About Kepler-33 d
Kepler-33 d is an epic exoplanet. It lies about 3,943.7 light-years from Earth, has an equilibrium temperature near 853 K, spans roughly 5.35 Earth radii and weighs about 3.91 Earth masses.
So low-density it would float on water.
Epic exoplanet 54 EP
Kepler-33 d
RA 289.0775° · Dec 46.0052° · exoplanet
Score breakdown
· 7 badgesEpic 68 pts → Anomaly
- Richly packed system +14
- Puffy low-density world +12
- Distant (>1000 ly) +10
- Multi-planet system +6
- Confirmed exoplanet +5
- Neptune-like +4
- Found by Kepler +3
Total score 54
14 more points to reach Anomaly.
Badges
- Confirmed exoplanet · +5
- Neptune-like · +4
- Puffy low-density world · +12
- Multi-planet system · +6
- Richly packed system · +14
- Found by Kepler · +3
- Distant (>1000 ly) · +10
Trivia
What makes it special
- Cotton-candy planet. So low-density it would float on water.
- Packed system. Crammed into a system of five or more planets.
Could we get there?
- Verdict. Impossible with our current technology — and the next millennium of it.
Getting there
- Aboard Voyager 1. ≈ 69.3 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 6.2 million years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 39.4 thousand years in a starship at a tenth of light speed.
- Distance. 3944 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 7887 years round-trip.
Standing on it
- A year here. A full year lasts just 21.8 Earth days.
By the numbers
- Size. About 5.3× the width of Earth.
- Volume. About 153 Earths could fit inside it.
- Mass. About 3.9× the mass of Earth.
- Your weight. You'd weigh about 0.1× your Earth weight standing here.
- Density. Less dense than water — drop it in a big enough ocean and it would float.
- Temperature. Around 580°C — hotter than a self-cleaning oven.
How we found it
- Discovery. Found by Kepler using the transit method.
Cosmic context
- Crowded system. One of at least 5 planets orbiting its star.
Properties
- density gcc
- 0.25
- discovery facility
- Kepler
- discovery method
- Transit
- dist ly
- 3943.7479
- eccentricity
- 0
- eq temp k
- 853
- insolation
- 123.691
- mass earth
- 3.91
- name
- Kepler-33 d
- orbital period days
- 21.776
- radius earth
- 5.35
- sys num planets
- 5
How to see it
Like any astronomical target, Kepler-33 d 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 Kepler-33 d is an epic exoplanet
Kepler-33 d scores 54 points on Spacedle's rarity scale, which places it in the epic tier. Another 14 points would lift it into a rarer tier.
That score comes from 7 science badges — Confirmed exoplanet, Neptune-like, Puffy low-density world, Multi-planet system, Richly packed system, Found by Kepler 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.