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Asteroid

Iduna

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176 Iduna (A877 TB)

Where is it now

Distance from Sun
3.284 AU
True anomaly
110.3°
Distance from Earth
3.897 AU
As of
11 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.998 AU from the Sun Earth Iduna — 3.284 AU from the Sun Iduna
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Iduna is 3.897 AU from Earth today (32.4 light-minutes).

In the sky

Right ascension
10h 03m 31s
Declination
-05° 39′ 08″
Constellation
Sextans
Distance from Earth
3.89 AU
Elongation from the Sun
46.56° — near the Sun — look low at dusk or dawn

Visible from both hemispheres.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
3.182 AU
Eccentricity
0.1726
Inclination
22.67°
Orbital period
5.68 years
Perihelion
2.633 AU
Aphelion
3.731 AU
Longitude of ascending node
200.4°
Argument of periapsis
189.18°
Epoch · J2000
2461200.5
Orbit class · MBA
Main-belt asteroid
Earth MOID · 637.3 LD
1.6376 AU
Tisserand (Jupiter)
3.057

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
11,469
Data arc
148.5 years
First observed
15 October 1877
Last observed
13 April 2026
Residual RMS
0.25 ″
Solution · Otto Matic
5 June 2026

Physical properties

Mean radius
53 km
Rotation period
11.29 hours

Visual & observation

Geometric albedo
0.065
Absolute magnitude (H)
8.41
Spectral type (SMASS)
Ch
Spectral type (Tholen)
G

Discovery & classification

Discovered by
Peters, C. H. F.
Discovery date
14 October 1877
Discovery site
Clinton

Also known as 176 · A877 TB · 1945 RQ

Main-Belt Asteroid Named

Close approaches 5 on record

When (UTC) Body Distance Lunar distances Relative speed
2113-03-24 08:41:00 Juptr 1.9197 AU 747.1 LD 5.3 km/s
2124-04-23 08:58:00 Juptr 1.7391 AU 676.8 LD 5.5 km/s
2135-05-29 15:32:00 Juptr 1.8975 AU 738.4 LD 5.5 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources