Pioneer 10 became the first spacecraft to pass beyond the orbit of Neptune on June 13, 1983

On June 13, 1983, Pioneer 10 became the first spacecraft to pass beyond the orbit of Neptune. So, it is the first spacecraft to pass beyond all the solar system planets.

Venera 4 was launched on June 12, 1967

On June 12, 1967, the Soviet Union launched Venera 4, which means “Venus 4” in English, a probe in the Soviet Venera program for the exploration of the planet Venus. It became the first successful probe to perform in-place analysis of the environment of another planet.

Einstein’s general theory of relativity was proven on May 29, 1919, during a solar eclipse

On May 29, 1919, Einstein’s General Theory of Relativity, which was just four-year-old at the time, was put to its first test during a total solar eclipse. Albert Einstein’s prediction of the bending of light by the gravity of the Sun, one of the components of his general theory of relativity, could be tested by …

Earth passed through the tail of Halley’s Comet on May 19, 1910

On May 19, 1910, the Earth passed through the tail of Halley’s Comet. Prior to the date, using spectroscopy, astronomers detected cyanogen, a very deadly poison in the comet’s tail. This caused panic. French astronomer Camille Flammarion (26 February 1842 – 3 June 1925) even claimed that life on Earth would end because of this.

Neptune’s Moon Nereid was discovered on May 1, 1949

On May 1, 1949, Neptune’s Moon Nereid was discovered by the Dutch astronomer and planetary scientist Gerard Kuiper, who is the eponymous namesake of the Kuiper belt. Nereid is also named Neptune II because it is the second moon of Neptune to be discovered. It is also the last satellite of Neptune to be discovered …

Halley’s Comet made the closest approach to Earth on April 11, 1986

On April 11, 1986, with about 63 million kilometers (39 million miles), Halley’s Comet made its closest approach to Earth on its outbound journey (while moving away from the Sun).

The first moon in orbit around an asteroid (243 Ida) was discovered on March 26, 1994

On March 26, 1994, a photo was released showing the first moon discovered be in orbit around an asteroid, 243 Ida. Today’s (March 26) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.

Christiaan Huygens discovered Titan on March 25, 1655

On March 25, 1655, the Dutch mathematician, physicist, astronomer, and inventor Christiaan Huygens discovered Titan, Saturn’s largest moon and the second-largest natural satellite in the Solar System (after Jupiter’s Ganymede). Today’s (March 25) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.

Cassini discovered Saturn’s moons Tethys and Dione on March 21, 1864

On March 21, 1864, the Italian mathematician, astronomer, and engineer Giovanni Domenico Cassini (8 June 1625 – 14 September 1712) discovered Saturn’s moons Tethys and Dione. Cassini used a refractor telescope with an aperture of 108 mm to make this observation. Today’s (March 21) story of what happened this day in Science, Technology, Astronomy, and Space …

A large solar storm can knock out the internet and electricity. Here’s how

On September 1 and 2, 1859, telegraph systems around the world failed catastrophically. The operators of the telegraphs reported receiving electrical shocks, telegraph paper catching fire, and being able to operate equipment with batteries disconnected. During the evenings, the aurora borealis, more commonly known as the northern lights, could be seen as far south as …