Iron-rich asteroids may pose greater threat to Earth

Scientists have discovered that some asteroids, called M-type asteroids, which are rich in metals, can become stronger and tougher when they enter Earth's atmosphere.

This is different from what scientists previously thought, where asteroids would break apart due to the stress.

The scientists did this by using a special machine to shoot high-energy particles at a piece of an iron meteorite and watched how it reacted.

They found that the meteorite absorbed more energy and became stronger as the stress increased.

This is important because if such an asteroid were to hit Earth, it might not break apart in the atmosphere as expected, making it a bigger threat.

There are currently 37,000 known near-Earth asteroids and 120 near-Earth comets, but scientists say Earth is safe from these for at least the next 100 years.