What Are Perigee and Apogee? When Are Perigee and Apogee?

Primary Image

Lunar Perigee and Apogee and the Moon's Orbit

Print Friendly and PDF
No content available.

Ever heard the terms perigee and apogee? The Moon’s orbit periodically grows rounder and then more oval; it is never a perfect circle. Therefore, sometimes, the Moon is closer to the Earth than at other times.

What is Perigee and Apogee? 

A simple definition: 

  • The point at which it is nearest Earth each month is called its perigee (this varies throughout the year).
  • The point at which the Moon is farthest from Earth each month is called its apogee (this varies throughout the year as well).

According to NASA, “During every 27-day orbit around Earth, the Moon reaches both its perigee, about 226,000 miles (363,300 km) from Earth, and its farthest point, or apogee, about 251,000 miles (405,500 km) from Earth.”

In recent times, the news media has taken to calling a full Moon near perigee a “Supermoon” because its nearness to Earth causes the Moon to appear bigger and brighter. This effect can be enhanced by what we call the “Moon Illusion.”

Image credit: NASA

When are Perigee and Apogee?

Lunar Perigees and Apogees in 2024

Lunar Perigees and Apogees in 2024
January 01
January 13January 29
February 10February 25
March 10March 23
April 07April 20
May 05May 17
June 02June 14
June 27July 12
July 24August 09
August 21September 05
September 18October 02
October 17October 29
November 14November 26
December 12December 24

Lunar Perigees and Apogees in 2025

Lunar Perigees and Apogees in 2025
January 08January 21
February 02February 18
March 01March 17
March 30April 13
April 27May 11
May 26June 07
June 23July 05
July 20August 01
August 14August 29
September 10September 26
October 08October 23
November 05November 20
December 04December 17

Perigee and apogee also affect the tides.

During the final quarter of the 20th century, the Moon was as close to Earth as 216,500 miles (surface to surface) at its most extreme perigee and as far away as 247,700 miles at its most extreme apogee. At perigee, tidal ranges are increased; at apogee, they are decreased.

To a lesser degree, the Sun has a similar tidal effect, a consequence of its location just 91.5 million miles away in early January but some 94 million miles distant in July.

The punctual tide draws up the bay
With ripple of wave and hiss of spray.
–Susan Coolidge, American writer (1835-1905)

About The Author

Bob Berman

Bob Berman, astronomer editor for The Old Farmer’s Almanac, covers everything under the Sun (and Moon)! Bob is the world’s most widely read astronomer and has written ten popular books. Read More from Bob Berman

No content available.