Asteroids, Comets, and Saving the World
Kya Sorli (Duke ’18) loves talking about the end of the world. So much so, that this month she’s giving a talk on the Science of SciFi at the Fiske Planetarium called “Armageddon 101: A Crash Course in Saving the World.”
Kya is a PhD candidate at CU-Boulder studying astrophysics & planetary science, including planetary defense. She’s studying asteroids and comets – and their orbits. “How often are we having close calls? It’s a complicated question because we have to differentiate between both of these two small bodies – asteroids and comets,” she shared.
“Asteroids are what people are familiar with when it comes to space rocks; they’re the thing in many Armageddon movies and they’re the thing you see in TV shows. Asteroids take a lot of different forms but they also have a lot of different sizes. Some asteroids are almost dwarf planets while some are the size of grains of sand or pebbles and burn up in the atmosphere. But there are still a lot that can cause damage in the size range of several tens of meters and once you get to a couple hundred meters you’re talking city-wide or region-scale damage. Once you get to a kilometer you’re talking continent-scale damage, and anything above that you’re talking about a global extinction. And there’s a fair number of those. The good news is we know where pretty much all of them are, and we can calculate their orbits so we know where they’ll be in the future too,” she laughed, nonplussed.
“Ironically the comets, which no one really thinks of as dangerous objects, are potentially far more dangerous and that’s because they’re really big – every single comet known is a “dinosaur killer” – and they’re fast. They’re coming in from outer orbits, and the further out they come from the solar system, the faster they move. With a large asteroid we have years to decades, maybe even hundreds of years to prepare for something like that coming to earth. That’s in contrast to comets, which we might have a couple of months of warning time for.”
If you’re starting to get nervous, don’t.
“The good news is we have ways to stop asteroids & comets from making impact. There’s a lot of very sci-fi ideas that are really far out there, but there are two big mitigation techniques: nuclear deflection and kinetic impact,” Kya said. “The first involves sending a nuclear device into space and blowing it up near the object – you’re not trying to blow the object up. That’s an important distinction because then you’ll have several smaller objects hurtling towards you, each of which can still cause large scale damage – rather, you’re trying to vaporize the surface of the object, meaning you want to knock enough stuff off of it to give its momentum a push in another direction. As you might imagine there’s some political issues with this. We have very few international space laws, but basically the big one is the 1967 United Nations Outer Space Treaty which states ‘no nukes in space.’” Kinetic impact on the other hand, according to Kya, is the equivalent of sending a battering ram into space, knocking the object off its orbit and shifting its destination.
Currently, Kya is working on an advanced thermophysical model for binary asteroid systems which will be targeted by NASA’s Janus Mission. When Janus launches, it will deploy space probes that will image two asteroids and interpret data using the model Kya created.
“With Janus, I’m watching my decisions impact how the mission goes. I’m contributing to the parameters and calibration for the cameras which are going to be launched and visit asteroids, and I’m tracking my work throughout all of this and using what we know about objects millions of kilometers away; it’s wild and incredible. Nothing enthralls or terrifies me more than space and I feel like if that’s not a good reason to study something, I don’t know what is,” she shared.
Janus is the first in a range of small concentrated missions; for Kya it is an opportunity to work at a level that most graduate students don’t experience. “I’m on calls with NASA representatives and engineers from Lockheed Martin and the camera manufacturers, photometry experts and data analysts. There’s all this back and forth, between these incredible scientists who have these very different skillsets, but you have this one common goal and its incredible to see it all happening and come together.”
For Kya, working on the Janus Mission is a study in leadership. “Everything we’re doing for the mission requires organization, collaboration, delegation, self-motivation – it’s all incredibly important. And then there’s the addition of holding yourself accountable: really making sure your work is good work. Because even though there are other people in the mission, you’re the expert – people are going to believe what you have to say, so you need to produce good work. It’s really easy in this field to feel imposter syndrome, especially when you’re working with people who are literally breaking down the barriers of what we consider possible as a species. It’s very easy to doubt yourself and think ‘Am I really at this level? Am I this person?’ but you have to have faith in your ability and that’s something that I, and people I know in this field, constantly work on. Having that faith in your own abilities is important especially if you temper it with accountability and collaboration. And pretty much every one of these leadership skills, I learned as a Robertson.”
Kya credits her summers especially for helping her hone her transformational leadership practice, “That’s where all these skills come into play, especially self-motivation. By doing my work in Hawaii’s Institute for Astronomy during Exploration Summer, or the Lawrence Livermore National Laboratory during Launch Summer, even in Kentucky for Community Summer – I had to learn how to self-motivate and ask questions. I didn’t know how to run a radio show, or put on a music festival, but you ask questions, you try things – you go for it and fix it later. That’s science. You try a hypothesis, you see how it works, and then you fix it, that’s the whole scientific method!”