- weight
- 0.60 g
- sun
- 3.6× wider
- sky
- warm white
Illustration computed from this world’s measured and derived values, not a photograph.
HIP 9618 c
HIP 9618 c is a confirmed sub-Neptune exoplanet 220 ly from Earth in the constellation Aries, discovered in 2023 by Transiting Exoplanet Survey Satellite (TESS).
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.
Standing on HIP 9618 c, you would weigh about 40% less than you do on Earth. Its yellow, Sun-like star looks 3.6× wider than ours, bathing the surface in warm white light. It is likely tidally locked, so that sun never moves in the sky: one hemisphere in endless day, the other in permanent night. A year passes in just 53 days, and at an estimated 197°C (387°F) it is blistering.
How closely this world matches Earth in size and warmth, from 0 to 1 (Earth = 1.0). Computed by gravityfinder. See every world ranked →
What these mean: surface gravity · tidal locking · equilibrium temperature · Earth similarity
If your children grew up herea playful thought experiment
Lighter than home, at 0.60 times Earth's gravity. A child raised here would likely grow taller and more slender than their Earth-raised parents, about 1.1x taller than on Earth: a 5 ft 10 in adult could stand nearer 6 ft 6 in.
- Bones
- Light and slender
- With little weight to carry, the growing skeleton lays down far less bone, the way astronauts' bones thin in months of low gravity.
- Movement
- Bounding and springy
- So little weight means each step would carry the body up and forward in long, floating strides.
A playful thought experiment from this world’s gravity, not a prediction about any real person. No human has ever grown up off Earth, so no one truly knows; the direction (taller in low gravity, shorter and stockier in high) follows how growing bodies respond to weight.
Hear how a voice sounds herea computed acoustic demo
Your voice would sound high and thin, almost cartoonish.
Assuming Earth-like air at this world's temperature of about 197°C (387°F), sound would travel roughly 28% faster than on Earth, so your voice would sound high and thin, almost cartoonish. The real atmosphere is unknown, so this is a best guess.
A real voice sample, pitch-shifted (tempo held constant) to suggest the acoustics: a playful approximation, not a precise simulation. Voice: Lingua Libre / Vealhurl, CC BY-SA 4.0.
- !Blistering at about 197°C (387°F), far too hot for liquid water on the surface.
- !Low gravity, 0.60 times Earth's, would hold only a thin, unbreathable atmosphere at best.
- !Likely tidally locked: one hemisphere in endless day, the other in permanent night.
A playful read of HIP 9618 c’s measured and computed values, not a real advisory.
How long to get there · 220 ly away
Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.
Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.
What is the gravity on HIP 9618 c?
HIP 9618 c's surface gravity is about 0.60 times Earth's.
How much would you weigh on HIP 9618 c?
Someone who weighs 150 pounds on Earth would weigh about 89 pounds on HIP 9618 c.
How far is HIP 9618 c from Earth?
HIP 9618 c lies about 220 light-years from Earth.
How long would it take to get to HIP 9618 c?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 343,599 years.
How hot is HIP 9618 c?
HIP 9618 c's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 197°C (387°F).
How long is a year on HIP 9618 c?
HIP 9618 c completes one orbit of its star in 53 days.
Illustration generated from HIP 9618 c's confirmed parameters, not a photograph.