(85) Io
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	22 Jan 2026	12.9	2.503 AU	2.395 AU	01h45m	+04°53'	84.7°	23.0°
Opposition	22 Jan 2027	12.5	3.102 AU	2.148 AU	08h03m	+02°50'	162.8°	5.4°

The interactive orbit chart above shows the body's path through the solar system and its position at the given date. Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below. (Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)

The orbital elements of Io are:

            e (Eccentricity)                : 0.1930854
            a (Semimajor axis)              : 2.6530325
            i (Inclination)                 : 11.96082
            Ω (Longitude of ascending node) : 203.04207
            ω (Argument of perihelion)      : 122.89557
            M (Mean anomaly)                : 48.27419
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 146.51370
            B (Latitude of perihelion)      : 10.02128
            P (Orbital period in years)     : 4.32            
        

The light curve chart below shows the estimated development of the minor planet's magnitude.

The all-sky chart below shows the path of the minor planet over the same period as the light curve. The current position is marked yellow.

The following chart shows the path of the minor planet in the next few days. The field of view is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-01-22 00:00 UT   01 45 28.0   +04 53 26     2.395    2.503   84.7   23.0    70   12.9 
2026-01-22 22:34 UT   01 46 31.5   +04 58 25     2.409    2.505   84.0   23.0    70   12.9 
2026-01-23 00:00 UT   01 46 35.6   +04 58 44     2.410    2.505   83.9   23.0    70   12.9 
2026-01-24 00:00 UT   01 47 43.9   +05 04 05     2.425    2.507   83.2   22.9    70   12.9 
2026-01-25 00:00 UT   01 48 52.8   +05 09 31     2.440    2.509   82.5   22.9    70   13.0 
2026-01-26 00:00 UT   01 50 02.5   +05 15 00     2.455    2.511   81.8   22.8    70   13.0 
2026-01-27 00:00 UT   01 51 12.9   +05 20 33     2.470    2.514   81.1   22.8    70   13.0 
2026-01-28 00:00 UT   01 52 23.8   +05 26 10     2.485    2.516   80.4   22.7    70   13.0 
2026-01-29 00:00 UT   01 53 35.5   +05 31 49     2.500    2.518   79.7   22.6    70   13.0 
2026-01-30 00:00 UT   01 54 47.7   +05 37 32     2.515    2.520   79.0   22.6    71   13.0 
2026-01-31 00:00 UT   01 56 00.6   +05 43 18     2.530    2.522   78.3   22.5    71   13.0 
2026-02-01 00:00 UT   01 57 14.1   +05 49 06     2.545    2.524   77.6   22.4    71   13.0 
2026-02-02 00:00 UT   01 58 28.2   +05 54 57     2.559    2.526   76.9   22.3    71   13.1 
2026-02-03 00:00 UT   01 59 42.8   +06 00 51     2.574    2.528   76.2   22.3    71   13.1 
2026-02-04 00:00 UT   02 00 58.1   +06 06 47     2.589    2.530   75.6   22.2    71   13.1 
2026-02-05 00:00 UT   02 02 13.9   +06 12 46     2.604    2.532   74.9   22.1    71   13.1 
2026-02-06 00:00 UT   02 03 30.2   +06 18 47     2.618    2.534   74.2   22.0    72   13.1 
2026-02-07 00:00 UT   02 04 47.1   +06 24 50     2.633    2.536   73.5   21.9    72   13.1 
2026-02-08 00:00 UT   02 06 04.6   +06 30 54     2.648    2.538   72.9   21.8    72   13.1 
2026-02-09 00:00 UT   02 07 22.5   +06 37 01     2.662    2.541   72.2   21.7    72   13.1 
2026-02-10 00:00 UT   02 08 41.1   +06 43 10     2.677    2.543   71.5   21.6    72   13.1 
2026-02-11 00:00 UT   02 10 00.1   +06 49 20     2.691    2.545   70.9   21.5    72   13.2 
2026-02-12 00:00 UT   02 11 19.6   +06 55 31     2.706    2.547   70.2   21.4    73   13.2 
2026-02-13 00:00 UT   02 12 39.7   +07 01 45     2.720    2.549   69.5   21.3    73   13.2 
2026-02-14 00:00 UT   02 14 00.2   +07 07 59     2.734    2.551   68.9   21.2    73   13.2 
2026-02-15 00:00 UT   02 15 21.2   +07 14 14     2.749    2.553   68.2   21.1    73   13.2 
2026-02-16 00:00 UT   02 16 42.7   +07 20 31     2.763    2.555   67.6   20.9    73   13.2 
2026-02-17 00:00 UT   02 18 04.7   +07 26 49     2.777    2.557   66.9   20.8    73   13.2 

    Terminology:
            
    delta:  distance between minor planet and earth in AU
    radius: distance between minor planet and sun in AU
    magn:   magnitude (brightness) estimate    
    ra:     right ascension in hours (24h = 360deg)
    dec:    declination in degrees
    elong:  elongation in degrees (angle sun-earth-minor planet)    
    phase:  phase angle in degrees (angle sun-minor planet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km
    

Orbital elements provided by the MPC (Minor Planet Center).
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.