What are the odds of an asteroid of dangerous dimensions striking the planet? If you wait long enough, it’s 100 percent. And they don’t even have to be especially gargantuan to cause widespread harm: So-called city killers — football stadium-size asteroids that can handily vaporize a metropolis with their nuclear weapon-style explosion — are disturbingly common in near-Earth space.
If we do find that a city killer is barreling toward us, there are only three possible outcomes: the asteroid hits the planet, impacts a densely populated area, and millions of people perish; the asteroid impacts a remote spot in the desert or the middle of the ocean, and nobody dies; or, the intruder is detected well in advance of its destined impact day, and we somehow manage to deflect it or blow it to smithereens.
On paper, planetary defense is one of the easier global problems to solve. If you can find Earthbound asteroids in space before they find us, and you’ve got the technology available to knock them away from our blue marble — or, if you are short on time, the technology to obliterate them entirely — then you can rule out almost all but the smallest asteroid impacts. You can effectively cancel out an entire category of natural disaster.
Remarkably, it seems we’re well on our way to doing just that. NASA’s Double Asteroid Redirection Test, or DART, rammed an uncrewed spacecraft into a (harmless) city killer back in 2022, successfully deflecting it and demonstrating that humanity can rearrange the cosmos to keep the Earth safe. And before the decade’s end, an asteroid-hunting space-based telescope, NASA’s Near-Earth Object Surveyor mission, will be launched; with its infrared eye, it is set to find almost all the city killers orbiting perilously close to the planet.
Planetary defense is a global imperative, of course, but for the time being, NASA — and, by extension, the United States — is leading the charge. Others players, including the European Space Agency, Japan, and (imminently, with their own DART-like mission) China, are also contributing to the fight against lethal asteroids.
For the moment, though, the world appears to be America’s to save. Yet planetary defense only operates if the government funds it and has space policies that prioritize it. NASA’s Planetary Defense Coordination Office — which is responsible for things like DART, the NEO Surveyor mission, and America’s suite of ground-based asteroid detecting telescopes — gets funding from the federal government to work toward all its goals. The annual funding amount changes year-on-year, but it’s risen from the single-digit millions to well over $100 million in just the past 15 years.
If you can find Earthbound asteroids in space before they find us, and knock them away from our blue marble, you can effectively cancel out an entire category of natural disaster.
Now it seems that the Department of Government Efficiency, or DOGE, run by SpaceX CEO and billionaire Elon Musk, is set to take an axe to much of the federal government. Several agencies have already been cited as targets, perhaps including, as some have suggested, NASA itself. With Musk’s frequent overtures about sending astronauts to Mars, and with tech billionaire Jared Isaacman — who made the first private spacewalk with SpaceX — being nominated by Donald Trump to lead NASA — it’s also not difficult to imagine a strong U.S. pivot toward Mars, with other key programs in the space agency’s purview left in the dust. “Elon, get those rocket ships going, because we want to reach Mars before the end of my term,” Trump said during a campaign rally, according to a video clip of the speech tweeted by Musk in September.
So the future of America’s planetary defense research is uncertain. But there are reasons to be sanguine.
The first is that, as of 2022, NASA’s Planetary Defense Coordination Office gets around $150 million per year. That’s almost a rounding error on a federal government spending spreadsheet. (As a point of comparison, the Artemis program, which hopes to get American astronauts back to the lunar surface in the next few years, is costing tens of billions.) For that low cost, the benefit is extremely high: Defending everyone on the planet, which, to state the obvious, also includes America, something that should hold sway with the new government.
But, perhaps more importantly, planetary defense has long been one of the few issues that has had strong bipartisan support both inside and outside of Congress.
In 1998, Congress gave NASA a legal requirement to find 90 percent of the kilometer-size asteroids — those capable of causing global devastation — orbiting near Earth as soon as possible. (They managed it in 12 years.) In 2005, Congress also legally required NASA to find 90 percent of the near-Earth city killers, a target they are still working on but toward which they are rapidly making progress. Congressional acts, caucuses, and hearings involving planetary defense have often been given support by Democrats, Republicans, and Independents.
“Elon, get those rocket ships going, because we want to reach Mars before the end of my term.”
NEO Surveyor, in particular, has garnered immovable bipartisan support in recent years. In 2022, NASA’s senior leadership, which was struggling to manage ballooning planetary science mission budgets, was reluctant to ask Congress for the full amount of annual funding for the Surveyor mission. (It needed $170 million for 2023, but NASA asked for $40 million.) Congress gave them more than they requested anyway, $90 million.
