Scientists have unlocked clues about the earliest forms of life on Earth by studying fossils found across our planet. Similarly, we’re now learning more about the earliest formation of our solar system from a different kind of fossil – a Kuiper Belt Object (KBO) known as 2014 MU69. 

Travel back in time to the solar system’s very beginning. There, two objects were formed that eventually came together in a body resembling a flattened bowling pin. When looking at the object from the vicinity of the Earth, which is 4 billion miles (6.4 billion km) away, MU69 looked like a point of light, even when using the powerful Hubble Space Telescope. But thanks to the New Horizons spacecraft, this is what it looked like on New Year’s Day, 2019, from approximately 4,100 miles (6,600 km) away, about 7 minutes before the spacecraft’s closest approach.

New Horizons is a grand piano-sized spacecraft that was launched back in 2006, with the undertaking of exploring the Kuiper Belt – that donut-shaped disc of space that begins just beyond the orbit of Neptune. Dwarf planet Pluto and its largest moon Charon reside in the Kuiper Belt, as do over 100,000 KBOs. MU69 was discovered by the New Horizons team, and was found to be located in the neighborhood of New Horizons’ trajectory when the spacecraft reached the Kuiper Belt in 2015. Its location led to its selection as a flyby target.

New Horizons Project Scientist Hal Weaver, of the Johns Hopkins Applied Physics Lab, notes three wondrous impressions about this 22 mile (35 km) long primeval object.

“First, this is the most primitive object ever encountered by a spacecraft. By that I mean the least changed since the time of the solar system’s formation.”

“Second, the shape of MU69’s body is giving us new insights into how planets formed. Scientific hypotheses change as New Horizons delivers new data. Until we saw it up close, we didn’t know for sure if MU69 was a single object or two distinct pieces. Now we know it’s actually composed of two distinct pieces – a large, flat lobe and a smaller, rounder lobe, that have merged into one entity. This fusion gives us clues regarding the initial steps that were taken to form a planet.”

“Third, the flyby showed MU69’s red color – redder even than Pluto – and we believe that this may come from organic material – the same material that may have contributed to the origin of life on Earth.“

Fossils of once-living things on Earth convey vital clues about the past. In space, KBOs can also convey fossil-like clues – about 4.5 billion years’ worth of solar system history. Scientists are poring over the information they’ve received so far, and the data transmissions from the MU69 flyby will continue through the late summer of 2020. In the meantime, New Horizons is traveling farther into the Kuiper Belt at about 31,500 miles (51,000 km) per hour. The spacecraft is now observing additional KBOs and exploring the region’s concentration of charged particle radiation and dust within the Kuiper Belt.  

To discover more about our solar system’s earliest times, visit science.nasa.gov