SkyTracko

TOI-700 d

Orbits TOI-700 · 102 light-years from Earth

RockyTransit2020ESI 92 · Very Earth-like
Earth1.07 R⊕
Radius
1.07×
Earth
Mass
1.3×
Earth
Year
37d
Temp
269 K
-4°C
Gravity
1.1×
Earth
Distance
102
ly

What it would be like

TOI-700 d is a rocky world, potentially similar in composition to Earth or Mars — a solid surface you could, in theory, stand on.

Surface gravity is about 1.1g — noticeably heavier what you're used to on Earth.

With an equilibrium temperature around -4°C, this planet sits in the temperature range where liquid water could potentially exist on the surface — a key ingredient for life as we know it.

An orbital period of 37 days makes the year 9.8× shorter than Earth's. You'd celebrate your birthday more often here.

Earth comparison

Logarithmic bars so Jupiter-class planets fit the same scale as Earth-size worlds.

Radius1.07R⊕
1/25×Earth = 125×
Mass1.25M⊕
1/10000×Earth = 110000×
Surface gravity1.09g
1/100×Earth = 1100×
Equilibrium temp269 K(-4°C)
0 KEarth 255 K2500 K

Side-by-side with Earth

Radius
1.07 R⊕
1.00 R⊕
Mass
1.25 M⊕
1.00 M⊕
Surface gravity
1.09g
1.00g
Year length
37.42 days
365.25 days
Eq. temperature
269 K (-4°C)
255 K (−18°C)
Orbital eccentricity
0.0420
0.0167
Semi-major axis
0.163 AU
1.000 AU

Temperature in context

Liquid N₂Mars avgEarth eq.Earth sfc.Boiling H₂OVenus

Host star — TOI-700

Spectral type
M2.5 V

Red dwarf — the most common type of star. Cool and small.

Temperature
3,459 K

Very cool — a faint red dwarf.

Radius
0.42 R☉
Mass
0.41 M☉
Luminosity
0.023 L☉
Distance
31.1 pc (102 ly)

Discovery & orbit

Method
Transit

Detected by measuring the tiny dip in starlight as the planet crosses in front of its star.

Year
2020
Facility
Transiting Exoplanet Survey Satellite (TESS)
Semi-major axis
0.1633 AU
Period
37.42 days
Eccentricity
0.0420

Mildly elliptical — similar to most Solar System planets.

Density
5.56 g/cm³

Rocky composition likely. Earth is 5.51 g/cm³.

Discovered via · Transit

Tiny dip in starlight as the planet crosses in front of its star

A transit photometer watches a star nonstop and measures its brightness to ~0.01%. When a planet passes between us and the star, the star dims briefly — the deeper the dip, the bigger the planet. This is how Kepler and TESS found most known exoplanets.

Overall share
~75% of all confirmed worlds
Best for
Earth-to-Neptune-sized planets on short orbits

Orbital Animation

TOI-700TOI-700 dOrbitHabitable zone
Drag to rotate · scroll to zoom
Semi-major axis: 0.163 AUEccentricity: 0.0420Period: 37.4 days

Hertzsprung–Russell Diagram

Where this host star sits among exoplanet host stars. The main sequence band runs diagonally — giants and supergiants sit above, white dwarfs below.

OBAFGKMCurrent star

How far is 102 light-years?

  • A light beam leaving Earth right now would arrive in 102 years.
  • At Voyager 1's speed (17 km/s), the trip would take approximately 1.8 million years.
  • A radio signal sent today would arrive in 101.5 years — and the reply wouldn't come back for twice that.

Earth Similarity Index

92/100
0 — Nothing like Earth100 — Identical to Earth

ESI combines radius similarity and equilibrium temperature similarity. Earth = 100. Mars ≈ 73. Venus ≈ 44. This score reflects two physical parameters only — not atmosphere, water, or magnetic field.