Image: NASA/Johns Hopkins University APL
Image: NASA/Johns Hopkins University APL

EXPERT REACTION: NASA's DART mission smashes into an asteroid

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NASA's DART mission has successfully smashed into the asteroid Dimorphus, hopefully proving that we can redirect dangerous objects heading for Earth. Here's what Aussie experts have to say about the DART mission.

Organisation/s: Australian Science Media Centre

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Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Professor Phil Bland is Director of the Space Science and Technology Centre at Curtin University

Just amazing to see those images this morning! We’ll learn so much about how to deflect asteroids from this mission. And it’s a technical triumph as well. To be that precise in targeting is just incredible. Science missions bring together the brightest and best scientists and engineers, working together to develop solutions to really tough problems. My hunch is that there’ll be a lot of value flowing from the R&D that went into delivering DART.

Last updated: 27 Sep 2022 4:26pm
Declared conflicts of interest:
None declared.
Prof Gretchen Benedix is an astrogeologist and leads the Intelligent Digital Mapping group within the Space Science and Technology Centre at Curtin University.

I have to say – what an amazing mission and success – and being able to watch it live has been amazing.  I can’t wait to see the coming data about how the experiment has worked. Just an amazing step toward building planetary protection!

Last updated: 27 Sep 2022 3:42pm
Declared conflicts of interest:
None declared.
Dr Vanessa Moss is an Astronomer at CSIRO

Incredibly, DART has managed to successfully travel 11 million km to crash into the tiny moonlet Dimorphos, just 160 metres across, and mark the milestone of the first full-scale planetary defence mission. This is the first step towards truly defending Earth from the threat of near earth objects, by improving our space situational awareness and proving we can divert objects if needed.

It's great to see the continued collaboration between CSIRO and NASA via the Deep Space Network and the operations of the Canberra Deep Space Communication Complex. In fact, CDSCC was the primary station responsible for capturing the final images of DART as it hurtled towards the surface of Dimorphos.

Future missions such as ESA's Hera and NASA's Near Earth Object Surveyor will continue to push the frontiers of our ability to protect our precious home planet and pave the way towards an effective planetary defence system.

Last updated: 27 Sep 2022 1:18pm
Declared conflicts of interest:
None declared.
Susan Scott is a Distinguished Professor at The Australian National University

This is such a timely mission in terms of our planet Earth and humanity. We know that we have been struck by asteroids in the past, causing very large-scale impact on our lifeforms, including, of course, the dinosaurs! It is so important that we have proven technology at hand to avert this happening again in the future.

DART is a precision technology mission designed to deflect a potentially threatening asteroid off course from hitting the Earth. The spacecraft has successfully hit its mark, and hurtled headlong into the asteroid this morning, successfully ending its intended purpose. The beauty of the chosen asteroid is that it is sufficiently close to Earth that our telescopes can now monitor how well it has been deflected. Once this step can be confirmed, then humanity can sleep a lot easier at night!

Last updated: 27 Sep 2022 1:09pm
Declared conflicts of interest:
None declared.
Dr Eleanor Sansom is a Research Associate at Curtin University in Perth

The DART mission is a very clever idea, impacting the moon of an asteroid to see how much we can change that moon's orbit. It won't change the direction of the main asteroid so there is no risk to Earth. It's the perfect way to test our technology and understanding in case we ever do discover something heading toward Earth. This is the first real test humanity has done toward the future protection of Earth from the threat of asteroids. Planetary defence is an international concern, and this NASA mission will be followed up by ESA's HERA mission in 2026, and is becoming the main focus of space agencies around the world.

Last updated: 27 Sep 2022 12:19pm
Declared conflicts of interest:
None declared.
Associate Professor Katarina Miljkovic is from Curtin University’s Space Science and Technology Centre and the School of Earth and Planetary Sciences

I watched the NASA live TV feed this morning, while attending the Australian Space Research Conference in Sydney, just before we started a session about planetary exploration. We hurled around a screen and watched the countdown to impact. When the feed cut off, we knew that impact happened. That left a lot for my imagination to project – as an impact crater modeller! DART travelled millions of km to reach a tiny asteroid orbiting another asteroid. Such an amazing engineering achievement on its own. Now the science can start. From this one impact event, we can learn more about the mechanics of impacts into small bodies, momentum transfer and the ability to use artificial impactors to nudge asteroids out of their orbits. This hasn’t been done before, although impact simulations have been made in the past. We needed a large-scale experiment, to get a validation against the real data. This is to ensure that should Earth ever encounters a dangerous asteroid hurling towards us, we would know what to do.

