SOHO

Orbit and dynamics

Between its closest point (0.039 AU) and its farthest (5.125 AU), the heliocentric distance changes by 5.086 AU over every revolution.

One full revolution takes 4.15 yr (1,515 days), computed from the semi-major axis of 2.582 AU.

The high eccentricity (0.985) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 5.37° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 212.5 km/s at perihelion and falls to 1.6 km/s at aphelion.

Because q < 1 AU and Q > 1 AU, this orbit geometrically intersects the region of Earth's orbit.

Its Tisserand parameter with respect to Jupiter is T_J = 2.26, a standard discriminator between asteroidal and cometary dynamics.

Size and surface

Neither a measured diameter nor a reliable absolute magnitude is available for SOHO, so its physical size remains unconstrained.

Observation record and orbit quality

Astrometry from 171 individual observations underpins this orbit; the fit leaves an RMS residual of 0.2576 arcseconds.

Condition code U = 0 means the orbit is very well determined, leaving only a small uncertainty in the future ephemeris.