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Asteroid

Ianthe

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98 Ianthe (A868 HA)

Ianthe is an asteroid in the Main-belt asteroid orbit class. Its orbit takes it from 2.18 AU to 3.19 AU from the Sun; one orbit takes 4.41 years; it is about 133 km across. Discovered 18 April 1868 by Peters, C. H. F.. Orbit from the JPL solution of 5 June 2026.

Where is it now

Distance from Sun
2.224 AU
True anomaly
28.03°
Distance from Earth
3.108 AU
As of
25 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 — 0.994 AU from the Sun Earth Ianthe — 2.224 AU from the Sun Ianthe
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Ianthe is 3.108 AU from Earth today (25.8 light-minutes).

In the sky

Right ascension
12h 35m 03s
Declination
-05° 06′ 25″
Constellation
Virgo
Distance from Earth
3.1 AU
Elongation from the Sun
23.09° — 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
2.688 AU
Eccentricity
0.1878
Inclination
15.58°
Orbital period
4.41 years
Perihelion
2.183 AU
Aphelion
3.193 AU
Longitude of ascending node
353.85°
Argument of periapsis
158.07°
Epoch · J2000
2461200.5
Orbit class · MBA
Main-belt asteroid
Earth MOID · 466.8 LD
1.1994 AU
Tisserand (Jupiter)
3.296

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
8,963
Data arc
155.5 years
First observed
17 October 1870
Last observed
5 April 2026
Residual RMS
0.26 ″
Solution · Otto Matic
5 June 2026

Physical properties

Mean radius
66 km
Rotation period
16.48 hours

Visual & observation

Geometric albedo
0.029
Absolute magnitude (H)
8.94
Colour index (B–V)
0.75
Spectral type (SMASS)
Ch
Spectral type (Tholen)
CG
Colour index (U–B)
0.38

Discovery & classification

Discovered by
Peters, C. H. F.
Discovery date
18 April 1868
Discovery site
Clinton

Also known as 98 · A868 HA · 1931 RK1 · 1949 SE1 · 1975 XO

Main-Belt Asteroid Named

Close approaches 6 on record

When (UTC) Body Distance Lunar distances Relative speed
2082-01-27 02:31:00 Juptr 1.885 AU 733.6 LD 4.3 km/s
2117-02-02 14:55:00 Juptr 1.8065 AU 703.0 LD 4.3 km/s
2152-02-09 10:43:00 Juptr 1.9051 AU 741.4 LD 4.1 km/s

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

Sources