Jan 1, 2019 - Science

NASA's New Horizons phones home after flyby of Ultima Thule

NASA New Horizons scientists brief the media on the Ultima Thule flyby on Dec. 31, 2018.

New Horizons scientists discuss the flyby of Ultima Thule. Credit: Joel Kowsky/NASA via Getty Images

NASA's New Horizons spacecraft phoned home on Tuesday morning, confirming that the spacecraft successfully completed the most distant flyby ever conducted of a space object. At 12:33 a.m., the craft passed within about 2,200 miles of a Kuiper Belt object known as Ultima Thule.

Why it matters: Ultima Thule, which is located about 4 billion miles from Earth, is thought to be a time capsule from the formation of the solar system itself about 4.6 billion years ago. Information from New Horizons is expected to provide researchers with new data about how planets form.

  • The flyby required scientists to stretch the capabilities of the New Horizons spacecraft to its limit. As it sped past Ultima Thule, which is about 80 times smaller than Pluto, New Horizons was traveling at about 32,000 miles per hour, while gathering data from its seven instruments on board.

The big picture: Researchers say they know a very limited amount about Ultima Thule, whose nickname means "beyond the known world." It's the first Kuiper Belt object ever to be closely explored by a spacecraft.

  • The Kuiper Belt, where Ultima Thule is located, is a region of icy bodies beyond the orbit of Neptune that are thought to be leftovers from the solar system's early days.
  • Based on imagery and other data from New Horizons' approach, scientists think it's an elongated, spinning object closely resembling a peanut. It's also thought to be reddish in color.
  • There are thought to be hundreds of thousands of objects like Ultima Thule in the Kuiper Belt, and the spacecraft will attempt to gather data on others to learn more about them, and how Ultima Thule might differ from them.

What's next: Expect to see more images and data from Ultima Thule later Tuesday and over the next 20 months. Given the spacecraft's distance from Earth, it takes about six hours for data to be transmitted one way back to Earth at 1,000 bits per second.

Go deeper: NASA is about to make space exploration history

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