This object moves — fetching its current position…
Score breakdown
· 6 badges
98 pts · Anomaly
Anomaly120 pts → Mythic
Sedna, out in the deep freeze+26
Giant body (>500 km)+22
Dwarf planet+16
Far-flung orbit (a > 50 AU)+14
Trans-Neptunian object+12
Has a proper name+8
Total score98
22 more points to reach Mythic.
Badges
⚪Dwarf planet· +16
🏔️Giant body (>500 km)· +22
🏷️Has a proper name· +8
🌨️Trans-Neptunian object· +12
🛤️Far-flung orbit (a > 50 AU)· +14
🐋Sedna, out in the deep freeze· +26
✨ Trivia
Hard to believe
🥇Round under its own weight. Big enough that its own gravity has pulled it into a sphere — most of its neighbours are potato-shaped rubble.
What it actually is
🛸Its orbit family. A trans-Neptunian object from the Kuiper Belt, out where the Sun is little more than the brightest star in a very dark sky.
🔁One lap. A single orbit around the Sun takes it about 11.4 thousand years.
🥏How far it roams. Its orbit swings between 73.37 and 938.63 AU from the Sun.
🌀Wild orbit. Its highly elliptical path swings between scorching and frozen each lap.
Sense of scale
🧱Sense of scale. In everyday terms it is about 29% as wide as our Moon.
🚶Walk around it. Walking its equator at a steady pace, eight hours a day, would take about 78.5 days.
🌍Against Earth. It is only 8% of Earth's width — you could pack about 2069 of it inside our planet.
Properties
aphelion au
938.63
color
#a23a2a
diameter km
1000
eccentricity
0.855
inclination
11.93
name
Sedna
named
yes
num moons
0
orbit class
TNO
orbital period days
4404000
perihelion au
73.37
radius km
500
semi major au
506
About Sedna
Sedna is an anomaly dwarf planet. It completes an orbit every 4,404,000 days and swings within 73.37 AU of the Sun at perihelion.
A trans-Neptunian object from the Kuiper Belt, out where the Sun is little more than the brightest star in a very dark sky.
How to see it
Like any astronomical target, Sedna 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. Because it moves against the background stars, the live position panel on this page tracks where it is right now. The visibility panel above works out tonight's viewing window for your saved location.
Why Sedna is an anomaly dwarf planet
Sedna scores 98 points on Spacedle's rarity scale, which places it in the anomaly tier. Another 22 points would lift it into a rarer tier.
That score comes from 6 science badges — Dwarf planet, Giant body (>500 km), Has a proper name, Trans-Neptunian object, Far-flung orbit (a > 50 AU) and Sedna, out in the deep freeze — 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.
📷 Real photo