Penumbral Lunar Eclipse, 5-6th June 2020 . . . . . . #lunar #lunarbeauty #lunar2020 #lunareclipse2020

charupic

4 years ago

#ClimateStrikeOnline It’s International Day for Biological Diversity 2020 today, so let’s take a minute to reflect on how important biodiversity is! . . . #FridaysForFuture #BiodiversityDay #biodiversity #naturalbeauty #naturelovers #diversity #bio #birdlover #biodiversity2020 https://www.instagram.com/p/CAgCTK_Dejy/?igshid=nk8sbgjrkin9

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diversity bio naturelovers naturalbeauty biodiversity climatestrikeonline fridaysforfuture biodiversityday birdlover biodiversity2020

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charupic

5 years ago

It's very useful information about White Dwarfs.

What are white dwarfs?

Some curiosities about white dwarfs, a stellar corpse and the future of the sun.

Where a star ends up at the end of its life depends on the mass it was born with. Stars that have a lot of mass may end their lives as black holes or neutron stars.

A white dwarf is what stars like the Sun become after they have exhausted their nuclear fuel. Near the end of its nuclear burning stage, this type of star expels most of its outer material, creating a planetary nebula.

In 5.4 billion years from now, the Sun will enter what is known as the Red Giant phase of its evolution. This will begin once all hydrogen is exhausted in the core and the inert helium ash that has built up there becomes unstable and collapses under its own weight. This will cause the core to heat up and get denser, causing the Sun to grow in size.

It is calculated that the expanding Sun will grow large enough to encompass the orbit’s of Mercury, Venus, and maybe even Earth.

A typical white dwarf is about as massive as the Sun, yet only slightly bigger than the Earth. This makes white dwarfs one of the densest forms of matter, surpassed only by neutron stars and black holes.

The gravity on the surface of a white dwarf is 350,000 times that of gravity on Earth.

White dwarfs reach this incredible density because they are so collapsed that their electrons are smashed together, forming what is called “degenerate matter.” This means that a more massive white dwarf has a smaller radius than its less massive counterpart. Burning stars balance the inward push of gravity with the outward push from fusion, but in a white dwarf, electrons must squeeze tightly together to create that outward-pressing force. As such, having shed much of its mass during the red giant phase, no white dwarf can exceed 1.4 times the mass of the sun.

While many white dwarfs fade away into relative obscurity, eventually radiating away all of their energy and becoming a black dwarf, those that have companions may suffer a different fate.

If the white dwarf is part of a binary system, it may be able to pull material from its companion onto its surface. Increasing the mass can have some interesting results.

One possibility is that adding more mass to the white dwarf could cause it to collapse into a much denser neutron star.

A far more explosive result is the Type 1a supernova. As the white dwarf pulls material from a companion star, the temperature increases, eventually triggering a runaway reaction that detonates in a violent supernova that destroys the white dwarf. This process is known as a single-degenerate model of a Type 1a supernova.

If the companion is another white dwarf instead of an active star, the two stellar corpses merge together to kick off the fireworks. This process is known as a double-degenerate model of a Type 1a supernova.

At other times, the white dwarf may pull just enough material from its companion to briefly ignite in a nova, a far smaller explosion. Because the white dwarf remains intact, it can repeat the process several times when it reaches the critical point, briefly breathing life back into the dying star over and over again.

Image credit: www.aoi.com.au, NASA, Wikimedia Commons, Fsgregs, quora.com, quora.com, NASA’s Goddard Space Flight Center, S. Wiessinger, ESO, ESO, Chandra X-ray Observatory

Source: NASA, NASA, space.com

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charupic

4 years ago

International Asteroid Day aims to raise public awareness about the asteroid impact hazard and to inform the public about the crisis communication actions to be taken at the global level in case of a credible near-Earth object threat. . . . . . . #asteroid #universe #space #spacetime #astronomy #astronomer #spacestation #spacetravel #sunrise #satellite https://www.instagram.com/p/CCDuhL2DN0Z/?igshid=5vxzze8zzajg

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space universe astronomy asteroid sunrise satellite spacetime spacestation astronomer spacetravel

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charupic

5 years ago

What’s aboard SpaceX’s Dragon?