Last updated: 27 Sep 2022 12:19pm
Declared conflicts of interest:
None declared.
Professor Trevor Ireland is from the Research School of Earth Sciences in the College of Science at The Australian National University (ANU)

It’s interesting to note that the asteroid moon Dimorphos is another rubble pile asteroid.  Even in the NASA promo photos, the moonlet is shown as a solid object.   Given what we’ve seen from Ryugu (JAXA Hayabusa2 mission) and Bennu (NASA Osiris REx) these rubble piles may be a lot more common than we thought and will have an affect on how we deal with these bodies. The idea for planetary defence is that we nudge these objects by transferring momentum from a spacecraft to the body. But now we can see that if we hit these rubble piles too hard, it will fly apart. So then you end up with a shotgun scatter rather than a bullet heading at us.  So in terms of momentum transfer, we might want to have larger spacecraft with lower impact velocities. The modellers will have a field day with the DART experiment.  Hugely successful and informative.

Last updated: 27 Sep 2022 12:17pm
Declared conflicts of interest:
None declared.
Glen Nagle is the Outreach and Visitor Centre Manager at the CSIRO-managed Canberra Deep Space Communication Complex, part of NASA’s Deep Space Network

Spectacular! Amazing! Wonderous! These words flooded my mind during that final 10 seconds before NASA’s DART spacecraft impacted with asteroid Dimorphos. And what a beautiful little asteroid it is. It’s appearance suggests that it may be similar to other asteroids that have been visited in recent years, a loose rubble pile of house-sized boulders and car-sized and smaller rocks bound together by gravity. There’s just so much science still to be discovered from today’s event.
 
“Incredibly proud of our CSIRO team in the control room today. Just like DART, they were laser focussed on the task at hand and maintained communications lock right throughout these final hours. I couldn’t be more proud of what they have achieved today. Along with the DART mission scientists, they made history!

Last updated: 27 Sep 2022 12:15pm
Declared conflicts of interest:
None declared.
Professor Jonti Horner is an astronomer and astrobiologist, and one of the architects of the Minerva-Australis exoplanet observatory, based at the University of Southern Queensland

It's absolutely fantastic to see the successful death of the DART mission, as it crashed into the tiny asteroid Dimorphos. It's actually slightly surreal - I think it's only the second time I've seen astronomers so thrilled to see a spacecraft destroyed - but in this case, that destruction tells the story of a job very well done. It was incredible watching the live feed from the DRACO Camera on the DART spacecraft, and seeing the final image of the impact sight loom large before the screen went red and the connection was lost, and then seeing the excitement among the mission team celebrating the impact. It's an incredible achievement, and in the weeks and months to come, we will learn a huge amount about asteroids, and about our capacity to deflect them, as a direct result of this amazing mission. I can't wait to see the follow-up images from the Italian cubesats that were flying past Dimorphos at the time of the impact. The thing that really amazes me, though, is that this means we're living in a truly unique period in time. For the first time in the history of our planet, we have a species that can recognise the threat posed by asteroids and comets. Not just that, but we can predict the impacts of those asteroids and comets on the Earth - something we're seeing happen more and more often. And, as of today, we can demonstrate we have the capacity to do something about a threat - we can do what the dinosaurs couldn't, and protect ourselves from the threat from Rocks From Space. It's a really exciting time, and I can't wait to see what comes next!

Last updated: 27 Sep 2022 12:13pm
Declared conflicts of interest:
None declared.
Professor Alan Duffy is Director of the Space Technology and Industry Institute, Swinburne University of Technology

The incredible achievement by NASA of impacting an asteroid and changing its motion has shown that humanity doesn’t have to go the way of the dinosaurs, we have the technology now to find and deflect a killer asteroid. Now we need to be ever vigilant but no longer fearful of that threat from the heavens. 

The technical ability to hit a target just 160 metres wide after a distance of 11 million kilometres is akin to striking a dartboard from across the Earth, and to do that at 25,000 kilometres an hour is simply beyond amazing as the target grows in view from something no larger than your thumb at arms length to impact within two seconds.

Preventing an object the size of Dimorphos from hitting the Earth is key as while they’re not common they are by no means rare, expected to hit every 20,000 years or so. Thanks to their great speed even this small an object would impact with an energy release equivalent to thousands of nuclear bombs, leaving a crater 3 kilometres across and annihilating everything in a blastwave stretching hundreds of kilometres. We want to find and prevent these asteroids, and now thanks to NASA DART we know we can.

