Tuesday, April 25, 2017

Zeta Oph: Runaway Star

Zeta Oph: Runaway Star:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 April 8


See Explanation. Clicking on the picture will download the highest resolution version available.


Zeta Oph: Runaway Star

NASA, JPL-Caltech, Spitzer Space Telescope


Explanation: Like a ship plowing through cosmic seas, runaway star Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this stunning infrared portrait. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the left at 24 kilometers per second. Its strong stellar wind precedes it, compressing and heating the dusty interstellar material and shaping the curved shock front. What set this star in motion? Zeta Oph was likely once a member of a binary star system, its companion star was more massive and hence shorter lived. When the companion exploded as a supernova catastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than the Sun and would be one of the brighter stars in the sky if it weren't surrounded by obscuring dust. The image spans about 1.5 degrees or 12 light-years at the estimated distance of Zeta Ophiuchi.



Tomorrow's picture: back again in 4385



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Comet Hale Bopp Over Val Parola Pass

Comet Hale Bopp Over Val Parola Pass:

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2017 April 9


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Comet Hale-Bopp Over Val Parola Pass

Image Credit & Copyright: A. Dimai, (Col Druscie Obs.), AAC


Explanation: Comet Hale-Bopp, the Great Comet of 1997, became much brighter than any surrounding stars. It was seen even over bright city lights. Away from city lights, however, it put on quite a spectacular show. Here Comet Hale-Bopp was photographed above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy. Comet Hale-Bopp's blue ion tail, consisting of ions from the comet's nucleus, is pushed out by the solar wind. The white dust tail is composed of larger particles of dust from the nucleus driven by the pressure of sunlight, that orbit behind the comet. Comet Hale-Bopp (C/1995 O1) remained visible to the unaided eye for 18 months -- longer than any other comet in recorded history. This year marks the 20th anniversary of Comet Hale-Bopp's last trip to the inner Solar System. The large comet is next expected to return around the year 4385.

Tomorrow's picture: sky hole



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Galaxy Cluster Gas Creates Hole in Microwave Background

Galaxy Cluster Gas Creates Hole in Microwave Background:

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2017 April 10


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Galaxy Cluster Gas Creates Hole in Microwave Background

Image Credit: ALMA (ESO/NAOJ/NRAO), Kitayama et al., NASA/ESA Hubble Space Telescope


Explanation: Why would this cluster of galaxy punch a hole in the cosmic microwave background (CMB)? First, the famous CMB was created by cooling gas in the early universe and flies right through most gas and dust in the universe. It is all around us. Large clusters of galaxies have enough gravity to contain very hot gas -- gas hot enough to up-scatter microwave photons into light of significantly higher energy, thereby creating a hole in CMB maps. This Sunyaev–Zel'dovich (SZ) effect has been used for decades to reveal new information about hot gas in clusters and even to help discover galaxy clusters in a simple yet uniform way. Pictured is the most detailed image yet obtained of the SZ effect, now using both ALMA to measure the CMB and the Hubble Space Telescope to measure the galaxies in the massive galaxy cluster RX J1347.5-1145. False-color blue depicts light from the CMB, while almost every yellow object is a galaxy. The shape of the SZ hole indicates not only that hot gas is present in this galaxy cluster, but also that it is distributed in a surprisingly uneven manner.

Tomorrow's picture: man, dog, sun



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Man, Dog, Sun

Man, Dog, Sun:

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2017 April 11


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Man, Dog, Sun

Image Credit & Copyright: Jens Hackmann


Explanation: This was supposed to be a shot of trees in front of a setting Sun. Sometimes, though, the unexpected can be photogenic. During some planning shots, a man walking his dog unexpected crossed the ridge. The result was so striking that, after cropping, it became the main shot. The reason the Sun appears so large is that the image was taken from about a kilometer away through a telephoto lens. Scattering of blue light by the Earth's atmosphere makes the bottom of the Sun appear slightly more red that the top. Also, if you look closely at the Sun, just above the man's head, a large group of sunspots is visible. The image was taken just last week in Bad Mergentheim, Germany.

