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It vexes me when they would constrain science by the authority of the Scriptures, and yet do not consider themselves bound to answer reason and experiment.

Nature is relentless and unchangeable, and it is indifferent as to whether its hidden reasons and actions are understandable to man or not.

By denying scientific principles, one may maintain any paradox.

Facts which at first seem improbable will, even on scant explanation, drop the cloak which has hidden them and stand forth in naked and simple beauty.

I think that in the discussion of natural problems we ought to begin not with the Scriptures, but with experiments, and demonstrations.

Galileo Galilei

Saturn: Moons

Saturn has a great many more moons than our planet – a whopping 62. A single moon, Titan, accounts for an overwhelming 96% of all the material orbit the planet, with a group of six other smaller moons dominating the rest. The other 55 small satellites whizzing around Saturn make up the tiny remainder along with the gas giant’s famous rings.

 One of the subjects of this Cassini image, Rhea, belongs to that group of six. Set against a backdrop showing Saturn and its intricate system of icy rings, Rhea dominates the scene and dwarfs its tiny companion, one of the 55 small satellites known as Epimetheus.

 Although they appear to be close to one another, this is a trick of perspective – this view was obtained when Cassini was some 1.2 million km from Rhea, and 1.6 million km from Epimetheus, meaning the moons themselves had a hefty separation of 400 000 km.

 However, even if they were nearer to each other, Rhea would still loom large over Epimetheus: at 1528 km across and just under half the size of our own Moon, Rhea is well over 10 times the size of Epimetheus, which is a modest 113 km across.

 As is traditional for the earliest discovered moons of Saturn, both are named after figures from Greek mythology: the Titan Rhea (“mother of the gods”) and Prometheus’ brother Epimetheus (“after thinker” or “hindsight”).

This image was taken by Cassini’s narrow-angle camera on 24 March 2010, and processed by amateur astronomer Gordan Ugarković. A monochrome version was previously released by NASA as PIA12638: Big and Small Before Rings.

 Caption: ESA
  NASA/JPL-Caltech/Space Science Institute; Processed image copyright: G. Ugarković

Spectacular supernova’s mysteries revealed

Date: August 22, 2014
Source: Manchester University

Summary: Astronomers are delving into the mystery of what caused a spectacular supernova in a galaxy 11 million light years away, seen earlier this year. The supernova, a giant explosion of a star and the closest one to the Earth in decades, was discovered earlier this year by chance. These phenomena are extremely important to study because they provide key information about our universe, including how it is expanding and how galaxies evolve.

New research by a team of UK and European-based astronomers is helping to solve the mystery of what caused a spectacular supernova in a galaxy 11 million light years away, seen earlier this year.

Pic: Galaxy M82 in which the supernova exploded. Credit: NASA, ESA, & Hubble Heritage

The supernova, a giant explosion of a star and the closest one to Earth in decades, was discovered earlier this year by chance at the University of London Observatory. These phenomena are extremely important to study because they provide key information about our universe, including how it is expanding and how galaxies evolve.

The new research into its cause, published in the latest issue of the Astrophysical Journal, used vast networks of radio telescopes in the UK and across Europe including the seven telescopes of e-MERLIN operated from The University of Manchester’s Jodrell Bank Observatory. These enabled them to obtain extremely deep images revealing a lack of radio emission from the supernova.

Known as 2014J, this was a Type la supernova caused by the explosion of a white dwarf star, the inner core of star once it has run out of nuclear fuel and ejected its outer layers. A white dwarf star can explode if its mass increases to about 1.4x times that of the Sun. At this point its core temperature reaches the point where carbon starts to undergo nuclear fusion. This spreads rapidly through the star resulting in a catastrophic thermonuclear explosion which rips the star apart, causing it to appear like a brilliant ‘new star’ shining billions of times brighter than the Sun.

For decades there has been a dispute about how this happens but these new results rule out the vast majority of models and show the merger of two white dwarf stars is by far the most likely cause.

