Space mysteries 3

Space Mysteries

The Mystery of Auroras


If you are standing in Alaska, Canada, or the Northern United States on a clear dark night and looking up into the sky, you may see a bright greenish-white band of light that stretches across the sky from the East to the West. You are seeing the Northern Lights, also known as the Aurora Borealis. These types of lights also occur near the South Pole, where they are known as the Southern Lights and Aurora Australis.


On a lucky night, you may watch this auroral band continue to brighten as it moves toward the South. Then, within minutes, you may see the band of light break into many bands of light some of which will move back overhead and to the North, dancing rapidly and turning red, purple, and white. If you've been lucky to see this sequence of events, you have witnessed the beginning phases of an auroral substorm.




When we see these dancing auroral lights evolve suddenly from a slowly moving auroral arc across the sky, we know that there are two distinct processes occurring in Earth's magnetosphere. But which one triggered the abrupt change from a calm aurora to a dancing aurora?

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The Study of Black Holes, Cosmic X-ray Mysteries


NASA has selected a science mission that will allow astronomers to explore, for the first time, the hidden details of some of the most extreme and exotic astronomical objects, such as stellar and supermassive black holes, neutron stars and pulsars.Objects such as black holes can heat surrounding gases to more than a million degrees. The high-energy X-ray radiation from this gas can be polarized vibrating in a particular direction. The Imaging X-ray Polarimetry Explorer (IXPE) mission will fly three space telescopes with cameras capable of measuring the polarization of these cosmic X-rays, allowing scientists to answer fundamental questions about these turbulent and extreme environments where gravitational, electric and magnetic fields are at their limits.


We cannot directly image whats going on near objects like black holes and neutron stars, but studying the polarization of X-rays emitted from their surrounding environments reveals the physics of these enigmatic objects, said Paul Hertz, astrophysics division director for the Science Mission Directorate at NASA Headquarters in Washington. NASA has a great history of launching observatories in the Astrophysics Explorers Program with new and unique observational capabilities. IXPE will open a new window on the universe for astronomers to peer through. Today, we can only guess what we will find.

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Exploring the Mysteries of Comets


Comets are formed of dust and icy gases. They travel highly elliptical orbits that bring them close to the Sun, then swing them back, deep into space. Usually the farthest point of their journey is beyond the distance of Pluto's orbit. Close to the heat of the Sun, comets develop tails millions-of-miles in length, some creating easily viewable spectacles as they visit the vicinity of Earth.


In centuries past, comets seemed to appear suddenly, generating excessive reactions from people who did not understand them. They were blamed for everything from the death of kings to the demise of great empires to the creation of plagues. The passage of Halley's Comet in 1066, for example, appeared to foretell of the English loss at the Battle of Hastings. More recently, during its 1910 passage, the infant science of spectroscopy discovered toxic gases in Halley's Comet. Fearing that the Earth would pass through the poisonous tail, charlatans sold comet insurance policies and homeopathic medicines for the coming "comet fever."


To probe the mysteries of comets, the NASA Stardust spacecraft will fly close to a comet and, for the first time ever, bring material back to Earth for analysis by scientists worldwide. This cometary material, it is hoped, will help unlock some of the secrets of these small bodies that are often described as "dirty ice balls" hurling through space. By learning something about these little bits of a comet, scientists hope it may be possible to discover more far reaching secrets about the materials that make up our universe and possibly more about its origins. A big question that scientists hope to better answer is whether comets brought water to the Earth.Learn more here .

Sources

https://www.nasa.gov/mission_pages/themis/auroras/aurora_feature.htmlhttps://www.nasa.gov/press-release/nasa-selects-mission-to-study-black-holes.htmlhttps://www.nasa.gov/mission_pages/stardust/mission/comets-index.html

Space mysteries 3

Science

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