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K2-268 d

Super Earth Cancer

K2-268 d is a super-Earth orbiting K2-268 in the constellation Cancer. It lies about 1,069 light-years from Earth and was discovered in 2021 using the transit method.

1.49×Earth radius
4.5 dOrbital period
888 KEquilibrium temp.
0.29Earth similarity
1,069 lyDistance
2021Discovered

How Big Is K2-268 d?

Earth1.00 R⊕K2-268 d1.49 R⊕
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K2-268 d has a radius of 1.49 times that of Earth.

Is K2-268 d in the Habitable Zone?

The position of K2-268 d relative to the habitable zone of K2-268 cannot be precisely determined from the available orbital data.

Too hot Optimistic habitable zone Conservative habitable zone Too cold

Habitable zone of K2-268: 0.475–1.143 AU (conservative: 0.601–1.083 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.

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Temperature on K2-268 d

The equilibrium temperature of K2-268 d is about 888 K (615 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.

Orbit and Year Length

A year on K2-268 d — one full orbit around K2-268 — lasts 4.53 Earth days, shorter than Mercury's 88-day year.

How Was K2-268 d Discovered?

K2-268 d was discovered in 2021 using the transit method, with observations from K2.

The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.

How Far Away Is K2-268 d?

K2-268 d is 1,069.1 light-years (327.8 parsecs) from Earth. Light arriving here tonight left the planet about 1,069 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 18,816,160 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. K2-268 d scores 0.29, ranking #1,867 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.

The Host Star: K2-268

K2-268

Surface temperature
5,106 K (Sun: 5,772 K)
Mass
0.84 M☉
Radius
0.78 R☉

The K2-268 Planetary System

K2-268 d is one of 5 known planets in the K2-268 system. Its siblings:

K2-268 d — Complete Data

Radius1.490 Earth radii (0.133 Jupiter radii)
Orbital period4.53 days
Equilibrium temperature888 K (615 °C)
Earth Similarity Index0.29
Distance from Earth1,069.1 light-years (327.8 parsecs)
ConstellationCancer
Discovery methodTransit
Discovery facilityK2
Discovery year2021

Data: NASA Exoplanet Archive, last updated 2021-08-23. Earth Similarity Index: PHL @ UPR Arecibo.

Frequently Asked Questions About K2-268 d

Is K2-268 d habitable?

K2-268 d is not known to orbit within the habitable zone of K2-268, and as a super-Earth it is an unlikely candidate for life as we know it.

How far away is K2-268 d?

K2-268 d is about 1,069 light-years from Earth in the constellation Cancer. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 18,816,160 years to get there.

How big is K2-268 d compared to Earth?

K2-268 d has 1.49 times the radius of Earth.

How long is a year on K2-268 d?

One orbit around K2-268 takes 4.5 Earth days — short enough that 81 of its years would fit into one Earth year.

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