The research was led by Miguel Pérez-Torres, researcher of the Spanish National Research Council who explained: “Supernovae play a fundamental role in the chemistry of galaxies and their evolution, as they are responsible for ejecting most of the heavy elements we see around us, including elements that cannot be formed in the interior of normal stars. A Nobel Prize was awarded in 2011 for the use of Type Ia supernovae to discover that the expansion of the Universe is accelerating. Yet, the basic question of what causes a Type Ia supernova was still a mystery.”

Rob Beswick, a co-author of the research paper from the University of Manchester’s Jodrell Bank Centre for Astrophysics added: “The explosion of a Type Ia supernova is a rare event in the nearby Universe. Supernova 2014J is the closest Type Ia supernova to Earth since 1986, and it’s likely that more than a hundred years will pass until we see another such supernova so close to us. This was an amazing opportunity to learn more about these extremely important astrophysical phenomena and their underlying cause.”

Story Source: The above story is based on materials provided by Manchester University. Note: Materials may be edited for content and length.

Journal Reference: M. A. Pérez-Torres, P. Lundqvist, R. J. Beswick, C. I. Björnsson, T. W. B. Muxlow, Z. Paragi, S. Ryder, A. Alberdi, C. Fransson, J. M. Marcaide, I. Martí-Vidal, E. Ros, M. K. Argo, J. C. Guirado. CONSTRAINTS ON THE PROGENITOR SYSTEM AND THE ENVIRONS OF SN 2014J FROM DEEP RADIO OBSERVATIONS. The Astrophysical Journal, 2014; 792 (1): 38 DOI: 10.1088/0004-637X/792/1/38

Cite This Page: MLA APA Chicago: Manchester University. “Spectacular supernova’s mysteries revealed.” ScienceDaily. ScienceDaily, 22 August 2014. .

Source: http://www.sciencedaily.com/releases/2014/08/140822083933.htm

universal-abyss: Oh, the precious, rare event of a Type Ia supernova, so close to home. It may help us further understand the chemistry of galaxies and the accelerating expansion of the universe. And, who knows what other mysteries it may reveal? This is so cool.

The Beautiful Rings of Saturn

The Saturn system reveals tantalizing vistas. NASA’s robotic spacecraft named Cassini carries with it 12 instruments designed to take precise measurements of Saturn and its surroundings, including Titan, other icy moons, and the rings, as well as the magnetic environment.

For many of us, however, the images are what put us there, at Saturn, almost a billion miles away from home. Some of those images unveil overwhelming beauty. Others show tricks of light and seemingly magical oddities. Some reveal events from the distant past that have been preserved for eons, while other views depict processes that are changing now, like live news.

Credit: NASA/Cassini
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What is the Multiverse, and why do we think it exists? 

[…] Our observable Universe caps out at about 92 billion light-years in diameter, less than a thousand times as large in all directions as our previous scale. It contains some 10^80 atoms, clumped together in maybe a trillion galaxies, each with typically hundreds of billions of stars. But one of the most remarkable things about the Big Bang is that all of this, some 13.8 billion years ago, was once contained in a very small region of space, a region much smaller than our Solar System is today!

The thing that you might immediately wonder is whether there’s more Universe beyond the part that’s observable to us today, and — if so — how far does it go on? And what does it look like? And what are the physical laws in that part of the Universe?

Based on our observations of everything we’ve been able to see, from stars to galaxies to the leftover glow from the Big Bang to the matter in intergalactic space, we can learn some amazing things.

Read the full article by Ethan Siegel

The Sun is better than art

This incredible image was produced using data from NASA’s Solar Dynamics Observatory (SDO) taken on January 17, 2003. This is the sun photographed as it was building towards a major eruption.