Last updated: 27 Sep 2022 12:12pm
Declared conflicts of interest:
None declared.
Glen Nagle is the Outreach and Visitor Centre Manager at the CSIRO-managed Canberra Deep Space Communication Complex, part of NASA’s Deep Space Network

The CSIRO-managed Canberra Deep Space Communication Complex will receive the final signals from the DART spacecraft as it approaches and impacts asteroid Dimorphos. Canberra’s giant antennas will also receive images and data from the LICIA cubesat as it follows DART’s impact with the 160-metre wide asteroid.

We are proud to work alongside our colleagues at the European Space Agency’s New Norcia tracking station, which is also operated by Australia’s national science agency CSIRO.

The impact of the DART spacecraft is an important step in understanding how to protect the Earth from any future objects that may come our way. This historic mission is a proud moment for our team at the tracking station. Any final commands to the spacecraft and all of the images and data will be beamed down to our antennas and then immediately relayed to the waiting DART mission scientists.

This mission has been years in the planning, and now it comes down to these final hours. The last 23,000 kilometres of this journey will be covered in just 60 minutes, the final 100 kilometres in only 15 seconds; and 11 million kilometres away here on Earth, we’ll be listening, watching and ready to share this moment with the entire world.

Last updated: 27 Sep 2022 12:10pm
Declared conflicts of interest:
None declared.
Professor Fred Jourdan, Specialist of Earth and Planetary sciences and sample return material at Curtin University

So glad it’s finally happening! All we know about asteroid deflections is currently based on theoretical knowledge and computer simulations. Absolutely great tools, but still, the problem with that is that, if an asteroid is coming our way to smack into the Earth, we will have only one shot to deflect it.

Now, imagine one crucial parameter in all our estimations on how an asteroid is supposed to behave is off … we would not have a second chance and miscalculation could have potentially devastating consequences. What DART is designed for is testing many of these assumptions by smashing a deflector (aka a small spacecraft) into a small moonlet asteroid to see if we could deflect it even so slightly, as we currently predict we could.

It’s a one-way mission for the probe which will be obliterated upon impact, but we will gain tremendous knowledge that will definitely improve our planetary defence system. Hopefully, we will never have to use it in the coming decades or centuries but wait long enough and eventually we would. So better be safe than sorry!

Last updated: 27 Sep 2022 12:08pm
Declared conflicts of interest:
None declared.
Dr Paul Abell is Chief Scientist for Small Body Exploration and Astromaterials Research and Exploration Science at the NASA Johnson Space Center

This is uncharted territory, we’ve never been to a binary asteroid before. We know a little bit about the bigger one (Didymos), because it’s big enough that we can determine its size and shape and other physical properties from the ground. We do have some indications of how big the little one (Dimorphos) is, but in terms of shape and everything else, we don’t have much information.
 
In a real planetary defence situation, you don’t get to pick the asteroid — the asteroid picks you! In this case, we don’t know much about the target, but that’s why we’re doing it. It’s an easy one to see and study because it’s going to be very close to Earth at the moment of impact, but also one that is safe to test.

DART is a culmination of a lot of work for which many people have devoted several years of their lives. For me, personally, I have been working on this mission for a long time — more than 10 years — from concept and then actually the mission itself, trying to get all this together. I’m really, really excited about Monday. I’ve got goosebumps.

Last updated: 27 Sep 2022 12:07pm
Declared conflicts of interest:
None declared.
Dr Benjamin Montet is a Scientia Senior Lecturer in the School of Physics at UNSW

We've never had a mission like DART before! Today as the probe slams into the asteroid Dimorphos, we will learn a tremendous amount about near-Earth asteroids. First, it is a demonstration of planetary protection---we get to practice for a real-life Armageddon situation to demonstrate how to deflect an asteroid that could impact Earth.

While there are other opportunities to deflect an asteroid if we have a long time to prepare, such as painting one side of it, it's realistic to imagine this approach being our best bet to bump a small asteroid that could destroy a city out of harm's way.

The impact will also teach us quite a bit about the structure and composition of small, binary asteroids. We don't know what Dimorphos is made of, whether it is soft and porous and will swallow up DART or be rock-hard and cause a big collision. And we'll be able to watch it in nearly real-time, as the mission sends back a movie of the impact that will be streamed for all to watch. It's going to be a fascinating experience!

Last updated: 27 Sep 2022 12:06pm
Declared conflicts of interest:
None declared.

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