Disaster on Earth when the Sun is obscured for many years

Some events that have occurred on Earth significantly block sunlight for a long time, seriously affecting living organisms.

Collision with asteroids

Large asteroids colliding with the Earth can push many materials into the air, blocking sunlight.(Photo: Sun.)

About 65 million years ago, the Creta mass extinction event - the Third High (K-T), erased 80% of the species that live on Earth, according to Live Science. Many scientists believe that this event was caused by a giant comet or meteorite colliding with the Earth, creating a 180-km-wide crater on the Yucatan Peninsula, Mexico.

"Fragments and dust from the collision are blown to the upper atmosphere, quickly covering the Earth or at least one hemisphere. This prevents sunlight from reaching the ground , " said Linda Ivany. , ancient climate specialist at Syracuse University, USA, said.

In addition, the large amount of heat generated from the collision burned many forests and other vegetation, dispersing more ash into the atmosphere."The ash particles can survive for a long time in the atmosphere, years after the event , " Ivany said.

Dust ash does not completely block sunlight like a total solar eclipse but only reduces the intensity of light, but it is also enough to kill living plants through photosynthesis and animals eat them.

"Sunlight energy has been declining for months or years, hurting the ability of the organism to grow and reproduce , " Ivany said.

Volcanic ash

Volcanic volcanic eruptions can create a lot of ash to cover the sky.(Photo: iStock.)

The impact of asteroids is not the only event capable of blocking sunlight. Volcanoes can also "obscure" the sky on a global scale.

On April 5, 1815, the Tambora volcano in Indonesia erupted, releasing 150 km3 of rock and ash to a height of 29 km. This is the most powerful volcanic eruption in modern history. Immediately after the volcano erupted, the ash cloud gradually expanded to cover an area approximately equal to Australia. The air temperature in the area drops to 11 degrees Celsius, according to Scientific American.

Volcanic ash exists in the atmosphere for a long time, then spreads throughout the Earth. BBC said the dust cloud from Tambora volcano caused global temperatures to drop from 0.4 to 0.7 degrees C. A year later, many areas in Europe and North America had no summer. Frost destroys crops in Canada and New England, USA.