Presentation on theme: "The Planet we live on. * Earth is the third planet from the Sun and is the largest of the terrestrial planets. * The Earth was formed approximately 4.54."— Presentation transcript:
The Planet we live on
* Earth is the third planet from the Sun and is the largest of the terrestrial planets. * The Earth was formed approximately 4.54 billion years ago and is the only known planet to support life. * The Earth’s rotation is gradually slowing * Earth has a powerful magnetic field * Of all the planets in our solar system, the Earth has the greatest density * It takes sunlight a full 8 minutes to go from the Sun to reach Earth.
* Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. * About 71% of the surface is covered by salt water oceans
* Only 3% water of the earth is fresh, rest 97% salted. Of that 3%, over 2% is frozen in ice sheets and glaciers. Means less than 1% fresh water is found in lakes, rivers and underground * The Earth tilts at roughly 66 degrees * The Earth is not actually round in shape; in fact it is geoid. This simply means that the rounded shape has a slight bulge towards the equator. So what causes this geoid shape? This happens solely because the rotation of the Earth which causes the bulge around the equator * Earth is mostly iron, oxygen and silicon * If you could separate the Earth out into piles of material, you’d get 32.1 % iron, 30.1% oxygen, 15.1% silicon, and 13.9% magnesium
* You may feel like you're standing still, but you're actually moving — fast. Depending on where you are on the globe, you could be spinning through space at just over 1,000 miles per hour * The oceans cover some 70 percent of Earth's surface, yet humans have only explored about 5 percent, meaning 95 percent of the planet's vast seas have never been seen. * The Earth is approximately 93 million miles (150 million kilometers) from the sun * Finally, there could be more planets like ours. Space scientists have found evidence of Earth-like planets orbiting distant stars, including an alien planet called Kepler 22-b circling in the habitable zone of a star much like ours. Whether any of these planets will harbor life is an open question.
* Estimates on how much longer the planet will be able to continue to support life range from 500 million years (myr), to as long as 2.3 billion years (byr). The future of the planet is closely tied to that of the Sun. As a result of the steady accumulation of helium at the Sun's core, the star's total luminosity will slowly increase. The luminosity of the Sun will grow by 10% over the next 1.1 byr and by 40% over the next 3.5 byr. Climate models indicate that the rise in radiation reaching the Earth is likely to have dire consequences, including the loss of the planet's oceans. * The Earth's increasing surface temperature will accelerate the inorganic CO2 cycle, reducing its concentration to levels lethally low for plants (10 ppm for C4 photosynthesis) in approximately myr. The lack of vegetation will result in the loss of oxygen in the atmosphere, so animal life will become extinct within several million more years. After another billion years all surface water will have disappeared and the mean global temperature will reach 70 °C (158 °F). The Earth is expected to be effectively habitable for about another 500 myr from that point, although this may be extended up to 2.3 byr if the nitrogen is removed from the atmosphere. Even if the Sun were eternal and stable, 27% of the water in the modern oceans will descend to the mantle in one billion years, due to reduced steam venting from mid-ocean ridges.
* One thing that is unique to the planet Earth is the fact that our continents move and that we have tectonic plates. * Earth is the only planet on which water can exist in liquid form on the surface.
Days The Earth rotates on its axis in less than 24 hours. It is actually 23 hours, 56 minutes and 4 seconds. Night