SDO carries imaging instruments that photograph different wavelengths of light released from the sun. If you remember your physics, there is a relationship between the wavelength of light, the frequency of the light, and the energy of the light, so SDO images basically reflect the temperature of the sun.

The colors in this shot are 3 different wavelengths of light. Temperature across the sun’s surface and in its corona varies as gases are moved around by convection and by the sun’s powerful magnetic field. Images like this are both gorgeous and help scientists understand the forces churning beneath the surface of the body at the heart of the solar system.

-JBB

Image credit: NASA Goddard/SDO

"Maybe we’re on Mars because of the magnificent science that can be done there - the gates of the wonder world are opening in our time. Maybe we’re on Mars because we have to be, because there’s a deep nomadic impulse built into us by the evolutionary process, we come after all, from hunter gatherers, and for 99.9% of our tenure on Earth we’ve been wanderers. And, the next place to wander to, is Mars. But whatever the reason you’re on Mars is, I’m glad you’re there. And I wish I was with you.

— Carl Sagan

A peek into the Tarantula Nebula - 30 Doradus

Like lifting a giant veil, the near-infrared vision of NASA’s Hubble Space Telescope uncovers a dazzling new view deep inside the Tarantula Nebula. Hubble reveals a glittering treasure trove of more than 800,000 stars and protostars embedded inside the nebula.

These observations were obtained as part of the Hubble Tarantula Treasury Program. When complete, the program will produce a large catalog of stellar properties, which will allow astronomers to study a wide range of important topics related to star formation.

Credit: NASA/Hubble

There are two great mysteries that overshadow all other mysteries in science. One is the origin of the universe. That’s my day job. However, there is also the other great mystery of inner space. And that is what sits on your shoulders, which believe it or not, is the most complex object in the known universe. But the brain only uses 20 watts of power. It would require a nuclear power plant to energise a computer the size of a city block to mimic your brain, and your brain does it with just 20 watts. So if someone calls you a dim bulb, that’s a compliment.
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MODEL UNIVERSE RECREATES EVOLUTION OF THE COSMOS

Astronomers have created the first realistic virtual universe using a computer simulation called “Illustris.” Illustris can recreate 13 billion years of cosmic evolution in a cube 350 million light-years on a side with unprecedented resolution.

The computer simulation began a mere 12 million years after the Big Bang. When it reached the present day, astronomers counted more than 41,000 galaxies in the cube of simulated space. 

The model requires a huge amount of computing power: running it on even a state-of-the-art desktop computer would take almost 2,000 years. Even run across more than 8,000 processors, the simulation still took several months.

VIDEO SIMULATION


CREDIT:
http://www.illustris-project.org/
http://www.cfa.harvard.edu/news/2014-10
http://www.nature.com/news/model-universe-recreates-evolution-of-the-cosmos-1.15178

How did scientists determine our location within the Milky Way galaxy—in other words, how do we know that our solar system is in the arm of a spiral galaxy, far from the galaxy’s center?

There is no short answer to this question, because astronomers have followed many lines of evidence to determine the location of the solar system in the Milky Way. But some of the general techniques can be outlined briefly.

Finding one’s location in a cloud of a hundred billion stars—when one can’t travel beyond one’s own planet—is like trying to map out the shape of a forest while tied to one of the trees. One gets a rough idea of the shape of the Milky Way galaxy by just looking around—a ragged, hazy band of light circles the sky. It is about 15 degrees wide, and stars are concentrated fairly evenly along the strip. That observation indicates that our Milky Way Galaxy is a flattened disk of stars, with us located somewhere near the plane of the disk. Were it not a flattened disk, it would look different. For instance, if it were a sphere of stars, we would see its glow all over the sky, not just in a narrow band. And if we were above or below the disk plane by a substantial amount, we would not see it split the sky in half—the glow of the Milky Way would be brighter on one side of the sky than on the other.

