About Simeisa
Simeisa is an epic asteroid. It has spectral type P and swings within 3.203 AU of the Sun at perihelion.
An outer main-belt asteroid, out towards Jupiter where the rocks grow darker and richer in carbon and ice.
Epic asteroid 52 EP
Simeisa
Position computed live · asteroid
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Live ephemeris
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Score breakdown
· 7 badgesEpic 78 pts → Anomaly
- Large body (100-500 km) +12
- Primitive outer-belt type +12
- Darker than charcoal +10
- Notably bright (low H) +8
- Has a proper name +8
- Asteroid +1
- Main-belt asteroid +1
Total score 52
26 more points to reach Anomaly.
Badges
- Asteroid · +1
- Large body (100-500 km) · +12
- Notably bright (low H) · +8
- Has a proper name · +8
- Main-belt asteroid · +1
- Darker than charcoal · +10
- Primitive outer-belt type · +12
Trivia
What it actually is
- Its orbit family. An outer main-belt asteroid, out towards Jupiter where the rocks grow darker and richer in carbon and ice.
- Closest approach. At its nearest it comes within 3.2 AU of the Sun — inside the orbit of Jupiter.
- One lap. A single orbit around the Sun takes it about 7.9 years.
- How far it roams. Its orbit swings between 3.2 and 4.7 AU from the Sun.
Sense of scale
- Sense of scale. In everyday terms it is about 4.8× the length of Manhattan island.
- Walk around it. Walking its equator at a steady pace, eight hours a day, would take about 8.1 days.
By the numbers
- Size. Roughly 104 km across.
What's in a name
- Named. Notable enough to have earned a proper name, not just a catalogue number.
Properties
- albedo
- 0.041
- aphelion au
- 4.7
- designation
- 748
- diameter km
- 103.714
- eccentricity
- 0.1896
- full name
- 748 Simeisa (A913 EL)
- h mag
- 9.08
- inclination
- 2.26
- mean motion deg day
- 0.1254
- moid au
- 2.22
- name
- Simeisa
- named
- yes
- orbit class
- OMB
- perihelion au
- 3.203
- rotation period h
- 11.905
- semi major au
- 3.952
- spec taxonomy
- P
- spect
- P
How to see it
Like any astronomical target, Simeisa 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 Simeisa is an epic asteroid
Simeisa scores 52 points on Spacedle's rarity scale, which places it in the epic tier. Another 26 points would lift it into a rarer tier.
That score comes from 7 science badges — Asteroid, Large body (100-500 km), Notably bright (low H), Has a proper name, Main-belt asteroid, Darker than charcoal and Primitive outer-belt type — 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.