Jun 9, 2020 - Science

Titan is drifting away

Titan in front of Saturn and its rings.

Titan in front of Saturn and its rings. Photo: NASA/JPL-Caltech/SScI

Saturn's largest moon, Titan, is drifting away from the ringed planet far faster than scientists initially thought.

Why it matters: The discovery could help researchers figure out exactly how old Saturn's system of rings and moons might be.

Details: The new research suggests that Titan likely formed much closer to Saturn than initially thought before migrating out to where it orbits today.

  • The moon is moving away from Saturn at a rate of about 4 inches per year, about 100 times faster than expected, according to a study in the journal Nature Astronomy.
  • A moon's gravity pulls ever so slightly on the planet it orbits, making the world temporarily bulge out.
  • "Over time, the energy created by the bulging and subsiding transfers from the planet to the moon, nudging it farther and farther out," NASA said in a statement.

Between the lines: The new finding pokes holes in some long-standing theories explaining how moons drift away from their planets.

  • Earlier hypotheses suggested moons like Titan, which orbit relatively far from their planets, drift away more slowly than inner moons, which are closer to their planet's gravity.
  • The new study is evidence that these outer moons can still move at a quick clip as they drift away from their planets.

The big picture: Titan isn't the only moon drifting from its home planet. The Moon is also slowly moving away from Earth at a rate of about 1.5 inches per year.

Go deeper: Saturn's rings may be more ancient than previously thought

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