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ohmysagan:

we-are-star-stuff:

Astronomers searching for the building blocks of life in a giant dust cloud at the heart of the Milky Way have concluded that it would taste vaguely of raspberries.
The unanticipated discovery follows years of work by astronomers who trained their 30m radio telescope on the enormous ball of dust and gas in the hope of spotting complex molecules that are vital for life.
Finding amino acids in interstellar space is a Holy Grail for astrobiologists, as this would raise the possibility of life emerging on other planets after being seeded with the molecules.
In the latest survey, astronomers sifted through thousands of signals from Sagittarius B2, a vast dust cloud at the centre of our galaxy. While they failed to find evidence for amino acids, they did find a substance called ethyl formate, the chemical responsible for the flavour of raspberries.
“It does happen to give raspberries their flavour, but there are many other molecules that are needed to make space raspberries,” Arnaud Belloche, an astronomer at the Max Planck Institute for Radio Astronomy in Bonn, told the Guardian.
Curiously, ethyl formate has another distinguishing characteristic: it also smells of rum.
The astronomers used the IRAM telescope in Spain to analyse electromagnetic radiation emitted by a hot and dense region of Sagittarius B2 that surrounds a newborn star.
Radiation from the star is absorbed by molecules floating around in the gas cloud, which is then re-emitted at different energies depending on the type of molecule.
While scouring their data, the team also found evidence for the lethal chemical propyl cyanide in the same cloud. The two molecules are the largest yet discovered in deep space.
Dr Belloche and his colleague Robin Garrod at Cornell University in New York have collected nearly 4,000 distinct signals from the cloud but have only analysed around half of these.
“So far we have identified around 50 molecules in our survey, and two of those had not been seen before,” said Belloche.
Last year, the team came tantalisingly close to finding amino acids in space with the discovery of a molecule that can be used to make them, called amino acetonitrile.
The latest discoveries have boosted the researchers’ morale because the molecules are as large as the simplest amino acid, glycine. Amino acids are the building blocks of proteins and are widely seen as being critical for complex life to exist anywhere in the universe.
“The difficulty in searching for complex molecules is that the best astronomical sources contain so many different molecules that their ‘fingerprints’ overlap and are difficult to disentangle,” Belloche said.
The molecules are thought to form when chemicals that already exist on some dust grains, such as ethanol, link together to make more complex chains.
“There is no apparent limit to the size of molecules that can be formed by this process, so there’s good reason to expect even more complex organic molecules to be there,” said Garrod.

I LOVE raspberries! Space just got more awesome.

ohmysagan:

we-are-star-stuff:

Astronomers searching for the building blocks of life in a giant dust cloud at the heart of the Milky Way have concluded that it would taste vaguely of raspberries.

The unanticipated discovery follows years of work by astronomers who trained their 30m radio telescope on the enormous ball of dust and gas in the hope of spotting complex molecules that are vital for life.

Finding amino acids in interstellar space is a Holy Grail for astrobiologists, as this would raise the possibility of life emerging on other planets after being seeded with the molecules.

In the latest survey, astronomers sifted through thousands of signals from Sagittarius B2, a vast dust cloud at the centre of our galaxy. While they failed to find evidence for amino acids, they did find a substance called ethyl formate, the chemical responsible for the flavour of raspberries.

“It does happen to give raspberries their flavour, but there are many other molecules that are needed to make space raspberries,” Arnaud Belloche, an astronomer at the Max Planck Institute for Radio Astronomy in Bonn, told the Guardian.

Curiously, ethyl formate has another distinguishing characteristic: it also smells of rum.

The astronomers used the IRAM telescope in Spain to analyse electromagnetic radiation emitted by a hot and dense region of Sagittarius B2 that surrounds a newborn star.

Radiation from the star is absorbed by molecules floating around in the gas cloud, which is then re-emitted at different energies depending on the type of molecule.

While scouring their data, the team also found evidence for the lethal chemical propyl cyanide in the same cloud. The two molecules are the largest yet discovered in deep space.

Dr Belloche and his colleague Robin Garrod at Cornell University in New York have collected nearly 4,000 distinct signals from the cloud but have only analysed around half of these.

