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Earth – 3rd rock from the sun

Earth is the only world known to support life -intelligent life, making it doubly unique. But the most impressive attribute of the Earth is the existence and amount of liquid water on its surface. Water is what lubricates plate tectonics, which leads to the extreme difference between continents and seafloors, the large amount of earthquakes and volcanoes, fresh mountain-building.

Venus has no water, no plate tectonics, no deep sea floor, no steep mountains, no continents, probably few earthquakes or volcanoes. A much less geologically interesting place!  The size of Earth is ‘just right’ – if it was much smaller, it would not be able to hold on to our precious atmosphere. And much larger, it might be a gas giant too hot for life.

But we must not forget about our nearest celestial neighbour, our friendly moon, of which, life on Earth owes a debt. Earth’s moon stabilizes our planet’s rotation, preventing drastic movements of the poles that could cause massive changes in climate that some scientists think could have doomed any chance for budding life to form or evolve. The moon also pulls the ocean’s tides, which was the perfect place for early life to begin evolving to survive on land.

15 interesting facts about Earth:

1. The Pacific Ocean is the biggest basin

The Pacific Ocean is by far Earth’s largest ocean basin, covering an area of about 59 million square miles (155 million square kilometers) and containing more than half of the free water on Earth, according to NOAA. It’s so big that all of the world’s continents could fit into the Pacific basin.

2. The driest spot

is the Atacama Desert of Chile and Peru. In the center of this desert, there are places where rain has never been recorded.

3. The Mariana Trench is the deepest spot.

The deepest point on the ocean floor is in the Mariana Trench; 35,813 feet (10,916 meters) below sea level. But, have you ever wondered how low can you go? The lowest point on Earth not covered by ocean is 8,382 feet (2,555) meters below sea level is in the Bentley Subglacial Trench in Antarctica, buried under lots and lots more ice.

4, The Dead Sea is the lowest point on land

The lowest point on land is relatively accessible. It is the Dead Sea, between Jordan, Israel and the West Bank. The surface of this super-salty lake is 1,388 feet (423 m) below sea level.

5. Coral reefs are the largest living structures

Coral reefs support the most species per unit-area of any of the planet’s ecosystems, rivaling rain forests. While they are made up of tiny coral polyps, coral reefs are the largest living structures on Earth — a community of connected organisms. Some are so large they are visible from space.

6. Earth is a squashed sphere

Earth is not a perfect sphere. As Earth spins, gravity points toward the center of our planet, and a centrifugal force pushes outward. Gravity-opposing forces acts perpendicular to the axis of Earth, which is tilted, making the centrifugal force at the equator not exactly opposed to gravity. At the equator, there is an imblalnce of gravity, where it pushes extra masses of water and earth into a bulge, or spare-tire affect around our planet.

7. Mother Earth has a generous waistline

At the equator, the circumference of the globe is 24,901 miles (40,075 kilometers). And oddly enough, at the equator you would weigh less than if standing at one of the poles.

8. Earth is on the move

You may feel like you’re standing still, but you’re actually moving — very fast. Depending on where you are on the globe, you could be spinning through space at just over 1,000 miles per hour. People on the equator move the fastest, while someone standing on the North or South pole would be perfectly still. Imagine a basketball spinning on your finger. The point on the ball’s equator has farther to go in a single spin as the point near your finger. therefore the point on the equator moves faster.

9. The planet orbits the sun

The Earth isn’t just spinning. It’s also moving around the sun at 67,000 miles (107,826 km) per hour.

10. Older than dirt

Researchers calculate the age of the Earth by dating both the oldest rocks on the planet and meteorites that have been discovered on Earth. Earth is about 4.54 billion years old.

11. The planet has recycled

The ground you’re walking on is recycled. Earth’s rock cycle transforms igneous rocks to sedimentary rocks to metamorphic rocks and back again. The cycle is not a perfect circle. The basic formula works like this: magma from deep in the Earth emerges and hardens into rock. Tectonic processes uplift that rock to the surface, where erosion shaves bits off. These tiny fragments get deposited and buried, and the pressure from above compacts them into sedimentary rocks such as sandstone. If sedimentary rocks get buried even deeper, they “cook” into metamorphic rocks under lots of pressure and heat.

Along the way,sedimentary rocks can be re-eroded or metamorphic rocks re-uplifted. But if metamorphic rocks get caught in a subduction zone where one piece of crust is pushing under another, they may find themselves transformed back into magma.

12. Our moon quakes

Earth’s moon looks rather dead and inactive, but moonquakes, or earthquakes on the moon, though less common and less intense than those that shake Earth, do occur.

According to USGS scientists, moonquakes seem to be related to tidal stresses associated with the varying distance between the Earth and moon. Moonquakes also tend to occur at great depths, about midway between the lunar surface and its center.

13. The hottest spot is in Libya

The fiery award for Earth’s hottst spot goes to El Azizia, Libya, where temperature records from weather stations have hit 136 degrees Fahrenheit (57.8 degrees Celsius) on Sept. 13, 1922, according to NASA Earth Observatory. Meteorologists suggest that there have likely been hotter locations beyond the network of weather stations. Baby, it’s hot in Lybia!

14. The coldest place is Antarctica

It may come as no surprise that the coldest place on Earth is Antarctica, with the chill factor somewhat unbelievable. Winter temperatures there can drop below minus 100 degrees F (minus 73 degrees C).

Moving northward, the lowest temperature ever recorded on Earth came from Russia’s Vostok Station, where records show the air plunged to a bone-chilling minus 128.6 degrees F (minus 89.2 degrees C) on July 21,1983, according to the USGS.

15. Uneven gravity on Earth

Because our globe isn’t a perfect sphere, its mass is distributed unevenly. And uneven mass means slightly uneven gravity. One mysterious gravitational anomaly is in the Hudson Bay of Canada, where there is lower gravity than in other regions. A 2007 study found that now-melted glaciers are to blame.

The ice that once cloaked the area during the last ice age has long since melted, but the Earth hasn’t entirely snapped back from the burden. Since gravity over an area is proportional to the mass atop that region, the glacier’s imprint pushed aside some of the Earth’s mass, making gravity is a bit less strong in the ice sheet’s imprint. The slight deformation of the crust explains 25 percent to 45 percent of the unusually low gravity; the rest may be explained by a downward drag caused the motion of magma in Earth’s mantle (the layer just beneath the crust).

 

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