BBC - Schools Science Clips - Earth, Sun and Moon
butaivilniuje.info brings you the latest images, videos and news from America's NASA Retires Prolific RHESSI Solar Observatory After 16 Years. An interactive model of the motions of the Earth, Sun and Moon for children aged The tilt of the Earth's axis and the effect this has as Earth orbits the Sun.
Nobody knows for sure. The Biosphere Out With the Bad, in With the Good Different elements joining, colliding, breaking apart, and joining again is a very ferocious stage in the life of any planet. Even after the Earth formed, when the atmosphere began to stabilize, it was under siege. Early microbes, in their struggle for life, clashed with and consumed hydrogen gas.
Hundreds of millions of years passed. These microbes evolved into prokaryotes and adapted further, finding energy in sunlight. Then, in a process called photosynthesis, they flooded the atmosphere with oxygen. The rise of oxygen formed a protective layer around the Earth and also helped cool the Earth, eventually encasing the planet with ice in a series of "Snowball Earths" 2.
Some life forms survived, some proliferated, pushing oxygen levels higher.
This enabled a greater diversity of life. Naming the biosphere Combining "bio," meaning life, and "sphere," referencing the Earth's rounded surface, English-Austrian Geologist Eduard Suess coins the term that expressed the portion of the Earth that supports life.
Suess invented the word because he felt it was important to try to understand life as a whole rather than singling out particular organisms. He believed "biosphere" combines an understanding of the distinct layers that make up the Earth, its atmosphere, and an awareness of all life on our planet and relationships surrounding us.
Meet the young Earth 5: Here's an early look at how the Earth warmed, cooled, and built its biosphere over time. Activity Goldilocks Conditions Not too hot Where in our Solar System are the conditions just right to support life?
So, yes, way too hot. Earth Our planet contains just the right amount of energy and water to support a diverse variety of life. Saturn Saturn is too cold and gassy. Life-supporting planets usually posses a heavy-metal core surrounded by a rocky mantle.
Uranus The surface of Uranus is mostly composed of ices: Neptune The only energy is lightning, ultraviolet light, and charged particles. Although it's the kind of environment in which scientists believe life began, it's not viable today. Pluto Not only does liquid freeze solid on this dwarf planet, but even gases, like methane, will harden when Pluto is at its most distant, 5.
Along the edges where the continental and oceanic crust plates meet, all sorts of crazy things happen. These massive plates scrape past each other sideways. They dive under each other.
And in places, they get snagged, causing tremendous pressures to build. When this tension suddenly releases things happen much, much faster than two centimeters per year. But how do we know that the Earth's surface is moving? Some of the early scholars studying the first world maps began to notice some very odd things — for instance, that West Africa seems to fit nicely into Brazil. In the early 20th century, a German meteorologist named Alfred Wegener began assembling evidence suggesting that the continents were once connected.
BBC Bitesize - KS2 Science - How big is the Sun in relation to Earth?
He found very similar geological strata in West Africa and in Brazil. And during World War I, he wrote a book arguing that at one time all the continents on Earth had been united in a single supercontinent that he called Pangaea.
Why we're all Lava Surfers Journey with our Big Historian team on assignment in Iceland, a land of fire and ice, as they walk upon the spot the North American and Eurasian plates collide. Proving Continental Drift A Case for Pangaea Courtesy of the Alfred Wegener Institute for Polar and Marine Research While other scientists put forth the theory that the Earth's landmasses had once been connected by land bridges that had since sunk into the ocean, and had always been located where they are today, a few renegade scientists postulated that the Earth once contained one huge supercontinent.
InAustrian geologist Eduard Suess postulated a supercontinent called Gondwanaland, and American astronomer William Henry Pickering suggested in that the continents broke up when the Moon was separated from the Earth.
How big is the Sun in relation to Earth?