Tomorrow's picture: open space



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Leo Trio

Leo Trio:

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2017 April 12


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: This group is popular in the northern spring. Famous as the Leo Triplet, the three magnificent galaxies gather in one field of view. Crowd pleasers when imaged with even modest telescopes, they can be introduced individually as NGC 3628 (left), M66 (bottom right), and M65 (top). All three are large spiral galaxies but they tend to look dissimilar because their galactic disks are tilted at different angles to our line of sight. NGC 3628 is seen edge-on, with obscuring dust lanes cutting across the plane of the galaxy, while the disks of M66 and M65 are both inclined enough to show off their spiral structure. Gravitational interactions between galaxies in the group have also left telltale signs, including the warped and inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous view of the region spans about one degree (two full moons) on the sky. The field covers over 500 thousand light-years at the trio's estimated distance of 30 million light-years.

Moons and Jupiter

Moons and Jupiter:

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2017 April 13


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Moons and Jupiter

Image Credit & Copyright: Göran Strand


Explanation: On April 10, a Full Moon and Jupiter shared this telephoto field of view. Both were near opposition, opposite the Sun in Earth's night sky. Captured when a passing cloud bank dimmmed the bright moonlight, the single exposure reveals the familiar face of our fair planet's own large natural satellite, along with a line up of the ruling gas giant's four Galilean moons. Labeled top to bottom, the tiny pinpricks of light above bright Jupiter are Callisto, Europa, Ganymede, and Io. Closer and brighter, our own natural satellite appears to loom large. But Callisto, Ganymede, and Io are physically larger than Earth's Moon, while water world Europa is only slightly smaller. In fact, of the Solar System's six largest planetary satellites, only Saturn's moon Titan is missing from the scene.



Tomorrow's picture: shadowrise



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Luminous Salar de Uyuni

Luminous Salar de Uyuni:

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2017 April 15


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Luminous Salar de Uyuni

Image Credit & Copyright: Stephanie Ziyi Ye


Explanation: A scene in high contrast this thoughtful night skyscape is a modern composition inspired by M. C. Escher's lithograph Phosphorescent Sea. In it, bright familiar stars of Orion the Hunter and Aldebaran, eye of Taurus the Bull, hang in clear dark skies above a distant horizon. Below, faintly luminous edges trace an otherworldly constellation of patterns in mineral-crusted mud along the Uyuni Salt Flat of southwest Bolivia. The remains of an ancient lake, the Uyuni Salt Flat, Salar de Uyuni, is planet Earth's largest salt flat, located on the Bolivian Altiplano at an altitude of about 3,600 meters. Escher's 1933 lithograph also featured familiar stars in planet Earth's night, framing The Plough or Big Dipper above waves breaking on a more northern shore.

Tomorrow's picture: food for enceladus



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Life Enabling Plumes above Enceladus

Life Enabling Plumes above Enceladus:

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2017 April 16


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Life-Enabling Plumes above Enceladus

Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA


Explanation: Does Enceladus have underground oceans that could support life? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, was originally unknown. Since discovery, evidence has been accumulating that Enceladus has a deep underground sea, warmed by tidal flexing. Pictured here, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. A recent fly-through has found evidence that a plume -- and so surely the underlying sea -- is rich in molecular hydrogen, a viable food source for microbes that could potentially be living there.

Tomorrow's picture: sky alive



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Night Glows

Night Glows:

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2017 April 18


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Night Glows

Image Credit & Copyright: Taha Ghouchkanlu


Explanation: What glows in the night? This night, several unusual glows were evident -- some near, but some far. The foreground surf glimmers blue with the light of bioluminescent plankton. Next out, Earth's atmosphere dims the horizon and provides a few opaque clouds. Farther out, the planet Venus glows bright near the image center. If you slightly avert your eyes, a diagonal beam of light will stand out crossing behind Venus. This band is zodiacal light, sunlight scattered by dust in our Solar System. Much farther away are numerous single bright stars, most closer than 100 light years away. Farthest away, also rising diagonally and making a "V" with the zodiacal light, is the central band of our Milky Way Galaxy. Most of the billions of Milky Way stars and dark clouds are thousands of light years away. The featured image was taken last November on the Iranian coast of Gulf of Oman.

