The Royal Observatory in Greenwich has just celebrated its 350th anniversary, having been founded by King Charles II on 22 June 1675.

The observatory was tasked with solving the “longitude problem” of precise timekeeping during long sea voyages.

John Flamsteed from Derby was appointed as the first Astronomer Royal making him the country’s first professional astronomer and he led meticulous observations of the Moon and stars to rectify celestial tables and perfect navigation.

The facility came to be considered as the home of time and navigation and in 1884 it established the Prime Meridian as the world’s zero longitude and Greenwich Mean Time (GMT), with it going on to become a global standard.

The Prime Meridian is essentially an imaginary line that runs around the Earth, basically dividing the planet into two halves, the Eastern Hemisphere and the Western Hemisphere.

Present day the Royal Observatory exists mainly as a museum.

Critical longitude solution

As a maritime nation with a global reach, it became vital to the national interest to solve the practical problem of determining longitude at sea.

In the seventeenth century seafaring was the only way for nations to communicate and assert influence over one another, consequently finding a solution was crucial for everything from trade, to diplomacy, exploration to warfare.

King’s intervention

Sailors and astronomers had long since figured out how to establish their latitude at sea, but despite centuries of of crossing the oceans, nobody had found a system for determining longitude.

King Charles II commissioned a purpose-built scientific institution and so the Royal Observatory’s story began in the year 1675.

Flamsteed appointed

The King had been made aware of the work being undertaken by John Flamsteed in the Midlands town of Derby, and duly appointed him as the country’s “Astronomical Observator” a title that later was changed to “Astronomer Royal”.

He also tasked architect Christopher Wren to design the initial structure that the institution currently on the site grew up around.

Meridiem Derbiensis

Flamsteed carried out his developmental work in his back garden in the centre of Derby using a north-south meridian and referred to the imaginary line as Meridiem Derbiensis.

It was his wish for the meridian to be drawn through Derby, as this was where he had conducted his observations, but the authorities subsequently preferred to have it going through a naval port and it was agreed that it should go through Greenwich, east London.

Showing the way for future scientific minds

His early efforts in bringing a new accuracy to astronomy were pivotal for the later work of the likes of: Nicholas Copernicus, Tycho Brahe, Galileo Galilei, Edmund Halley and Sir Isaac Newton, as it enabled them to clearly model the visible universe.

Newton and Flamsteed often clashed, as a strong rivalry between the two men developed. Sir Isaac had wanted to use the Derby man’s star charts to refine his theories, but his request was rejected because Flamsteed refused to release the charts until he was 100% certain the information was correct.

This led to a frustrated Newton publishing an imperfect version of the work without the Astronomer Royal’s permission.

It was through Flamsteed’s Royal Observatory charting that the planet Uranus was first unwittingly observed, a long time before it was officially “discovered” by William Herschel in 1781.

Prime Meridian accepted

By the 1880s two-thirds of the world’s ships were navigating with maps that used the Greenwich meridian as a reference line. As such, when a conference was held in 1884 to decide the world’s first global, or “Prime” Meridian, Greenwich was the obvious choice.

Added to this was the invention of railway travel which also necessitated the establishment of a unified time zone, which was provided by the Royal Observatory and adopted by the railway companies. 

Telescope finds home in a dome 

With the quest for longitude over, the Royal Observatory explored other avenues of astronomy, such as tracking Earth’s magnetic field, viewing planetary transits and characterizing binary star systems.

This was done with the aid of powerful new equipment, such as the Great Equatorial Telescope – an 8.5 metre refracting telescope – which had to be housed in a vast circular shell known as the ‘Onion Dome’ when installed in 1893.

Enormous visitor numbers

As centuries passed, generations of Astronomers Royal came and went, each leaving their own scientific achievements and personal marks on the historic site, which grew larger as new facilities and buildings sprung up around the original Wren-designed Observatory, respectfully named Flamsteed House.

Now 350 years on the Royal Observatory features prominently as part of the National Maritime Museum and attracts close to two million visitors a year to view its historic buildings, cutting-edge astronomy, navigational artefacts, precious instruments and the UK’s premier planetarium.