About Ceto
Ceto is a rare kbo. It swings within 17.728 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.
Rare kbo 47 EP
Ceto
Position computed live · sbdb
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Live ephemeris
This object moves — fetching its current position…
Score breakdown
· 5 badgesRare 50 pts → Epic
- Far-flung orbit (a > 50 AU) +14
- Trans-Neptunian object +12
- Notably bright (low H) +8
- Has a proper name +8
- Kuiper-belt object +5
Total score 47
3 more points to reach Epic.
Badges
- Kuiper-belt object · +5
- Notably bright (low H) · +8
- Has a proper name · +8
- Trans-Neptunian object · +12
- Far-flung orbit (a > 50 AU) · +14
Trivia
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.
- Closest approach. At its nearest it comes within 17.73 AU of the Sun — inside the orbit of Uranus.
- One lap. A single orbit around the Sun takes it about 1014 years.
- How far it roams. Its orbit swings between 17.73 and 184.07 AU from the Sun.
Sense of scale
- Sense of scale. In everyday terms it is about 8.4× the length of Manhattan island.
- Walk around it. Walking its equator at a steady pace, eight hours a day, would take about 14.2 days.
By the numbers
- Estimated size. Nobody has measured its size directly. Assuming it reflects light like a typical asteroid, its brightness implies something roughly 180 km across.
What's in a name
- Named. Notable enough to have earned a proper name, not just a catalogue number.
Properties
- aphelion au
- 184.06
- designation
- 65489
- eccentricity
- 0.8243
- full name
- 65489 Ceto (2003 FX128)
- h mag
- 6.47
- inclination
- 22.29
- mean motion deg day
- 0.001
- moid au
- 16.8
- name
- Ceto
- named
- yes
- orbit class
- TNO
- perihelion au
- 17.728
- rotation period h
- 4.43
- semi major au
- 100.9
How to see it
Like any astronomical target, Ceto 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 Ceto is a rare kbo
Ceto scores 47 points on Spacedle's rarity scale, which places it in the rare tier. Another 3 points would lift it into a rarer tier.
That score comes from 5 science badges — Kuiper-belt object, Notably bright (low H), Has a proper name, Trans-Neptunian object and Far-flung orbit (a > 50 AU) — 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.