Create your free account

Enter your email and we'll send a 6-digit code — no password needed.
We only keep your email and the username you choose. We never share or sell your email, and we don't send marketing — we use it only to email you a sign-in code. Read our privacy policy.
Planet profiles

TOI-700 b

Rocky Terrestrial · 101 light-years away · Last reviewed October 15, 2026

TOI-700 b rendered in TerraForge from its measured mass, orbit and star
TerraForge's rendering of TOI-700 b, generated by our physics engine from its measured mass, size, orbit and star. An illustration of what the science suggests, not a photograph.
TerraForge classification
Rocky Terrestrial
Host star
TOI-700 (M2.5 V)
Distance
101 light-years
Orbit
9.98 days
Mass
0.85 × Earth
Radius
0.96 × Earth
Discovered
2020, transit

Figures from the NASA Exoplanet Archive. The classification is TerraForge’s, from its physics model.

TOI-700 b is the innermost of four planets around TOI-700, a quiet red dwarf about 100 light-years away. It is about Earth's size and orbits every 9.98 days. It was found together with two of its siblings, TOI-700 c and d, by NASA's TESS satellite, which caught the small dips in starlight as each planet crossed the star.

A team led by Emily Gilbert reported the system in 2020 from 11 sectors of TESS data. Using ground-based follow-up and a series of tests, the team ruled out the common false alarms and validated all three planets. The outer one, TOI-700 d, became the first Earth-sized planet in a habitable zone found by TESS. A fourth, TOI-700 e, was found in 2023 between c and d.

TOI-700 b is the hot inner sibling of those habitable-zone worlds. According to the NASA Exoplanet Archive, it receives about five times the light Earth gets from the Sun, too much for liquid water. Its mass has not been measured; the archive's figure is an estimate from its size. The discovery team stressed that TOI-700 shows low levels of activity, unlike many red dwarfs with Earth-sized planets, which makes the system a good place to compare small planets that receive very different amounts of starlight from the same calm star.

Sources

  1. The First Habitable Zone Earth-sized Planet from TESS. I: Validation of the TOI-700 System — arXiv (The Astronomical Journal)
  2. A Second Earth-Sized Planet in the Habitable Zone of the M Dwarf, TOI-700 — arXiv (The Astrophysical Journal Letters)
A banded gas giant with four moons in different colors: a yellow sulfur moon, two rust-red rock moons and a blue water moon

New: Choose What Your Moons Are Made Of 🌙

Every moon used to be grey rock, white ice or blue ocean, decided for you. Now each one has a "Made of" choice in the builder's Moons tab — silicate rock, iron, water ice, carbon, sulfur, or nitrogen and methane ice — and the physics decides what that becomes. Put water ice too close to the star and it boils off to bare rock. Put sulfur where a neighbouring moon keeps it tidally flexed and it erupts in Io's yellows. Give a Titan-sized moon nitrogen ice far from the sun and it wraps itself in haze. Hang a water moon about the mass of Earth off a giant planet in the habitable zone and it can hold air and open seas — scored for life on the same scale as a planet, with a day as long as its orbit. A tint slider nudges the colour, but only as far as that material could really go.

Create your free account

Enter your email and we'll send a 6-digit code — no password needed.
We only keep your email and the username you choose. We never share or sell your email, and we don't send marketing — we use it only to email you a sign-in code. Read our privacy policy.

Send feedback

We're still building out the best experience we can — and we'd love your input. Tell us about features you enjoy, ideas you'd like to see, or pain points where something feels off, and we'll know where to look next.

Type
Idea
Bug
Pain point
Other