The Spacecraft Tarot: New Horizons
Justice cuts a path to the truth.
In times of darkness or doubt, Justice is needed to even the scales. Justice speaks to the moral compass that exists within all of us — whether we choose to ignore it or not. With Justice in our hands, we can expect that things will be made right and true — even if we have to wait a very long time.
NASA’s New Horizons is the first and only mission to visit Pluto, and in doing so the spacecraft completed a half-century long reconnaissance quest to send probes to every planet in our solar system. After investigating the Pluto system, New Horizons ventured even deeper into the mysterious Kuiper Belt — a rich frontier for learning about comets, the solar nebula, and planet formation. Today, New Horizons wanders even farther into the unknown on a search for answer to questions about the history of the little corner of space we call home. For Justice, space and time are nothing on a quest for truth.
Pluto, beloved by many, was once considered to be the ninth planet in our solar system. We understand now that Pluto fits more neatly into a new class of worlds called dwarf planets, given that it’s even smaller than Earth’s moon.
Although Pluto is small by a planet’s standards, it is the largest member of the Kuiper Belt, a region beyond Neptune’s orbit filled with icy bodies and remnant ingredients of our ancient solar system.
Pluto is named after the Roman god for the underworld, while Pluto’s moons are named after other characters and creatures from the Greco-Roman underworld mythos: Charon, Nix, Hydra, Kerberos, and Styx. The initial purpose of the New Horizons mission was to understand how Pluto “fits in” with other objects in our solar system.
New Horizons launched aboard in Atlas V rocket from Cape Canaveral Air Force Station in Florida on January 19, 2006. After reaching Earth orbit, the upper stage of the rocket fired a second time, propelling the spacecraft to the highest launch velocity attained by a human-made object relative to Earth — 36,400 miles per hour. In February 2007, New Horizons flew by Jupiter and used the planet’s gravity to increase its speed by 9,000 miles per hour.
Even with record-breaking speeds, New Horizons took eight more years to reach its destination. On July 14, 2015, after a decade-long journey of 3 billion miles, New Horizons finally arrived at Pluto.
During its encounter with Pluto and its moons, New Horizons captured the icy system in vivid detail never before seen. The spacecraft identified geologic formations and processes on the dwarf planet, not unlike scenes from a fantasy novel: a million-square-mile nitrogen glacier in the shape of a heart, evidence of cryovolcanos that erupt ammonia-rich slush instead of lava, and dunes of methane ice blowing off mountains of water-ice.
Overall, New Horizons revealed Pluto to be an active, dynamic dwarf planet, and perhaps even an ocean world. New Horizons imagery of Pluto’s tectonic structures unveiled evidence of a liquid water ocean underneath the icy exterior. New Horizons also discovered evidence for a long-past water ice ocean on Charon, Pluto’s largest moon.
After over a year of exploring the Pluto system, New Horizons set its sights and adjusted its course toward a new destination: Ultima Thule, a Kuiper Belt object and the farthest world ever explored.
Four billion miles from Earth, Ultima Thule presented an opportunity to examine a well-preserved relic of planet formation. The shape of the object resembles a red-colored snowman, with a round “body” connected to a smaller “head.” The entire object is about 22 miles long.
New Horizons flew past Ultima Thule on January 1, 2019. Data from the New Year flyby revealed that Ultima Thule probably started as two separate objects tightly orbiting one another until they gently merged together. In addition, the intense red hue of the object is believed to be a combination of organic molecules on its surface, including methanol and water ice. This combination is not considered usual compared to other icy objects explored by spacecraft.
After reaching Ultima Thule, New Horizons has continued to probe farther into the mysteries of the Kuiper Belt.
From its unique vantage point, New Horizons is able to capture imagery of near stars that reveal the “parallax effect” — the way that stars seem to shift when seen from distant locations. There is a clear discrepancy between where New Horizons sees our closest stars and where we locate them here on Earth.
In 2020, New Horizons revealed that the interstellar medium, the no-man’s land between stars, contains 40% more hydrogen atoms than previously suggested. Because most of the interstellar particles that drift into our Sun’s influence are zapped by solar wind, we aren’t able to make the direct observations that New Horizons is afforded.
Additionally, as New Horizons journeys farther into the darkness, scientists can measure how much light the spacecraft picks up from distant galaxies compared to other spacecraft like Hubble Space Telescope. A 2021 study revealed that the previous estimate for the total amount of galaxies in the universe — 2 trillion — may not be constrained to that number.
Today, the New Horizons team continues to use telescopes to search for another potential target for the spacecraft to pay a visit. On April 17, 2021, the spacecraft reached a unique deep-space milestone: New Horizons traveled 50 astronomical units from our Sun, or 50 times the distance between the Earth and the Sun. In the meantime, New Horizons remains healthy and continues to study the Kuiper Belt environment.
As New Horizons journeys farther and farther into the unknown, the spacecraft is gathering more and more information about our universe. The search for truth is rewarding for the patient and perseverant.