Tomorrow's picture: big spider



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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The Red Spider Planetary Nebula

The Red Spider Planetary Nebula:

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2017 April 19


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The Red Spider Planetary Nebula

Image Credit: NASA, ESA, Hubble, HLA; Reprocessing & Copyright: Jesús M.Vargas & Maritxu Poyal


Explanation: Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds emanating from the central stars, visible in the center, have been measured in excess of 1000 kilometers per second. These winds expand the nebula, flow along the nebula's walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the above representative-color picture by the Hubble Space Telescope. The Red Spider Nebula lies toward the constellation of the Archer (Sagittarius). Its distance is not well known but has been estimated by some to be about 4,000 light-years.

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Tomorrow's picture: planetary defense



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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NGC 4302 and NGC 4298

NGC 4302 and NGC 4298:

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2017 April 21


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NGC 4302 and NGC 4298

Image Credit: NASA, ESA, M. Mutchler (STScI)


Explanation: Seen edge-on, spiral galaxy NGC 4302 (left) lies about 55 million light-years away in the well-groomed constellation Coma Berenices. A member of the large Virgo Galaxy Cluster, it spans some 87,000 light-years, a little smaller than our own Milky Way. Like the Milky Way, NGC 4302's prominent dust lanes cut along the center of the galactic plane, obscuring and reddening the starlight from our perspective. Smaller companion galaxy NGC 4298 is also a dusty spiral. But tilted more nearly face-on to our view, NGC 4298 can show off dust lanes along spiral arms traced by the bluish light of young stars, as well as its bright yellowish core. In celebration of the 27th anniversary of the launch of the Hubble Space Telescope on April 24, 1990, astronomers used the legendary telescope to take this gorgeous visible light portrait of the contrasting galaxy pair.



Tonight Watch: The Lyrid Meteor Shower

Tomorrow's picture: light-weekend



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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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Space Station View of Auroras

Space Station View of Auroras: Expedition 50 Flight Engineer Thomas Pesquet of the European Space Agency (ESA) photographed brightly glowing auroras from his vantage point aboard the International Space Station on March 27, 2017. Pesquet wrote, "The view at night recently has been simply magnificent: few clouds, intense auroras. I can’t look away from the windows."


Original enclosures:


New Full-hemisphere Views of Earth at Night

New Full-hemisphere Views of Earth at Night: NASA scientists are releasing new global maps of Earth at night, providing the clearest yet composite view of the patterns of human settlement across our planet. This composite image, one of three new full-hemisphere views, provides a view of the Americas at night.


Original enclosures:

Illustration of Cassini Spacecraft Diving Through Plume of 'Ocean World' Enceladus

Illustration of Cassini Spacecraft Diving Through Plume of 'Ocean World' Enceladus: This illustration shows NASA's Cassini spacecraft diving through the plume of Saturn's moon Enceladus, in 2015. Two veteran NASA missions are providing new details about icy, ocean-bearing moons of Jupiter and Saturn, further heightening the scientific interest of these and other "ocean worlds" in our solar system and beyond.


Original enclosures:


Hubble Sees Starbursts in Virgo

Hubble Sees Starbursts in Virgo: Starburst galaxies contain regions where stars are forming at such a breakneck rate that the galaxy is eating up its gas supply faster than it can be replenished.


Original enclosures:


The Arrhythmic Beating of a Black Hole Heart

The Arrhythmic Beating of a Black Hole Heart: At the center of the Centaurus galaxy cluster, there is a large elliptical galaxy called NGC 4696. Deeper still, there is a supermassive black hole buried within the core of this galaxy. New data from NASA’s Chandra X-ray Observatory and other telescopes has revealed details about this giant black hole.


Original enclosures:

NASA's Fleet of Satellites Keep an Eye on Earth

NASA's Fleet of Satellites Keep an Eye on Earth: NASA's fleet of 18 Earth science missions in space, supported by aircraft, ships and ground observations, measure aspects of the environment that touch the lives of every person around the world. This visualization shows the NASA fleet in 2017.


Original enclosures:


James Webb Space Telescope Mirror Seen in Full Bloom

James Webb Space Telescope Mirror Seen in Full Bloom: It's springtime and the deployed primary mirror of NASA's James Webb Space Telescope looks like a spring flower in full bloom. Once launched into space, the Webb telescope’s 18-segmented gold mirror is specially designed to capture infrared light from the first galaxies that formed in the early universe.


