A team of Southwest Research Institute researchers helped make history this week by releasing images of the most distant object ever explored.
Nicknamed Ultima Thule, the snowman-shaped figure is about 4.5 billion years old. Formed at the dawn of the solar system, the newly explored world could hold the answers to questions that have stood since the beginning of time, scientists say.
"It's an exciting object to fly by because it has implications for how the solar system formed," said Randy Gladstone, mission co-investigator, who leaves the John Hopkins University Applied Physics Laboratory in Maryland to return to San Antonio on Saturday.
The flyby was conducted as part of NASA's New Horizons mission, which began in 2006, flew past Jupiter in 2007, and reached the closest exploration of Pluto in 2015.
Ultima Thule is in the Kuiper Belt, a region beyond the orbit of Neptune that includes Pluto and is the highest priority of solar system exploration, according to the National Academy of Science.
Planets and dwarf planets, such as Pluto, were assembled out of smaller objects like Ultima Thule, which are many throughout the solar system. Not only does Ultima Thule provide an example of similar planetary objects – with its color, shape, and rotation rate – it can provide a window into what the solar system was like during its inception, Gladstone said.
"The nice thing about it is we think it's very pristine – nothing much has happened to it," he said. "It's a primordial object. It's had a very boring existence. It's been circling around the sun at the same distance where it formed."
Gladstone said the distance between Ultima Thule and the sun is about 43 times greater than the distance between Earth and the sun.
Because of its small size – the object is 19 miles from end to end – observing it from Earth with telescopes provides little information. The images released Wednesday are taken from as close as 17,000 miles.
Even then, capturing images of Ultima Thule was tricky, Gladstone said. New Horizons is traveling in excess of 35,000 mph, at least 60 times faster than a commercial airliner.
"This is a very tiny object, we're moving very fast," he said. "So it's like you're zipping along the freeway, and you're trying to take a picture of a bug crawling along the side of the road when you're going by it at 70 mph."
Data will continue to stream into NASA at 1,000 bits per second, a "slow trickle" because of how distant the spacecraft is, Gladstone said. In the weeks ahead, New Horizons scientists will receive images with 10 times better resolution than the more detailed images released Wednesday. In earlier images, the picture was blurry, and the object looked closer to a bowling pin than a snowman. New data will continue to come in for the next 20 months.
"[When the new images come in] the geologists get different viewing angles where they see more shadowing and could look for craters," he said. "Right now we only have images from where the sun was right overhead, and it doesn't give you much shape information. The geologists are very impatient to see the later images."
New Horizons will continue past Ultima Thule and out of the solar system. Like the Voyager spacecraft before it, it will cross the boundary of the solar system, known as the heliopause, and into the interstellar medium.
"We will be getting data from New Horizons to tell us about the space environment out there for the next decade or two," Gladstone said. "We hope."
In the early hours of New Year’s Day, @NASANewHorizons flew past #UltimaThule, an object located in a region of primordial objects 1 billion miles past Pluto. Join us live from @JHUAPL today at 2pm ET as we explore the latest science from the spacecraft: https://t.co/oJKHgKpQjH pic.twitter.com/6IMiS0XGNt
— NASA (@NASA) January 2, 2019