Learn about the history of science by reading about the significant scientific events that took place on this day in history.
1964 - NASA's Mariner 4 was launched.
NASA's Mariner 4 spacecraft was launched from Cape Canaveral on its way to Mars. It was the first spacecraft to approach the planet Mars and send back pictures of the planet's surface. Mariner 4 sent back 22 pictures that showed impact craters and vast stretches of barren terrain much like the Moon. It was later learned the terrain mapped by Mariner 4 was atypical of most of the Martian surface.
1954 - Enrico Fermi died.
Fermi was an Italian physicist who made many pioneering advances in nuclear physics. He was awarded the 1938 Nobel Prize in Physics for producing radioactive elements by neutron irradiation and reactions caused by slow neutrons. His work during the Manhattan Project involved building the first nuclear reactor pile. The element fermium, the elementary particle family fermions and Fermilab outside of Chicago are all named in his honor
1950 - Russell Alan Hulse was born.Hulse is an American astrophysicist who shares the 1993 Nobel Prize in Physics with Joseph H. Taylor Jr. for the discovery of binary pulsars. A pulsar is a rapidly spinning neutron star that emits radio bursts at regular intervals. Hulse and Taylor discovered an unusual pulsar that appeared to be a pulsar with a neutron star locked into a tight orbit together. Further investigation showed the stars are rotating steadily faster around each other suggesting their orbits are losing energy in the form of gravity waves. This discovery is considered the first experimental evidence of the existence of gravity waves predicted by the general theory of relativity.
1876 - Karl Ernst von Baer died.
Baer was a Estonian biologist who is considered the father of embryology. He was the first to isolate the mammalian egg cell. He was the first to show that mammals develop from eggs and outlined four laws of embryology. He also made contributions to geology and entomology.