← Back to dex - Brilliantly reflective surface +10
- Near-Earth object +5
- Amor: shadows Earth's orbit from outside +4
- Catalogue designation only +0
Total score 19
3 more points to reach Uncommon.
Badges
- 🌠 Near-Earth object · +5
- 🔢 Catalogue designation only
- 💘 Amor: shadows Earth's orbit from outside · +4
- 🪙 Brilliantly reflective surface · +10
✨ Trivia
What it actually is
- 🛸 Its orbit family. An Amor-class object. It approaches Earth's orbit from outside without ever crossing it — named for the asteroid Amor, which swept past at 16 million km in 1932.
- 🌞 Closest approach. At its nearest it comes within 1.24 AU of the Sun — inside the orbit of Mars.
- 🔁 One lap. A single orbit around the Sun takes it about 2.1 years.
- 🥏 How far it roams. Its orbit swings between 1.24 and 2.06 AU from the Sun.
Sense of scale
- 🧱 Sense of scale. In everyday terms it is roughly 0.1× the height of Mount Everest.
Standing on it
- 🦘 Don't jump. Escape velocity here is only around 0.69 m/s. A determined jump would launch you off it and into your own orbit around the Sun.
By the numbers
- 📐 Size. Roughly 1.1 km across.
What's in a name
- 🔢 Designation. Known only by its catalogue designation — no name yet.
Properties
- albedo
- 0.405
- aphelion au
- 2.06
- designation
- 85839
- diameter km
- 1.14
- eccentricity
- 0.2481
- full name
- 85839 (1998 YO4)
- h mag
- 16.58
- inclination
- 9.32
- mean motion deg day
- 0.4636
- moid au
- 0.241
- name
- (85839) 1998 YO4
- number only
- yes
- orbit class
- AMO
- perihelion au
- 1.243
- rotation period h
- 2.45
- semi major au
- 1.653
About (85839) 1998 YO4
(85839) 1998 YO4 is a common neo. It swings within 1.243 AU of the Sun at perihelion.
An Amor-class object. It approaches Earth's orbit from outside without ever crossing it — named for the asteroid Amor, which swept past at 16 million km in 1932.
How to see it
Like any astronomical target, (85839) 1998 YO4 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 (85839) 1998 YO4 is a common neo
(85839) 1998 YO4 scores 19 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.
That score comes from 4 science badges — Near-Earth object, Catalogue designation only, Amor: shadows Earth's orbit from outside and Brilliantly reflective surface — 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.