Pin It
 Tarantula Nebula, via Webb’s Near-Infrared Camera (NIRCam)
Tarantula Nebula, via Webb’s Near-Infrared Camera (NIRCam)Courtesy NASA, ESA, CSA, STScI, Webb ERO Production Team

From the cosmic cliffs to the Hand of God: unpicking the poetry of space

How do the intergalactic objects captured by the James Webb Space Telescope get their names? We asked astronomer Bob Fosbury, AKA the man who christened the Cartwheel Galaxy

An intergalactic tarantula. A cosmic whirlpool. A diamond necklace of galactic proportions. The tadpole and the porpoise, the sunflower and the sombrero. A cosmic cloud with a mysterious “heartbeat”. These are just a few of the images that astronomy conjures up to describe the objects we see in space, from distant stars, to galaxies, to whole nebulas, rightly earning it a reputation as the artsy sibling of the science family.

Just last week, NASA shared new images of the majestically-named Pillars of Creation: stunning clouds of gas and dust that were captured by the Hubble Space Telescope in 1995, and have now been brought into sharper focus. These “pillars” are incredible to look at – like dusty, glowing rock formations sticking up out of the Eagle Nebula, 6,500 light-years away from Earth – and it could be argued that they’re deserving of their spiritual sobriquet, but how did they come to be called that?

This question has been increasingly on our minds since July this year, when the recently-launched James Webb Space Telescope began beaming images back to Earth from 1.5 million kilometres away (including, most recently, the near-infrared images of the Pillars of Creation). These images have offered us unprecedented views of the Tarantula Nebula, the “cosmic cliffs” of the Carina Nebula, WR 140 – a pair of stars that leave their “fingerprint” on the universe as they dance through space – and more, which have continued to capture the public imagination.

Since astronomical nicknames are more popular than ever, we sought out an expert to tell us where they come from, what they mean, and how they help spread the word about space.

Introducing: Bob Fosbury, an emeritus astronomer at the European Southern Observatory, who worked for 26 years at the European Space Agency as part of its collaboration with NASA on the Hubble Space Telescope. Bob also helped to decide what instruments were sent up with the James Webb Space Telescope, and – if that wasn’t enough to qualify him for this very unscientific investigation into the poetics of space – he himself named a galaxy, the Cartwheel Galaxy, back in 1977.

In fact, the Cartwheel Galaxy had taken a back seat in Bob’s memory – beyond its significance as the subject of one of his first scientific papers – until recently, when the JWST turned its eye toward the distant object, which is spinning through space some 500 million light-years away. Now, the story has “crystallised into something much more interesting and much more surprising”, he says. “It’s much more important to me now than it was if you’d asked me 20 years ago… and it’s been triggered by this crystallisation process, having the Webb picture taken.”

To unpack the name of the Cartwheel Galaxy, we have to run the clock back a few decades to the mid-70s, when Bob was selected to work on the newly-opened Anglo-Australian Telescope in New South Wales, Australia. There, he collaborated with the late South African astronomer Tim Hawarden, who was working at a different telescope on the same mountain, and together they studied what would become known as the Cartwheel Galaxy, which they referred to at the time by a much-less-catchy name: A0035.

They weren’t the first to stumble across the galaxy; the famed astronomer Fritz Zwicky discovered the rare structure in 1941 (“He didn’t name it, but he noticed it”) and it was also included in a catalogue of peculiar galaxies by the Russian astronomer Boris Vorontsov-Velyaminov. Nevertheless, Bob and Tim “rediscovered” it from their base in Australia, and the fact that they – unlike Zwicky – gave it a nickname may be part of the reason we’re still talking about it today.

In case you haven’t seen the JWST images of the Cartwheel Galaxy (above), it’s made up of two rings: the inner ring is bright and fuzzy, while the outer ring – which has been expanding for hundreds of millions of years – is multi-coloured, dotted with newborn stars and supernovae. Columns of dust spiral out from the galaxy’s centre like spokes on a wheel. This kind of galaxy is formed by a collision of massive proportions. Bob concluded that a separate galaxy had passed through the middle of the Cartwheel, sucking dust and stars inward toward the core, before “bouncing” them back to the outer rim as it came out the other side.

Bob isn’t exactly sure when he and Tim began referring to the galaxy as the Cartwheel, but says that its appearance made the name “absolutely obvious”. Naming a galaxy isn’t a particularly difficult process, either, so long as you have the research to back it up. “It probably originated while we were walking between the two telescopes at night or something like that,” Bob adds. “It was such an obvious name, we just called it the Cartwheel as a shortcut, a way of communicating between ourselves.” The two astronomers would make it “official” in their 1977 paper on their observations.

Evidently, the name stuck. Decades later, astronomers, science writers, and space fans alike are still talking about the Cartwheel Galaxy (after all, it’s not every day you get to see the aftermath of two galaxies crashing into each other). In public, most prefer to refer to it by its descriptive nickname, instead of its technical names, ESO 350-40 or PGC 2248. Even those that disagree with Bob and Tim – such as the astronomers locked in a dispute about which galaxy crashed through its centre hundreds of millions of years ago – call it the Cartwheel, and the prominence of this name has only grown as the conversation sprawls out into a broader debate about the dynamics of interacting galaxies.

Does Bob think that the poetic name is responsible for the sustained interest in the Cartwheel Galaxy, which has seen NASA dedicate valuable time with the JWST to studying its structure? “Absolutely, yes,” he says. “We didn’t do this on purpose, it was a nickname for us. We put it in the title of the paper, but we were totally unaware of the future history. But I think it does make a big difference.”

Ok, so Bob and Tim naming the Cartwheel on an evening stroll between two telescopes might not be a particularly dramatic origin story. But the name – alongside the stunning images taken by the likes of JWST – acts as an entry point into a much richer and more complex conversation about what’s going on up there, hundreds of millions of light-years away. 

The relative mystery of these objects might also explain astronomy’s tendency to christen them with particularly poetic names, including both real-world analogies, like the Cartwheel, and more spiritual images (see: the Pillars of Creation or the Hand of God, which both draw upon Christian tradition). Just like ancient civilisations christened our own galaxy, the Milky Way, via myths based on its appearance in the night sky, modern astronomy uses these poetic metaphors to describe celestial objects we don’t fully understand, and to inspire future generations to uncover more of their secrets.