Let’s face it: the Universe is way too big in order to be physically possible for astronomers to detect all the threats. But unfortunately, a collision with an asteroid can wipe out all life on Earth, if the space rock is big enough. It happened before when the dinosaurs got extinct 65 million years ago, it may happen again someday. But by the day of the encounter, we can truly hope that humanity will have the necessary tools to destroy or deflect “unwanted guests” who can obliterate us.
This is what the engineers of NASA may have in mind since cosmochemist Dr Natalie Starkey stated that the space agency is currently working on building a better database of “sneaky objects that could be due to impact Earth in one to three weeks.” by analyzing their trajectory.
Destroy or divert the asteroids? Not yet
A simple solution that comes to mind when talking about dangerous asteroids is to destroy or redirect them. But Dr Starkey says that is unlikely, at least for now. What can we do instead is to warn the population: “Of course, it’s unlikely we could do much about these objects in time to divert or destroy them, but it would allow us to instead work on evacuating and preparing the forecasted target region in the same way we would for a predicted volcanic eruption.” says Dr Starkey.
She also adds: “As we don’t know the exact shape, albedo and composition of some of these PHOs, they must remain on the list until scientists study them in space and better refine their characteristics to calculate how the subtle non-gravitational phenomena will affect them and whether their orbits will intersect our planet.”
PHOs are Potentially Hazardous Objects, referring to asteroids that are predicted to pass very close to Earth. They are defined as having an orbit insertion distance with respect to Earth of less than 0.05AU, or around 19.5 lunar distances, and as having a magnitude of 22, a measure of their brightness which corresponds to size.
We simply can’t see them all
Dr Starkey confirms what it is obvious and sent a warning to the public in her new book called “Catching Stardust” and released in 2018. She explained there how the space agency cannot track every piece of rock in the sky.
Dr Starkey also said in her book “The prospect of our planet experiencing a devastating, life-destroying impact by a comet or an asteroid may sound highly unlikely, but it is something that is almost certainly going to happen at some point in the future.
“The question is when?”
Luckily for us, most rambling asteroids are getting attracted by the Sun and Jupiter’s gravitational pull, the two celestial objects being the “vacuum cleaners” of our Solar System.