HD 18143 b
HD 18143 b is a Neptune-like planet orbiting HD 18143 in the constellation Aries. It lies about 74 light-years from Earth and was discovered in 2022 using the radial velocity method.
Is HD 18143 b in the Habitable Zone?
The position of HD 18143 b relative to the habitable zone of HD 18143 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 18143 b — one full orbit around HD 18143 — lasts 10.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.088 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.22).
How Was HD 18143 b Discovered?
HD 18143 b was discovered in 2022 using the radial velocity method, with observations from Multiple Observatories.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is HD 18143 b?
HD 18143 b is 73.5 light-years (22.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1953. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,293,600 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. HD 18143 b scores 0.22, ranking #3,677 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 18143
HD 18143
- Mass
- 0.85 M☉
The HD 18143 Planetary System
HD 18143 b is one of 2 known planets in the HD 18143 system. Its siblings:
- HD 18143 c (Cold Gas Giant)
HD 18143 b — Complete Data
| Mass (best estimate) | 10.81 Earth masses |
|---|---|
| Orbital period | 10.29 days |
| Orbital distance | 0.088 AU |
| Eccentricity | 0.224 |
| Earth Similarity Index | 0.22 |
| Distance from Earth | 73.5 light-years (22.5 parsecs) |
| Constellation | Aries |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2023-06-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 18143 b
Is HD 18143 b habitable?
HD 18143 b is not known to orbit within the habitable zone of HD 18143, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is HD 18143 b?
HD 18143 b is about 74 light-years from Earth in the constellation Aries. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,293,600 years to get there.
How long is a year on HD 18143 b?
One orbit around HD 18143 takes 10.3 Earth days — short enough that 36 of its years would fit into one Earth year.
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