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The solar system is an amazing place with its mysterious planets, mysterious satellites and strange phenomena that are so out of this world that they cannot be explained.
Scientists have discovered volcanoes on Pluto spewing ice, while Mars is home to a truly “great” canyon the size of the United States. Or maybe there is a giant undiscovered planet lurking outside of Neptune?
We bring to your attention a list of the 10 most interesting facts about space for children, students in grade 4 – short stories about the universe.
10 Milky Way
Let’s start with the fact that The Milky Way is a disk about 120 light years in diameter with a central bulge 000 light years in diameter.. The disk is far from being perfectly flat and has a distorted shape, and astronomers attribute this fact to the two neighbors of our galaxy – the Large and Small Magellanic Clouds.
These two dwarf galaxies, which are part of our “Local Group” of galaxies and may be orbiting the Milky Way, are thought to be pulling dark matter into our galaxy like in a game of galactic tug of war. The tug creates a kind of oscillating frequency that affects the galaxy’s hydrogen gas, which is plentiful in the Milky Way.
9. Black holes
A perfectly logical question is, how dangerous is a black hole, is the Earth in imminent danger of being swallowed? Astronomers say the answer is no, though a huge supermassive black hole lurks at the center of our galaxy. Fortunately, we are not approaching this monster – we are about two-thirds of the way from the center relative to the rest of our galaxy – but we can certainly observe its effects from afar.
For example, the European Space Agency claims that it is four million times more massive than our Sun and is surrounded by surprisingly hot gas.
8. neutron stars
When a massive star dies, spewing much of its “innards” across the universe in a supernova explosion, its iron heart, the star’s core, collapses, creating the densest form of observable matter in the universe, the neutron star.
A neutron star is basically a giant core, says Mark Alford, a professor at the University of Washington. «Imagine a small lead ball with cotton candy around it.”Alford says:This is an atom. The whole mass is in a small lead ball in the middle, and there is a big plump cloud of electrons around it, like cotton wool.».
In neutron stars, all the atoms have decayed. Clouds of electrons have been completely absorbed, and it all becomes one with electrons moving side by side with protons and neutrons in a gas or liquid.
7. Rogue planets
A rogue planet (or free-floating planet) is typically a Jupiter-sized body that lives in the space between stars, unbound by the gravity of its parent star.
It is believed that these planets either formed directly from the collapse of interstellar gas clouds (like stars) with no mass to ignite (like a brown dwarf), or they were formed in a planetary system and they somehow overcame their star’s gravity and were thrown out of the system.
The first rogue planets were discovered in the late 1990s by a group of Japanese astronomers when they found evidence supporting the existence of objects whose masses resemble those of planets in a chameleon cluster located about 500 light-years from Earth.
Due to their complete lack of order, rogue planets can prove extremely difficult to spot. However, they can still be found using various methods such as microlensing (a phenomenon in which a star acts like a gravitational lens as it passes in front of a background star).
6. Magnets
Super-powerful magnetic neutron stars are playing hide-and-seek with astronomers. They have been known to flare up without warning, some for hours and others for months, then dim and disappear again.
The magnetar is a widely accepted variant of the neutron star and a common explanation for some phenomena (such as anomalous X-ray pulsars). The magnetar is currently the most powerful known magnetic object.. In fact, a magnetar’s magnetic field is powerful enough to make it deadly to approach it (and that’s an understatement).
If we could suddenly make a magnet about a thousand times more powerful, magnetars would be twenty billion times more powerful than anything we can do. The magnetic field of a magnetar could be four billion times stronger than that of Earth. In fact, it can erase all your credit cards from a distance of 200 kilometers.
5. Hypernovae
Hypernovae are incredibly rare. In fact, the frequency of hypernovae in the entire Milky Way is estimated to be one million times a year., which makes it especially difficult to observe celestial explosions.
Twenty-five million light-years from Earth in another galaxy, astronomers have found what appear to be the remnants of a giant hypernova, providing new information about these huge explosions, but there are currently several theories as to what actually causes them.
One idea is that a massive star, spinning at a very high speed or encased in a powerful magnetic field, explodes, ripping apart the inner core. Alternatively, a hypernova could be the result of two stars colliding, merging into one giant mass, and then exploding.
4. The speed of light in space
The speed of light in a vacuum is 186 miles per second (282 kilometers per second), and theoretically nothing can travel faster than light. In miles per hour, the speed of light is very high: about 299 miles per hour. If you could travel at the speed of light, you could circle the Earth 7,5 times in one second.
Early scientists, unable to perceive the movement of light, thought that it must travel instantaneously. However, over time, measurements of the motion of these undulating particles became more and more accurate.
2. Microgravity
Microgravity is the measure to which an object in space is subjected to acceleration. In general, the term is used as a synonym for “weightlessness”, but the prefix “micro” refers to accelerations equivalent to one millionth (10 – 6) of the force of gravity on the Earth’s surface.
Microgravity makes you taller. In microgravity, the vertebrae in the spine no longer compress under the force of Earth’s gravity, causing the discs between them to expand and the spinal column to lengthen, making you taller.
2. gamma rays
Gamma rays have the smallest wavelength and most of the energy of any other wave in the electromagnetic spectrum. These waves are generated by radioactive atoms and during nuclear explosions. Gamma rays can kill living cells, and this is an advantage that medicine takes advantage of using gamma rays to kill cancer cells.
Gamma rays travel to us across the vast distances of the universe, only to be absorbed by the Earth’s atmosphere. Different wavelengths of light penetrate the Earth’s atmosphere to different depths.. Instruments aboard high-altitude balloons and satellites, such as the Compton Observatory, give us the only view of the gamma-ray sky.
1. Dark matter and dark energy
Dark matter is five times larger than ordinary matter. It seems to exist in clusters around the universe, forming a kind of forest where visible matter coalesces into galaxies.. The nature of dark matter is unknown, but physicists have suggested that it, like visible matter, consists of particles.
At this point, several experiments are being conducted to search for dark matter. But scientists actually discovered its existence decades ago.
In the 1930s, astrophysicist Fritz Zwicky observed the rotations of the galaxies that form the Coma Cluster, a group of over 1000 galaxies located more than 300 million light-years from Earth. He estimated the mass of these galaxies based on the light they emitted.
He was surprised to find that, if this estimate is correct, at the speed at which galaxies are moving, they should have flown apart. In fact, the cluster needed at least 400 times its mass to hold itself together. Something mysterious seemed to be holding a finger on the scale; it seemed that invisible “dark” matter was added to the mass of galaxies.