“While light pollution in London is bad, planets are very bright, and the biggest problem is not light, but the wobbly atmospheric conditions created by the heat rising off the city. Conditions were not the best last week, but we tried to see as many planets as possible. Some planets were particularly hard to photograph – mainly Mercury, because it’s small, and close to the horizon.”
Professor Malcolm Fairbairn, of the Department of Physics
03 March 2025
Physicists capture rare 'planetary parade' at King's observatory
Alignment of planets captured from King's observatory at the Strand.
Physicists have captured a rare ‘planetary parade’ in the night skies using King’s College London’s rooftop observatory.
During the rare alignment of Mars, Jupiter, Uranus, Venus, Neptune, Mercury, and Saturn last week, the planets appeared close together, due to their respective orbital positions, despite being millions of kilometres apart. This phenomenon will not be seen again for another 15 years.
While some planets could be seen by the naked eye, the King’s observatory enabled astronomers to capture every planet in the alignment – even in central London’s skies.
The King’s observatory includes a telescope fitted in a large dome, on top of the King’s Building in the centre of Strand campus. It was created by Professor Malcolm Fairbairn, who noticed the domed roof when he first joined King’s and secured funding for a functioning telescope. It has since served to educate students on astrophysics and how to use astronomy equipment.
Professor Malcolm Fairbairn, of the Department of Physics, was joined by third-year project students, Zain El Bakali, Aiden-Thomas Cabourne and Marta Bugallo Pizarro to see what they could observe from the roof of the King’s building, which was not without its challenges.
He said the main part of the project for the students was completing computational image processing to answer questions about the evolution of stars.
“Planets are fun to observe, though, and in previous years we have use spectography – the process of analysing the spectrum of light – to identify the presence of methane in Jupiter.”
Dr Shyam Balaji, a researcher in astroparticle physics and cosmology at King’s, explained the science behind the parade.
“Planetary alignments occur because the planets in our solar system orbit the Sun within roughly the same plane, known as the ecliptic plane. As they orbit at different speeds and distances from the Sun, there are moments when they appear to line up from Earth's perspective. This alignment is a visual phenomenon rather than a physical one, as the planets remain separated by millions or even billions of kilometres in space.”
Dr Shyam Balaji, a researcher in astroparticle physics and cosmology
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