“So far we have identified around 50 molecules in our survey, and two of those had not been seen before,” said Belloche.

Last year, the team came tantalisingly close to finding amino acids in space with the discovery of a molecule that can be used to make them, called amino acetonitrile.

The latest discoveries have boosted the researchers’ morale because the molecules are as large as the simplest amino acid, glycine. Amino acids are the building blocks of proteins and are widely seen as being critical for complex life to exist anywhere in the universe.

“The difficulty in searching for complex molecules is that the best astronomical sources contain so many different molecules that their ‘fingerprints’ overlap and are difficult to disentangle,” Belloche said.

The molecules are thought to form when chemicals that already exist on some dust grains, such as ethanol, link together to make more complex chains.

“There is no apparent limit to the size of molecules that can be formed by this process, so there’s good reason to expect even more complex organic molecules to be there,” said Garrod.

I LOVE raspberries! Space just got more awesome.

Post by we-are-star-stuff (via ohmysagan)
January 12, 2013 at 12:37 PM | Post Permalink | 1,531 notes



starsaremymuse:

Einstein Was Right: Space-Time Is Smooth, Not Foamy
Space-time is smooth rather than foamy, a new study suggests, scoring a possible victory for Einstein over some quantum theorists who came after him.
In his general theory of relativity, Einstein described space-time as fundamentally smooth, warping only under the strain of energy and matter. Some quantum-theory interpretations disagree, however, viewing space-time as being composed of a froth of minute particles that constantly pop into and out of existence.
It appears Albert Einstein may have been right yet again.
A team of researchers came to this conclusion after tracing the long journey three photons took through intergalactic space. The photons were blasted out by an intense explosion known as a gamma-ray burst about 7 billion light-years from Earth. They finally barreled into the detectors of NASA’s Fermi Gamma-ray Space Telescope in May 2009, arriving just a millisecond apart.
Their dead-heat finish strongly supports the Einsteinian view of space-time, researchers said. The wavelengths of gamma-ray burst photons are so small that they should be able to interact with the even tinier “bubbles” in the quantum theorists’ proposed space-time foam.
If this foam indeed exists, the three protons should have been knocked around a bit during their epic voyage. In such a scenario, the chances of all three reaching the Fermi telescope at virtually the same time are very low, researchers said.
So the new study is a strike against the foam’s existence as currently imagined, though not a death blow.
“If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved,” study leader Robert Nemiroff, of Michigan Technological University, said in a statement. (The Planck length is an almost inconceivably short distance, about one trillionth of a trillionth the diameter of a hydrogen atom.)
“There is a possibility of a statistical fluke, or that space-time foam interacts with light differently than we imagined,” added Nemiroff, who presented the results Wednesday (Jan. 9) at the 221st meeting of the American Astronomical Society in Long Beach, Calif.
If the study holds up, the implications are big, researchers said.
“If future gamma-ray bursts confirm this, we will have learned something very fundamental about our universe,” Bradley Schaefer of Louisiana State University said in statement.

starsaremymuse:

Einstein Was Right: Space-Time Is Smooth, Not Foamy

Space-time is smooth rather than foamy, a new study suggests, scoring a possible victory for Einstein over some quantum theorists who came after him.

In his general theory of relativity, Einstein described space-time as fundamentally smooth, warping only under the strain of energy and matter. Some quantum-theory interpretations disagree, however, viewing space-time as being composed of a froth of minute particles that constantly pop into and out of existence.

It appears Albert Einstein may have been right yet again.

A team of researchers came to this conclusion after tracing the long journey three photons took through intergalactic space. The photons were blasted out by an intense explosion known as a gamma-ray burst about 7 billion light-years from Earth. They finally barreled into the detectors of NASA’s Fermi Gamma-ray Space Telescope in May 2009, arriving just a millisecond apart.

Their dead-heat finish strongly supports the Einsteinian view of space-time, researchers said. The wavelengths of gamma-ray burst photons are so small that they should be able to interact with the even tinier “bubbles” in the quantum theorists’ proposed space-time foam.

If this foam indeed exists, the three protons should have been knocked around a bit during their epic voyage. In such a scenario, the chances of all three reaching the Fermi telescope at virtually the same time are very low, researchers said.

