New Movie Shows Ultima Thule from an Approaching New Horizons
NASA Spacecraft Begins Returning New Images, Other Data from Historic New Year's Flyby
This movie shows the propeller-like rotation of Ultima Thule in the seven hours between 20:00 UT (3 p.m. ET) on Dec. 31, 2018, and 05:01 UT (12:01 a.m.) on Jan. 1, 2019, as seen by the Long Range Reconnaissance Imager (LORRI) aboard NASA's New Horizons as the spacecraft sped toward its close encounter with the Kuiper Belt object at 05:33 UT (12:33 a.m. ET) on Jan. 1.
During this deep-space photo shoot – part of the farthest planetary flyby in history – New Horizons' range to Ultima Thule decreased from 310,000 miles (500,000 kilometers, farther than the distance from the Earth to the Moon) to just 17,100 miles (28,000 kilometers), during which the images became steadily larger and more detailed. The team processed two different image sequences; the bottom sequence shows the images at their original relative sizes, while the top corrects for the changing distance, so that Ultima Thule (officially named 2014 MU69) appears at constant size but becomes more detailed as the approach progresses.
All the images have been sharpened using scientific techniques that enhance detail. The original image scale is 1.5 miles (2.5 kilometers) per pixel in the first frame, and 0.08 miles (0.14 kilometers) per pixel in the last frame. The rotation period of Ultima Thule is about 16 hours, so the movie covers a little under half a rotation. Among other things, the New Horizons science team will use these images to help determine the three-dimensional shape of Ultima Thule, in order to better understand its nature and origin.
The raw images included in the movie are available on the New Horizons LORRI website. New Horizons downlinked the two highest-resolution images in this movie immediately after the Jan. 1 flyby, but the more distant images were sent home on Jan. 12-14, after a week when New Horizons was too close to the Sun (from Earth's point of view) for reliable communications. New Horizons will continue to transmit images – including its closest views of Ultima Thule – and data for the next many months.
Image credits: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory
The PI's Perspective: We Did It — The Bullseye Flyby of Ultima Thule!
As I suspect everyone who follows this blog knows, on New Year's Day, the New Horizons team successfully completed the flyby exploration of an ancient Kuiper Belt object we nicknamed Ultima Thule (officially called 2014 MU69).
As a result — and for the first time — a primordial Kuiper Belt object (KBO) has been explored, and now the data have begun to rain down to Earth. A handful of images were sent back during flyby week; then we had to pause Jan. 4-9 because New Horizons, as seen from Earth, slipped into the solar corona (as it does every January), hampering communications. But on Jan. 10 the data began to flow again, and over the next several months, hundreds of images and spectra and other precious Ultima Thule datasets, now stored in New Horizons' solid-state memory, will be sent home.
There are many places to read about the results we've already obtained, but I want to summarize just a few. For a detailed overview of the first science results, see the abstract for my invited talk at the 50th Lunar and Planetary Science Conference, to be held in Houston this March. That report elaborates on several key results, including that Ultima Thule (UT)...
- is clearly a contact binary of two roughly spheroidal worldlets that gently merged billions of years ago, with much to teach us about the formation era of the planets.
- has no satellites or rings or atmosphere (at least in the early data returns).
- is clearly red, but shows little color difference between its two lobes.
- shows a variety of distinct and fascinating surface reflectivity markings, including a remarkably bright "neck" between the two lobes.
And, by the way, my report is just one of 40 abstracts that our team submitted for the conference, containing many, many more findings.
So far New Horizons has returned just 1% of all the data it gathered on Ultima Thule. It will send the rest over the next 20 months; but even by late February we'll have far more detailed geologic, color and stereo images than we have now. We'll also have more information on UT's shape and composition, and better constraints on (or maybe even detections of) moons, rings and an atmosphere.
And if that wasn't enough, New Horizons had already resumed observing distant KBOs as well as the radiation, gas and dust environment as it pushes farther into the Kuiper Belt. Notably, in March, we'll look at a KBO called 2014 PN70 — which was one of our alternate flyby targets to Ultima Thule. Don't expect PN70 to be more than a dot in those images, but they should yield valuable information on the object's rotation period, surface properties, shape and any satellites — which we'll compare to Ultima Thule.
The flyby of Ultima Thule was much more difficult for our spacecraft and mission team than the flight past Pluto. But both team and spacecraft rose to the challenge and conducted a flawless flyby, with record-accurate navigation and spectacularly successful scientific results. There were a lot of dramatic and emotional scenes around the flyby at the Johns Hopkins Applied Physics Laboratory, which built New Horizons and manages spacecraft operations. Images of a just few of those moments are shown below.
