http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190208
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.
See also: https://www.bbc.com/news/amp/science-environment-47187733
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New Horizons Spacecraft Returns Its Sharpest Views of Ultima Thule
The most detailed images of Ultima Thule -- obtained just minutes before the spacecraft's closest approach at 12:33 a.m. EST on Jan. 1 -- have a resolution of about 110 feet (33 meters) per pixel. Their combination of higher spatial resolution and a favorable viewing geometry offer an unprecedented opportunity to investigate the surface of Ultima Thule, believed to be the most primitive object ever encountered by a spacecraft. This processed, composite picture combines nine individual images taken with the Long Range Reconnaissance Imager (LORRI), each with an exposure time of 0.025 seconds, just 6 ½ minutes before the spacecraft's closest approach to Ultima Thule (officially named 2014 MU69). The image was taken at 5:26 UT (12:26 a.m. EST) on Jan. 1, 2019, when the spacecraft was 4,109 miles (6,628 kilometers) from Ultima Thule and 4.1 billion miles (6.6 billion kilometers) from Earth. The angle between the spacecraft, Ultima Thule and the Sun – known as the "phase angle" – was 33 degrees.
[...] Project Scientist Hal Weaver, of the Johns Hopkins Applied Physics Laboratory, noted that the latest images have the highest spatial resolution of any New Horizons has taken – or may ever take – during its entire mission. Swooping within just 2,200 miles (3,500 kilometers), New Horizons flew approximately three times closer to Ultima than it zipped past its primary mission target, Pluto, in July 2015.
This was from about 6,628 km away rather than the 3,500 km of the closest approach. Will we get to see ~17.5 meters per pixel from the moment of the flyby (about 4 times the quality)?
Previously: New Horizons Departing View of Ultima Thule Reveals Flattened Shape
(Score: 1, Interesting) by Anonymous Coward on Monday February 11 2019, @05:14PM (7 children)
Why are so many of these objects shaped like dumbbells?
(Score: 1, Informative) by Anonymous Coward on Monday February 11 2019, @05:19PM (5 children)
That's part of how matter coalescences. It's two smaller objects that came in contact with each other gently enough to not destroy each other. Just look at how many binary objects exist in the universe and it shouldn't be so surprising that smaller objects can be binary as well.
But, IANAAstrophysicists
(Score: 0) by Anonymous Coward on Monday February 11 2019, @05:35PM (4 children)
I would expect there is only a very small window of velocity that would allow this though. Wouldn't it be much more likely for them to bounce off or obliterate each other?
(Score: 1, Interesting) by Anonymous Coward on Monday February 11 2019, @06:07PM
There is still a gravity component of about .002 m/s^2 at their surfaces of the major axis, so that even if they bounce off each other the first time, there is an opportunity for them to eventually achieve equilibrium as two objects bound by a small gravitational force. The velocity vectors of their original approach relative to each other determines what the behaviour would be.
(Score: 2) by JoeMerchant on Monday February 11 2019, @07:18PM (2 children)
Take the total number of objects observed vs the number observed to be dumbell shaped, for local conditions I'd say that's your likelihood, and it is on the rare, but not impossible, side. Sort of like planets with showy rings.
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Monday February 11 2019, @08:24PM (1 child)
It seems like every single one they send a probe to has a dumbbell shape.
(Score: 1) by anubi on Tuesday February 12 2019, @03:36AM
Is it spinning?
Maybe centrifugal force is at play like a disk of pizza dough?
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2, Funny) by Anonymous Coward on Monday February 11 2019, @06:27PM
Presumably the nearest alien civilization has genitalia shaped like dumbells--it is the only logical explanation.