The Sky at Night TV show, past, present and future
Inside The Sky at Night
In September’s episode of The Sky at Night, Jen Gupta looked at how ever more stunning astronomical photos have revolutionised our understanding of the cosmos
Saying this will probably get me in trouble with my art-loving colleagues, but… I don’t think there’s a painting in the world that can compare to the beauty of the Universe.
From the classic ‘Pillars of Creation’ photo taken by the Hubble Space Telescope, to Curiosity Rover’s selfies on Mars, and now the stunning first images coming from the James Webb Space Telescope, photographs of (and from) space are a source of inspiration to countless people around the world. But these images aren’t just taken so that space nerds like me have pretty pictures to use as our computer backgrounds. Astrophotography has fundamentally changed our understanding of the Universe.
Back in 1883, an amateur astronomer called Andrew Ainslie Common took a long-exposure photograph through his telescope of the Orion Nebula, revealing details in his astrophoto that were normally invisible to the eye. By the early 20th century, astrophotography was commonplace in professional observatories like the Harvard Observatory, where women including Williamina Fleming and Henrietta Swan Leavitt worked as human ‘computers’, cataloguing and classifying stars in photographic plates. Later, in 1925, Edwin Hubble was examining photographs of the Andromeda Galaxy and spotted Cepheid variable stars, which he then used to calculate the galaxy’s distance. His measurements placed the Andromeda Galaxy firmly outside our Milky Way Galaxy, finally resolving the debate about the nature of ‘spiral nebulae’ (as they were referred to then) and the size of our Universe.
Seeing the really big picture
Modern telescopes have moved beyond photographic plates, but the principles remain the same. Point a telescope at something, gather as much light as possible during a long exposure to bring out the details, and perhaps see something unexpected. The Hubble Deep Field image is probably my favourite example of this. In 1995, Robert Williams, director of the Space Telescope Science Institute, pointed Hubble at a tiny, seemingly empty, part of the sky for over 100 hours. The resulting image revealed around 3,000 distant galaxies crammed into a patch of sky the size of a pinhead held at arm’s length.
The analysis of astronomical images can also lead us down unexpected paths, as my colleagues at the University of Portsmouth recently found out during the pandemic. It turns out that computer codes used to automatically find galaxies in astronomical images can also be used to identify cough droplets! The team used fluorescent dye in a ‘cough machine’ to simulate a person coughing. They then took photos of the resulting cough spray and applied the same computer code to these photographs to pick out where the cough droplets landed. This unusual application of an astronomical tool allowed the team to study how droplets spread from a cough, something that’s obviously important in fighting the spread of COVID-19.
Of course, we need to remember that these beautiful images are not accessible for everyone. A reliance on using imagery to convey how aweinspiring the cosmos is has the potential to exclude people who are blind and vision-impaired. This is why there’s a growing number of projects around the world that are working on ways for people to interact with astronomical observations through the other senses. At the University of Portsmouth we run the Tactile Universe project where we make 3D printed versions of astronomical images so that they can be felt instead of seen, allowing everyone to experience the wonder of the Universe that surrounds us.
Looking back: The Sky at Night
18 October 1979
In this episode of The Sky at Night, Patrick Moore took a look towards our nearest star, the Sun. Even in the 1970s, many of the fainter wonders of the night sky were hidden from urban viewers by light pollution, but the Sun was just as visible from the middle of a city as a remote mountainside.
To prove this, he met Peter Gill, an amateur astronomer who observed the Sun using just a small, filtered telescope from the window of his third-floor flat in London. Normally, observing out of the window is inadvisable. The glass will disrupt the view or if it’s open, the temperature difference between inside and outside will create turbulent air currents and an unstable image.
But astronomy through a window is better than no astronomy at all. And solar astronomy is a great option because not only is the temperature less unbalanced during the day, the Sun is large enough that an unstable image won’t affect the view too much.
Gill was also a long-time member of the British Astronomical Association. The BAA collects amateur observations here in the UK and sends its results to the World Data Centre in Brussels, where they contribute to humanity’s understanding of our star. It welcomes images of the whole disc or specific regions, taken in white light, hydrogen-alpha and calcium K, including hand-drawn observations. Visit britastro.org/sections/solar for details.
OCTOBER
The Sky at Night: Question Time
The lively – and live – panel discussion on all things astronomy, astrophysics and cosmology returns! In this special episode, presenters Chris, Maggie and Pete, host Dallas Campbell, plus special guests from the worlds of spaceflight and astronomy, face questions from a live studio audience at De Montfort University, Leicester, as part of the 2022 British Science Festival.
BBC Four, 10 October,10 pm (first repeat will be on BBC Four, 13 October, time tbc)
Check www.bbc.co.uk/skyatnight for more up-to-date information
Jen Gupta is a senior public engagement fellow at Portsmouth University’s Institute of Cosmology and Gravitation