Human observation of Earth gains a new participant

Mariner 2 showed that interplanetary spacecraft could return measurements from distant worlds.

The flyby provided direct data to compare with Earth-based astronomical observations.

Valentina Tereshkova became the first woman to travel in space.

The Vostok 6 mission began from Soviet Central Asia and went on to orbit Earth 48 times.

Tereshkova’s launch showed a woman could perform an orbital spaceflight despite earlier exclusion.

The satellites recorded the first known cosmic gamma-ray burst; its extraterrestrial source was recognized later.

The gamma-ray signal was initially detected by instruments built to monitor nuclear explosions.

The detection later helped establish the study of transient cosmic gamma-ray sources.

The recorded burst had no precise sky position at detection; its meaning became clear only with later analysis.

Armstrong and Aldrin landed in the Sea of Tranquility while Collins remained in lunar orbit.