About 1P/Halley
1P/Halley is an uncommon comet. It swings within 0.576 AU of the Sun at perihelion.
Orbits against the grain — retrograde to almost everything else.
Uncommon comet 32 EP
1P/Halley
Position computed live · sbdb
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Live ephemeris
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Score breakdown
· 3 badgesUncommon 33 pts → Rare
- Retrograde orbit +18
- Has a proper name +8
- Comet +6
Total score 32
1 more point to reach Rare.
Badges
- Comet · +6
- Retrograde orbit · +18
- Has a proper name · +8
Trivia
What makes it special
- Backwards orbit. Orbits against the grain — retrograde to almost everything else.
How we found it
- Named. Notable enough to have earned a proper name, not just a catalogue number.
Cosmic context
- Wild orbit. Its highly elliptical path swings between scorching and frozen each lap.
- Size. Roughly 11 km across.
- Tail. Its tail always points away from the Sun, never trailing behind its motion.
Properties
- diameter km
- 11
- eccentricity
- 0.9679
- inclination
- 162.19
- name
- 1P/Halley
- named
- yes
- orbit class
- HTC
- perihelion au
- 0.5756
- semi major au
- 17.93
How to see it
Like any astronomical target, 1P/Halley 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 1P/Halley is an uncommon comet
1P/Halley scores 32 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 1 point would lift it into a rarer tier.
That score comes from 3 science badges — Comet, Retrograde orbit and Has a proper name — 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.