Original enclosures:

Thursday, February 16, 2017

WONDERFUL Crop Circle at Cooks Plantation 23rd August, 2013 England

AMAZING Crop Circle at All Cannings 15th July 2013, England





Saturday, September 3, 2016

MYSTERY - What is the Speed of Light?

What is the Speed of Light?:



Artist's impression of a spaceship making the jump to "light speed". Credit: NASA/Glenn Research Center


Since ancient times, philosophers and scholars have sought to understand light. In addition to trying to discern its basic properties (i.e. what is it made of - particle or wave, etc.) they have also sought to make finite measurements of how fast it travels. Since the late-17th century, scientists have been doing just that, and with increasing accuracy.



In so doing, they have gained a better understanding of light's mechanics and the important role it plays in physics, astronomy and cosmology. Put simply, light moves at incredible speeds and is the fastest moving thing in the Universe. It's speed is considered a constant and an unbreakable barrier, and is used as a means of measuring distance. But just how fast does it travel?



Speed of Light (c):

Light travels at a constant speed of 1,079,252,848.8 (1.07 billion) km per hour. That works out to 299,792,458 m/s, or about 670,616,629 mph (miles per hour). To put that in perspective, if you could travel at the speed of light, you would be able to circumnavigate the globe approximately seven and a half times in one second. Meanwhile, a person flying at an average speed of about 800 km/h (500 mph), would take over 50 hours to circle the planet just once.







To put that into an astronomical perspective, the average distance from the Earth to the Moon is 384,398.25 km (238,854 miles ). So light crosses that distance in about a second. Meanwhile, the average distance from the Sun to the Earth is ~149,597,886 km (92,955,817 miles), which means that light only takes about 8 minutes to make that journey.



Little wonder then why the speed of light is the metric used to determine astronomical distances. When we say a star like Proxima Centauri is 4.25 light years away, we are saying that it would take - traveling at a constant speed of 1.07 billion km per hour (670,616,629 mph) - about 4 years and 3 months to get there. But just how did we arrive at this highly specific measurement for "light-speed"?



History of Study:

Until the 17th century, scholars were unsure whether light traveled at a finite speed or instantaneously. From the days of the ancient Greeks to medieval Islamic scholars and scientists of the early modern period, the debate went back and forth. It was not until the work of Danish astronomer Øle Rømer (1644-1710) that the first quantitative measurement was made.



In 1676, Rømer observed that the periods of Jupiter's innermost moon Io appeared to be shorter when the Earth was approaching Jupiter than when it was receding from it. From this, he concluded that light travels at a finite speed, and estimated that it takes about 22 minutes to cross the diameter of Earth's orbit.







Christiaan Huygens used this estimate and combined it with an estimate of the diameter of the Earth's orbit to obtain an estimate of 220,000 km/s. Isaac Newton also spoke about Rømer's calculations in his seminal work Opticks (1706). Adjusting for the distance between the Earth and the Sun, he calculated that it would take light seven or eight minutes to travel from one to the other. In both cases, they were off by a relatively small margin.



Later measurements made by French physicists Hippolyte Fizeau (1819 - 1896) and Léon Foucault (1819 - 1868) refined these measurements further - resulting in a value of 315,000 km/s (192,625 mi/s). And by the latter half of the 19th century, scientists became aware of the connection between light and electromagnetism.



This was accomplished by physicists measuring electromagnetic and electrostatic charges, who then found that the numerical value was very close to the speed of light (as measured by Fizeau). Based on his own work, which showed that electromagnetic waves propagate in empty space, German physicist Wilhelm Eduard Weber proposed that light was an electromagnetic wave.



The next great breakthrough came during the early 20th century/ In his 1905 paper, titled "On the Electrodynamics of Moving Bodies", Albert Einstein asserted that the speed of light in a vacuum, measured by a non-accelerating observer, is the same in all inertial reference frames and independent of the motion of the source or observer.

