The latest images of Ultima Thule are there, and they are the sharpest yet!

On December 31, 2018, the New Horizons The probe made the first overview of the history of an object of the Kuiper Belt (KBO). About half an hour later, the mission controllers were treated to the first clear images of Ultima Thule (aka 2014 MU69). Over the next two months, the first high resolution images of the object were released, as well as some pretty interesting results regarding the shape of KBOs.

NASA has recently released other images of Ultima Thule, which are the clearest and most detailed to date! The images were taken as part of what the mission team described as an "ambitious goal," an ambitious goal of taking photos of Ultima Thule just minutes before the spacecraft gets closer. the closest possible. And as you can probably deduce images provided by NASA, mission accomplished!

The images were all obtained by the New Horizons LORRI (Long Range Reconnaissance Imager) instrument just six and a half minutes before the probe was reconciled at 12:33 pm EST (09:33 PST) on January 1, 2019. The clarity of the images is due to the combination of high resolution LORRI spacecraft – 33 m (110 ft) per pixel – and the favorable angle of view provided by the New Horizons mission team.

Before this last version, the most detailed images taken by LORRI had been acquired 30 minutes before New horizons & # 39; closest approach, when the satellite was 28,000 km (18,000 mi) from Ultima Thule. Although these provide a detailed overview of the object, the latest images allow scientists to examine the surface of Ultima Thule, as well as its origin and evolution.

Like Alan Stern, the principal investigator of New Horizons mission of the Southwest Research Institute (SwRI), as stated in a recent NASA press release, this was not a small feat

"Bullseye! The obtaining of these images asked us to know exactly where were – at any time – the smallest Ultima and New Horizons, crossing at more than 50 000 km / h in the twilight of the Kuiper belt, to a billion kilometers from Pluto. It was an observation much more difficult than anything we had attempted during our flyby of Pluto in 2015. "

The clarity of these images highlights many surface features that were not noticeable in previous ones. For example, there are bright, nearly circular terrain zones and the many dark pits near the terminator (the line marking the day-night boundary) that are now visible but not previously, thanks to the improved resolution. .

According to John Spencer, assistant scientific director of the SwRI project, the exact cause of these features remains a mystery. At present, the scientific team is trying to determine if they result from impactors, sublimation dips (surface fusion), collapse troughs (internal cavities), a combination of these factors, or something completely different. But with a clear picture, the mission team is sure to come up with some interesting theories soon.

"These" objective stretched "observations were risky because there was a real chance that we would only get some, if any, of Ultima in the narrow field of view of the camera, "added Stern. "But the scientific, operational and navigation teams have understood the situation and the result is a field day for our scientific team! Some of the details we see now on the surface of Ultima Thule do not look like anything ever explored before. "

In addition to being the most detailed images of Ultima Thule to date, these images have the highest spatial resolution of all images taken so far (or perhaps ever) by users. New Horizons mission. For example, Hal Weaver, a project scientist with Johns Hopkins' Applied Physics Laboratory, also noted that the probe's encounter with the KBO was the most accurate flyby flight ever made by a spacecraft.

When New Horizons made its historic flyby of Pluto in 2015 (the first spaceship in history to do so), it traveled 12,500 km (7,750 mi) from the surface of the planet. This allowed the spacecraft to take the first truly detailed images of Pluto's surface, which shed light on the geological history of the frozen world and the types of activities in progress.

But when flying over Ultima Thule, the New Horizons Spacecraft are approximately three times closer than Pluto, reaching a minimum distance of 3,500 km. This unprecedented precision was made possible by the ground concealment campaigns conducted in 2017 and 2018 in Argentina, Senegal, South Africa and Colombia.

The European Space Agency Gaia Observatory also provided the locations of the stars that were used during the occultation campaigns to facilitate the navigation of the mission. In the coming days, weeks, and months, the mission team will review the probe data before, during, and after its close-up approach to find additional clues about the origin and evolution of the first KBO ever. meet.

Of particular interest is whether Ultima Thule could have moons or a ringing system. In addition to detailed images of its surface features, these discoveries will help scientists learn more about this KBO, not to mention the way our solar system was formed billions of years ago and has evolved since. And in the coming years, it is hoped that another appointment with an old object will take place.

In the meantime, be sure to watch this video of new high resolution images from Ultima Thule, taken by New Horizons during its flyby, courtesy of NASA Video and the New Horizons mission team:

Further reading: NASA