We've all seen movies in which the world is threatened by an extinction-level asteroid collision. But, with just seconds to spare, we escape such a fate thanks to the quick-thinking and bold sacrifices by good-looking lead characters.

That scenario is quite possible... and also impossible, notes John L. Remo, an astrophysicist and research associate at Harvard University who studies real-life "killer" asteroids. He's not trying to be ambiguous – just highly precise, which is par for the course for this noted man of science.

Remo, originally from Brooklyn, N.Y., attended Manhattan College before continuing his graduate studies at State University of New York in Stony Brook before getting his Ph.D. in physics at (what is currently called) the Polytechnic Institute of New York University. The study of near-Earth objects has filled Remo's life – from his work as a graduate student to his studies now as a 73-year-old, simulating planetary collisions using high-powered lasers at Sandia National Laboratories in New Mexico. Remo told Headlines and Global News he'll probably "retire with (his) boots on," which is preferable, he believes, to retiring and watching the world's reality-TV "mess."

Before his desert experiments and major appointment at the Department of Earth and Planetary Sciences at Harvard and the Astronomy Department at Harvard (which automatically made him a member of Harvard-Smithsonian Center for Astrophysics), Remo taught at various universities. Backed by a Ph.D. in quantum optics, he also set up his own company that designed electro-optic, high-powered lasers. That company had contracts with NASA, "Star Wars," as well as other governmental agencies and private companies.

This is what Remo told HNGN about near-Earth objects and what we can do about them...

HNGN: Tell us a little bit about your research with asteroids.

Remo: Well, it started in the early 1970s with the mechanical properties of meteorites, which are pieces of asteroids, and I gained an understanding of the different types of meteorites and the associated asteroids. Anytime we had to discuss an asteroid, we knew what the microstructure was like. We had some possibilities of what the microstructure was like. When the problem of the near-Earth objects came about, you had to know how to calculate orbits. You had to know how high-energy density radiation would interact, and for the latter having an understanding of the meteorites as surrogates for asteroids was the key to understanding how they'd interact with high-energy-density radiation and how, therefore, they could be moved.

In '95 you organized a United Nations conference on near-Earth objects.

Yes, in New York City in the U.N. world headquarters at the Dag Hammarskjold Auditorium.

How did that come about?

Well, people started to be concerned in the early '90s that the near-Earth objects were a threat to humanity, civilization, and I'd given a talk at the Explorer's Club in New York, of which I was a fellow, and there in discussions, it was suggested that we go to the U.N. to sponsor a conference on near-Earth objects.

Are near-Earth objects a real threat?

Yes, they're a serious threat. I mean, what happened in Tunguska in 1908, and then what happened in Chelyabinsk in 2013 are examples of meteorite impact. Fortunately they weren't over highly populated areas. Impact in a highly populated area could be considerable damage.

What is the possibility – maybe not necessarily a percentage, if you can't predict – but what is the likelihood of a catastrophic event that could wipe out our civilization?

In the long term it's almost a certainty. It's inevitable that sooner or later a large piece of asteroid on the order of 100 meters to 200 meters is going to hit the Earth. It's a given that it's going to happen.

Is there any way to avoid this?

Yes. You could deflect it using explosives – nuclear explosives.

What about the radiation? Would it cause any harm to us here on Earth?

It should be hundreds of thousands, if not millions, of kilometers from the Earth, so it will have no effect on the Earth in terms of any radioactive fallout. Besides, it will be in space, so radioactivity will be minimized. You'll have a blast which won't interact with matter. Just some radiation will affect the asteroid and shift its orbit, but there should be no deleterious effects on the earth.

Do you think we're prepared?

No, we're not prepared.

What do we have to do in order to get prepared?

We have to take existing nuclear explosives, but you need them to be already mounted on a rocketship with several stages to launch at the right time to set before the object hits the Earth. But even before any of that, you have to be able to predict which asteroid fragment is likely to hit the earth, and predicting that is almost – well, it's not almost difficult, it's very difficult to do – because during the last period of its orbit, these objects change direction, so you can't predict too many orbits in advance of when it's going to hit. You have to get it on the last go-around.

So how much time would you have? When you watch the movies and Bruce Willis comes in and saves the world, they seem to know for the full two and a half hours of the movie what's going to happen. How much time do you have for an asteroid to flip its course?

You need at least several months to a few years warning time. You have to have the rockets ready to go, and the rocket could be ready to go on the surface of the earth or a certain Lagrangian point.

