October 18, 1867: Alaska Day. On this day in 1867, in Sitka, Alaska, the Russian flag came down and the American flag went up. The United States had bought Alaska from Russia. Alaska is home to Denali, the highest mountain in North America.
1954 π‘ Texas Instruments announced the Regency TR-1, the first transistor radio made in large numbers. Small enough to carry, it let people listen to music anywhere.
1967 π The Soviet probe Venera 4 reached Venus and dropped into its thick clouds. It was the first spacecraft to measure the air of another planet.
2019 π NASA astronauts Jessica Meir and Christina Koch stepped outside the International Space Station together in the first spacewalk done only by women.