And in other news that portends especially well for our hoped-for future extended mission (beginning in late 2021) to explore still farther into the Kuiper Belt: post-flyby engineering results show that we even managed to pocket some extra fuel for future missions that we had reserved for Ultima Thule, but didn't need!
Well, that's my initial post-Ultima Thule flyby report. I plan to write again in the spring. Meanwhile, I hope you'll always keep exploring — just as we do!
PSI Scientist Anticipated "Snowman" Asteroid Appearance
Hartmann visualization of "contact binary" asteroids formed in low-velocity collisions 1978 painting (upper left), 1980 painting (upper right), 1996 painting (lower left) – compared to an image of Ultima Thule by the NASA New Horizons mission (lower right, credit NASA/APL/SWRI).
Tucson, Ariz. -- On Jan. 2, the New Horizons spacecraft made the most distant flyby ever attempted, successfully returning images of the Kuiper Belt object Ultima Thule. While the world is agog at the so-called “snowman” shape of this icy asteroid, the concept is nothing new to PSI scientist and artist, Bill Hartmann. The figure shows paintings that Hartmann made from 1978 to 1996, to illustrate the possible outcome of very low-velocity collisions of distant asteroids. These are compared with the first released color image of Ultima Thule. The story goes back 50 years.
In 1969, University of Arizona astronomers at the Lunar and Planetary Lab (“LPL”), Larry Dunlap and Tom Gehrels, noticed that as the asteroid 624 Hektor, far beyond the main asteroid belt in the region of Jupiter showed extreme changes in brightness as it rotated. In the late 1970s, Hartmann (having recently founded PSI) and Dale Cruikshank (then at the University of Hawaii), observing at 14,000-foot Mauna Kea Observatory, proved that the brightness change was not caused by one side having brighter materials, but rather by a very unusual elongated shape.
Hartmann became intrigued with how such bodies might have formed in the primordial solar system by low-velocity collisions of asteroidal bodies, from which the planets were growing. These still-theoretical bodies were called “contact binary” asteroids – “binary” meaning two bodies, and “contact” indicating that they were touching each other, instead orbiting around each other. PSI’s Stu Weidenschilling published a paper on how the shapes of the two halves of the contact binary might have their shapes distorted, depending on their bulk strengths and the rotation rate of the object.
Hartmann’s 1978 painting showed the contact binary concept with grey colors as found on the Moon. No such bodies had been seen at close range, but Hartmann wanted to depict them. “My astronomical paintings are not just flights of fancy, but a serious attempt to make something both beautiful and realistic out of what we humans have learned about other worlds,” Hartmann said. By 1980, Cruikshank and Hartmann had shown that many bodies in the outermost solar system had a dark, reddish brown color, and his 1980 and 1996 paintings added Hartmann’s estimate of how this color might look.
Ultima Thule was not only the first obvious example of a contact binary structure, but also looked strikingly like Hartmann’s 1996 visualization from 22 years ago. Hartmann happily notes that his 1978 and 1996 paintings show bright material in the “contact zone” where the two bodies collided, and sure enough, the New Horizon spacecraft photo also show bright material there. “We live in an era where scientific findings are being criticized, but if we can predict phenomena we see on other worlds, we must know something about what we are doing,” Hartmann said.
New Horizons' Newest and Best-Yet View of Ultima Thule
The wonders – and mysteries – of Kuiper Belt object 2014 MU69 continue to multiply as NASA's New Horizons spacecraft beams home new images of its New Year's Day 2019 flyby target.
This image, taken during the historic Jan. 1 flyby of what's informally known as Ultima Thule, is the clearest view yet of this remarkable, ancient object in the far reaches of the solar system – and the first small "KBO" ever explored by a spacecraft.
Obtained with the wide-angle Multicolor Visible Imaging Camera (MVIC) component of New Horizons' Ralph instrument, this image was taken when the KBO was 4,200 miles (6,700 kilometers) from the spacecraft, at 05:26 UT (12:26 a.m. EST) on Jan. 1 – just seven minutes before closest approach. With an original resolution of 440 feet (135 meters) per pixel, the image was stored in the spacecraft's data memory and transmitted to Earth on Jan. 18-19. Scientists then sharpened the image to enhance fine detail. (This process – known as deconvolution – also amplifies the graininess of the image when viewed at high contrast.)
The oblique lighting of this image reveals new topographic details along the day/night boundary, or terminator, near the top. These details include numerous small pits up to about 0.4 miles (0.7 kilometers) in diameter. The large circular feature, about 4 miles (7 kilometers) across, on the smaller of the two lobes, also appears to be a deep depression. Not clear is whether these pits are impact craters or features resulting from other processes, such as "collapse pits" or the ancient venting of volatile materials.