So the new study is a strike against the foam’s existence as currently imagined, though not a death blow.

“If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved,” study leader Robert Nemiroff, of Michigan Technological University, said in a statement. (The Planck length is an almost inconceivably short distance, about one trillionth of a trillionth the diameter of a hydrogen atom.)

“There is a possibility of a statistical fluke, or that space-time foam interacts with light differently than we imagined,” added Nemiroff, who presented the results Wednesday (Jan. 9) at the 221st meeting of the American Astronomical Society in Long Beach, Calif.

If the study holds up, the implications are big, researchers said.

“If future gamma-ray bursts confirm this, we will have learned something very fundamental about our universe,” Bradley Schaefer of Louisiana State University said in statement.

(Source: )

Post by starsaremymuse (via scinerds)
January 10, 2013 at 10:52 PM | Post Permalink | 5,797 notes



sagansense:

60-Second Adventures in Astronomy via The Open University
Ever wondered where the Universe came from? Or more importantly, where it’s headed? Voiced by David Mitchell, this series of twelve 60 second animations examines different scientific concepts from the big bang to relativity, from black holes to dark matter. The series also explores the possibility of life beyond Earth and considers why David Bowie is still none the wiser about life on Mars. Narrated by David Mitchell [Episodes 8-12 will follow in 2013]
The Big BangSupernovaeExoplanetsA Day on MercuryThe Rotating MoonLife on MarsEvent Horizons

sagansense:

60-Second Adventures in Astronomy via The Open University

Ever wondered where the Universe came from? Or more importantly, where it’s headed? Voiced by David Mitchell, this series of twelve 60 second animations examines different scientific concepts from the big bang to relativity, from black holes to dark matter. The series also explores the possibility of life beyond Earth and considers why David Bowie is still none the wiser about life on Mars. Narrated by David Mitchell [Episodes 8-12 will follow in 2013]

The Big Bang
Supernovae
Exoplanets
A Day on Mercury
The Rotating Moon
Life on Mars
Event Horizons

Post by sagansense (via ohmysagan)
December 30, 2012 at 12:26 PM | Post Permalink | 61 notes



sciencesoup:

Stellar formation is slowing down

An international team of astronomers have recently conducted the first comprehensive survey of stellar formation—a kind of ‘star census.’ Since light has a maximum speed, researchers were able to use enormous telescopes (including the imaginatively named Very Large Telescope in Chile) to look into the past and study several star-forming galaxies from 4, 7, 9, and 11 billion years ago. They found that the rate of stellar formation in the early universe was far greater than it is today, and that that 95% of stars have already been formed. Half of these were created at a peak between 9 and 11 billion years ago, when the universe was still in infancy—a casual observer would’ve seen stars rapidly igniting the darkness all around. Since then, the rate of stellar formation has gradually slowed to a fraction of its former pace, and is currently 3% of its peak. After churning out the remaining 5% of stars, the universe will run out of star-making materials and star production will grind to a halt. In the future, over billions and billions of years, the universe’s stars will run out of fuel and extinguish one by one, and eventually the universe will be a very dark place.

(Image Credit: NASA)

Post by sciencesoup (via scinerds)
November 11, 2012 at 11:15 PM | Post Permalink | 698 notes



ikenbot:

Space Science Stamps Launched by Royal Mail

This year marks the 50th anniversary of Britain’s first contribution to space exploration.

On 26 April 1962, its first satellite, Ariel 1, was launched by NASA, carrying experiments designed by British universities and making Britain the world’s third spacefaring nation, after Russia and America. Royal Mail is celebrating with a set of six commemorative stamps, which went on sale the 16th of October, featuring images from European Space Agency missions.

Post by afro-dominicano (via scinerds)
November 7, 2012 at 10:35 PM | Post Permalink | 890 notes



ikenbot:

Molecular Clouds

Large, dense molecular clouds are very special environments in space. Composed mainly of molecular hydrogen and helium, with small amounts of heavier gases, they are the birth place of new stars and planets.