These theories found near-hostile scorn in the scientific community. So did a theory of a meteorologist named Alfred Wegener. He regarded the Earth as fundamentally dynamic. He believed the great continent, eventually named Pangaea, had broken apart due to continental drifting. Together, decades apart, they proved it Courtesy of the Alfred Wegener Institute for Polar and Marine Research Alfred Wegener — Alfred Wegener was not the first to present continental drifting, but he was the first to put together extensive evidence from several different scientific approaches.
Submitting fossil evidence of tropical life on Arctic islands to matching geographical features and formations on separate continents, he argued against transcontinental land bridge claims. He also disputed the theory that mountains formed like wrinkles on the skin of a drying apple, proposing instead that they were created by continents drifting. But he was unable to explain what force could be immense enough to cause continents to plow through the Earth's crust.
Wegener would eventually perish during a ski journey on the Greenland ice cap conducting his scientific research. His ship was using a new sonar technology that emitted underwater sound waves to detect enemy submarines. But, driven by his own scientific curiosity even during wartime, he kept the sonar turned on to read the topography of the ocean bottom. So it would be times-- I could dobut just for approximate-- it's roughly times the circumference of the earth. So times 40 is equal to 4, hours.
And just to get a sense of what 4, is-- actually, since I have the calculator out, let's do the exact calculation. It's times the circumference of the earth times 40 hours.
That's what it would take to do the circumference of the Earth. So it's 4, hours to circumnavigate the sun, going at the speed of a bullet or a jetliner.
Big History Project: Our Solar System & Earth
And so that is-- 24 hours in the day-- that is days. It would take you roughly half a year to go around the sun at the speed of a jetliner. Let me write this down. The sun is huge. Now, that by itself may or may not be surprising--and actually let me give you a sense of scale here, because I have this other diagram of a sun.
And we'll talk more about the rest of the solar system in the next video. But over here, at this scale, the sun, at least on my screen-- if I were to complete it, it would probably be about 20 inches in diameter.
The earth is just this little thing over here, smaller than a raindrop. If I were to draw it on this scale, where the sun is even smaller, the earth would be about that big. Now, what isn't obvious, because we've all done our science projects in third and fourth grade--or we always see these diagrams of the solar system that look something like this-- is that these planets are way further away.
Even though these are depicted to scale, they're way further away from the sun than this makes it look. So the earth is million kilometers from the sun. So if this is the sun right here, at this scale you wouldn't even be able to see the earth. It wouldn't even be a pixel. But it would be million kilometers from the earth. And this distance right here is called an astronomical unit-- and we'll be using that term in the next few videos just because it's an easier way to think about distance-- sometimes abbreviated AU, astronomical unit.
And just to give a sense of how far this is, light, which is something that we think is almost infinitely fast and that is something that looks instantaneous, that takes eight minutes to travel from the sun to the earth. If the sun were to disappear, it would take eight minutes for us to know that it disappeared on earth. Or another way, just to put it in the sense of this jet airplane-- let's get the calculator back out.
So we're talking about million kilometers. So if we're going at 1, kilometers an hour, it would take ushours at the speed of a bullet or at the speed of a jet plane to get to the sun. And just to put that in perspective, if we want it in days, there's 24 hours per day. So this would be 6, days. Or, if we divided byroughly 17 years.
Scale of earth and sun
If you were to shoot a bullet straight at the sun it would take 17 years to get there, if it could maintain its velocity somehow. So this would take a bullet or a jet plane 17 years to get to the sun. Or another way to visualize it-- this sun right over here, on my screen it has about a five- or six-inch diameter.
If I were to actually do it at scale, this little dot right here, which is the earth, this speck-- I would have to put this back about 50 feet away from the sun. If you were to look at the solar system-- and obviously there's other things in the solar system, and we'll talk more about them in the next video-- you wouldn't even notice this speck.
This is a little dust thing flying around this sun. And as we go further and further out of this solar system, you're going to see even this distance starts to become ridiculously small.
Or another way to think about it-- if the sun was about this size, then the earth at this scale would be about feet away from it.