Category Archives: Earth Facts

Is Earth as smooth as a billiard ball? No, here’s why

You may have heard it has been said that if our planet were shrunk down to the size of a billiard ball, it would be smoother than it. In other words, the Earth is smoother than a billiard ball. Is that true?

Back in 2008, on the “Bad Astronomy” blog on discovermagazine.com, in the article titled “Ten things you don’t know about the Earth“, Phil Plait wrote about that, and he said “…according to the World Pool-Billiard Association, a pool ball is 2.25 inches in diameter and has a tolerance of +/- 0.005 inches.” and after making some calculations, he concluded that “… the urban legend is correct. If you shrank the Earth down to the size of a billiard ball, it would be smoother.”

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What would happen if the Earth stopped rotating?

The Earth rotates from west to east with a linear velocity of 465.1013 m/s (1674.365 km/h) at the equator. But what would happen if the Earth stopped rotating abruptly? Online magazine Tech Insider presented a video demonstrating the development of events in this case.

Related: What Would Happen If the Earth Started Spinning Backward?

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Why Do We See Only One Side of the Moon?

You have probably heard references been made to the “dark side” of the Moon – there’s even a Pink Floyd album with that name. But, in fact, there’s no “dark side” of the moon. Because it is not illuminated by the Earth, it is illuminated by the Sun. All the surface of the moon lit by the Sun as the Moon rotates. But, yes, we see only one side of the moon and here’s why.

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What would Antarctica look like if all its ice melted

Have you ever wondered what would Antarctica look like if all its ice melted? This may seem extraordinary and unlikely, but, this has actually happened in the past. In fact, there have been no major ice sheets over the South Pole for most of the Earth’s history.

In the video below, NASA Goddard strip away Antarctic ice to reveal a new, and much more detailed map of the bedrock below. This map, called Bedmap2, was compiled by the British Antarctic Survey and incorporates millions of new measurements, including substantial data sets from NASA’s ICESat satellite and an airborne mission called Operation IceBridge.

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NASA Detects a Human-Made Barrier Surrounding Earth

We, humans, are changing our planet drastically that scientists say the world entered a completely a new geological era called “Anthropocene”. But, it seems we are not shaping only the surface and the atmosphere of Earth, human activities are changing our near-space environment as well. The change is so big that NASA’s Van Allen probes have detected a human-made barrier surrounding Earth.

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Why astronauts float in space

We see images and videos from the International Space Station (ISS) where astronauts floating in the space freely. That’s because they’re in the space, so there is no gravitational force of Earth there, right?

Wrong.

The International Space Station is in Low Earth OrbitSee notes 1 with an altitude of between 330 and 435 km (205 and 270 mi). It is so close to the Earth that on a clear day easily visible to the naked eye from the ground as it is the third brightest object in the sky (NASA has actually launched a new interactive map at its Spot the Station web site). At that altitude, the Earth’s gravity is about 90 percent of what it is on the planet’s surface – still pretty strong, right? To reduce the gravity of the Earth by a factor of one million, one needs to be at a distance of 6 million kilometers (around 3,728,227 miles) from the Earth – more than fifteen times the distance between the Earth and Moon.

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How Earth Could Die – 8 Horrible Ways

Now we’re living on a warm, hospitable planet. As Carl Sagan has said “That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.” We, humans, are the unquestionable rulers of our little oasis in a hostile universe. But all things must pass. The life on Earth, even the planet itself, won’t last forever. What’s more, the humans may go extinct before our planet (and probably before the life on it) dies out. Here some possible (and horrible) ways how planet Earth could die.

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Jeff’s Earth – Amazing HD Video from ISS

On his most recent trip the International Space Station (Expedition 48),recently-retired NASA astronaut Jeff Williams has recorded a great HD video of Earth using an Ultra High Definition video camera.

Here in the video titled “Jeff’s Earth” below, he shares some of those images and talks about the beauty of the planet, the variety of things to see, and the value of sharing that perspective with everyone who can’t go to orbit in person.

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What would the Earth be like if humans never existed

Around 4 millions year ago, the ancestors of humans and chimpanzees diverged, genetic evidence suggests. What, if Chimpanzee–human last common ancestor(1) would suddenly die before giving birth to any babies? What would the Earth be like if humans never existed?

Researchers from Aarhus University in Denmark demonstrated that the Earth without humans would resemble Serengeti(2), a geographical region in Africa which hosts the largest terrestrial mammal migration in the world.

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