That year, several Republicans on the House science committee demanded that NASA make sure the mission gets the funding it needed. Writing to then-NASA administrator Bill Nelson, they complained that NASA’s senior leadership wasn’t doing enough to find potentially hazardous asteroids, that they had no plan to replace the collapsed Arecibo Observatory in Puerto Rico — a radar facility that, among other things, helped characterize asteroids — and seemed to be dawdling with NEO Surveyor’s budget unnecessarily. Referring to the 2005 act that directed NASA to find those city killers, they wrote that “NASA failed to plan, develop, and implement a program to achieve this goal.”
The makeup of the House of Representatives and the Senate has ebbed and flowed dramatically over the past three decades. But it seems that, no matter which party has control, planetary defense — even if it lingers deep in the background, behind many other issues — gets its due. Perhaps that’s because the benefits of protecting the world from asteroid strikes is obvious to politicians, especially if the U.S. can take credit.
Or perhaps it’s because the electorate, too, seem to be very keen on planetary defense. In recent years, the Pew Research Center has surveyed the American public regarding their opinions on NASA, and asked them what its objectives should be. Its 2023 survey revealed that “monitor asteroids, other objects that could hit Earth” came in at number one, with 60 percent of respondents saying it should be a top priority for NASA; another 30 percent said it shouldn’t be of paramount importance but still something NASA should pursue. (Pew’s 2018 survey on the same subject had similar results.)
Among respondents, both Democrats (64 percent) and Republicans (57 percent) said that monitoring potentially Earthbound asteroids should be a top priority. As it happens, sending astronauts to the moon and Mars ranked at the bottom of the list of priorities — something that probably won’t affect Musk’s incorrigible enthusiasm for the red planet.
At the bare minimum, then, NASA’s ongoing planetary defense work should tick along as planned, with NEO Surveyor continuing to be funded, as well as its ground-based asteroid-questing telescopes.
Casey Dreier, chief of space policy at the Planetary Society, a nonprofit planetary exploration and planetary defense advocacy group, recently wrote that it’s difficult to predict what’s going to happen with NASA during the second Trump administration. The Artemis program is likely to be a huge focus during the transition; planetary defense hasn’t emerged as a talking point for the administration.
In a 2023 Pew survey, both Democrats (64 percent) and Republicans (57 percent) said that monitoring potentially Earthbound asteroids should be a top priority.
It is worth noting, though, that during Trump’s first term, the administration made moves to secure greater funding for planetary defense research. And in its final days, it released a report looking into America’s asteroid impact emergency protocols, suggesting planetary defense is an issue that it sees as important.
If Republicans remain die-hard fans of planetary defense, there is also a chance that anti-asteroid efforts will be accelerated over the next four years. DART is a method of planetary defense known as a kinetic impactor: a partly autonomous spacecraft slams into an asteroid, just at the right speed and angle, to knock it onto a different orbit around the sun, one that doesn’t terminate in a violent collision with Earth.
Deflecting an asteroid with something like DART clearly works well, but if miscalculated, and that asteroid is punched with too much oomph, it could fracture the asteroid, turning an Earthbound cannonball into a shotgun spray of still-lethal objects.
But there are many more methods of planetary defense; it’s just that, for now, they are purely conceptual. Take the gravity tractor, for example: If you park a hefty spacecraft next to an asteroid, you could potentially use that spacecraft’s own gravity to gradually pull the asteroid out of Earth’s way. (This is a concept that’s spoken about not just in planetary defense circles, but in asteroid capture and mining discussions.) Such a program would require many years, perhaps decades, of work, but it’s a more precise, gentler method of planetary defense.
Some officials at NASA, and those further afield, are keen to try out alternative methods of planetary defense, including something like a gravity tractor. Others, meanwhile, want to proceed with DART 2 — to impact other types of asteroids. Not all of the objects have the same structure, size or composition, and some act more like boulders flying in formation than anything rigid and monolithic. So, these experts say, we need to deflect a variety of space rocks to see if they all respond the same way to a kinetic impactor.
Planetary defense experiments are inherently imaginative, almost sci-fi-esque, so the appeal to people of any political persuasion seems obvious — particularly with how ingrained dangerous asteroids (and comets) are in our collective pop culture-infused psyche. But conducting these space-based experiments also shores up humanity’s ability to prevent a cosmic catastrophe.
In 2021, Lindley Johnson, who was then the head of NASA’s Planetary Defense Coordination Office, said during an interview: “I think we've gotten the Planetary Defense program at NASA now to about the right level of resource and attention,” before adding: “Our challenge will be to keep it there.”
The hope back then is the same as it is now: that no matter who holds political power, NASA gets to keep looking up, and is granted the ability to protect the only home we know.
Robin George Andrews is an award-winning science journalist who regularly writes about space and geosciences for outlets including The New York Times, The Atlantic, National Geographic, Scientific American, Atlas Obscura, and Quanta Magazine. His previous book is “Super Volcanoes: What They Reveal About Earth and the Worlds Beyond.” He lives in London.
This article was originally published on Undark. Read the original article.
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