Having the rocket almost seems like it should be the easy part, because it's just a matter of putting it together, but with the current political situation and everyone's so afraid of everyone else having nuclear arms...

I just wrote a paper for the Bulletin of the Atomic Scientists about the dilemma of nuclear energy in space, pointing out that you have treaties and agreements and clauses that you shouldn't use nuclear weapons in space, but you also have non-proliferation agreements. You have things that are proliferating. It's a problem. Nuclear weapons can destroy the human race, or they could be used to save the human race. It's up to human beings to make the right decision, which we don't apparently seem to be doing.

"Threats from Space, 20 Years of Progress" is the last paper you authored showing on the Bulletin's website...

That was an article I did last year, which was very optimistic, showing what progress had been made and the relationship between meteorites and asteroids. It mentions Chelyabinsk, how it happened without warning. A minute before the Chelyabinsk asteroid hit, nothing was out of the ordinary. One minute later, it was a near catastrophe on Earth.

This is a new paper coming out of the bulletin in April/May on the dilemma of nuclear energy in space. It's a pretty provocative story, and it goes into the fact of whether civilizations in the past on other planets could survive near-Earth objects without blowing themselves up with their nuclear weapons.

Other countries don't trust Americans to be the guardians of nuclear weapons. Americans don't trust North Korea or Iran with nuclear weapons. The world doesn't trust Russia with nuclear weapons. So basically, it would really have to be a trust situation among scientists, because they kind of seem to have more of an international ability to work together as opposed to politicians, it seems.

Well, scientists work from a book – a common set of beliefs and understandings and rationale – where politicians work from a lot of mythology and personal belief and tribal instincts, and the scientists don't have tribal instincts. They have more a scientific objectivity, and they can solve the problems scientifically, but you won't be able to solve it politically, because political solution implies tribal trust, and you're absolutely right – that's the problem. That's the dilemma of survival. We have to be learning together. The earth is getting polluted and biodiversity is disappearing. In the end, the tribal instincts and greed dominate the motivations of the powerful.

We're looking at going to Mars. We're looking at deep space. Do you feel it's hubris for us to be going there, or are we just kind of taking the Earth for granted and then going on to ruin the next planet?

Going to Mars is a good story. It sounds good. Human exploration sounds good, because we've been pressed by science fiction and the movies. However, we're not really ready for that. It has to be done in more unmanned satellite observation and satellite missions to Mars. Maybe someday we'll be ready for it, but right now just the radiation in space going from Earth to Mars could kill astronauts, and there's no way of returning, so it's a one-way trip. The first priority should be for defending Earth.

Can you tell us a little bit about what you're working on currently?

Well, we're now extending the research to moving comets, because comets are even a bigger threat in the sense that they can move faster and are much more massive than asteroid fragments, and comet chemistry is uncertain as the current Rosetta mission points out. And also comets may be very difficult to detect, because they can be very opaque and dark like coal, like dirty ice.

How do you feel about the Rosetta mission? They're saying they might not be able to get the Philae lander back online. Do you feel like the mission still had success or is it a disappointment?

No, the Rosetta mission with the Philae lander is a tremendous success; but, bear in mind, it took 10 years to do the rendezvous interception, so it's not trivial racing out to intercept a near-Earth object, and then doing a rendezvous with blow-off nuclear explosives. It's very complicated and difficult, and that's a good question that you ask, because that brought out the fact that just because you know how to do it doesn't mean you can do it.

Do you think it's important then to give it another try? Is that the key to unlocking more of these mysteries: launch more landers, even if we might lose them on comets?

We could lose them on comets, but it's well worth the effort. There should be more of these satellites, unmanned, automated rendezvous, because when we have to do the interception, it's going to be automated. You can't joystick it from the earth. It has to be a totally automated mission, and so all the experience we can get on rendezvous and automated rocket interceptions is very valuable.

Is there anything that I didn't ask about that you think is important for people to know?

Support basic research. It's a necessity. It's not a luxury. It's the only way we're going to survive to the future. You can't put the genie back in the bottle. We have the good and the bad in technology, and we have to learn how to maximize the good and minimize the bad. It shouldn't be a political issue, because science serves the benefit of humankind, and we've got to make the first priority in taking care of the planet that we were endowed with by nature. Once we ruin the earth, we're not going to be recoverable.

This interview was edited for length.

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