Molecular clouds that exceed the mass of 100,000 suns are called giant molecular clouds. Giant molecular clouds are the largest inhabitants of galaxies, reaching up to 300 light years in diameter. They contain enough dense gas and dust to form hundreds of thousands of Sun-like stars. These stars are formed in the densest parts of the clouds. Molecular clouds are very cold, having temperatures ranging from about -440 to -370 degrees Fahrenheit (-263 to -223 degrees Celcius or 10 to 50 degrees Kelvin).

They usually do not radiate their own visible light and appear dark when viewed with an optical telescope. In these cold, dense environments, many atoms can combine into molecules. Giant molecular clouds can last for 10 to 100 million years before they dissipate, due to the heat and stellar winds from newly formed stars within them. An average spiral galaxy, like our own Milky Way, contains about 1,000 to 2,000 Giant Molecular Clouds in addition to numerous smaller clouds.

ikenbot:

Molecular Clouds

Large, dense molecular clouds are very special environments in space. Composed mainly of molecular hydrogen and helium, with small amounts of heavier gases, they are the birth place of new stars and planets.

Molecular clouds that exceed the mass of 100,000 suns are called giant molecular clouds. Giant molecular clouds are the largest inhabitants of galaxies, reaching up to 300 light years in diameter. They contain enough dense gas and dust to form hundreds of thousands of Sun-like stars. These stars are formed in the densest parts of the clouds. Molecular clouds are very cold, having temperatures ranging from about -440 to -370 degrees Fahrenheit (-263 to -223 degrees Celcius or 10 to 50 degrees Kelvin).

They usually do not radiate their own visible light and appear dark when viewed with an optical telescope. In these cold, dense environments, many atoms can combine into molecules. Giant molecular clouds can last for 10 to 100 million years before they dissipate, due to the heat and stellar winds from newly formed stars within them. An average spiral galaxy, like our own Milky Way, contains about 1,000 to 2,000 Giant Molecular Clouds in addition to numerous smaller clouds.

(Source: afro-dominicano)

Post by afro-dominicano (via scinerds)
November 4, 2012 at 12:01 AM | Post Permalink | 374 notes



skeptv:

The Origin of Light

These exquisite images are a must see at full resolution. Space imagery from NASA’s Conceptual Image Lab. An elegant interaction powers the sun, producing the light and energy that makes life possible. That interaction is called fusion, and it naturally occurs when two atoms are heated and compressed so intensely that their nuclei merge into a new element. This process often leads to the creation of a photon, the particles of light that are released from the sun.

However, before exiting our star, each photon must first undergo a long journey. Over the course of 40,000 years it will be absorbed by other atoms and emitted repeatedly until reaching the sun’s surface. Once there, the photons stream out, illuminating Earth, the solar system and beyond. The number released from the surface every second is so vast that it is more than a billion billion times greater than the number of grains of sand on our planet.

This movie takes us on a space weather journey from the center of the sun to solar eruptions in the sun’s atmosphere all the way to the effects of that activity near Earth. The view starts in the core of the sun where atoms fuse together to create light and energy. Next we travel toward the sun’s surface, watching loops of magnetic fields rise up to break through the sun’s atmosphere, the corona.

In the corona is where we witness giant bursts of radiation and energy known as solar flares, as well as gigantic eruptions of solar material called coronal mass ejections or CMEs. The movie follows one of these CME’s toward Earth where it impacts and compresses Earth’s own protective magnetic bubble, the magnetosphere. As energy and particles from the sun funnel along magnetic field lines near Earth, they ultimately produce aurora at Earth’s poles.

Post by skeptv (via skeptv)
October 30, 2012 at 8:02 AM | Post Permalink | 22 notes



ikenbot:

Meteor, Moon and Milky Way

This shot was taken at -5C° on a windy night in Paso de San Francisco, Argentina. On the left you can see El Nevado de Incahuasi, a volcano with a height of 6.638 meters. On the right there’s Nevado Ojos del Salado, another volcano with a height of 6.864 meters.

ikenbot:

Meteor, Moon and Milky Way

This shot was taken at -5C° on a windy night in Paso de San Francisco, Argentina. On the left you can see El Nevado de Incahuasi, a volcano with a height of 6.638 meters. On the right there’s Nevado Ojos del Salado, another volcano with a height of 6.864 meters.

