Andromeda
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Structure round the Sun

The Local Interstellar Cloud

Also Local Fluff · LIC

Open in Ouranos

The wisp of thin, warm interstellar gas around the Solar System, which sits very close to its edge.

Measured

Distance
3.7 light-years
Size
about 8.6 light-years across (approximate)
Position (J2000)
RA 2h 09m 22s, Dec +39.84°

How far, from the Sun

About 3.7 light-years. To cross it:

  • Light3.7 years
  • Voyager 1's speed65,700 years
  • Driving at 100 km/h39.9 million years

Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.

Facts

  • The Sun lies near its edge and may leave it within the next few thousand years.
  • Its gas is about 6,300 to 7,500 kelvin but extremely thin: about 0.2 hydrogen atoms per cubic centimetre near the Sun, perhaps 0.1 across the cloud.
  • The Solar System is thought to have entered it within the past 40,000 years. Estimates run from under 10,000 to about 40,000 years ago.

Where this comes from

  • Linsky, Redfield & Tilipman 2019: geometric centre (−0.8, +0.7, −0.4) pc Galactic; radius approximate

Every catalogue Ouranos draws is credited on the credits page.