Named after the English astronomer Edmund Halley, Halley’s Comet is one of the most famous comets in the history of astronomy. Halley is the only comet that can be seen twice in a human lifetime. Having appeared throughout human history, the last time Halley’s Comet ‘visited’ Earth was in 1986. The average orbital period of Halley’s Comet is 76 years, and it is predicted to next appear on July 28, 2061.
Like other comets, Halley’s Comet also carries an extremely destructive potential if it collides with any planet in the Solar System, including Earth. Compared to meteors of similar size, comets have a much greater destructive power. Composed mainly of ice, gas, and dust, comets travel around the Sun at incredibly high speeds, reaching up to 160,000 km/h. Therefore, comets bring about far more death and destruction than slower-moving meteors.
For instance, in 1994, the comet Shoemaker-Levy 9, when crashing into the deep atmosphere of Jupiter, created an extremely catastrophic explosion, releasing energy equivalent to one thousand of the largest hydrogen bombs in the world, or 10 million tons of TNT. If Halley’s Comet were to crash directly into Earth, all life on our planet would be completely wiped out.
However, according to scientists’ estimates, the probability of a collision with large comets like Halley, which could cause extinction, is very low. Most comets that pass beyond the Roche limit (the closest distance a celestial body can approach the Sun) will suffer severe damage. Radiation from the Sun will cause the ice that covers the comet to melt. As a result, the size of the comet will shrink significantly and become less dangerous to Earth.
However, have you ever wondered: What would happen if Halley’s Comet crashed directly into the Moon during its ‘visit’ in 2061?
To answer this highly ‘fantastical’ question, the popular science YouTube channel What If has created a video explaining the potential impacts on Earth if Halley’s Comet collides directly with the Moon.
Reference: What If