Using this and Galileo’s principle of relativity as a basis, Einstein derived the Theory of Special Relativity, in which the speed of light in vacuum (c) was a fundamental constant. Prior to this, the working consensus among scientists held that space was filled with a "luminiferous aether" that was responsible for its propagation - i.e. that light traveling through a moving medium would be dragged along by the medium.



This in turn meant that the measured speed of the light would be a simple sum of its speed through the medium plus the speed of that medium. However, Einstein's theory effectively  made the concept of the stationary aether useless and revolutionized the concepts of space and time.





Not only did it advance the idea that the speed of light is the same in all inertial reference frames, it also introduced the idea that major changes occur when things move close the speed of light. These include the time-space frame of a moving body appearing to slow down and contract in the direction of motion when measured in the frame of the observer (i.e. time dilation, where time slows as the speed of light approaches).



His observations also reconciled Maxwell’s equations for electricity and magnetism with the laws of mechanics, simplified the mathematical calculations by doing away with extraneous explanations used by other scientists, and accorded with the directly observed speed of light.



https://youtu.be/q74suqg5pCk



During the second half of the 20th century, increasingly accurate measurements using laser inferometers and cavity resonance techniques would further refine estimates of the speed of light. By 1972, a group at the US National Bureau of Standards in Boulder, Colorado, used the laser inferometer technique to get the currently-recognized value of 299,792,458 m/s.



Role in Modern Astrophysics:

Einstein's theory that the speed of light in vacuum is independent of the motion of the source and the inertial reference frame of the observer has since been consistently confirmed by many experiments. It also sets an upper limit on the speeds at which all massless particles and waves (which includes light) can travel in a vacuum.



One of the outgrowths of this is that cosmologists now treat space and time as a single, unified structure known as spacetime - in which the speed of light can be used to define values for both (i.e. "lightyears", "light minutes", and "light seconds"). The measurement of the speed of light has also become a major factor when determining the rate at cosmic expansion.



Beginning in the 1920's with observations of Lemaitre and Hubble, scientists and astronomers became aware that the Universe is expanding from a point of origin. Hubble also observed that the farther away a galaxy is, the faster it appears to be moving. In what is now referred to as the Hubble Parameter, the speed at which the Universe is expanding is calculated to 68 km/s per megaparsec.



https://youtu.be/cw7MTOosfeU



This phenomena, which has been theorized to mean that some galaxies could actually be moving faster than the speed of light, may place a limit on what is observable in our Universe. Essentially, galaxies traveling faster than the speed of light would cross a "cosmological event horizon", where they are no longer visible to us.



Also, by the 1990's, redshift measurements of distant galaxies showed that the expansion of the Universe has been accelerating for the past few billion years. This has led to theories like "Dark Energy", where an unseen force is driving the expansion of space itself instead of objects moving through it (thus not placing constraints on the speed of light or violating relativity).



Along with special and general relativity, the modern value of the speed of light in a vacuum has gone on to inform cosmology, quantum physics, and the Standard Model of particle physics. It remains a constant when talking about the upper limit at which massless particles can travel, and remains an unachievable barrier for particles that have mass.



Perhaps, someday, we will find a way to exceed the speed of light. While we have no practical ideas for how this might happen, the smart money seems to be on technologies that will allow us to circumvent the laws of spacetime, either by creating warp bubbles (aka. the Alcubierre Warp Drive), or tunneling through it (aka. wormholes).



https://youtu.be/lF8Ehk7JbkY



Until that time, we will just have to be satisfied with the Universe we can see, and to stick to exploring the part of it that is reachable using conventional methods.



We have written many articles about the speed of light for Universe Today. Here's How Fast is the Speed of Light?, How are Galaxies Moving Away Faster than Light?, How Can Space Travel Faster than the Speed of Light?, and Breaking the Speed of Light.



Here's a cool calculator that lets you convert many different units for the speed of light, and here's a relativity calculator, in case you wanted to travel nearly the speed of light.



Astronomy Cast also has an episode that addresses questions about the speed of light - Questions Show: Relativity, Relativity, and more Relativity.



Sources:



The post What is the Speed of Light? appeared first on Universe Today.

