Original project · 2026

Complete star-system information

K2-18

A red-dwarf system containing the atmosphere-rich sub-Neptune K2-18 b.

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Host starK2-18

M-type red dwarf

Distance from EarthApprox. 124 light-years

One-way light time: 124 years

Worlds listed here1

1 catalog candidates flagged for habitability discussion.

Communication round trip248 years

Before any scientific processing or response delay.

System architecture

K2-18

Star typeM-type red dwarf
ArchitectureA compact system containing the transiting sub-Neptune K2-18 b and additional planetary evidence.
How it is observedTransit spectroscopy allows atmospheric measurements unavailable for most smaller candidates.
Research importanceK2-18 b is a major atmosphere target, but it is not confirmed to have an inhabited or Earth-like surface.
Main uncertaintyInterior, ocean, clouds and surface conditions remain debated and model-dependent.
Catalog worldK2-18 b
DetectionTransit
Atmosphere studiesYes
Direct surface imageNo

System travel calculation

How long to reach K2-18?

This is the approximate distance from Earth to the host star system. Every listed planet in the system is effectively at the same interstellar distance for travel estimates.

At light speed124 years299,792 km/s

A physical reference only. A spacecraft with mass cannot reach light speed.

At 10% of light speed1,240 years29,979 km/s — hypothetical

No operational spacecraft can sustain this interstellar cruise speed.

At 1% of light speed12,400 years2,998 km/s — hypothetical

Still far beyond current spacecraft propulsion.

At Parker Solar Probe peak193,392 yearsAbout 692,000 km/h

Parker reaches this speed only very close to the Sun; it is not an interstellar cruise speed.

At New Horizons launch speed2.29 million yearsAbout 58,536 km/h

A comparison using a real high-energy launch from Earth.

At Voyager 1 speed2.19 million yearsAbout 61,200 km/h

A practical comparison with a spacecraft already moving into interstellar space.

Catalog worlds in this system

1 listed worlds

Primary catalog source: NASA Science ↗