World Asteroid Day 2026: 5 huge asteroid impacts that completely rewrote Earth's history. One created trillions of diamonds within seconds

June 30 is Asteroid Day, a day that marks the anniversary of the Tunguska event in 1908. A nearly 330-foot asteroid exploded over Siberia, Russia, and was 1,000 times more powerful than the Hiroshima atomic bomb. Asteroids have become the biggest celebrities of the astronomy world today, with even the common man talking about it. Earth has witnessed some historic asteroid impacts in its 4.6 billion-year history. Here are the biggest ones, some of which caused mass extinction.

Vredefort Crater - 2.02 billion years

An approximately 20 to 25 kilometre wide asteroid moving at a speed of roughly 54,000 to 90,000 km/hr collided with Earth 2 billion years ago in South Africa, gouging a 40 kilometre deep cavity that was 300 kilometres wide. Today, it is known as the Vredefort Impact Structure or Vredefort Dome and is the largest verified asteroid impact crater on Earth. The impact sent the Earth's crust splashing upwards and froze it back into solid. A 25-kilometre-thick slice of Earth’s crust turned completely on its side, exposing 3.5-billion-year-old granites.

Sudbury Basin - 1.85 billion years

This crater is located in Ontario, Canada and was made by an asteroid measuring 15 kilometres wide and moving at a speed of tens of thousands of kilometres per hour. The crater was roughly 30 kilometres deep and measured around 200 to 250 kilometres across. The impact was so strong that it melted a massive volume of Earth's crust, forming a subterranean lake of superheated liquid rock. Today, it is 60 km long and 30 km wide because tectonic forces changed it over 1.8 billion years.

The Chicxulub Event - 66 million years

An asteroid 10 to 15 kilometres in diameter slammed into Earth 66 million years ago and killed the dinosaurs. The impact crater is present in the Yucatán Peninsula of modern-day Mexico and measures 150 to 300 kilometres wide. It wiped out roughly 75% of all species on Earth. The asteroid triggered landslides, tsunamis and earthquakes. The dust and vaporised rock shrouded Earth, blocking sunlight and causing a winter that lasted for years. Plant and animal life perished in the aftermath, with acid rain poisoning the oceans.

Popigai Crater - 35.7 million years

Located in northern Siberia, Russia, it is the fourth-largest confirmed impact crater on Earth. Interestingly, it is the world’s largest known diamond field, which was formed because of the asteroid that slammed into this region. The asteroid (which scientists say could also have been a comet) measured nearly 8 kilometres wide. The crater measures roughly 100 kilometres in diameter, and the impact triggered what is known as shock metamorphism.

This area was rich in ancient graphite deposits, and so when the space rock struck, the shockwave led to pressures spiking up to 60 gigapascals and temperatures soaring to thousands of degrees. This instantly compressed the molecular structure of the graphite, leading to impact diamonds being formed within seconds.

This event is even linked to the Eocene–Oligocene extinction event because it happened within a few hundred thousand years of another asteroid collision that struck the Chesapeake Bay area in the United States. Together, they disrupted the climate and killed several marine and terrestrial species.

The Tunguska Event - 125 years

This remains the largest impact event in recorded human history. The asteroid that entered Earth over Siberia did not hit the ground but exploded 5 to 20 kilometres above the ground. Even this triggered the release of energy equivalent to 10–15 megatons of TNT. Over 80 million trees across 2,150 square kilometres of area were flattened instantly