Asteroid alert! Plane-sized objects hurtling towards Earth this week

Several asteroids, each approximately the size of an airplane, are set to make close approaches to Earth this week, according to a recent statement from NASA. Among the five asteroids, the largest measures about 110 feet in diameter, and the closest one will pass within 447,000 miles of our planet.

**What Does It Mean?**

While it’s common for large asteroids to safely pass by Earth, this week’s cluster is notable for the sheer number of close encounters. On Monday, June 17, asteroid 2024 LU1, measuring around 71 feet in diameter, made its closest approach at a distance of 1,150,000 miles from Earth.

The next notable close approach is scheduled for June 19, featuring the largest asteroid of the group, which will still maintain a safe distance of 447,000 miles.

**Which Asteroids Can Be Hazardous?**

Asteroids are generally composed of rocky, dusty, and metallic materials. Most orbit within the main asteroid belt between Mars and Jupiter, but some have orbits that bring them closer to Earth. These are known as near-Earth asteroids and fall under the broader category of near-Earth objects (NEOs), which also includes comets. NEOs are defined as celestial bodies that come within 1.3 astronomical units of the Sun and 0.3 astronomical units of Earth’s orbit.

One astronomical unit is about 93 million miles, so 0.3 astronomical units is roughly 28 million miles.

To be classified as a potentially hazardous asteroid (PHA), an asteroid must be at least 140 meters in diameter and come within 7.48 million kilometers of Earth. An asteroid of this size that enters Earth’s atmosphere and does not completely burn up could cause significant damage, particularly if it strikes a populated area.

**Difference Between Asteroids and Meteoroids**

Asteroids differ from meteoroids in size. Asteroids are smaller sun-orbiting rocks or particles less than three feet in size. When a meteoroid enters Earth’s atmosphere, it creates a light phenomenon known as a meteor. If any part of a meteoroid or asteroid survives its passage through the atmosphere and lands on Earth’s surface, it is called a meteorite.

NASA’s Planetary Defense Coordination Office (PDCO) is essential for monitoring and preparing for potential asteroid threats. The PDCO coordinates efforts and develops plans to protect Earth from the potential impacts of hazardous space objects.