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The secrets of the universe

 


Journey to Mars

 

On the night of Oct. 8, a photographer in Harstad, Norway captured this image of the dancing northern lights. Auroras are created when fast-moving, magnetic solar material strikes Earth's magnetic bubble, the magnetosphere. This collision rattles the magnetosphere in an event called a geomagnetic storm, sending trapped charged particles zooming down magnetic field lines towards the atmosphere, where they collide brilliantly with molecules in the air, creating auroras. Though many geomagnetic storms are associated with clouds of solar material that explode from the sun in an event called a coronal mass ejection, or CME, this storm was caused by an especially fast stream of solar wind. "Geomagnetic storms caused by high-speed solar wind streams aren't uncommon," said Leila Mays, a space physicist at our Goddard Space Flight Center in Greenbelt, Maryland. "Near solar minimum-when solar activity like CMEs are less frequent-these fast streams are actually the most common cause of geomagnetic storms that create auroras." Image courtesy of Johnny Henriksen/Spaceweather.com #nasa #space #photography #aurora #spaceweather #nasabeyond #sun #earth #science

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When stars that are around the mass of the sun reach their final stages of life, they shed their outer layers into space, which appear as glowing clouds of gas called planetary nebulae. The ejection of mass in stellar burnout is irregular and not symmetrical, so that planetary nebulae can have very complex shapes. In the case of this one, the nebula forms a winding blue cloud that perfectly aligns with two stars at its center. In 1999 astronomers discovered that the star at the upper right is in fact the central star of the nebula, and the star to the lower left is probably a true physical companion of the central star. For tens of thousands of years the stellar core will be cocooned in spectacular clouds of gas and then, over a period of a few thousand years, the gas will fade away into the depths of the universe. The curving structure of this planetary nebula resembles a last goodbye before the star reaches its final stage of retirement as a white dwarf. Image credit: ESA/Hubble & NASA, Acknowledgement: Serge Meunier #nasa #nebula #stars #space #astronomy #nasabeyond #science #hubble #hst #hubble25

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Scientists compared ground-based videos of pulsating auroras—a certain type of aurora that appears as patches of brightness regularly flickering on and off—with satellite measurements of the numbers and energies of electrons raining down towards the surface from inside Earth’s magnetic bubble, the magnetosphere. The team found something unexpected: A drop in the number of low-energy electrons, long thought to have little or no effect, corresponds with especially fast changes in the shape and structure of pulsating auroras. This image of a colorful aurora was taken in Delta Junction, Alaska, on April 10, 2015. All auroras are created by energetic electrons, which rain down from Earth’s magnetic bubble and interact with particles in the upper atmosphere to create glowing lights that stretch across the sky. Credits: Image courtesy of Sebastian Saarloos #nasa #aurora #earth #earthrightnow #science

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This is the expanding remains of a massive star that exploded about 8,000 years ago. Called the Veil Nebula, the debris is one of the best-known supernova remnants, deriving its name from its delicate, draped filamentary structures. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. This view is a mosaic of six pictures from our Hubble Space Telescope of a small area roughly two light-years across, covering only a tiny fraction of the nebula's vast structure. This close-up look unveils wisps of gas, which are all that remain of what was once a star 20 times more massive than our sun. The fast-moving blast wave from the ancient explosion is plowing into a wall of cool, denser interstellar gas, emitting light. The nebula lies along the edge of a large bubble of low-density gas that was blown into space by the dying star prior to its self-detonation. Image Credit: NASA/ESA/Hubble Heritage Team #nasa #hubble #hst #hubble25 #space #astronomy #nebular #star #nasabeyond #science

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It's #BlackFriday, but for us, it's the 2nd annual #BlackHoleFriday. Today, we'll post pics & info about black holes. Not the right #BlackFriday shopping weather? In this artist's illustration, turbulent winds of gas swirl around a black hole. Some of the gas is spiraling inward toward the black hole, but another part is blown away. A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars. Artwork Credit: NASA, and M. Weiss (Chandra X -ray Center)

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It's #BlackFriday, but for us, it's the second annual #BlackHoleFriday. Today, we'll post pics & info about black holes. What Is a Black Hole? A black hole is a region in space where the pulling force of gravity is so strong that light is not able to escape. The strong gravity occurs because matter has been pressed into a tiny space. This compression can take place at the end of a star's life. Some black holes are a result of dying stars. Because no light can escape, black holes are invisible. However, space telescopes with special instruments can help find black holes. They can observe the behavior of material and stars that are very close to black holes. Pictured here is an artist's drawing a black hole named Cygnus X-1. It formed when a large star caved in. This black hole pulls matter from blue star beside it. Image Credit: NASA/CXC/M.Weiss #NASA #Space #Blackhole #blackholes

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