(Source: afro-dominicano)

Post by afro-dominicano (via scinerds)
October 22, 2012 at 8:54 PM | Post Permalink | 403 notes



sagansense:

NASA’s Suomi Satellite: The Suomi National Polar-orbiting Partnership (NPP)

The Suomi National Polar-orbiting Partnership (NPP) mission represents a critical first step in building the next-generation Earth-observing satellite system that will collect data on both long-term climate change and short-term weather conditions. NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense.

NPP will extend and improve upon the Earth system data records established by NASA’s Earth Observing System (EOS) fleet of satellites that have provided critical insights into the dynamics of the entire Earth system: clouds, oceans, vegetation, ice, solid Earth and atmosphere.

The NPP spacecraft lifted off aboard a United Launch Alliance Delta II rocket from Space Launch Complex 2 at Vandenberg Air Force Base in California on Oct. 28, 2011 at 5:48 a.m. EDT.

Image 1: Overnight on October 4-5, 2012, a mass of energetic particles from the atmosphere of the Sun were flung out into space, a phenomenon known as a coronal mass ejection. Three days later, the storm from the Sun stirred up the magnetic field around Earth and produced gorgeous displays of northern lights. NASA satellites track such storms from their origin to their crossing of interplanetary space to their arrival in the atmosphere of Earth.

Using the “day-night band” (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS), the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite acquired this view of the aurora borealis early on the morning of October 8, 2012. The northern lights stretch across Canada’s Quebec and Ontario provinces in the image, and are part of the auroral oval that expanded to middle latitudes because of a geomagnetic storm.

The DNB sensor detects dim light signals such as auroras, airglow, gas flares, city lights, and reflected moonlight. In the case of the image above, the sensor detected the visible light emissions as energetic particles rained down from Earth’s magnetosphere and into the gases of the upper atmosphere. The images are similar to those collected by the Operational Linescan System flown on U.S. Defense Meteorological Satellite Program (DMSP) satellites for the past three decades. “When I first saw images like this as a graduate student, I was immediately struck by the fluid dynamic characteristics of the aurora,” said Tom Moore, a space physicist at NASA’s Goddard Space Flight Center. “Viewing the aurora in this way makes it immediately clear that space weather is an interaction of fluids from the Sun with those of the Earth’s upper atmosphere. The electrodynamics make for important differences between plasmas and ordinary fluids, but familiar behaviors (for example, waves and vortices) are still very apparent. It makes me wonder at the ability of apparently empty space to behave like a fluid.”

Auroras typically occur when solar flares and coronal mass ejections—or even an active solar wind stream—disturb and distort the magnetosphere, the cocoon of space protected by Earth’s magnetic field. The collision of solar particles and pressure into our planet’s magnetosphere accelerates particles trapped in the space around Earth (such as in the radiation belts). Those particles are sent crashing down into Earth’s upper atmosphere—at altitudes of 100 to 400 kilometers (60 to 250 miles)—where they excite oxygen and nitrogen molecules and release photons of light. The results are rays, sheets, and curtains of dancing light in the sky.

Auroras are a beautiful expression of the connection between Sun and Earth, but not all of the connections are benign. Auroras are connected to geomagnetic storms, which can distort radio communications (particularly high frequencies), disrupt electric power systems on the ground, and give slight but detectable doses of radiation to flight crews and passengers on high-latitude airplane flights and on spacecraft.

The advantage of images like those from VIIRS and DMSP is resolution, according to space physicist Patrick Newell of the Johns Hopkins University Applied Physics Laboratory. “You can see very fine detail in the aurora because of the low altitude and the high resolution of the camera,” he said. Most aurora scientists prefer to use images from missions dedicated to aurora studies (such as Polar, IMAGE, and ground-based imagers), which can offer many more images of a storm (rather than one per orbit) and can allow researchers to calculate the energy moving through the atmosphere. There are no science satellites flying right now that provide such a view, though astronauts regularly photograph and film auroras from the International Space Station.

NASA Earth Observatory image by Jesse Allen and Robert Simmon, using VIIRS Day-Night Band data from the Suomi National Polar-orbiting Partnership (Suomi NPP) and the University of Wisconsin’s Community Satellite Processing Package. Suomi NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense. Caption by Mike Carlowicz.

