The Royal Greenwich Observatory reopens 60 years after London smog forced it to shut down.

The famous Royal Observatory in Greenwich, UK, reopens more than 60 years after London smog forced its closure in 1957.

The Royal Observatory was founded in 1675 by King Charles II of England, with the aim of improving navigation at sea and reducing shipwrecks by mapping the locations of the stars. The Greenwich Observatory is the site of the main meridian, the line that separates the western hemispheres east and west (in the same way that the equator divides the northern and southern hemispheres). It is also the historic site of Greenwich Mean Time, which is the basis of the world system of time zones.

In the 1940s and 1950s, the industrialization of London – which expanded the city's railways and resulted in extreme light pollution – began to interfere with the operations of the Royal Urbanized Observatory. Louise Devoy, curator of the Royal Observatory of Greenwich, said in a recent interview with the Telegraph: "The observatory really began to close in 1948 because … [the] The Greenwich power station was spitting smoke and the telescopes were becoming useless. She added that nearby train vibrations and signals from metal frame buildings made it difficult to accurately read sensitive equipment from the observatory.

In addition, the air pollution of the city was so bad that astronomers could no longer do their job. In the middle of the 20th^th century, London was periodically plagued by thick yellow smog blankets, which were so severe that they stopped traffic and even closed the theaters because the audience could not see the artists on stage through the haze . (The phenomenon appeared in an episode of season 1 of The crown.) Seeing distant stars through telescopes was almost impossible under such conditions.

Due to the challenges and limitations of running an observatory in an urban setting, the Royal Observatory began transferring its instruments and functions to Sussex in 1948, whose skies were darker and lighter than those from London. In 1957, the Royal Greenwich Observatory reopened at Herstmonceux Castle and the late London Observatory became a museum and outreach center to educate the public on astronomy.

In 2017, the Royal Museums Greenwich launched a successful campaign to raise funds to restore the Greenwich Observatory and modernize the building in which it was housed.

The revamped Royal Observatory was equipped with a new telescope named after Annie Maunder, who was one of the first female scientists to work at the Greenwich Observatory. Maunder was hired in 1891 to process data as "lady computer". His subsequent research mapping sunspots and observing solar eclipses helped shed light on the link between sun activity and the Earth's climate.

The astronomical telescope Annie Maunder of the Royal Observatory consists of four different telescopes fulfilling different functions. The taller one can produce enlarged views of the moon and planets in our solar system. Another telescope will track and record the changes in the sun. The observatory will also be able to observe nebulae and galaxies with a specialized digital camera.

Many of the world's observatories are located in remote areas with little light pollution, like the Very Large Telescope (yes, that's really its name) in the heart of the Atacama Desert in Chile. However, advances in technology have made urban astronomy more feasible. Astronomer Brendan Owens explained to the Telegraph: "We now have filters that completely block the wavelengths of light from streetlights and focus on hydrogen, oxygen and oxygen. sulfur dioxide from stars and planets.

Astronomers from the reopened Royal Observatory hope to witness the lunar eclipse "blood moon" on July 27, during which the moon will turn a reddish color as it goes through the shadows of the earth.

"It should be pretty spectacular," Owens said of the upcoming eclipse. "We can also use the red hue to talk about air pollution because it changes the [Moon’s color] during an eclipse. Fortunately, although the London air is still very polluted, the air quality has visibly improved since the time of the Great Smog.