April 16, 2016

A Cosmic Searchlight

M87 jet

Streaming out from the centre of the galaxy M87 like a cosmic searchlight is one of nature's most amazing phenomena, a black-hole-powered jet of electrons and other sub-atomic particles traveling at nearly the speed of light. In this Hubble telescope image, the blue jet contrasts with the yellow glow from the combined light of billions of unseen stars and the yellow, point-like clusters of stars that make up this galaxy. Lying at the centre of M87, the monstrous black hole has swallowed up matter equal to 2 billion times our Sun's mass. M87 is 50 million light-years from Earth.

Image Credit: The Hubble Heritage Team (STScI/AURA) and NASA/ESA
Explanation from: https://www.spacetelescope.org/images/opo0020a/

The Rho Ophiuchi star formation region

The Rho Ophiuchi star formation region

This wide-field view shows a spectacular region of dark and bright clouds, forming part of a region of star formation in the constellation of Ophiuchus (The Serpent Bearer). This picture was created from images in the Digitized Sky Survey 2.

Image Credit: ESO/Digitized Sky Survey 2, Davide De Martin

Milky Way Galaxy, Large Magellanic Cloud Galaxy and Small Magellanic Cloud Galaxy above La Silla Observatory in Chile

Milky Way Galaxy, Large Magellanic Cloud Galaxy and Small Magellanic Cloud Galaxy above La Silla Observatory in Chile

Image Credit: P. Horálek/ESO

Popocatépetl Volcano Eruption

Popocatépetl Volcano Eruption

Mexico-Puebla-Morelos, Mexico
July 4, 2013

Image Credit: Pablo Spencer

April 15, 2016

Wide-field view of the area of NGC 6357

NGC 6357 Pismis 24

Part of the constellation Scorpius centred on NGC 6357 which has star cluster Pismis 24 in its centre. This image is a colour composite taken by the Digitized Sky Survey (DSS), the field of view is 3.8x3.3 degrees.

Image Credit: Davide De Martin (ESA/Hubble)

Solar Prominence

Solar Prominence

A round solar prominence burst from the sun on March 13, 2016, shortly after it rotated into the view of NASA’s Solar Dynamics Observatory, or SDO. Much of the solar material did not escape the sun’s gravitational pull, falling back to the solar surface. Prominences – called filaments when seen against the sun’s face instead of over the horizon – are notoriously unstable clouds of solar material suspended above the solar surface by the sun’s complex magnetic forces. They often break apart after a few days.

This video was made from images taken every 12 seconds by SDO – the fastest-ever cadence for solar observations from space. This prominence was captured in wavelengths of 304 angstroms, a type of extreme ultraviolet light that is typically invisible to our eyes, but is colorized here in red.

Video Credit: NASA/SDO
Explanation from: http://www.nasa.gov/feature/goddard/2016/nasa-s-sdo-sees-circular-outburst

Lava & Ocean

Lava & Ocean

Bardarbunga Volcano, Iceland
September 14, 2014

Image Credit: Bernard Meric

Hubble Frontier Fields view of MACSJ0717.5+3745

galaxy cluster MACSJ0717.5+3745

This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACSJ0717.5+3745. This is one of six being studied by the Hubble Frontier Fields programme, which together have produced the deepest images of gravitational lensing ever made.

Due to the huge mass of the cluster it is bending the light of background objects, acting as a magnifying lens. It is one of the most massive galaxy clusters known, and it is also the largest known gravitational lens. Of all of the galaxy clusters known and measured, MACS J0717 lenses the largest area of the sky.

Image Credit: NASA, ESA and the HST Frontier Fields team (STScI)
Explanation from: http://www.spacetelescope.org/images/heic1523b/

April 14, 2016

Total Solar Eclipse seen from plane above Atlantic Ocean

Total Solar Eclipse seen from plane above Atlantic Ocean

Plane above Faroe Islands, Atlantic Ocean
March 20, 2015

Image Credit & Copyright: Philippe Rowland

The Lagoon Nebula

Lagoon Nebula

Situated some 5,000 light years away, the stellar nursery of the Lagoon Nebula lies in the constellation of Sagittarius. Despite being light years away, the Lagoon Nebula is in fact one of the few star-forming nebulae that it is possible to see with the naked eye (in optimum conditions) from mid-northern latitudes.

