-- Perihelion . . . Point in Earth's orbit where we're closest to the sun.
We get there sometime during the first few days of January.
-- Aphelion . . . Point in Earth's orbit where we're farthest from the sun.
We get there sometime during the first few days of July.
-- Perigee . . . Point in the orbit of the Moon or any artificial satellite
where it's closest to the Earth.
-- Apogee . . . Point in the orbit of the Moon or any artificial satellite
where it's farthest from the Earth.
