A Descent Landmark for Apollo 15

Feature Profile & Selenographic Data

Feature type

landing

Coordinates

26.10° N · 3.66° E

Diameter

0.32 km

IAU approval

1973/01/01 00:00:00

LAC quadrangle

LAC-41 · Montes Apenninus

Geological Chronicle

Index is a 0.32-kilometer-wide crater in the Hadley–Apennine region of the Moon. During the 1971 Apollo 15 mission, astronauts David Scott and James Irwin used Index as the southernmost of a line of four craters that served as landmarks during descent to the surface.

Scott and Irwin landed the Lunar Module Falcon northwest of Index in 1971, though they did not visit the feature. The crew intended to land closer to Index, but touched down next to Last crater instead.

The other three craters in the line were called Luke, Mark, and Matthew, after three of the major Gospels of the Bible. The astronauts were not allowed to call the crater John because atheist Madalyn Murray O'Hair had sued NASA for astronauts reading from Genesis during Apollo 8. The International Astronomical Union formally adopted the name Index in 1973, while the other three crater names were not.

Chronology & Exploration

1. 1971 Apollo 15 landing descent

   David Scott and James Irwin used Index as a descent landmark before landing Lunar Module Falcon northwest of the crater near Last crater.

2. 1973 Official IAU adoption

   The International Astronomical Union formally adopted the name Index for the crater.

Scientific Sources & References

• IAU Gazetteer of Planetary Nomenclature — Registry coordinates, diameter, and quadrangle details.
• Wikipedia - Index (crater) — Source text for crater location, descent landmark history, naming history, and IAU adoption.

Name Origin

Astronaut-named feature, Apollo 15 site.