字幕表 動画を再生する 英語字幕をプリント Our planet is amazing. Orbiting around the sun at a whopping speed of 107,218 km/h, that's pretty fast for such a big body - and though Earth can't step on a scale - NASA calculates its mass at 5,972,190,000,000,000,000,000,000 kg (five septillion, nine hundred seventy two sextillion, one hundred ninety quintillion kilograms). However, our planet is continually gaining and losing mass. We take on an estimated 40,000 tonnes of space dust that the earth's gravity pulls in like a giant vacuum - this dust is vestiges of our solar system, broken up asteroids and the matter that never turned into planets. But we lose mass largely due to gases (farting earth drawing). Gases like hydrogen are so light that they are escaping through the atmosphere at a rate of 3 kg per second - that's 95,000 tonnes a year. But what about us? The human population in 1987 was 5 billion and it is now estimated at 7.6 billion! Do our bodies and all the structures we put on the surface of the earth affect the mass of the planet? No, because we are actually made up of existing matter on the planet. That matter is atoms - and we've been able to identify 118 different kinds (elements) but what makes up 90% of us is just 3 elements: oxygen (65%), carbon (18.5%) and hydrogen (9.5%). Two of those elements make up the liquid vital for life: water. Our oceans cover 70% of the planet. At its deepest depth the Mariana Trench is measured at 10,994m - for context if you put the base of Mount Everest at the bottom of the Trench, the peak would still be 1.6km underwater. Our oceans are still largely a mystery - with only 5% of it explored. With more knowledge we could better understand how the Deep-Sea Octopus (Graneledone boreopacifica) had the longest egg-brooding period ever recorded (pregnancy). This committed mama located in Monterey Bay wrapped her arms around her 160 plus eggs, protecting them for 53 months without eating the entire time, how she survived so long is still a mystery. Though it may seem obvious to you that animals like your cats and dogs have unique personalities, several scientists had long rejected the idea. Now there are confirmed surveys to measure the unique personalities of chimps which are a product of natural selection. All of this action occurs on the earth's crust which by volume only makes up 1% of the earth. There's a lot of life on our amazing pale blue dot.