On Dec 5. 2019, a SpaceX Falcon 9 rocket blasted off from Cape Canaveral Air Force Station in Florida carrying a Dragon cargo capsule filled with dozens of scientific experiments. Those experiments look at everything from malting barley in microgravity to the spread of fire.

Not only are the experiments helping us better understand life in space, they also are giving us a better picture of our planet and benefiting humanity back on Earth.

📸 A Better Picture of Earth 🌏

Every material on the Earth’s surface – soil, rocks, vegetation, snow, ice and human-made objects – reflects a unique spectrum of light. The Hyperspectral Imager Suite (HISUI) takes advantage of this to identify specific materials in an image. It could be useful for tasks such as resource exploration and applications in agriculture, forestry and other environmental areas.

🌱 Malting Barley in Microgravity 🌱

Many studies of plants in space focus on how they grow in microgravity. The Malting ABI Voyager Barley Seeds in Microgravity experiment is looking at a different aspect of plants in space: the malting process. Malting converts starches from grain into various sugars that can be used for brewing, distilling and food production. The study compares malt produced in space and on the ground for genetic and structural changes, and aims to identify ways to adapt it for nutritional use on spaceflights.

🛰️ A First for Mexico 🛰️

AztechSat-1, the first satellite built by students in Mexico for launch from the space station, is smaller than a shoebox but represents a big step for its builders. Students from a multidisciplinary team at Universidad Popular Autónoma del Estado de Puebla in Puebla, Mexico, built the CubeSat. This investigation demonstrates communication within a satellite network in low-Earth orbit. Such communication could reduce the need for ground stations, lowering the cost and increasing the number of data downloads possible for satellite applications.

🚀 Checking for Leaks 🚀

Nobody wants a spacecraft to spring a leak – but if it happens, the best thing you can do is locate and fix it, fast. That’s why we launched the first Robotic External Leak Locator (RELL) in 2015. Operators can use RELL to quickly detect leaks outside of station and help engineers formulate a plan to resolve an issue. On this latest commercial resupply mission, we launched the Robotic Tool Stowage (RiTS), a docking station that allows the RELL units to be stored on the outside of space station, making it quicker and simpler to deploy the instruments.

🔥 The Spread of Fire 🔥

Understanding how fire spreads in space is crucial for the safety of future astronauts and for controlling fire here on Earth. The Confined Combustion investigation examines the behavior of flame as it spreads in differently-shaped spaces in microgravity. Studying flames in microgravity gives researchers a chance to look at the underlying physics and basic principles of combustion by removing gravity from the equation.

💪 Staying Strong 💪

Here on Earth you might be told to drink milk to grow up with strong bones, but in space, you need a bit more than that. Astronauts in space have to exercise for hours a day to prevent substantial bone and muscle loss. A new experiment, Rodent Research-19, is seeing if there is another way to prevent the loss by targeting signaling pathways in your body at the molecular level. The results could also support treatments for a wide range of conditions that cause muscle and bone loss back here on Earth.

Want to learn about more investigations heading to the space station (or even ones currently under way)? Make sure to follow @ISS_Research on Twitter and Space Station Research and Technology News on Facebook.

If you want to see the International Space Station with your own eyes, check out Spot the Station to see it pass over your town.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

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charupic

11 years ago

hello Friendss how r u???

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charupic

5 years ago

What’s aboard SpaceX’s Dragon?

On Dec 5. 2019, a SpaceX Falcon 9 rocket blasted off from Cape Canaveral Air Force Station in Florida carrying a Dragon cargo capsule filled with dozens of scientific experiments. Those experiments look at everything from malting barley in microgravity to the spread of fire.

Not only are the experiments helping us better understand life in space, they also are giving us a better picture of our planet and benefiting humanity back on Earth.