Both lobes also show many intriguing light and dark patterns of unknown origin, which may reveal clues about how this body was assembled during the formation of the solar system 4.5 billion years ago. One of the most striking of these is the bright "collar" separating the two lobes.
"This new image is starting to reveal differences in the geologic character of the two lobes of Ultima Thule, and is presenting us with new mysteries as well," said Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado. "Over the next month there will be better color and better resolution images that we hope will help unravel the many mysteries of Ultima Thule."
New Horizons is approximately 4.13 billion miles (6.64 billion kilometers) from Earth, operating normally and speeding away from the Sun (and Ultima Thule) at more than 31,500 miles (50,700 kilometers) per hour. At that distance, a radio signal reaches Earth six hours and nine minutes after leaving the spacecraft.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
New Horizons' Evocative Farewell Glance at Ultima Thule
Images Confirm the Kuiper Belt Object's Highly Unusual, Flatter Shape
New Horizons took this image of the Kuiper Belt object 2014 MU69 (nicknamed Ultima Thule) on Jan. 1, 2019, when the NASA spacecraft was 5,494 miles (8,862 kilometers) beyond it. The image to the left is an "average" of ten images taken by the Long Range Reconnaissance Imager (LORRI); the crescent is blurred in the raw frames because a relatively long exposure time was used during this rapid scan to boost the camera’s si'gnal level. Mission scientists have been able to process the image, removing the motion blur to produce a sharper, brighter view of Ultima Thule's thin crescent.
An evocative new image sequence from NASA's New Horizons spacecraft offers a departing view of the Kuiper Belt object (KBO) nicknamed Ultima Thule – the target of its New Year's 2019 flyby and the most distant world ever explored.
These aren't the last Ultima Thule images New Horizons will send back to Earth – in fact, many more are to come -- but they are the final views New Horizons captured of the KBO (officially named 2014 MU69) as it raced away at over 31,000 miles per hour (50,000 kilometers per hour) on Jan. 1. The images were taken nearly 10 minutes after New Horizons crossed its closest approach point.
"This really is an incredible image sequence, taken by a spacecraft exploring a small world four billion miles away from Earth," said mission Principal Investigator Alan Stern, of Southwest Research Institute. "Nothing quite like this has ever been captured in imagery."
The newly released images also contain important scientific information about the shape of Ultima Thule, which is turning out to be one of the major discoveries from the flyby.
The first close-up images of Ultima Thule – with its two distinct and, apparently, spherical segments – had observers calling it a "snowman." However, more analysis of approach images and these new departure images have changed that view, in part by revealing an outline of the portion of the KBO that was not illuminated by the Sun, but could be "traced out" as it blocked the view to background stars.
Stringing 14 of these images into a short departure movie, New Horizons scientists can confirm that the two sections (or "lobes") of Ultima Thule are not spherical. The larger lobe, nicknamed "Ultima," more closely resembles a giant pancake and the smaller lobe, nicknamed "Thule," is shaped like a dented walnut.
"We had an impression of Ultima Thule based on the limited number of images returned in the days around the flyby, but seeing more data has significantly changed our view," Stern said. "It would be closer to reality to say Ultima Thule's shape is flatter, like a pancake. But more importantly, the new images are creating scientific puzzles about how such an object could even be formed. We've never seen something like this orbiting the Sun."
The departure images were taken from a different angle than the approach photos and reveal complementary information on Ultima Thule's shape. The central frame of the sequence was taken on Jan. 1 at 05:42:42 UT (12:42 a.m. EST), when New Horizons was 5,494 miles (8,862 kilometers) beyond Ultima Thule, and 4.1 billion miles (6.6 billion kilometers) from Earth. The object's illuminated crescent is blurred in the individual frames because a relatively long exposure time was used during this rapid scan to boost the camera's signal level – but the science team combined and processed the images to remove the blurring and sharpen the thin crescent.
Many background stars are also seen in the individual images; watching which stars "blinked out" as the object passed in front them allowed scientists to outline the shape of both lobes, which could then be compared to a model assembled from analyzing pre-flyby images and ground-based telescope observations. "The shape model we have derived from all of the existing Ultima Thule imagery is remarkably consistent with what we have learned from the new crescent images," says Simon Porter, a New Horizons co-investigator from the Southwest Research Institute, who leads the shape-modeling effort.
"While the very nature of a fast flyby in some ways limits how well we can determine the true shape of Ultima Thule, the new results clearly show that Ultima and Thule are much flatter than originally believed, and much flatter than expected," added Hal Weaver, New Horizons project scientist from the Johns Hopkins Applied Physics Laboratory. "This will undoubtedly motivate new theories of planetesimal formation in the early solar system."
The images in this sequence will be available on the New Horizons LORRI website this week. Raw images from the camera are posted to the site each Friday.