The discovery, made using amateur telescopes, could give researchers a better understanding of how planets evolve.

The findings: You don’t need anything fancy to make discoveries in space. Using just two 28-centimeter telescopes on the roof of a building, researchers from the National Astronomical Observatory of Japan have discovered the first Kuiper Belt object with a radius between one and 10 kilometers. It measures just 2.6 kilometers in diameter. This may seem like an oddly specific thing to be celebrating, but objects like this can provide important clues about how planets are made.

Way out there: The Kuiper Belt is filled with a mix of items, likely left over from the solar system’s formation, that reside beyond Neptune’s orbit. Probably the most famous Kuiper Belt object: Pluto.

Why are we just finding the first one? Objects this size aren’t very bright, and that makes them incredibly difficult to pick up, even with powerful telescopes. So rather than looking for it directly, the research team spotted it using occultation, a technique in which you watch for objects moving in front of a number of stars. When the object passes in front, it blocks out some of the light the star emits. To find this one item, the two amateur telescopes watched 2,000 stars for 60 hours.

Why it matters: While scientists expected objects of this size to exist, this confirmation—outlined in Nature Astronomy—supports models predicting that small planets began as kilometer-size objects before their growth took off.

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