Asteroid the size of a small island to fly past Earth this Friday

A massive asteroid the size of a small island is set to pass by Earth this Friday, according to NASA's asteroid tracker.

Designated 7335 (1989 JA), this large asteroid is estimated by NASA to be around 1.8 kilometers wide. For context, Plum Island, the small island off the coast of New York, is around 1.6 kilometers wide.

Heading towards our direction at a speed of around 13.12 kilometers per second, this asteroid is set to pass us by at a distance of over 4 million kilometers away, according to the Center for Near-Earth Object Studies (CNEOS) at NASA's Jet Propulsion Laboratory (JPL). For context, the Moon orbits the Earth at a distance of roughly 384,000 kilometers, so this is considerably farther.

But on a cosmic scale, this is much closer.

In addition, 7335 (1989 JA) is an Apollo-class asteroid. This means its orbit around the Sun overlaps with Earth's own orbit as well.

It is this distance and the object's sheer size that have resulted in NASA labeling 7335 (1989 JA) a potentially hazardous asteroid. And that is fitting since while it is extremely unlikely to hit us, the result if it did, could be catastrophic.

Asteroid impacts: How bad can it be?

Asteroid impacts are one of the worst possible natural disasters that could possibly occur due to their potential for sheer destruction.

According to research from the Davidson Institute of Science, the educational arm of Israel's Weizmann Institute of Science, an asteroid over 140 meters in diameter would release an amount of energy at least a thousand times greater than that released by the first atomic bomb if it impacted Earth.

Something even larger — over 300 meters wide like the asteroid Apophis — could destroy an entire continent. An asteroid over a kilometer in width — like 7335 (1989 JA) — could trigger a worldwide cataclysm.

There are also other asteroids of this size out of the over 1 million known asteroids in the solar system, and some of them do orbit the Earth.

According to CNEOS, 7335 (1989 JA) has a rarity of 2, meaning an asteroid of this size or larger passes by the Earth once a year on average. This is far more often than many other asteroids, where they can pass us by roughly every few days.

But what is it like when an asteroid hits the planet?

There are no recorded reactions in history of what it was like when an asteroid of this size struck the Earth. However, the closest thing we do have are testimonies from those who experienced the Tunguska incident, when an asteroid thought to be around 190 meters wide struck the Earth over Siberia, Russia in 1908.

When the asteroid exploded in the air several kilometers above the area, it produced a massive 12 megaton explosion, causing widespread destruction for thousands of kilometers. That would make it about 800 times more powerful than "Little Boy," the approximately 15-kiloton atomic bomb detonated during World War II over Hiroshima, and 600 times more than "Fat Man," the 20-kiloton one detonated over Nagasaki three days later.

The death toll from the Tunguska event was extremely low, however, with only around three people thought to have been killed in it, due to how remote and sparsely populated the region was. But the damage was still evident, with about 80 million trees completely flattened by winds of around 27 km per second. Tremors and airwaves were even felt as far away as Washington and Indonesia.

The few eyewitness accounts that do exist recounted the terrifying explosion, strong winds, and tremors.

"The sky split in two and fire appeared high and wide over the forest," recounted a man who was about 65 kilometers south of the explosion.

"The split in the sky grew larger, and the entire northern side was covered with fire," he said. "At that moment I became so hot that I couldn't bear it as if my shirt was on fire; from the northern side, where the fire was, came strong heat. I wanted to tear off my shirt and throw it down, but then the sky shut closed, and a strong thump sounded, and I was thrown a few meters. I lost my senses for a moment, but then my wife ran out and led me to the house.

"After that such noise came as if rocks were falling or cannons were firing; the Earth shook, and when I was on the ground, I pressed my head down, fearing rocks would smash it," he said.

"When the sky opened up, hot wind raced between the houses, like from cannons, which left traces in the ground like pathways, and it damaged some crops. Later we saw that many windows were shattered, and in the barn, a part of the iron lock snapped."

The Tunguska event is the largest in recorded history — though larger prehistoric ones happened — and is one of the largest explosions ever recorded, far more powerful than many nuclear bombs.

And if 7335 (1989 JA) hit the planet, it would be much worse.

But we're safe, right?

Almost certainly. 

NASA has thoroughly checked its orbit and there is almost no chance 7335 (1989 JA) will hit the planet. 

In fact, NASA has also calculated that Earth is risk-free from a major asteroid impact for the next 100 years. 

Impacts can still happen, in fact, one recently did in March when 2022 EB5, a small asteroid three meters wide, roughly the size of half a giraffe, struck the Earth. But these are small impacts and not on the level of a global catastrophe like 7335 (1989 JA).

But even so, scientists have continued to advance methods of asteroid detection and defense, including NASA's groundbreaking Double Asteroid Redirection Test (DART) mission that is set to test the possibility of asteroid deflection.