Image and caption: NASA Earth Observatory

Image 2: Early on August 28, 2012, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi-NPP satellite captured this nighttime view of Tropical Storm Isaac and the cities near the Gulf Coast of the United States. The image was acquired just after local midnight by the VIIRS “day-night band,” which detects light in a range of wavelengths from green to near-infrared and uses light intensification to enable the detection of dim signals. In this case, the clouds of Isaac were lit by moonlight.

Image: NASA Earth Observatory

Image 3: This image was taken from the VIIRS instrument aboard NASA’s Earth-observing satellite, Suomi NPP. This composite image uses a number of swaths of the Earth’s surface taken on January 4, 2012. The NPP satellite was renamed ‘Suomi NPP’ on January 24, 2012 to honor the late Verner E. Suomi of the University of Wisconsin.

Image and caption: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring

Image 4: The new image is a composite of six separate orbits taken on January 23, 2012 by the Suomi National Polar-orbiting Partnership satellite. Both of these new ‘Blue Marble’ images are images taken by a new instrument flying aboard Suomi NPP, the Visible Infrared Imaging Radiometer Suite (VIIRS).

Compiled by NASA Goddard scientist Norman Kuring, this image has the perspective of a viewer looking down from 7,918 miles (about 12,742 kilometers) above the Earth’s surface from a viewpoint of 10 degrees South by 45 degrees East. The four vertical lines of ‘haze’ visible in this image shows the reflection of sunlight off the ocean, or ‘glint,’ that VIIRS captured as it orbited the globe. Suomi NPP is the result of a partnership between NASA, NOAA and the Department of Defense.

Image and Caption: NASA/NOAA

Image 5: Fifteen orbits of the recently launched Suomi NPP satellite provided the VIIRS instrument enough time (and longitude) to gather the pixels for this synthesized view of Earth showing the Arctic, Europe, and Asia.

Image: NASA/GSFC/Suomi NPP

Image 6: The world is currently in an active period for the production of atmospheric aerosols, according to Colin Seftor, an atmospheric physicist at NASA Goddard Space Flight Center in Greenbelt, Md., who compiled this image. Seftor works for Science Systems and Applications, Inc. This image is a combination of a VIIRS RGB image with OMPS aerosol index (AI) data for September 15, 2012.

The OMPS AI shows dust from the Sahara over northern Africa that is being blown over the Atlantic (with yellow, less opaque colors representing less dust and pink, more opaque colors representing more dust). Dust can also be seen over Saudi Arabia and parts of Iran, Afghanistan, and Pakistan. However, the aerosol index signal over the Western U.S. is due to dense smoke from wildfires, while smoke from agricultural biomass burning is visible over both South American and southern Africa. The sun glint in the middle of each swath shows the pattern of the satellite’s view in orbit.

Image: NASA Goddard Space Flight Center

Image 7: A ‘true-color’ image of the Southeastern United States taken on January 19, 2012, the first day the full complement of VIIRS’ 22 channels were active. This images was taken between 5:57 pm USA EST and 6:04 pm USA EST (17:57 - 18:04 UTC).

Suomi NPP is carrying five instruments on board. The biggest and most important instrument is The Visible/Infrared Imager Radiometer Suite or VIIRS.

Image and caption: NASA/Suomi NPP/Atmosphere PEATE/Univ. of Wisconsin-Madison/Liam Gumley

Image 8: From its vantage 824 kilometers (512 miles) above Earth, the Visible Infrared Imager Radiometer Suite (VIIRS) on the NPOESS Preparatory Project (NPP) satellite gets a complete view of our planet every day. This image from November 24, 2011, is the first complete global image from VIIRS.

The NPP satellite launched on October 28, 2011, and VIIRS acquired its first measurements on November 21. To date, the images are preliminary, used to gauge the health of the sensor as engineers continue to power it up for full operation.

Rising from the south and setting in the north on the daylight side of Earth, VIIRS images the surface in long wedges measuring 3,000 kilometers (1,900 miles) across. The swaths from each successive orbit overlap one another, so that at the end of the day, the sensor has a complete view of the globe. The Arctic is missing because it is too dark to view in visible light during the winter.

