July 4: George Everest born, Marie Curie dies, NASA Mars Pathfinder launches

George Everest: the man behind the mountain

Sir George Everest was born on 4 July 1790 (and died on 1 December 1866 aged 76).

He was a Welsh military engineer and geodesist, whose major work was the Great Trigonometrical Survey of India (1818–43). It was the first accurate mapping of the subcontinent. The trigonometrical survey was commenced in 1802, acquired the Great Trigonometrical Survey of India name in 1818, and was completed in 1871. Everest was its leader (superintendent) from 1823 to 1843

The task took nearly 70 years, and such was Everest’s pursuit of accuracy that he made many modifications and adaptions to the equipment and methods used, let alone the mathematics required.

We obviously know his name well: Mount Everest, formerly called Peak XV, was renamed in his honour in 1865. The name was first proposed in 1856 and adopted in 1865; Everest was against it.

Marie Curie dies

Marie Curie died on this day in 1934 aged 66.

Curie was a Polish-French chemist and physicist; her experiments in 1898 on uranium minerals led to discovery of two new elements: polonium and radium. With Henri Becquerel and her husband, Pierre Curie, she was awarded the 1903 Nobel Prize for Physics. She was also the sole winner of a second Nobel Prize in 1911, for Chemistry. Her family won five Nobel prizes across two generations. She died of radiation poisoning from her pioneering work before the need for protection was understood.

Mars Pathfinder lands

The Mars Pathfinder was launched on 4 December 1996 aboard a Delta II booster and landed on 4 July 1997 on Mars’ Ares Vallis, in a region called Chryse Planitia in the Oxia Palus quadrangle. Its main scientific mission was to study the Martian atmosphere and investigate the geology and chemistry of the planet’s rocks and soils.

Pathfinder was made up of two parts: a lander, renamed the Carl Sagan Memorial Station, and a 10.6kg wheeled robotic Mars rover named Sojourner, which became the first rover to ever operate outside the Earth–Moon system.