Today In 1984, DNA fingerprinting was discovered in Leicester, England, by Alec Jeffreys as X-ray films of his tests first revealed the possibility.

Today In 1945, the term “bug” in a computer program was discovered by Grace Hopper when a moth was removed with tweezers from a relay and taped into the log.

On this day In 2040, the first visible conjunction during the 21st century of the crescent Moon with the five naked-eye visible planets - Mercury, Venus, Mars, Jupiter and Saturn - will occur.

Today In 1776, the first U.S. submarine built for wartime use, the American Turtle, was used in New York harbour to attach explosives to the hull of the Eagle, Admiral Howe's flagship.

Today in In 1947, the aircraft-carrier Midway became the first U.S. vessel from which a long-range rocket was launched.

Opened today In 1882, the first central electric station to supply light and power was the Edison Electric Illuminating Company at 257 Pearl Street in New York City.

Today In 1803, John Dalton recorded in his notebook “Observations on the Ultimate Particles of Bodies and their Combinations,” in which he introduced his atomic symbols.

Christa Corrigan McAuliffe, Born 2 Sep 1948; died 28 Jan 1986 at age 37. American teacher who was chosen to be the first private citizen in space. Aboard the space shuttle Challenger, she was one of the seven astronauts killed when the rocket exploded 73 seconds after takeoff.

Today 1881, in a Presidential Address to the British Association, at York, Sir William Thomson (Lord Kelvin) spoke On the Sources of Energy in Nature Available to Man for the Production of Mechanical Effect. He summarized the natural sources of energy derive energy from the sun

Today in 1836, a second U.S. patent was granted to one of the earliest African-American inventors, Henry Blair, a free man of Glenross, Maryland, for a cotton seed planter (No. 15). His first patent was for a corn planter (14 Oct 1834, No. X8447).

Sylvia A. Earle, Born 30 Aug 1935. Sylvia Alice Earle is an American oceanographer who is a devoted advocate of public education regarding the importance of the oceans as an essential environmental habitat.

John Locke, Born 29 Aug 1632; died 28 Oct 1704 at age 72. English physician who was the most important philosopher during the Age of Reason.

Today In 1789, Sir William Herschel discovered Saturn's moon Enceladus.

Today in 1875, the element gallium was discovered by P.E. Lecoq de Boisbaudran.

Hertha Marks Ayrton, born 28 Apr 1854. An English electrical engineer, inventor and mathematician whose aptitude for science and mathematics began in school. She invented a sphygmograph (a device that charts pulse beats, , a line divider and an anti-gas fan

Today in 1973, the first scan was made using CAT (Computer Assisted Tomography).

Today in 1932, Amelia Earhart became the first woman to fly non-stop across the United States, traveling from Los Angeles to Newark, N.J., in just over 19 hours.

Today in 1609, the telescope was demonstrated by Galileo.

In 1989, the first complete ring around Neptune was discovered in photographs transmitted by Voyager 2 to the Jet Propulsion Laboratory in the U.S. Dusty debris was seen to form a tenuous but complete ring about 17,000 miles above Neptune

In 1888, William Seward Burroughs of St. Louis, Missouri, received patents on four adding machine applications (No. 388,116-388,119), the first U.S. patents for a "Calculating-Machine" that the inventor would continue to improve and successfully market.