February 23rd, 2019
A dangerous maneuver by the New Horizons group geared toward acquiring closeup, very excessive decision pictures of Ultima Thule’s floor simply earlier than the spacecraft’s closest method has succeeded, revealing that floor in unprecedented detail.
The pictures, captured by the Lengthy Vary Reconnaissance Imager’s (LORRI) telephoto lens simply six-and-a-half minutes earlier than closest method, from a distance of simply 2,200 miles (three,500 kilometers), have a decision of roughly 110 toes (33 meters) per pixel. They’re the most recent to be returned by the spacecraft.
Taken as New Horizons was rushing towards Ultima Thule at 32,000 mph (51,000 kph), the pictures present considerably extra floor element than these beforehand returned by the spacecraft, together with vivid round areas and small darkish pits close to the terminator that divides the KBO’s day and evening sides.
Understanding the challenges of acquiring such sharp pictures because the probe sped by, mission scientists described their plans to acquire them as a “stretch objective,” one thing fascinating however dangerous, with questionable probabilities of success. The trouble did profit from the spacecraft having been in a positive viewing angle and LORRI’s excessive spatial decision.
“Getting these pictures required us to know exactly the place each tiny Ultima and New Horizons had been—second by second—as they handed each other at over 32,000 miles per hour within the dim mild of the Kuiper Belt, a billion miles past Pluto. This was a a lot harder commentary than something we had tried in our 2015 Pluto flyby,” New Horizons Principal Investigator Alan Stern of the Southwest Analysis Institute (SwRI) in Boulder, Colorado, stated in a press launch.
New Horizons needed to fly 3 times nearer to Ultima Thule than it did to Pluto to acquire these pictures. The complete encounter was more difficult than the Pluto flyby as a result of Ultima Thule is far smaller than Pluto and is a billion miles farther from the Solar. Moreover, the spacecraft is three years older than it was at Pluto and incorporates much less gas than it did three years in the past.
A number of profitable ground-based observations of Ultima Thule occulting particular person stars in 2017 and 2018, seen from Argentina, Senegal, South Africa, and Colombia and assisted by the European Area Company’s (ESA) Gaia observatory, which supplied knowledge on the areas of stars used to look at the occultations, made the extraordinarily exact navigation wanted to acquire these newest pictures doable.
“These ‘stretch objective’ observations had been dangerous as a result of there was an actual probability we’d solely get half and even none of Ultima within the digicam’s slender filed of view,” Stern stated. “However the science, operations, and navigation groups nailed it, and the result’s a subject day for our science group. A number of the particulars we now see on Ultima Thule’s floor are in contrast to any object ever explored earlier than.”
Science group members are finding out these newest pictures in an try and discern what brought about the craters and pits on probably the most distant and primitive photo voltaic system object ever explored by a spacecraft.
“Whether or not these options are craters produced by impactors, sublimation pits, collapse pits, or one thing totally totally different, is being debated in our science group,” stated deputy mission scientist John Spencer, additionally of SwRI.
Utilizing 9 particular person high-resolution pictures, mission scientists created a composite picture during which Ultima Thule’s varied floor colours and textures are clearly seen. In addition they put collectively a really temporary film by combining 14 separate pictures, depicting the KBO passing by as seen from New Horizons.
All uncooked pictures returned by LORRI, together with those used to create the composite, are posted to the instrument’s website each Friday for public viewing.
Video courtesy of NASA
Laurel Kornfeld is an beginner astronomer and freelance author from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass Faculty, Rutgers College, and earned a Graduate Certificates of Science from Swinburne College’s Astronomy On-line program. Her writings have been revealed on-line in The Atlantic, Astronomy journal’s visitor weblog part, the UK Area Convention, the 2009 IAU Normal Meeting newspaper, The Area Reporter, and newsletters of varied astronomy golf equipment. She is a member of the Cranford, NJ-based Newbie Astronomers, Inc. Particularly within the outer photo voltaic system, Laurel gave a short presentation on the 2008 Nice Planet Debate held on the Johns Hopkins College Utilized Physics Lab in Laurel, MD.