Despite the fact that the scientific methods have been used since the start of the Middle Age, the first traces of modern science started during the 16th and the 17th century, the so-called Early modern period. The astronomy estimates there are more than 100 billion galaxies in the Universe, and our own galaxy, the Milky Way galaxy, has alone between 200-400 billion stars. So if an average galaxy has around 300 billion stars you can imagine the incredible number of all stars in our universe. Africa is considered to be an origin of today’s modern humans. According to the currently dominant theory Homo sapiens arose in Africa and migrated out of the continent around 50,000 to 100,000 years ago, replacing populations of Homo erectus in Asia and Neanderthals in Europe. The recent estimates say that there are more than 310,000 plant species on our planet. The oldest animal fossils (some sort of early sponges) originate from South Australia and are more than 665-million-year-old. People (and other hominids) have been using rocks for more than 2 million years. Up to now, scientists have identified more than 500 different dinosaur species. The smallest dinosaurs had the size of a chicken. The dinosaurs have gone extinct around 65 millions years ago probably due to very large meteorite hitting our planet. Our planet formed more than 4.5 billion years ago and it is estimated that it took around one billion years for life to develop on Earth. Oceans cover most of our planet, approximately 71% of our planet. Sputnik one that was launched in 1957 by Russians was the first Earth orbiting satellite. In 1947, a pilot Chuck Yeager was the first person to pass the speed of sound, flying the aircraft called Bell X-1. Planet Mars is called „Red planet“because of iron oxide which is prevalent on its surface and gives it a reddish look. The fastest wind speed ever recorded was 318 mph, in one of the tornadoes that hit the City in May, 1999. The world's longest rain streak happened in Hawaii in Kaneohe Ranch, Oahu, where there was rain for 247 straight days from August 27 1993 to April 30 1994. The world's biggest Earthquake in history occurred in Chile back in 1960. This earthquake had a magnitude of 9,5 and killed more than 1650 people. It is believed that the greatest volcano eruption in history occurred in Toba, Sumatra, around 71,000 years ago. This eruption was so powerful that it produced some 2800 cubic kilometers of ash and it is also believed to have caused major decline of human population to around 10,000 individuals. Around 80% of tsunamis occur in the Pacific Ocean but the possibility for tsunami is present in every larger water body, including the lakes. Gangkhar Puensum, Bhutan is the highest unclimbed mountain in the world with an elevation of 7,570 meters and a prominence of over 2990 meters. The jackfruit, widely cultivated in tropics, is the largest tree-born fruit, weighing up to 80 pounds (36 kg), up to 36 inches (90 cm) long and up to 20 inches (50 cm) in diameter. The blue whales are considered to be the largest animals on Earth in history. These huge animals can weigh up to 150 tons and reach length of more than 30 meters. The largest tree on Earth is General Sherman, in Tulare County, California. This gigantic sequoia is 83.8 meters (275 ft) tall, has a diameter of 7.7 meters (25 ft), an estimated bole volume of 1,487 cubic meters (52,513 cu ft), and an estimated age of more than 2500 years. World's largest salty lake is Caspian sea that covers an area of 143,200 square miles (370,886 km2) and the world's largest freshwater lake is Lake Superior that covers an area of 31,700 mi2 (82,103 km2) The lowest temperature ever recorded on our planet was −89.2 °C (−128.6 °F; 184.0 K) at the Russian Vostok Station in Antarctica July 21, 1983. The highest temperature ever recorded was 36° Fahrenheit (58° C) in Libya, back in 1922. An African Hunting dog can run at 50mph for up to 4 hours.