F Periaps, H Apoapsis and the red line between them is the line of apsides.

A full Moon occurs on average every 30 days, and is at its perigee every 28 days.

The periapsis altitude required for a successful aerocapture depends on the spacecraft's drag characteristics, its approach velocity, and the desired apoapsis of the resulting orbit.

The periapsis altitude required for a successful aerocapture depends on the spacecraft’s drag characteristics, its approach velocity, and the desired apoapsis of the resulting orbit.

in October 1977 and the periapsis was lowered to 300 km and the period changed to 24 hours on 23 October 1977.

in October 1977 and the periapsis was lowered to 300 km and the period changed to 24 hours on 23 October 1977.

The periapsis altitude required for a successful aerocapture depends on the spacecraft's drag characteristics, its approach velocity, and the desired apoapsis of the resulting orbit.

The periapsis altitude required for a successful aerocapture depends on the spacecraft’s drag characteristics, its approach velocity, and the desired apoapsis of the resulting orbit.

For example, with the Mun this means a polar orbit of 90 degrees, with a periapsis of 20 Km and an apoapsis of 620 Km.

This means that the point of closest approach — periapsis in general or perihelion for an orbit with respect to our Sun — rotates over time.

The Oberth effect is strongest at a point in orbit known as the periapsis, where the gravitational potential is lowest, and the speed is highest.

After the apoapsis is lowered to the desired height, it will be necessary to raise the periapsis once back outside the atmosphere to stop losing altitude on subsequent orbits.

Eeloo's relatively large distance from Kerbol reduces solar power to approximately 4% at Eeloo periapsis and 1.4% at Eeloo apoapsis of the values seen at Kerbin.

Every object orbiting a single mass (like our Sun) makes an ellipse, containing a point of closest approach that's unique to that particular orbit, known as periapsis.

Indeed, occultation observations conducted from the ground and the spacecraft showed that its normal optical depth[c] varies between 0.5 and 2.5,[21][22] being highest near the periapsis.