Maximilián Rudolf Hell was an important mathematician, physicist, astronomer and historian of the 18th century. From the local registry book we know that he was born on 15 May 1720 in Winthsachtensis, today Vindšachta – a historical part of the municipality of Štiavnické Bane. His father was Matej Kornel Hell, a known builder of mining reservoirs, and his mother was Juliana Victoria Staindl. He came from a large family; he had as many as 21 siblings, since his father also married a second time. He obtained his primary school education in Štiavnické Bane and secondary schooling at the gymnasium in Banská Bystrica. His interest in the study of mathematics and astronomy was inspired by a professor from Banská Štiavnica, Samuel Mikovíni.
After completing gymnasium studies Maximilián Hell requested acceptance to the Order of the Jesuits. In 1740 he left his monastic services and departed to study history, theology and philosophy in Vienna. He later taught in Levoča and at the Jesuit gymnasium in Banská Bystrica. In 1752 he completed his studies in Vienna and was graduated as a doctor of philosophy. He lectured in mathematics, physics and astronomy in Cluj (in contemporary Romania), where he built an observatory. In 1755 he was named to the function of director of the Imperial Observatory in Vienna, where he remained until his death.
The greatest event in the life of M. Hell as an astronomer was the expedition to the Arctic Circle on the island of Vardø (today the eastern-most island of the Kingdom of Norway), where in 1768 he observed the transit of Venus across the sun. The Danish King Christian VII had invited him on the expedition. As his assistant he chose his former pupil and fellow Jesuit Ján Nepomuk Sajnovics. The expedition achieved excellent results which were later highly valued in scientific circles.
M. Hell included the results in the work “Observatio transitus Veneris ante discum solis” which he published in 1770. Here he confirmed his previous discovery that Venus did not have any moons, and in this period he very exactly calculated the parallax of the Sun and determined the distance from the Sun to the Earth. With this expedition Hell obtained worldwide scientific acknowledgement.
The studies he performed on the northern lights and the magnetic field of the Earth are also pioneering. He likewise studied the sea tide and quadrature of a circle.
Of special importance from his publishing activities was the issuing of 26 scientific studies and 37 astronomical annuals Ephemerides Astronomicae ad meridianum Vindobonensem, which he began publishing in 1757 and continued to publish up to his death. It is quite remarkable that in them he even published a map of the Moon. Astronomers were still obtaining valuable information from these maps into the 20th century.
Maximilián R. Hell was a member of many scholastic societies in Paris, Stockholm, Bologna, Copenhagen and London. He collaborated with the English Royal Society, and in 1790 it awarded him the Order of the English Government for scientific work. In addition to exceptional results of scientific research, he is credited with the building of several observatories in different countries of Europe.
A crater on the dark side of the Moon bears his name. In addition, planetoid 3727, with a diameter of 73 km, is named after Maximilián Hell in the form of Maxhell; it was discovered on 7 August 1981 by astronomer Antonín Mrkos. In 1970 UNESCO put the 250th anniversary of his birth into the calendar of anniversaries of renowned world personalities.
In Slovakia the Regional Observatory and Planetarium of Maximilián Hell in Žiar nad Hronom bears his name, as does the Primary School and a Nursery School of Maximilián Hell in his native municipality of Štiavnické Bane. Several streets in Bratislava, Trnava and Košice also bear the name of Maximilián Hell. The Maximilián Hell and Slovakia Civic Association from Nitra, which in 2014 issued the publication Astronomický denník Maximiliána Hella vedený na ostrove Vardø (The Astronomical Diary of Maximilián Hell Kept on Vardø Island), devotes itself to his life and work.
Maximilián Hell died on 14 April 1792 and is buried in the town of Maria Enzersdorf, near Vienna.