Aftermath of DART collision with Dimorphos, captured by SOAR telescope. Tail visible as long white streak against black space.

October 14, 2022, by Brigitte Nerlich

Asteroids: Angst, amazement and avarice

On planet earth it is extremely difficult to change people’s, especially politicians’, behaviour to avert, say, climate catastrophe. Not so in space. Here humans boldly achieve the unthinkable, namely changing the motion of something that’s going in a dangerous direction. What I am talking about is, of course, NASA’s “first-ever mission dedicated to investigating and demonstrating one method of asteroid deflection by changing an asteroid’s motion in space through kinetic impact”.

On 24 November 2021 NASA launched the Double Asteroid Redirection Test (DART) spacecraft and, on 26 September 2022, crashed it into Dimorphos, a small celestial body just 160 metres in diameter, which orbits a larger asteroid called Didymos – a crash observed by space telescopes such as old man Hubble and newcomer James Webb.

On 11 October NASA announced that this collision had successfully shortened Dimorphos’ orbital period by about 32 minutes. To put it more memorably, they announced that: “This marks humanity’s first time purposely changing the motion of a celestial object”. Think about that! As India Today noted more prosaically: “Dinosaurs avenged”, referring to the asteroid that caused the extinctions of the dinosaurs some 66 million years ago. The New York Times put it more poetically, referencing the first time humans set foot on the moon: “One small shift in a space rock’s trajectory could, someday, mean one giant sigh of relief for humankind, if it pushes an asteroid off a collision course with Earth.”

(As an aside… It’s interesting to see how Dimorphos is framed in that article, as ‘poor little Dimorphos’ being ‘bullied’ by DART – a strange framing of an object that’s supposed to pose a danger to humanity. We just can’t avoid anthropomorphising space crafts and space objects.)

Asteroids and angst

We have been observing and fearing comets (celestial objects that have ‘tails’) and asteroids (space rocks of various shapes and sizes) for a long time, but, until now, ‘we’ have never pushed them.

What one may call asteroid angst was not only related to the worry that a celestial object might hit the earth but, even more, that it was the portend of some doom or other. This superstition has now waned but impact worries persist, especially after the discovery that the dinosaurs had been wiped out by an asteroid hit. Movies, from When Worlds Collide (1951) to Armageddon (1998), to Deep Impact (1998) to Don’t Look Up (2021) have been dealing with asteroid impacts since the 1950s. Interestingly, Don’t look up became an allegory for climate scientists’ vain warnings to governments that climate change poses a danger to planet earth.

Movies exploiting our asteroid angst build on a long tradition of asteroid fiction that began at the start of the 19th century when the asteroid belt was discovered, or rather when Giuseppe Piazzi spotted Ceres, the first member of the asteroid belt, in 1801. Science fiction greats like Isaac Asimov and Richard Heinlein have written about asteroid mining and asteroid moving – but there many more. And some of what they say is not informed by angst but by the anticipation of a ‘gold rush’, as in Heinlein’s 1952 novel The Rolling Stones, which deals with asteroid mining, a topic I’ll get back to below.

A classic of the genre that one may call ‘asteroids without the angst’ is Antoine de Saint-Exupéry’s 1943 novel The Little Prince “In this classic, the title character lives on an asteroid named B-612 and ventures from asteroid to asteroid making discoveries about the nature of humanity and the universe. An asteroid discovered in 1993 was named 46610 Bésixdouze, or B-612.”

Asteroids and amazement

Given this constant mixing of fact and fiction, it’s not surprising that NASA chief Bill Nelson said of the successful DART mission: “It felt like a movie plot, but this was not Hollywood.”

This time round, with DART as the protagonist, our interactions with asteroids happened live on our screens: “Live images of the collision were taken by cameras onboard the DART spacecraft. In the hours leading up to the crash, the cameras were taking images once per second that were transmitted back to Earth until the moment of impact. Also during this time, the spacecraft was totally autonomous. Using special guidance software, the spacecraft made the necessary course corrections to direct itself to the target. Like a scene out of ‘Armageddon’ or ‘Deep Impact’, people around the world held their breath until the signal was lost, confirming that the mission was successful.”

But there was more! Newer images of the collision showed something rather unique which was not anticipated in fiction. Mankind created an entirely new space phenomenon: an asteroid with a small comet orbiting around it, that is, a long tail formed by the debris left behind after the collision of DART with Dimorphos.

As El Pais reported: “Among the thousands of asteroids that revolve around the Sun, there is something for everyone. As large as minor planets (Ceres – designated a dwarf planet – Pallas, and Vesta) or minute; solitary or accompanied by tiny satellites; solid or simple accumulations of loose fragments. But there is probably only one that is accompanied by something resembling a comet, with a 10,000-kilometer (6,213-mile) tail wagging in the solar wind”.

Interestingly, the New York Times noted that: “A Hubble image taken last Saturday showed that the comet-like tail split into two, a separation scientists are still working to interpret. ‘The learning is going to continue for a long time to come,’ said Lori Glaze, director of planetary science at NASA.” This learning is important, because, as a NASA spokesperson said: “NASA is trying to be ready for whatever the universe throws at us”.

Asteroids and avarice

Some expect that the exploits and successes of the DART mission will not only contribute to learning about how to defend planet earth from dastardly danger; they might also contribute to learning more about exploiting the asteroids for human gain. There are speculations that the DART mission “could also fuel space mining technologies and unleash the space economy in decades to come.” Just as fears about impacts from space have fuelled human imagination, so have hopes and fears about space exploitation, and this from Jules Verne onwards.

Verne was deeply interested in astronomy and space travel all his life and wrote famous novels about travelling to the moon. However, I bet that not many people know about La Chasse au météore (1908, The Chase of the Golden Meteor), a posthumous novel rewritten by Jules Verne’s son Michel (1861–1925)”. It “narrates the rivalry between two amateur astronomers who both discovered a bolid (in fact an asteroid). The asteroid […] is made of gold, and the announcement of its fall on Earth provokes a financial crisis.” In this novel “Zéphyrin Xirdal is an absent-minded scientist […who] used a device based on the equivalence between mass and energy to deviate the orbit of the asteroid.” Now, if only there was a golden asteroid that would avert rather than provoke a financial crisis!

Between Verne and a recent, rather realistic, technothriller by Daniel Suarez lies a whole tradition of asteroid mining fiction, to which Isaac Asimov and Richard Heinlein contributed in the 1940s and 50s – as we have seen Heinlein even speculated about a ‘gold rush’. And alongside that strand of asteroid exploitation fiction, we have of course the other strand of asteroid impact fiction.

Which fictional strand of our imagination we want to turn into reality is of course our choice. We have now got closer to the point where we can actually choose, and that includes saving the planet from a destruction of our own making.

Image: Aftermath of DART collision with Dimorphos captured by SOAR Telescope (Wikimedia commons)