BINARY STARS - Talk About A Crowded Neighborhood: Closest Binary Stars With Multiple Planets Found

Talk About A Crowded Neighborhood: Closest Binary Stars With Multiple Planets Found:



Artist’s conception of the binary system with three giant planets discovered in this study. One star hosts two planets and the other hosts the third. The system represents the smallest-separation binary in which both stars host planets that has ever been observed. Image courtesy of Robin Dienel/Carnegie.


The more we look, the more we see the great diversity in planetary systems around other stars. And curiously, planet hunters are finding that most star systems are very different from our own.



An example is a recently discovered system that is extremely crowded. It consists of a three giant planets in a binary (two stars) system. One star hosts two planets and the other hosts the third. The system represents the smallest-separation binary in which both stars host planets that has ever been observed.



“The probability of finding a system with all these components was extremely small," said Johanna Teske from the Carnegie Institution for Science, “so these results will serve as an important benchmark for understanding planet formation, especially in binary systems.”







Teske and her team said this busy system might help explain the influence that giant planets like Jupiter have over a solar system’s architecture.



“We are trying to figure out if giant planets like Jupiter often have long and, or eccentric orbits,” Teske explained. “If this is the case, it would be an important clue to figuring out the process by which our Solar System formed, and might help us understand where habitable planets are likely to be found.”



The twin stars are named HD 133131A and HD 133131B. The former hosts two Jupiter-sized worlds and the latter a planet with a mass at least 2.5 times Jupiter’s. All three planets have “eccentric” or highly elliptical orbits. So far no smaller, rocky worlds have been detected but the team said those type of planets could be part of the system, or may have been part of the system in the past.



The two stars themselves are separated by only 360 astronomical units (AU – the distance between the Earth and the Sun, approximately 150,000,000 km or 93,000,000 miles). This is extremely close for twin stars with detected planets orbiting the individual stars. The next-closest known binary star system with planets has stars about 1,000 AU apart.



The two stars are more like fraternal twins rather than identical because they have slight different chemical compositions. The team said this could indicate that one star swallowed some baby planets early in its life, changing its composition slightly. Or another option is that the gravitational forces of the detected giant planets may have had a strong effect on fully-formed small planets, flinging them in towards the star or out into space.



But both stars are “metal poor,” meaning that most of their mass is hydrogen and helium, as opposed to other elements like iron or oxygen. This is another curious thing about this system, as most stars that host giant planets are "metal rich.”



The system was found using the Planet Finder Spectrograph, an instrument developed by Carnegie scientists and mounted on the Magellan Clay Telescopes at Carnegie’s Las Campanas Observatory. This finding represents the first exoplanet detection made based solely on data from the. PFS is able to find large planets with long-duration orbits or orbits that are very elliptical rather than circular.



This video tells more about the PFS:







You can read the team's paper here. It has been accepted for publication in the Astronomical Journal.

The post Talk About A Crowded Neighborhood: Closest Binary Stars With Multiple Planets Found appeared first on Universe Today.

JUPITER PLANET - Juno Captures Jupiter’s Enthralling Poles From 2,500 Miles

Juno Captures Jupiter’s Enthralling Poles From 2,500 Miles:



JunoCam captured this image of Jupiter's north pole region from a distance of 78,000 km (48,000 miles) above the planet.


Juno is sending data from Jupiter back to us, courtesy of the Deep Space Network, and the first images are meeting our hyped-up expectations. On August 27, the Juno spacecraft came within about 4,200 km. (2,500 miles) of Jupiter's cloud tops. All of Juno's instruments were active, and along with some high-quality images in visual and infrared, Juno also captured the sound that Jupiter produces.



Juno has captured the first images of Jupiter's north pole. Beyond their interest as pure, unprecedented eye candy, the images of the pole reveal things never before seen. They show storm activity and weather patterns that are seen nowhere else in our solar system. Even on the other gas giants.









"...like nothing we have seen or imagined before."
“First glimpse of Jupiter’s north pole, and it looks like nothing we have seen or imagined before,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “It’s bluer in color up there than other parts of the planet, and there are a lot of storms. There is no sign of the latitudinal bands or zone and belts that we are used to -- this image is hardly recognizable as Jupiter. We’re seeing signs that the clouds have shadows, possibly indicating that the clouds are at a higher altitude than other features.”







