Previously on this day

The Tunguska Event, or Tunguska explosion, was a massive explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai of Russia on June 30, 1908. The explosion was most likely caused by the air burst of a large meteoroid or comet fragment at an altitude of five to ten kilometers above Earth’s surface. Different studies have yielded varying estimates for the object’s size, with general agreement that it was a few tens of meters across.

Although, the meteor or comet burst in the air rather than directly hitting the surface, this event is still referred to as an impact. Estimates of the energy of the blast range are from five megatons to as high as 30 megatons or TNT, with 10-15 megatons the most likely – about 1000 times as powerful as the bomb dropped on Hiroshima, Japan and about one third the power of Tsar Bomba.

The explosion knocked over an estimated 80 million trees over 2,150 square kilometers. It is estimated that the earthquake from the blast would have measured 5.0 on the Richter scale. The Tunguska Event is believed to be the largest impact event on land in Earth’s recent history.

Share this page

The Moscow-Washington hot line is a system that allows direct communication between the leaders of the United States and the Soviet Union. It was originally designed by the Harris Corporation and is also known as the “red telephone,” linking the White House via the National Military Command Center with the Kremlin during the Cold War.

The “Hot Line,” as it would come to be known, was established following an agreement on June 20, 1963 by the signing of the “Memorandum of Understanding Regarding the Establishment of a Direct Communications Line” in Geneva, Switzerland, after the events of the Cuban Missile Crisis made it clear that reliable, direct communications between the two nuclear powers was a necessity. White House advisers at the time thought that the crisis could have been more quickly resolved and easily averted if communication had been faster.

The first generation of the hot line had no voice element at all and the memorandum called for a full-time duplex wire telegraph circuit. The first use of the hot line was in 1967, during the six-day Egypt-Israel War, when both superpowers informed each other of military moves that might have been provocative or ambiguous.

Share this page

Valentina Tereshkova was born in Bolshoye Maslennikovo. She became interested in parachuting at a young age and trained at the local Aeroclub, making her first jump at age 22. It was her expertise in parachute jumping that led to her selection as a cosmonaut.

After Yuri Gagarin’s flight into space in 1961, Sergey Korolyov, the head Soviet rocket engineer, came up with the idea of putting a woman in space. On February 16, 1962, Tereshkova was selected to join the female cosmonaut corps. Out of more than 400 applicants, five were selected. Tereshkova was considered a particularly worthy candidate, partly due to her “proletarian” background, and because her father had died as a war hero during World War II.

Training included weightless flights, isolation tests, centrifuge tests, rocket theory, spacecraft engineering and so on. After several months of intensive training concluding with examinations, four candidates were commissioned in the Soviet Air Force. Tereshkova was nominated to pilot the Vostok 6 which launched on June 16, 1963. Although she was in a state of nausea and physical discomfort for much of the flight, she orbited the Earth 48 times and spent almost three days in space.

Share this page