There are dire warnings coming from the American Geophysical Union Fall Meeting. If an asteroid or a comet was on a collision course with our planet, we would be unprepared to defend ourselves.

According to Dr Joseph Nuth, a researcher with NASA’s Goddard Space Flight Center, it would take five years to design, build, and launch a spacecraft to either deflect or destroy any space rock. And it appears to be imperative that the time is shortened.

“The biggest problem, basically, is there’s not a hell of a lot we can do about it at the moment,” Nuth said at the conference.

He and his colleagues have two suggestions to improve our chances: create a dedicated space observatory to gain data on the potential threat, and an intercepting spacecraft carrying a nuclear device to stop it from reaching us.

Both devices would be built and kept in storage (apart from the regular tests) until we need them. The observatory would be deployed when we discover a potentially hazardous asteroid, to collect more accurate data. The interceptor will be launch once we know the certainty of the impact is high.

The rest of the panel was composed of three scientists for the Los Alamos National Laboratory, Dr Robert Weaver, Dr Catherine Plesko, and Dr Galen Gisler, who discussed how to best deflect a potential bolide and some of the consequences on Earth, in the case of an impact.

The researchers stated that there are many factors to consider when we plan to repel an asteroid such as size, when the object was discovered, and so on. And based on those, one can decide which of two possible deflecting strategies to use, either a nuclear device or a kinetic impactor.

“The kinetic impactor technique can be very effective if you have long enough lead time,” stated Dr Weaver. This method uses a “cannonball” to hit the asteroid, which imparts a small momentum to the space rock and it pushes it on a different orbit.

We might need decades to successfully prepare and launch a kinetic impactor mission, so if one is pressed for time, a nuclear blast is the go-to option. The team has a few ideas of what might happen, and they are currently checking their models.

“We are very carefully doing our homework before finals week. We don’t want to be doing our calculations before something is coming. We need to have this work done,” Dr Plesko added.

This research will hopefully reiterate the importance of monitoring the heavens for threats. Out of the 1 million hazardous asteroids larger than 30 meters (100 feet) that orbit around our planet, we have only found 1.5 percent.

You can watch the entire presentation below.