The visible light images of Jupiter's north pole are very different from our usual perception of Jupiter. People have been looking at Jupiter for a long time, and the gas giant's storm bands, and the Great Red Spot, are iconic. But the north polar region looks completely different, with whirling, rotating storms similar to hurricanes here on Earth.



The Junocam instrument is responsible for the visible light pictures of Jupiter that we all enjoy. But the Jovian Infrared Auroral Mapper (JIRAM) is showing us a side of Jupiter that the naked eye will never see.







“JIRAM is getting under Jupiter’s skin, giving us our first infrared close-ups of the planet,” said Alberto Adriani, JIRAM co-investigator from Istituto di Astrofisica e Planetologia Spaziali, Rome. “These first infrared views of Jupiter’s north and south poles are revealing warm and hot spots that have never been seen before. And while we knew that the first-ever infrared views of Jupiter's south pole could reveal the planet's southern aurora, we were amazed to see it for the first time."









"No other instruments, both from Earth or space, have been able to see the southern aurora."
Even when we're prepared to be amazed by what Juno and other spacecraft show us, we are still amazed. It's impossible to see Jupiter's south pole from Earth, so these are everybody's first glimpses of it.



"No other instruments, both from Earth or space, have been able to see the southern aurora," said Adriani. "Now, with JIRAM, we see that it appears to be very bright and well-structured. The high level of detail in the images will tell us more about the aurora’s morphology and dynamics.”



[embed]https://www.youtube.com/watch?v=i9TtSCkoERw[/embed]



Beyond the juicy images of Jupiter are some sound recordings. It's been known since about the 1950's that Jupiter is a noisy planet. Now Juno's Radio/Plasma Wave Experiment (WAVE) has captured a recording of that sound.



“Jupiter is talking to us in a way only gas-giant worlds can,” said Bill Kurth, co-investigator for the Waves instrument from the University of Iowa, Iowa City. “Waves detected the signature emissions of the energetic particles that generate the massive auroras which encircle Jupiter’s north pole. These emissions are the strongest in the solar system. Now we are going to try to figure out where the electrons come from that are generating them.”



[embed]https://www.youtube.com/watch?v=slE2i0O0pDY[/embed]



Oddly enough, that's pretty much exactly what I expected Jupiter to sound like. Like something from an early sci-fi film.



There's much more to come from Juno. These images and recordings of Jupiter are just the result of Juno's first orbit. There are over 30 more orbits to come, as Juno examines the gas giant as it orbits beneath it.













The post Juno Captures Jupiter’s Enthralling Poles From 2,500 Miles appeared first on Universe Today.

GREAT IMAGES - How Cold Are Black Holes?

How Cold Are Black Holes?:

Today we’re going to have the most surreal conversation. I’m going to struggle to explain it, and you’re going to struggle to understand it. And only Stephen Hawking is going to really, truly, understand what’s actually going on.

But that’s fine, I’m sure he appreciates our feeble attempts to wrap our brains around this mind bending concept.

All right? Let’s get to it. Black holes again. But this time, we’re going to figure out their temperature.

The very idea that a black hole could have a temperature strains the imagination. I mean, how can something that absorbs all the matter and energy that falls into it have a temperature? When you feel the warmth of a toasty fireplace, you’re really feeling the infrared photons radiating from the fire and surrounding metal or stone.

And black holes absorb all the energy falling into them. There is absolutely no infrared radiation coming from a black hole. No gamma radiation, no radio waves. Nothing gets out.

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As with most galaxies, a supermassive black hole lies at the heart of NGC 5548. Credit: ESA/Hubble and NASA. Acknowledgement: Davide de Martin
Now, supermassive black holes can shine with the energy of billions of stars, when they become quasars. When they’re actively feeding on stars and clouds of gas and dust. This material piles up into an accretion disk around the black hole with such density that it acts like the core of a star, undergoing nuclear fusion.

But that’s not the kind of temperature we’re talking about. We’re talking about the temperature of the black hole’s event horizon, when it’s not absorbing any material at all.

The temperature of black holes is connected to this whole concept of Hawking Radiation. The idea that over vast periods of time, black holes will generate virtual particles right at the edge of their event horizons. The most common kind of particles are photons, aka light, aka heat.

