How astrophotography has revolutionized our view of the universe

Saying this might get me into trouble with my fellow art lovers, but… I don’t think there is a painting in the world that can compare to the beauty of the universe.

From the classic Hubble Space Telescope’s “Pillars of Creativity” image, to Curiosity rover selfies on Mars, and now the stunning first images to come from the James Webb Space Telescope, images (and from) space are inspiring countless people around the world.

The famous Hubble image in 1995

Hubble’s famous 1995 image “Pillars of Creation”. Credit: NASA, ESA, STScI, J. Hester, and P. Scowen (Arizona State University)

But these photos weren’t just taken so that space geeks like me would have nice ones to use as computer backgrounds.

Astrophotography has fundamentally changed our understanding of the universe.

In 1883, an amateur astronomer named Andrew Ainsley Common took a long-exposure image through his telescope of the Orion Nebula, revealing details in his astronomical image that were usually invisible to the eye.

Orion Nebula Andrew Ainslie Common

Andrew Ainsley Common’s amazing picture of the Orion Nebula, taken in 1883!

By the early 20th century, astrophotography was common in professional observatories such as the Harvard Observatory, where women including Williamina Fleming and Henrietta Swan-Levitt worked as human “computers”, cataloging and classifying stars in photographic plates.

Later, in 1925, Edwin Hubble was examining images of the Andromeda galaxy and spotted Cepheid-type variable stars, which he then used to calculate the galaxy’s distance.

His measurements placed the Andromeda galaxy outside our own Milky Way, and finally resolved the great debate in astronomy over the nature of “spiral nebulae” (as galaxies were referred to at the time) and the size of the universe.

In the modern era …

A self-portrait taken by the Curiosity rover on the surface of Mars.  Credit: NASA/JPL-Caltech/MSSS

A self-portrait taken by the Curiosity rover on the surface of Mars. Credit: NASA/JPL-Caltech/MSSS

Modern telescopes have outgrown photographic plates, but the principles have remained the same.

Point a telescope at something, and collect as much light as possible during the long exposure to bring out detail, and you might see something unexpected.

The Hubble Deepfield image is perhaps my favorite example of this.

In 1995, Robert Williams, director of the Space Telescope Science Institute, pointed Hubble toward a tiny, seemingly empty portion of the sky for more than 100 hours.

The resulting image revealed about 3,000 distant galaxies crammed into a pinhead-sized patch of sky pinned at arm’s length.

Hubble deep field.  Credit: R. Williams (STScI), Hubble Deep Field Team, and NASA/ESA

Hubble deep field. Credit: R. Williams (STScI), Hubble Deep Field Team, and NASA/ESA

Analysis of astronomical images can also lead us down unexpected paths, as my colleagues at the University of Portsmouth recently discovered during the Covid pandemic.

It turns out that the computer codes used to automatically find galaxies in astronomical images can also be used to identify cough drops!

The team used a fluorescent dye in a “cough machine” to simulate a person coughing.

Then they took pictures of the cough droplets produced and applied the same computer code to these pictures to determine where the cough droplets fell.

This unusual application of an astronomical instrument allowed the team to study how droplets spread from coughs, which is clearly important in the fight against the spread of COVID-19.

An image of cough drops surprisingly looks like an astronomical deep field image.  The Galactic Search Program at the University of Portsmouth is used to analyze the data.  Credit: University of Portsmouth

An image of cough drops surprisingly looks like an astronomical deep field image. The Galactic Search Program at the University of Portsmouth is used to analyze the data. Credit: University of Portsmouth

Of course, we have to remember that these beautiful pictures are not for everyone.

Relying on the use of images to express how wonderful the universe is has the potential to exclude people who are blind and visually impaired.

This is why there are a growing number of projects around the world working on ways in which people can interact with astronomical observations through 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 rather than seen, allowing everyone to experience the wonders of the universe that surrounds us.

This article originally appeared in the October 2022 issue of BBC Sky at Night Magazine.

Leave a Comment