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UNIVERSE
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2 Minutes Hubble's Eye on the Universe, NASA Jet Propulsion Laboratory

 

 
 
star formation
 
Dr. Michio Kaku is a theoretical physicist, best-selling author, and popularizer of science. He’s the co-founder of string field theory (a branch of string theory), and continues Einstein’s search to unite the four fundamental forces of nature into one unified theory.
The National Aeronautics and Space Administration (NASA) is the United States government agency responsible for the civilian space program as well as aeronautics and aerospace research.

President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA's predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

Since that time, most US space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the Space Launch System and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches.

Take the journey into the Orion Nebula for a look at the birth, life, death of a star, a star is born – literally. The star begins as a cloud of gas and dust to its eventual end. They devour each other and end their lives by scattering gas and dust across the cosmos. Aging bright stars in the cluster glow in intense shades of red and blue. The majority of middle-aged stars, several billions of years old, are whitish in color. A myriad of far distant background galaxies of varying shapes and structure are scattered around the image.

The most intriguing object, however, doesn’t seem to belong in the cluster. It is a faint green bubble near the bottom center of the image. This so-called ‘planetary nebula’ is the aftermath of the death of a star. The burned-out central star can be seen inside the bubble. It is uncertain whether the planetary nebula is a member of NGC 1846, or simply lies along the line of sight to the cluster. Measurements of the motion of the cluster stars and the planetary nebula’s central star suggest it might be a cluster member.

In the last stages of a sunlike star's 10 billion-year life, its hydrogen fuel runs out, and the stellar core begins to shrink and heat up. The star's outer layers are blown off and set aglow by the star's radiation, creating colorful shells of gas. When 18th-century astronomers looked at such stars through small telescopes, the extended shells looked like fuzzy planetary disks. That led observers to call the objects "planetary nebulae."

Even after astronomers understood what was really going on, the name stuck. Planetary nebulae that look like butterflies, cat's eyes, rings or glowing orbs rank among the most beautiful and awe-inspiring images in Hubble's collection. The Hubble team highlights yet another example of the genre.
The nebula's formal name is IRAS 19475+3119. It was imaged by Hubble's Advanced Camera for Surveys back in 2003, and is actually classified as a "preplanetary nebula" (abstract) because it's in the early stages of its blow-off. The newly released image has been compared to a "beautiful bird," and for that reason I'd propose that IRAS 19475+3119 be designated the Dying Swan Nebula.

It also helps that the dying star lies in the constellation Cygnus (the Swan), 15,000 light-years from Earth in the plane of the Milky Way galaxy.

Stars are born in nebulae. Huge clouds of dust and gas collapse under gravitational forces, forming protostars. These young stars undergo further collapse, forming main sequence stars.

Stars expand as they grow old. As the core runs out of hydrogen and then helium, the core contacts and the outer layers expand, cool, and become less bright. This is a red giant or a red super giant (depending on the initial mass of the star). It will eventually collapse and explode. Its fate is determined by the original mass of the star; it will become either a black dwarf, neutron star, or black hole.

the birth the death

 

Matter and energy

Some fields of science see nature as matter in motion, obeying certain laws of nature which science seeks to understand. For this reason the most fundamental science is generally understood to be "physics"—the name for which is still recognizable as meaning that it is the study of nature.

Matter is commonly defined as the substance of which physical objects are composed. It constitutes the observable universe. According to the theory of special relativity, there is no unchangeable distinction between matter and energy, because matter can be converted to energy (see annihilation), and vice versa (see matter creation). The visible components of the universe are now believed to compose only 4 percent of the total mass. The remainder is believed to consist of 23 percent cold dark matter and 73 percent dark energy. The exact nature of these components is still unknown and is currently under intensive investigation by physicists. The behavior of matter and energy throughout the observable universe appears to follow well-defined physical laws. These laws have been employed to produce cosmological models that successfully explain the structure and the evolution of the universe we can observe. The mathematical expressions of the laws of physics employ a set of twenty physical constants that appear to be static across the observable universe. The values of these constants have been carefully measured, but the reason for their specific values remains a mystery.

Nature beyond Earth

Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace (and terrestrial locations). There is no discrete boundary between the Earth's atmosphere and space, as the atmosphere gradually attenuates with increasing altitude. Outer space within the solar system is called interplanetary space, which passes over into interstellar space at what is known as the heliopause.

Although outer space is certainly spacious, it is far from empty. Outer space is sparsely filled with several dozen organic molecules discovered to date by microwave spectroscopy, blackbody radiation left over from the big bang and the origin of the universe, and cosmic rays, which include ionized atomic nuclei and various subatomic particles. There is also some gas, plasma and dust, and small meteors. Additionally, there are signs of human life in outer space today, such as material left over from previous manned and unmanned launches which are a potential hazard to spacecraft. Some of this debris re-enters the atmosphere periodically.

The planet Earth is currently the only known body within the solar system to support life (*). However, current evidence suggests that in the distant past the planet Mars possessed bodies of liquid water on the surface. For a brief period in Mars' history, it may have also been capable of forming life. At present though, most of the water remaining on Mars is frozen.

The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density

 

NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant.he deepest visible-light image of the universe, the Hubble Ultra Deep Field. Image Credit: NASA, ESA, S. Beckwith (STScI) and the HUDF team. Click for a journey through the universe
If life exists at all on Mars, it is most likely to be located underground where liquid water can still exist. Conditions on the other terrestrial planets, Mercury and Venus, appears to be too harsh to support life as we know it. But it has been conjectured that Europa, the fourth-largest moon of Jupiter, may possess a sub-surface ocean of liquid water and could potentially host life.
(*) Sara Seager OC (born 21 July 1971) is a Canadian–American astronomer and planetary scientist. She is a professor at the Massachusetts Institute of Technology and is known for her work on extrasolar planets (planets that orbit stars other than our sun) and their atmospheres and as a pioneer in her field and developed groundbreaking methods for discovering another Earth. “From the birth of a single star billions of years ago, to this meeting today, we are all part of an ongoing cosmic journey,” she said in her acceptance speech. “Let us commit to continuing to explore the unknown.”