The NPP satellite was placed in a Sun-synchronous orbit, a unique path that takes the satellite over the equator at the same local (ground) time in every orbit. So, when NPP flies over Kenya, it is about 1:30 p.m. on the ground. When NPP reaches Gabon—about 3,000 kilometers to the west—on the next orbit, it is close to 1:30 p.m. on the ground. This orbit allows the satellite to maintain the same angle between the Earth and the Sun so that all images have similar lighting.

The consistent lighting is evident in the daily global image. Stripes of sunlight (sunglint) reflect off the ocean in the same place on the left side of every swath. The consistent angle is important because it allows scientists to compare images from year to year without worrying about extreme changes in shadows and lighting.

The image also shows a band of haze along the right side of every orbit swath. When light travels through the atmosphere, it bounces off particles or scatters, making the atmosphere look hazy. The scattering effect is most pronounced along the edge of the swath, where the sensor is looking at an angle through more of the atmosphere. Scientists can correct for this scattering effect, but need measurements from a range of wavelengths to do so. The degree to which light scatters depends partly on the wavelength of the light. Blue light scatters more than red light, for example, which is why the sky is blue. VIIRS measures 22 different wavelengths of light, but not all of the sensor’s detectors are operating at peak performance yet. Those measuring thermal infrared light are not yet cold enough to collect reliable measurements.

Once VIIRS begins full operations, it will produce a range of measurements from ocean temperature to clouds to the locations of fires. These measurements will help extend the record from earlier sensors like the Moderate Resolution Imaging Spectroradiometer (MODIS). VIIRS is very similar to MODIS, but flies at a higher altitude to measure the whole planet without gaps. (MODIS daily measurements have gaps at the equator. See the MODIS image from November 24.) VIIRS also sees the Earth in less detail, 375 meters per pixel, compared to 250 meters per pixel for MODIS.

Image: NASA Earth Observatory

Post by sagansense (via scinerds)
October 14, 2012 at 10:49 PM | Post Permalink | 2,860 notes



staceythinx:

Spectacular stars and skies photographed by Joel Sjaarda

Post by staceythinx (via staceythinx)
October 14, 2012 at 6:05 PM | Post Permalink | 9,847 notes



proofmathisbeautiful:

wolframalpha:

Avogadro’s number is about twice the number of stars in the observable universe.

:O

proofmathisbeautiful:

wolframalpha:

Avogadro’s number is about twice the number of stars in the observable universe.

:O

Post by wolframalpha (via proofmathisbeautiful)
August 23, 2012 at 11:45 AM | Post Permalink | 316 notes



ikenbot:

Was the Big Bang Like Water Freezing into Ice?

How did the universe begin? The Big Bang is traditionally envisioned as the moment when an infinitely dense bundle of energy suddenly burst outward, expanding in three spatial directions and gradually cooling down as it did so. Now, a team of physicists says the Big Bang should be modeled as a phase change: the moment when an amorphous, formless universe analogous to liquid water cooled and suddenly crystallized to form four-dimensional space-time, analogous to ice.

Image: The Big Bang may have been the moment that a water-like universe froze to form the ice-like universe we see today, a new theory holds.

In the new study, lead author James Quach and colleagues at the University of Melbourne in Australia say the hypothesis can be tested by looking for defects that would have formed in the structure of space-time when the universe crystallized.

“Think of the early universe as being like a liquid,” Quach said in a statement. “Then as the universe cools, it ‘crystallises’ into the three spatial and one time dimension that we see today. Theorized this way, as the universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice.”

If they exist, these cracks should be detectable, the researchers said, because light and other particles would bend or reflect off of them as they trek across the cosmos.

The notion that space and time are emergent properties that suddenly materialized out of an amorphous state was first put forth by physicists at Canada’s Perimeter Institute in 2006. Called “quantum graphity,” the theory holds that the four-dimensional geometry of space-time discovered by Albert Einstein is not fundamental; instead, space-time is a lattice constructed of discrete space-time building blocks, just like matter looks continuous, but is actually made of building blocks called atoms.

Originally, at extremely high temperatures, the building blocks were like liquid water: they contained no structure, “representing a state with no space,” the researchers wrote in their paper. At the moment of the Big Bang, when the temperature in the universe dropped to the space-time building blocks’ “freezing point,” they crystallized to form the four-dimensional lattice we observe today.

