AK Learning Box

  What Is a Black Hole? The Short Answer: A black hole is an area of such immense gravity that nothing -- not even light -- can escape from it.

  Gravity   is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun. What else does gravity do? Why do you land on the ground when you jump up instead of floating off into space? Why do things fall down when you throw them or drop them? The answer is gravity: an invisible force that pulls objects toward each other. Earth's gravity is what keeps you on the ground and what makes things fall. An animation of gravity at work. Albert Einstein described gravity as a curve in space that wraps around an object—such as a star or a planet. If another object is nearby, it is pulled into the curve. Image credit: NASA Anything that has mass also has gravity. Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass. All its mass makes a combined gravitat...

  What Is an Impact Crater? Credit: NASA/JPL-Caltech An impact crater is formed when an object like an asteroid or meteorite crashes into the surface of a larger solid object like a planet or a moon. To form a true impact crater, this object needs to be traveling extremely fast—many thousands of miles per hour! When a solid object crashes into something at these super fast speeds, it forms a crater regardless of how hard or tough it is. It immediately vaporizes and creates enormous shockwaves through the ground that melt and recrystallize rock. All that's left is a big circular hole in the ground and some seriously mangled rocks! Some famous impact craters... Earth: Meteor Crater Meteor Crater in Arizona. Credit: image courtesy of the National Map Seamless Server (USGS)" Meteor Crater (also known as Barringer Crater) in Arizona was the first crater discovered to be formed by an extraterrestrial impact. It formed 50,000 years ago from a meteorite that may have been up ...

1. Water In Surah Al-Anbya, it was revealed: “We made every living thing from water, will they not believe?” (Quran, 21:30) and it was only after the discovery of the microscope that it was concluded that all living things consist mostly of water – while in the deserts of Arabia, the last thing a man could guess is that all of life ultimately came from water.  2. Universe: The Big Bang Theory In Surah Al-Anbya, Allah (SWT) also states: “Have those who disbelieved not considered that the heavens and the earth were a joined entity, and We separated them” (Quran, 21:30). In 1929, American astronomer Edwin Hubble proposed the Hubble’s Law according to which all entities in space are moving away from the Earth at speeds proportional to their distance i.e. the greater the distance from earth, the faster they are moving. Soon after this, he discovered that galaxies are moving away from each other as well which means that the universe is expanding overall. This laid the basis for the Bi...

  An asteroid or meteor is more likely to hit Earth because Earth is a lot bigger than the Moon, giving a meteoroid more area to hit! But we can see many thousands of craters on the Moon and we only know of about 180 on Earth! Why is that? The truth is both the Earth and the Moon have been hit many, many times throughout their long 4.5 billion year history. This view of the Moon's cratered South Pole was seen by NASA's Clementine spacecraft in 1996. Credit: NASA/JPL/USGS Where did all of Earth's craters go? The main difference between the two is that Earth has processes that can erase almost all evidence of past impacts. The Moon does not. Pretty much any tiny dent made on the Moon’s surface is going to stay there. Three processes help Earth keep its surface crater free. The first is called erosion. Earth has weather, water, and plants. These act together to break apart and wear down the ground. Eventually erosion can break a crater down to virtually nothing. Lake Manicouag...

How Scary Is Space? Get Ready for Galactic Goosebumps! In a scary Halloween movie, monsters, ghouls, and haunted houses can give you the creeps! Those things are, of course, just stories that were made up to give you a fright. If you want a real scare, check out these nine unearthly nightmares that could be happening right now in our own galaxy. Eek! Miranda the Monster Moon Miranda is an icy moon of Uranus, the seventh planet from our Sun. If you look closely at Miranda, you’ll notice a mismatched appearance. Are those scars a sign that this moon was patched together like Frankenstein’s monster? Nope! Those patches are actually deep craters, high ridges, and extreme cliffs. A Frightening Face on the Sun When NASA’s Solar Dynamics Observatory captured this picture of our Sun in October 2014, it looked like the Sun was getting ready for Halloween! You can light up the face of a jack-o-lantern at home with a candle or flashlight. What’s lighting up this Sun pumpkin’s face? Active reg...

  What Is a Barycenter? We say that planets orbit stars, but that’s not the whole truth. Planets and stars actually orbit around their common center of mass. This common center of mass is called the  barycenter . Barycenters also help astronomers search for planets beyond our solar system! What is a center of mass? Every object has a  center of mass . It is the exact center of all the material an object is made of. An object's center of mass is the point at which it can be balanced. Sometimes the center of mass is directly in the center of an object. For example, you can easily find the center of mass of a ruler. Try holding your finger under the middle of a ruler in a few different spots. You'll find a spot where you can balance the whole ruler on just one fingertip. That's the ruler's center of mass. The center of mass is also called the center of gravity. But sometimes the center of mass is  not  in the center of the object. Some parts of an object may have m...