A comet fragment explodes in the dark sky over Spain and Portugal

On Saturday, revelers across Spain and Portugal ventured out into the balmy spring evening, hoping for a night to remember. No one expected a visitor from outer space to explode above their heads.

At 11:46pm in Portugal, a fireball shot across the sky, leaving a trail of blazing graffiti in its wake. The footage was shared on social media Shows lowered jaws As the dark night briefly turns into day, ablaze with shadows Snow White, Earthly Green, and Arctic Blue.

Rocky asteroids cause streaks high in the sky as they self-destruct in Earth’s atmosphere with some frequency. But over the weekend, the projectile was heading toward Earth at a remarkable speed — about 100,000 miles per hour, more than twice what a typical asteroid would expect. Experts say that its path is strange, and does not match the type that nearby space rocks usually follow.

That’s because the intruder was not an asteroid. She was Part of a comet — an icy body that may have formed at the dawn of the solar system — lost its battle with our planet’s atmosphere 37 miles above the Atlantic Ocean. The European Space Agency said it was unlikely that either object would have reached Earth.

“It’s an unexpected interplanetary fireworks display,” he said. Meg Schwamba planetary astronomer at Queen’s University Belfast.

It is not rare for comets to produce shooting stars. “We have noticeable meteor showers throughout the year, which are the result of certain cometary debris clouds crossing the Earth,” Dr. Schwamb said. For example, the Perseid meteors, which occur every August, are the result of debris left behind by Comet Swift-Tuttle sweeping up our world.

This meteor shower, the only sliver over the weekend, lights up the sky in a similar way. The air in front of objects is compressed and heated, causing them to cook, corrode, crack, and erase debris. This destructive process releases light and, if the projectile is large enough, a powerful shock wave as it gives up its enormous kinetic energy to the sky.

“The weekend piece is likely to be a bit larger than a large portion of the meteors we see during meteor showers, so this provided a larger light show,” Dr. Schwamb said.

In addition to its showy performance, the breakup of the comet’s fragment has served as a trial run for experts hoping to defend the planet from… Big killer asteroids.

One of the principles of planetary defense is to find space rocks before they find us; This way, the planet’s protectors can try to do something about them. But the crust was not spied over Portugal and Spain before its demise.

“It was amazing to discover the object before it collided with the Earth,” he said. Juan Luis CanoMember of the Planetary Defense Office at the European Space Agency.

Anxiety is that object Just a little bigger That Saturday’s missile might once again evade detection and explode with deadly effect on an unaware and unwarned city. For example, the tiny 55-foot meteorite that exploded over the Russian city of Chelyabinsk in 2013 was not identified before arriving either, and its airburst, equivalent to nearly 500,000 tons of TNT, caused damage. Widespread attack, injuring at least 1,200 people.

But as technology improves on Earth and in space, the hope is that even small, harmless objects can be spotted from across the solar system (like this weekend’s icy visitor, which experts estimate was just a few feet away), providing training for planetary defense. . Researchers search the skies for common but elusive football field-sized boulders that could destroy a city.

Fortunately, a series of next-generation observatories are scheduled to become available for use in the next few years, including one named after an American astronomer, the Vera C. Rubin Observatory in Chile, which will detect millions of faint, previously undiscovered asteroids.

Right now, the scene in Spain and Portugal reminds us that Earth is a partner in the solar system’s endless game of planetary billiards, and that working to find as many deadly space rocks as possible is a mission of the utmost importance.