About K2-308 b
K2-308 b is an uncommon exoplanet. It lies about 4,287.4 light-years from Earth, has an equilibrium temperature near 1,214 K, spans roughly 9.92 Earth radii and weighs about 70.6 Earth masses.
About 9.9× the width of Earth.
Uncommon exoplanet 29 EP
K2-308 b
RA 78.3391° · Dec 16.4142° · exoplanet
Score breakdown
· 4 badgesUncommon 33 pts → Rare
- Hot Jupiter +10
- Distant (>1000 ly) +10
- Confirmed exoplanet +5
- Gas giant +4
Total score 29
4 more points to reach Rare.
Badges
- Confirmed exoplanet · +5
- Gas giant · +4
- Hot Jupiter · +10
- Distant (>1000 ly) · +10
Trivia
Could we get there?
- Verdict. Impossible with our current technology — and the next millennium of it.
Getting there
- Aboard Voyager 1. ≈ 75.3 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 6.7 million years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 42.9 thousand years in a starship at a tenth of light speed.
- Distance. 4287 light-years from Earth.
Look-back time
- Look-back time. Its light left before the last ice age ended.
Saying hello
- Say hello. A radio message and its reply would take 8575 years round-trip.
Standing on it
- A year here. A full year lasts just 3.4 Earth days.
By the numbers
- Size. About 9.9× the width of Earth.
- Volume. About 975 Earths could fit inside it.
- Mass. Roughly 70.6× Earth's mass — about 0.2 Jupiters.
- Your weight. You'd weigh about 0.7× your Earth weight standing here.
- Density. Less dense than water — drop it in a big enough ocean and it would float.
- Temperature. Around 941°C — hotter than a self-cleaning oven.
How we found it
- Discovery. Found by K2 using the transit method.
Properties
- density gcc
- 0.398
- discovery facility
- K2
- discovery method
- Transit
- dist ly
- 4287.4185
- eq temp k
- 1213.76
- insolation
- 512.9234
- mass earth
- 70.6
- name
- K2-308 b
- orbital period days
- 3.3863
- radius earth
- 9.916
- sys num planets
- 1
How to see it
Like any astronomical target, K2-308 b is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Why K2-308 b is an uncommon exoplanet
K2-308 b scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 4 points would lift it into a rarer tier.
That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter and Distant (>1000 ly) — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.