The position of the sun in the Milky Way can be further pinned down by measuring the distance to all the stars we can see. In the late 18th century, astronomer William Herschel tried to do this, concluding that the earth was in the center of a ‘grindstone’-shaped cloud of stars. But Herschel was not aware of the presence of small particles of interstellar dust, which obscure the light from the most distant stars in the Milky Way. We appeared to be in the center of the cloud because we could see no further in all directions. To a person tied to a tree in a foggy forest, it looks like the forest stretches equally away in all directions, wherever one is.

A major breakthrough in moving the earth from the center of the galaxy to a point about 3/5 away from the edge came in the early decades of this century, when Harlow Shapley measured the distance to the large clusters of stars called globular clusters. He found they were distributed in a spherical distribution about 100,000 light-years in diameter, centered on a location in the constellation Sagittarius. Shapley concluded (and other astronomers have since verified) that the center of the distribution of globular clusters is the center of the Milky Way as well, so our galaxy looks like a flat disk of stars embedded in a spherical cloud, or ‘halo,’ of globular clusters.

In the past 75 years, astronomers have refined this picture, using a variety of techniques of radio, optical, infrared and even x-ray astronomy, to fill in the details: the location of spiral arms, clouds of gas and dust, concentrations of molecules and so on. The essential modern picture is that our solar system is located on the inner edge of a spiral arm, about 25,000 light-years from the center of the galaxy, which is in the direction of the constellation of Sagittarius.

Credit: Laurence A. Marschall in the department of physics at Gettysburg College

The Astro Alphabet
By Ethan Siege

A is for Aurora, the Earth’s polar lights,
as the Sun’s hot electrons help color our nights.

B is for Black Hole, a star’s collapsed heart,
if you cross its horizon, you’ll never depart.

C is for Comet, with tails, ice, and dust,
a trip near the Sun makes skywatching a must!

D is for Dark Matter, the great cosmic glue
that holds clusters together, but not me and you!

E is for Eclipse, where the Moon, Earth and Sun
cast light-blocking shadows that can’t be outrun.

F is for Fusion, that powers the stars,
as nuclei join, their released light is ours!

G is for Galaxies, in groups and alone,
house billions of planets with lifeforms unknown.

H is for Hubble, for whom Earth’s no place;
a telescope like this belongs up in space.

I is for Ions, making nebulae glow;
as they find electrons, we capture the show.

J is for Jets, from a galaxy’s core,
if you feed them right, they’ll be active once more!

K is for Kepler, whose great laws of motion
keep planets on course in the great cosmic ocean.

L is for Libration, which makes our Moon rock,
it’s a trick of the orbit; it’s tidally locked!

M is for Meteors, which come in a shower,
if skies are just right, you’ll see hundreds an hour!

N is for Nebula, what forms when stars die,
this recycled fuel makes cosmic apple pie.

O is for Opaque, why the Milky Way’s dark,
these cosmic dust lanes make starlight appear stark!

P is for Pulsar, a spinning neutron star,
as the orbits tick by, we know just when we are.

Q is for Quasar, a great radio source,
accelerating matter with little remorse.

R is for Rings, all gas giants possess them,
even one found in another sun’s system!

S is for Spacetime, which curves due to matter,
this Universe-fabric can bend but won’t shatter!

T is for Tides, caused by gravity’s tune,
our oceans bulge out from the Sun and the Moon.

U is the Universe, our goal’s understanding,
with billions of galaxies, as spacetime’s expanding!

V is for Virgo, our nearest great cluster,
with thousands of galaxies, it’s a gut-buster!

W is for Wavelength, the energies of light,
that tell us what atoms are in stars just from sight!

X is for X-rays, high-energy light,
where bursts of new stars show an ionized might.

Y is the Year, where we orbit our Sun,
each planet’s is different; the Earth’s is just one.

Z is for Zenith, so gaze up at the sky!
The Universe is here; let’s learn what, how and why.

Source: Starts With A Bang!
Image credit: Galaxy Zoo’s writing tool

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