The Royal Observatory at Greenwich has been pivotal to astronomy and navigation since the beginning of time. Well, international standard time at least. But what few people realise is that the observatory has not actually observed anything for more than half a century.

Astronomers were forced to abandon their work in the 1950s as London smogs grew so bad that they could no longer see the stars through their telescopes.

As the railways expanded nearby, the rumble of trains also made it impossible to take accurate readings with sensitive instruments, while the ever-growing capital brought increasingly dazzling light pollution.

Now, after more than 60 years a new telescope has been installed at Greenwich to restore its status as a working observatory once again. Not only is London’s air cleaner now, but modern telescope filters can tune out the pollution to hone in on the stars, planets, nebulae and even galaxies.

Curator of Royal Observatory Greenwich, Dr Louise Devoy said: “The observatory really started to wind down in 1948 because Greenwich had been expanding, and Greenwich Power Station was belching out smoke so the telescopes were becoming useless.

“They also used to do magnetic and meteorological readings from here, but the railways and iron-framed buildings interfered with the signals and the vibrations from the trains made accuracy impossible. With the new telescope we can use filters and software to process it all out.”