✦APSIDES ORBITALES
OBSERVED
APSIDAL MECHANICS · APPARENT ANGULAR DIAMETER & DISTANCE

Perigee vs. Apogee Observatory

True-scale optical angular diameter comparator contrasting perigee (supermoon, 33.5 arcmin) with apogee (micromoon, 29.3 arcmin) along with tidal force differential physics.

JPL DE440 / Horizons EphemerisDiscipline: 02 // ASTRONOMIC

APSIDES ORBITALES · GUIDED DISTANCE SWEEP

Distance changes scale—and force.

Trace one orbital variable through the optics of the sky and the gradients of the tide.

01 · APSIDAL GEOMETRY

The Moon does not orbit at one distance.

The lunar orbit is an ellipse. Perigee is the near apsis; apogee is the far apsis. The difference is a measurable geometric range, not a change in the Moon itself.

Earth–Moon distance384,400 km
Tidal potential1.00×
ORBITAL DISTANCE31.08′ apparent diameter
PERIGEE · 356,500MEAN · 384,400APOGEE · 406,700
Apsidal comparatorTRUE SCALE
APSIDAL DISTANCE FIELDPERIGEEAPOGEEEARTHMOON384,400 km · 31.08′
Apparent diameter31.08′+0.0% vs mean
Tidal potential1.00×+0.0% vs mean

Physical reading

Near-apsis amplification

The visual diameter and inverse-cube tidal model update from the same distance slider.

A single distance variable drives the orbit marker, angular diameter, and tidal potential readouts.

Perigee vs. Apogee Observatory: The "Supermoon" Demystifier

Visualizing the true physical 14% angular diameter and 30% illuminated area difference at exact identical scale.

OBSERVED
PERIGEE FULL MOON ("SUPERMOON")
Distance: 356,500 km
Apparent Diameter: 33.5′ (+14% larger)

Illuminance: +30% brighter than at apogee

APOGEE FULL MOON ("MICROMOON")
Distance: 406,700 km
Apparent Diameter: 29.4′ (baseline smallest)

Illuminance: Standard baseline minimum

Interactive Earth–Moon Distance Slider:384,400 km (31.08′)
356,500 km (Closest Perigee)384,400 km (Mean Distance)406,700 km (Farthest Apogee)