Normally these virtual particles are able to recombine and disappear in a puff of annihilation as quickly as they appear. But when a pair of these virtual particles appear right at the event horizon, one half of the pair drops into the black hole, while the other is free to escape into the Universe.

From your perspective as an outside observer, you see these particles escaping from the black hole. You see photons, and therefore, you can measure the temperature of the black hole.

PIA18919: How Black Hole Winds Blow (Artist's Concept)
Artist’s concept of the black hole at the center of the Pinwheel Galaxy. Credit: NASA/JPL-Caltech
The temperature of the black hole is inversely proportional to the mass of the black hole and the size of the event horizon. Think of it this way. Imagine the curved surface of a black hole’s event horizon. There are many paths that a photon could try to take to get away from the event horizon, and the vast majority of those are paths that take it back down into the black hole’s gravity well.

But for a few rare paths, when the photon is traveling perfectly perpendicular to the event horizon, then the photon has a chance to escape. The larger the event horizon, the less paths there are that a photon could take.

Since energy is being released into the Universe at the black hole’s event horizon, but energy can neither be created or destroyed, the black hole itself provides the mass that supplies the energy to release these photons.

The black hole evaporates.

The most massive black holes in the Universe, the supermassive black holes with millions of times the math of the Sun will have a temperature of 1.4 x 10^-14 Kelvin. That’s low. Almost absolute zero, but not quite.

Artist's impression of a feeding stellar-mass black hole. Credit: NASA, ESA, Martin Kornmesser (ESA/Hubble)
Artist’s impression of a feeding stellar-mass black hole. Credit: NASA, ESA, Martin Kornmesser (ESA/Hubble)
A solar mass black hole might have a temperature of only .0.00000006 Kelvin. We’re getting warmer.

Since these temperatures are much lower than the background temperature of the Universe – about 2.7 Kelvin, all the existing black holes will have an overall gain of mass. They’re absorbing energy from the Cosmic Background Radiation faster than they’re evaporating, and will for an incomprehensible amount of time into the future.

Until the background temperature of the Universe goes below the temperature of these black holes, they won’t even start evaporating.

A black hole with the mass of the Earth is still too cold.

Only a black hole with about the mass of the Moon is warm enough to be evaporating faster than it’s absorbing energy from the Universe.

As they get less massive, they get even hotter. A black hole with the mass of the asteroid Ceres would be 122 Kelvin. Still freezing, but getting warmer.

A black hole with half the mass of Vesta would blaze at more than 1,200 Kelvin. Now we’re cooking!

Less massive, higher temperatures.

When black holes have lost most of their mass, they release the final material in a tremendous blast of energy, which should be visible to our telescopes.

Artist's conception of the event horizon of a black hole. Credit: Victor de Schwanberg/Science Photo Library
Artist’s conception of the event horizon of a black hole. Credit: Victor de Schwanberg/Science Photo Library
Some astronomers are actively searching the night sky for blasts from black holes which were formed shortly after the Big Bang, when the Universe was hot and dense enough that black holes could just form.

It took them billions of years of evaporation to get to the point that they’re starting to explode now.

This is just conjecture, though, no explosions have ever been linked to primordial black holes so far.

It’s pretty crazy to think that an object that absorbs all energy that falls into it can also emit energy. Well, that’s the Universe for you. Thanks for helping us figure it out Dr. Hawking.

The post How Cold Are Black Holes? appeared first on Universe Today.

Quebec Canada Aurora and Manicouagan Crater

Aurora and Manicouagan Crater: An astronaut aboard the International Space Station adjusted the camera for night imaging and captured the green veils and curtains of an aurora that spanned thousands of kilometers over Quebec, Canada.


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NASA IMAGE A Black Hole Story Told by a Cosmic Blob and Bubble

A Black Hole Story Told by a Cosmic Blob and Bubble: Two cosmic structures show evidence for a remarkable change in behavior of a supermassive black hole in a distant galaxy.


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Perseid Meteor Shower 2016 from West Virginia

Perseid Meteor Shower 2016 from West Virginia: In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Friday, Aug. 12, 2016 in Spruce Knob, West Virginia.


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