horizons’ science team on July 10 was taken by the onboard Long Range Reconnaissance Imager, or LORRI, a day earlier, while the spacecraft was approximately 5.4 million km away from Pluto. From this distance, the New Horizon’s imaging resolution is 27 km/pixel, which is high enough for scientists to get their first detailed glimpses of the planet’s wide variety of geologic features and its now famous high-contrast terrain, including an intriguing region know as the “whale’s tail,” which is located at the hemisphere of Pluto that always faces its biggest moon Charon and was first imaged a few days earlier, creating quite a buzz among scientists and space enthusiasts alike. “We’re close enough now that we’re just starting to see Pluto’s geology,” says Dr. Curt Niebur, New Horizons program scientist at NASA’s Headquarters in Washington, D.C. “It’s a unique transition region with a lot of dynamic processes interacting, which makes it of particular scientific interest.”
Staying true to the long-standing tradition of unexpected surprises that await us with every new planetary science mission to a previously unexplored world, this latest image by New Horizons is revealing Pluto as an active and fascinating world in its own right, full of unique characteristics that set it apart from all the other members of our Solar System’s planetary family. Even though the detailed interpretation of what is currently seen on Pluto will have to wait just a little longer as the New Horizons covers its last remaining few million kilometers prior to its close flyby on July 14, when the spacecraft will be returning its best ever views of the planet’s surface, the mission’s science team is already enthusiastically pouring over the images that have been beamed back so far in order to get a better appreciation of the Pluto’s tantalising terrain. “Among the structures tentatively identified in this new image are what appear to be polygonal features; a complex band of terrain stretching east-northeast across the planet, approximately 1,000 miles long; and a complex region where bright terrains meet the dark terrains of the whale,” says Dr. Alan Stern, principal investigator for New Horizons at the Southwest Research Institute, in Boulder, Colo. “After nine and a half years in flight, Pluto is well worth the wait.”
Not to be outdone, a host of other spacecraft and space-based observatories have been also tasked by NASA to join in humanity’s first, historic close-up exploration of the Pluto system. One of them, the intrepid Cassini orbiter, which has been studying Saturn and its assortage of moons with great success for more than a decade, will briefly turn its electronic eyes toward Pluto in the following days in order to do complementary observations of the distant dwarf planet from its unique vantage point around Saturn, just as New Horizons will be making its close flyby of Pluto.
“The Cassini team has been pleased to provide occasional imaging support for New Horizons for several years to aid with the Pluto-bound spacecraft’s navigation,” says Dr. Earl Maize, project manager for the Cassini mission at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It’s great to provide one last look at [New Horizons] soars through the Pluto system.”
Another set of different long-range observations of Pluto are expected as well, courtesy of the Kepler space spacecraft, which is placed in an Earth-trailing heliocentric orbit around our home planet. Kepler, which has already made history by discovering thousands of extrasolar planets ever since it was launched in 2009 and is now on an extended mission called K2, will gaze steadily at Pluto for three months beginning in October, in much the same way that it has done while hunting for alien worlds around other stars. This time, though, instead of studying starlight, Kepler will be studying the Sun’s reflected light off Pluto and Charon in order to detect any brightness variations which could yield important insights to the atmospheric dynamics of the double-planet pair. “K2 observations will expand the time coverage of the speedy New Horizons’ flyby of Pluto, making observations of the dwarf planet-moon system every 30-minutes,” says Dr. Steve Howell, project scientist for the Kepler/K2 mission at NASA’s Ames Research Center in California. “We are excited to turn the planet-hunting Kepler spacecraft’s attention to this distant solar system object to provide additional scientific insight into this far off, mysterious world, itself a miniature solar system of five moons in orbit about Pluto.”
Additional observations of the Pluto system will come from NASA’s Spitzer Space Telescope as well, another one of NASA’s space observatories which is also placed in an orbit similar to Kepler’s. With its unique observing abilities at infrared wavelengths, Spitzer will begin a seven-day study of Pluto at 18 different longitudes beginning July 23, which might uncover the presence of volatile materials on the distant world that might have been missed by previous observations. “Spitzer is around 4.8 billion km from Pluto,” explains Noemi Pinella-Alonso, a postdoctoral student at the University of Tennessee in Knoxville, who will be leading this Pluto observing campaign by Spitzer. “The spacecraft provides an effective tool to study the ice on the surface and search for other materials that have not yet been identified.”
Even from such great distances, such studies of the Pluto system are proving to be of great importance to astronomers, as evidenced by the recent observations of the enigmatic dwarf planet with NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, late last month. While New Horizons will be making its close passage through the Pluto system returning high-resolution images of unprecedented detail along the way, these long-range observations by NASA’s various space telescopes will give scientists a one-in-a-lifetime opportunity to study the mysterious world from many unique vantage points across the Solar System at the same time, thus helping to maximize New Horizons’ science output. “NASA is aiming some of our most powerful space observatories at Pluto,” says Dr. Paul Hertz, director of the Astrophysics Science Division at the agency’s headquarters in Washington, D.C. “With their unique capabilities combined, we will have a multi-faceted view of the Pluto system complementary to New Horizons data.”
Stay with AmericaSpace for regular updates and LIVE COVERAGE of New Horizons’ approach and flyby of the Pluto system.Missions » New Horizons »