• Earth's collision with a Mars-sized object created the Moon
  • Theia is an ancient planet from the early Solar System
  • Earth's collision with Theia may have triggered the evolution of life

An engineer described what would have happened to Earth if it didn’t collide with the Mars-sized cosmic billions of years ago to create the Moon. He said the evolution of life on the planet could be very different if the giant-impact hypothesis didn’t occur.

According to the giant-impact hypothesis, an ancient planet as big as Mars known as Theia collided with Earth around 4.5 billion years ago. This caused a massive impact event that not only changed Earth but its surroundings as well.

Due to the magnitude of the impact, a large portion of the Earth’s crust melted while some of it was blown off into space. Over time the chunks of debris that drifted outside Earth coalesced into a solid cosmic body. Eventually, this newly formed object became Earth’s Moon.

As various scientific reports have explained, both the Moon and the Sun have had significant effects on the evolution of the planet. For one, the gravitational pull from these cosmic objects is responsible for maintaining the tides of Earth’s oceans. This means that if not for the giant impact caused by Theia, Earth would have been very different.

In the question-and-answer site Quora, retired engineer Duncan Caincross attempted to explain what Earth would be like if it didn’t collide with Theia. According to Caincross, the cataclysmic event that happened billions of years ago could be responsible for the evolution of complex life on the planet.

He explained that if the impact event did not happen, Earth would be very different and would most likely look like Jupiter’s moon Europa, an ocean-filled world with an icy crust. Similar to the conditions on Europa, a pre-impact Earth would most likely not have the necessary elements to support the evolution of complex life.

This means there’s a strong chance that humans would not exist if Earth and Theia did not bump into each other.

“Without that impact, the Earth could have been like Europa - with a lot of water,” Caincross stated. “A planet with an Ocean that is kilometers deep at the shallowest parts. “That has major repercussions for the development of life - there would be no minerals in the top layers of the ocean - and no sunlight in the lower levels.”

“With such a planet there would be almost no life - the only life would be a tiny amount of life around the volcanic vents,” he continued.

Asteroid Impacts
A new report indicates that a total of 26 nuclear-level asteroid impacts have hit Earth since 2000. Donald Davis