Colourfulgalaxyexplorer-blog - Astrophysics Explorer

A nebula (Latin for "cloud";[2] pl. nebulae, nebulæ, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Originally, nebula was a name for any diffuse astronomical object, including galaxies beyond the Milky Way. The Andromeda Galaxy, for instance, was referred to as the Andromeda Nebula (and spiral galaxies in general as "spiral nebulae") before the true nature of galaxies was confirmed in the early 20th century by Vesto Slipher, Edwin Hubble and others.

Most nebulae are of vast size, even hundreds of light years in diameter.[3] Although denser than the space surrounding them, most nebulae are far less dense than any vacuum created in an Earthen environment - a nebular cloud the size of the Earth would have a total mass of only a few kilograms. Nebulae are often star-forming regions, such as in the "Pillars of Creation" in the Eagle Nebula. In these regions the formations of gas, dust, and other materials "clump" together to form larger masses, which attract further matter, and eventually will become massive enough to form stars. The remaining materials are then believed to form planets and other planetary system objects.

Record-Breaking Space Discoveries of 2016!

2016 was a lot of things, but for astronomers, it meant the discovery of some of the farthest, faintest, and youngest objects in the universe we’ve seen yet.

A very interesting documentary about the Universe.

Solar System: Things to Know This Week

The Quadrantid meteor shower peaked this morning. Here are some fun facts:

1. Where Is Quadrans Muralis?

The radiant of the Quadrantids lies in the demoted constellation Quadrans Muralis.

2. What Is a Mural Quadrant? 

The Mural Quadrant is an angle measuring device mounted on or built into a wall. Quadrans Muralis appears on some 19th-century star atlases between Hercules, Boötes and Draco, and different astronomers changed the stars from time to time.

3. New Constellations

In the early 1920’s, the International Astronomical Union divided up the sky into official constellations for consistency in star naming. 88 constellations remained, but over 30 historical constellations, including Quadrans Muralis, didn’t make the cut.

4. Where Is It Now?

Most of the Quadrans Muralis stars are now within the boundaries of the official constellation Boötes, but the name of the meteor shower did not change.

5. Where Do Meteor Showers Come From?

Meteor showers are usually the residue that collects in the orbits of comets. Unlike most meteor showers’ parent bodies, the Quadrantids are associated with an asteroid—2003 EH1.

Discover the full list of 10 things to know about our solar system this week HERE.

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Ask Ethan #103: Have We Solved The Black Hole Information Paradox?

“How is Hawking’s theory of black holes storing information on the shell of an event horizon different than what Susskind said decades ago about black holes storing information on the shell of an event horizon? Did Hawking just pull a Steve Jobs and proclaim something new that Android figured out years before? Or is this actually new stuff?”

Stephen Hawking is claiming that the black hole information paradox has now been resolved, with the information encoded on the event horizon and then onto the outgoing radiation via a new mechanism that he’ll detail in a paper due out next month, along with collaborators Malcom Perry and Andrew Strominger. Only, that’s not really what’s happening here. While he does have a new idea and there is a paper coming out, its contents do not solve the information paradox, but merely provide a hypothesis as to how it may be solved in the future.

Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but would account for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, on radiation, and on the large-scale structure of the universe. Dark matter has not been detected directly, making it one of the greatest mysteries in modern astrophysics.

Dark matter neither emits nor absorbs light or any other electromagnetic radiation at any significant level. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.[2][3] Thus, dark matter is estimated to constitute 84.5% [note 1] of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total mass–energy content of the universe.[4][5][6]

The Andromeda Galaxy (/ænˈdrɒmɨdə/), also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780 kiloparsecs (2.5 million light-years) from Earth.[4] It is the nearest major galaxy to the Milky Way and was often referred to as the Great Andromeda Nebula in older texts. It received its name from the area of the sky in which it appears, the constellation of Andromeda, which was named after the mythological princess Andromeda. Being approximately 220,000 light years across, it is the largest galaxy of the Local Group, which also contains the Milky Way, the Triangulum Galaxy, and about 44 other smaller galaxies.

The Andromeda Galaxy is the most massive galaxy in the Local Group as well.[7] Despite earlier findings that suggested that the Milky Way contains more dark matter and could be the most massive in the grouping,[12] the 2006 observations by the Spitzer Space Telescope revealed that Andromeda contains one trillion (1012) stars:[9] at least twice the number of stars in the Milky Way, which is estimated to be 200–400 billion.[13]

The Andromeda Galaxy is estimated to be 1.5×1012 solar masses,[7] while the mass of the Milky Way is estimated to be 8.5×1011 solar masses. In comparison, a 2009 study estimated that the Milky Way and M31 are about equal in mass,[14] while a 2006 study put the mass of the Milky Way at ~80% of the mass of the Andromeda Galaxy. The Milky Way and Andromeda are expected to collide in 3.75 billion years, eventually merging to form a giant elliptical galaxy [15] or perhaps a large disk galaxy.[16]

At 3.4, the apparent magnitude of the Andromeda Galaxy is one of the brightest of any Messier objects,[17] making it visible to the naked eye on moonless nights even when viewed from areas with moderate light pollution. Although it appears more than six times as wide as the full Moon when photographed through a larger telescope, only the brighter central region is visible to the naked eye or when viewed using binoculars or a small telescope.

Is Everything We Know About Universe Wrong?

How Close Are We To Nuclear Fusion?

“Naysayers love to claim that nuclear fusion is always decades away — and always will be — but the reality is we’ve moved ever closer to the breakeven point and solved a large number of technical challenges over the past twenty years. Nuclear fusion, if we ever achieve it on a large scale, will usher in a new era for humanity: one where energy conservation is a thing of the past, as the fuel for our heart’s desires will literally be without limits.”

The ultimate dream when it comes to clean, green, safe, abundant energy is nuclear fusion. The same process that powers the core of the Sun could also power everything on Earth millions of times over, if only we could figure out how to reach that breakeven point. Right now, we have three different candidates for doing so: inertial confinement, magnetic confinement, and magnetized target fusion. Recent advances have all three looking promising in various ways, making one wonder why we don’t spend more resources towards achieving the holy grail of energy.