9 phenomena that mankind has seen only once

There are countless events that have affected the history of mankind in one way or another. And while some of the more important developments have eclipsed the smaller ones, each of them has its own importance and encourages future scientific research.

We have collected 11 phenomena that we have only seen once in this strange world, which sometimes gives us big surprises.

9 PHOTOS

1. The Mississippi River flows in the opposite direction.

This river in the United States is the fourth longest in the world. In 2012, Hurricane Isaac caused the Mississippi River to run backward for 24 hours and also caused the river to reach nearly 3 meters above normal.

2. Tunguska meteorite.

This is an explosion that occurred in 1908 near the Podkamennaya Tunguska. Some theories say the explosion was caused by a meteorite that entered the atmosphere and exploded before it hit the ground, releasing the energy equivalent of 185 Hiroshima bombs. There were no craters because the giant rock disintegrated before hitting the ground, but it burned vegetation, killed animals, and to this day no trees grow in this area.

3. Geomagnetic storm of 1859.

This event occurred in 1859 and is considered one of the most extreme solar storms in history. More precisely, what happened was that several solar particles colliding with the Earth's magnetic field, which was a manifestation of another phenomenon known as the northern lights. But this radiance was much more powerful, and it was visible in many regions.

4. Direction Uranus.

In 1986, NASA was able to get close to Uranus for the first time thanks to the Voyager 2 space probe. It is the coldest planet in our solar system, though not the furthest from the Sun. This phenomenon, as scientists have found, is due to the fact that it does not have an internal heat source. In addition, there was evidence of a boiling ocean below the clouds.

5. Super-eruption of Toba.

The Toba supervolcano caused the near extinction of the human race about 74,000 years ago. Its explosion threw out so much ash and sulfuric gas that they blocked sunlight and made life on Earth impossible: plants and animals died, the air became toxic and it was difficult to breathe. Since that day, Lake Toba on the island of Sumatra has remained the largest crater lake in the world. But how did people survive after this terrible disaster? It is believed that the eruption likely created areas called refugia where humans can survive in harsh conditions.

6. Comet West.

This impressive comet crossed the skies during the 1970s leaving a bright trail.

7. Smallpox: The only human disease that has been successfully eradicated.

It is a unique disease because it is one of the deadliest known to mankind and the only one that has been completely eradicated. There is no cure for smallpox, and the smallpox vaccine was the first successful vaccine ever invented. It was found that peasants who worked with cattle were infected with a much more benign form of the disease, and through this, they were immunized against it. This showed that the introduction of an attenuated virus could generate antibodies to any strain of the same virus. This would later become the vaccine we know today.

8. Dance plague.

This strange event dates back to 16th century Strasbourg, were anywhere from 50 to 400 people took to the streets to dance uncontrollably for several days. About 15 people died every day due to exhaustion and heart attacks, and many more were taken to a medical facility. Although this phenomenon cannot be explained, there are many theories.

9. Cyclone Katharina, was the only hurricane recorded in the South Atlantic.

This hurricane is unique because it is the first and last to hit the coast of Brazil so far, and the only one on record in South America.