You know it’s serious when they bring in the big guns, or at least the big lenses. The European Space Agency confirms that the James Webb Space Telescope – humanity’s most powerful eye on the cosmos – will soon turn to observe asteroid 2024 YR4, the space rock with a small chance of impacting Earth in 2032.
“The chance of impact is very slim, and the asteroid is small enough that the effects of any potential impact would be on a local scale,” the ESA wrote in a blog post. “But the situation is significant enough to warrant the attention of the global planetary defence community.”
The Webb telescope is managed as an international partnership between NASA, ESA and the Canadian Space Agency (CSA).
The announcement is significant and reflects the level of concern because time using Webb is assigned and booked out by researchers and institutions well in advance. Using the telescope to take a closer look at the potentially hazardous asteroid on short notice is considered a “time-critical” emergency decision.
Chance of Impact Small and Rising
Asteroid 2024 YR4 was first spotted on December 27 and was added to the “risk list” of near-Earth objects (NEOs) that appear to have a chance of impacting our planet. It’s very common for new asteroids to be discovered and added to this list, only to fall off it completely as new observations come in.
Additional observations often refine the orbital path of an object, helping to eliminate any possibility of impact.
Asteroid 2024 YR4 is the rare case where the opposite has happened. In recent weeks, as more observations have come in, the odds of impact on December 22, 2032 have actually gone up, from about one percent to about two percent.
This means that it is still very likely the object will pass right by our planet without incident, but scientists are taking no chances and opting to use valuable Webb telescope time to get more precise measurements of its orbit and size.
Not a Planet-Killer Asteroid, But Still Dangerous
The latest data puts the diameter of the asteroid at between 40 and 90 meters. The lower end of that scale is what the bolide that impacted and exploded in the atmosphere over Russia in 2013 was thought to have measured before colliding with Earth.
The impact created a shock wave that blew out thousands of windows in the city of Chelyabinsk, leading to hundreds of minor injuries. The resulting meteorite impacted a nearby frozen lake and was later pulled up from the water. After its long and fiery journey to the ground, it measured little more than a meter across.
That’s what may happen to a 40-meter asteroid on impact, but the ESA points out that a 90 meter asteroid could be a very different story. The damage done could be significant, perhaps more on par with the 1908 Tunguska event in Siberia that leveled millions of trees and may be linked to a handful of deaths. If such an impact were centered on a major city rather than wilderness, the results could be truly catastrophic.
The first round of observations by the Webb telescope for the menacing rock are set to happen in March, with follow-ups scheduled for May.
Hopefully we’ll soon have a more clear picture of the threat and how serious we should be planning for science-fiction scale contingencies to confront it.
