Gravity and Orbital Motion
Conditions d’achèvement
Consulter le glossaire à l’aide de cet index
Spécial | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Tout
P
Perihelionthe point in an orbit closest to the Sun. | |
Planetary defenceefforts to detect and potentially prevent dangerous asteroid or comet impacts. | |
Planetary massthe total mass of a planet. | |
Planetary radiusthe distance from the centre of a planet to its surface. | |
Polar orbitan orbit that passes over or near Earth's poles. | |