What it’s like to stand here
NN Ser d
weight
4.10 g
sky
icy blue-white

Illustration computed from this world’s measured and derived values, not a photograph.

NN Ser d

NN Ser d is a confirmed gas-giant exoplanet 1,682 ly from Earth in the constellation Serpens, discovered in 2010 by Multiple Observatories.

1,682 lyDiscovered in 2010 by Multiple ObservatoriesDisputed detection

Eclipse Timing Variations: inferred from shifts in the timing of its eclipsing stars.

NN Ser
host star
13.30 R⊕
radius
725 M⊕
mass · measured
7.9 years
orbital period
avg temp
Human scale

NN Ser d is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud. Bathing the cloud tops in icy blue-white light. A year here lasts 7.9 Earth years.

4.10 g
surface gravity (no solid surface · measured mass)
7.9 years
one year, in Earth time
sun size, needs orbit
icy blue-white
midday sky tint
0.2×
how high you could jump vs Earth
normal
day/night cycle (not tidally locked)
Calculate your exact weight on NN Ser d

What these mean: surface gravity · tidal locking · equilibrium temperature

If your children grew up herea playful thought experiment
NO GROUND: A DRIFTER, NOT A WALKER

There is no ground here to grow up on, only bottomless sky. A child could never stand, walk, or even fall to a surface, because there isn't one. Under 4.1 times Earth's gravity and pressure that only climbs the deeper you go, anything built for this world would not look human at all: picture something closer to a deep-sea creature than a person, broad and buoyant, drifting through the cloud decks with no need for legs and no floor to land on.

Body plan
Floating, not upright
With no surface and no fixed up or down, a skeleton built for standing would be useless; a drifting, gas-filled body would not.
Build
Broad and pressure-hardened
Pressure rises without limit toward the interior, so anything alive would have to be built like a deep-sea animal, not a land one.

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 a thin, helium-fast squeak.

There is no surface to stand on, and we have no temperature for this world, so its cloud-top acoustics cannot be modelled. In hydrogen-helium air sound races, so a voice would leap to a thin, almost cartoonish squeak.

The journey
Cosmic travel advisory
☆☆☆☆
Do not travel
  • !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.

A playful read of NN Ser d’s measured and computed values, not a real advisory.

How long to get there · 1,682 ly away
Jet airliner
2.0 billion years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
2.6 million years
dies en route1000-yr cryo: fails
Light speed
1,682 years
dies en route1000-yr cryo: fails
Warp 10
2 years
arrives, just older
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthNN Ser d is 13× the width of Earth
Explore from here · roam the neighborhood

Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.

Can you see it tonight? · observe
FAINT: LARGE TELESCOPE NEEDED
Host-star brightnessmag 16.9
ConstellationSerpens
To see the host star10"+ (250 mm) telescope, dark sky
Gear bridge

Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.

Common questions

What is the gravity on NN Ser d?

NN Ser d is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls about 4.1 times as hard as Earth's.

How far is NN Ser d from Earth?

NN Ser d lies about 1,682 light-years from Earth.

How long would it take to get to NN Ser d?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 2.6 million years.

How long is a year on NN Ser d?

NN Ser d completes one orbit of its star in 7.9 years.

Illustration generated from NN Ser d's confirmed parameters, not a photograph.