While the concept of a solar wind was theorized earlier, these Soviet spacecraft provided the first direct observations of the phenomenon in 1959.
Here's why:
* Luna 1: It was the first spacecraft to pass by the Moon and detected a stream of charged particles coming from the Sun, providing the first evidence of solar wind.
* Luna 2: This spacecraft successfully impacted the Moon's surface and further corroborated the findings of Luna 1, confirming the presence of the solar wind.
While other spacecraft contributed to further understanding and characterizing the solar wind, the Luna missions provided the crucial initial observations that led to its discovery.
