This object moves — fetching its current position…
Score breakdown
· 6 badges
37 pts · Rare
Rare50 pts → Epic
Potentially hazardous+12
Aten: mostly inside Earth's orbit+8
Barely turning (over 100 hours)+8
Near-Earth object+5
Tiny fragment (<1 km)+4
Catalogue designation only+0
Total score37
13 more points to reach Epic.
Badges
🌠Near-Earth object· +5
⚠️Potentially hazardous· +12
🤏Tiny fragment (<1 km)· +4
🔢Catalogue designation only
⚱️Aten: mostly inside Earth's orbit· +8
🐌Barely turning (over 100 hours)· +8
✨ Trivia
Handle with care
🛡️What 'hazardous' means. 'Potentially hazardous' is bookkeeping, not a prediction: it means the orbit passes within 0.05 AU of Earth's and the body is big enough to matter. Nothing on that list is known to be on a collision course.
☄️If it ever hit. A rock this size arriving at a typical 20 km/s would release around 32.2 thousand megatons — enough to devastate a region the size of a small country.
What it actually is
🛸Its orbit family. An Aten-class object, spending most of its time inside Earth's orbit and crossing ours from the sunward side — which makes this family wretchedly hard to spot against the daylight.
🌞Closest approach. At its nearest it comes within 0.65 AU of the Sun — inside the orbit of Venus.
🔁One lap. A single orbit around the Sun takes it about 275 days.
🥏How far it roams. Its orbit swings between 0.65 and 1 AU from the Sun.
Sense of scale
🧱Sense of scale. In everyday terms it is about 7.5 football pitches across.
Standing on it
🦘Don't jump. Escape velocity here is only around 0.48 m/s. A determined jump would launch you off it and into your own orbit around the Sun.
Properties
albedo
0.34
aphelion au
1
designation
163899
diameter km
0.791
eccentricity
0.2094
full name
163899 (2003 SD220)
h mag
17.56
inclination
8.55
mean motion deg day
1.308
moid au
0.018
name
(163899) 2003 SD220
number only
yes
orbit class
ATE
perihelion au
0.654
pha
yes
rotation period h
285
semi major au
0.8279
About (163899) 2003 SD220
(163899) 2003 SD220 is a rare neo. It swings within 0.654 AU of the Sun at perihelion.
An Aten-class object, spending most of its time inside Earth's orbit and crossing ours from the sunward side — which makes this family wretchedly hard to spot against the daylight.
How to see it
Like any astronomical target, (163899) 2003 SD220 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 (163899) 2003 SD220 is a rare neo
(163899) 2003 SD220 scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.
That score comes from 6 science badges — Near-Earth object, Potentially hazardous, Tiny fragment (<1 km), Catalogue designation only, Aten: mostly inside Earth's orbit and Barely turning (over 100 hours) — 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.