The math describing the theory checks out, but “the challenge has been that these building blocks of space are very small, and so impossible to see directly,” Quach explained. From the human vantage point, space-time looks smooth and continuous.

However, while the building blocks themselves might be too small to detect, the physicists hope to observe the boundaries that would have formed as regions of crystallizing building blocks butted against one another at the time of the Big Bang, creating “cracks” in the universe. More work is needed to predict the average distance between the cracks — it isn’t known whether they are microscopic, or light-years apart — in order to characterize their effects on particles.

The research by Quach  and his team is detailed in this month’s edition of the journal Physical Review D.

ikenbot:

Was the Big Bang Like Water Freezing into Ice?

How did the universe begin? The Big Bang is traditionally envisioned as the moment when an infinitely dense bundle of energy suddenly burst outward, expanding in three spatial directions and gradually cooling down as it did so. Now, a team of physicists says the Big Bang should be modeled as a phase change: the moment when an amorphous, formless universe analogous to liquid water cooled and suddenly crystallized to form four-dimensional space-time, analogous to ice.

Image: The Big Bang may have been the moment that a water-like universe froze to form the ice-like universe we see today, a new theory holds.

In the new study, lead author James Quach and colleagues at the University of Melbourne in Australia say the hypothesis can be tested by looking for defects that would have formed in the structure of space-time when the universe crystallized.

“Think of the early universe as being like a liquid,” Quach said in a statement. “Then as the universe cools, it ‘crystallises’ into the three spatial and one time dimension that we see today. Theorized this way, as the universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice.”

If they exist, these cracks should be detectable, the researchers said, because light and other particles would bend or reflect off of them as they trek across the cosmos.

The notion that space and time are emergent properties that suddenly materialized out of an amorphous state was first put forth by physicists at Canada’s Perimeter Institute in 2006. Called “quantum graphity,” the theory holds that the four-dimensional geometry of space-time discovered by Albert Einstein is not fundamental; instead, space-time is a lattice constructed of discrete space-time building blocks, just like matter looks continuous, but is actually made of building blocks called atoms.

Originally, at extremely high temperatures, the building blocks were like liquid water: they contained no structure, “representing a state with no space,” the researchers wrote in their paper. At the moment of the Big Bang, when the temperature in the universe dropped to the space-time building blocks’ “freezing point,” they crystallized to form the four-dimensional lattice we observe today.

The math describing the theory checks out, but “the challenge has been that these building blocks of space are very small, and so impossible to see directly,” Quach explained. From the human vantage point, space-time looks smooth and continuous.

However, while the building blocks themselves might be too small to detect, the physicists hope to observe the boundaries that would have formed as regions of crystallizing building blocks butted against one another at the time of the Big Bang, creating “cracks” in the universe. More work is needed to predict the average distance between the cracks — it isn’t known whether they are microscopic, or light-years apart — in order to characterize their effects on particles.

The research by Quach and his team is detailed in this month’s edition of the journal Physical Review D.

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August 22, 2012 at 1:47 PM | Post Permalink | 601 notes



staceythinx:

Celestial serving bowls from Think Geek

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August 13, 2012 at 12:35 PM | Post Permalink | 81 notes



ihateallyourgods:

Neil deGrasse Tyson- “I don’t think he knew this”

ihateallyourgods:

Neil deGrasse Tyson- “I don’t think he knew this”

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July 27, 2012 at 9:31 PM | Post Permalink | 2,696 notes



the-star-stuff:

Pictures: Spiral Galaxies Eat, Digest Dwarfs

Larger spiral galaxies—each containing hundreds of billions of stars—are thought to grow by “eating” neighboring dwarf galaxies, which contain just a few billion stars.

As the smaller, satellite galaxy is pulled toward the hungry spiral, gravity distorts and shreds the dwarf, so that within a few billion years the smaller galaxy is reduced to wisps and tendrils called tidal streams. Over a few billion more years, the faint streams of stars are assimilated into the spiral.

Post by the-star-stuff (via the-star-stuff)
June 17, 2012 at 4:09 PM | Post Permalink | 241 notes




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