Image Credit & Copyright: László Francsics
Explanation by: Royal Observatory Greenwich

April 13, 2016

The MACS J0717.5+3745 Galaxy Cluster

The MACS J0717.5+3745 Galaxy Cluster

In October of 2013 Hubble kicked off the Frontier Fields programme, a three-year series of observations aiming to produce the deepest ever views of the Universe. The project’s targets comprise six massive galaxy clusters, enormous collections of hundreds or even thousands of galaxies. These structures are the largest gravitationally-bound objects in the cosmos.

One of the Frontier Fields targets is shown in this new image: MACS J0717.5+3745, or MACS J0717 for short. MACS J0717 is located about 5.4 billion light-years away from Earth, in the constellation of Auriga (The Charioteer). It is one of the most complex galaxy clusters known; rather than being a single cluster, it is actually the result of four galaxy clusters colliding.

This image is a combination of observations from the NASA/ESA Hubble Space Telescope (showing the galaxies and stars), the NASA Chandra X-ray Observatory (diffuse emission in blue), and the NRAO Jansky Very Large Array (diffuse emission in pink). The Hubble data were collected as part of the Frontier Fields programme mentioned above.

Together, the three datasets produce a unique new view of MACS J0717. The Hubble data reveal galaxies both within the cluster and far behind it, and the Chandra observations show bright pockets of scorching gas — heated to millions of degrees. The data collected by the Jansky Very Large Array trace the radio emission within the cluster, enormous shock waves — similar to sonic booms — that were triggered by the violent merger.

Image Credit: NASA, ESA, CXC, NRAO/AUI/NSF, STScI, and R. van Weeren
Explanation from: https://www.spacetelescope.org/images/potw1611a/

Aurora over Senja

Aurora over Senja

Senja, Troms, Norway
January 21, 2015

Image Credit & Copyright: Rune Engebo

Comet C/2014 Q2 Lovejoy

Comet C/2014 Q2 Lovejoy

Image Credit & Copyright: Michael Jaeger

Aurora over Glacier Lagoon

Aurora Vatnajökull

Vatnajökull National Park, Iceland

Image Credit & Copyright: James Woodend

April 12, 2016

Hubble Frontier Fields view of MACSJ0416.1–2403

galaxy cluster MACS J0416.1–2403

This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACS J0416.1–2403. This is one of six being studied by the Hubble Frontier Fields programme, which together have produced the deepest images of gravitational lensing ever made.

Due to the huge mass of the cluster it is bending the light of background objects, acting as a magnifying lens. Astronomers used this and two other clusters to find galaxies which existed only 600 to 900 million years after the Big Bang.

Image Credit: NASA, ESA and the HST Frontier Fields team (STScI)
Explanation from: http://www.spacetelescope.org/images/heic1523a/

Mars and Comet C/2013 A1

mars and comet

A close encounter between our neighbouring red planet Mars and Comet C/2013 A1, also known as Siding Spring, as it whizzes through the night sky on 22 October 2014. It was initially thought that there was a chance of collision between the comet and Mars when the comet was discovered in 2013, but this was ruled out when the comet’s orbit was determined more accurately. Siding Spring Observatory, Coonabarabran, New South Wales, Australia.

Image Credit & Copyright: Sebastian Voltmer
Explanation by: Royal Observatory Greenwich

Computer-Simulated Image of a Supermassive Black Hole

Supermassive Black Hole

This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole's event horizon, where no light can escape the massive object's gravitational grip. The black hole's powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole.

Astronomers have uncovered a near-record-breaking supermassive black hole, weighing 17 billion suns, in an unlikely place: in the center of a galaxy in a sparsely populated area of the universe. The observations, made by NASA's Hubble Space Telescope and the Gemini telescope in Hawaii, could indicate that these monster objects may be more common than once thought.

Until now, the biggest supermassive black holes — those roughly 10 billion times the mass of our sun — have been found at the cores of very large galaxies in regions of the universe packed with other large galaxies. In fact, the current record holder tips the scale at 21 billion suns and resides in the crowded Coma galaxy cluster, which consists of over 1,000 galaxies.

"The newly discovered supersized black hole resides in the center of a massive elliptical galaxy, NGC 1600, located in a cosmic backwater, a small grouping of 20 or so galaxies," said lead discoverer Chung-Pei Ma, a University of California-Berkeley astronomer and head of the MASSIVE Survey, a study of the most massive galaxies and supermassive black holes in the local universe. While finding a gigantic black hole in a massive galaxy in a crowded area of the universe is to be expected — like running across a skyscraper in Manhattan — it seemed less likely they could be found in the universe's small towns.

"There are quite a few galaxies the size of NGC 1600 that reside in average-size galaxy groups," Ma said. "We estimate that these smaller groups are about 50 times more abundant than spectacular galaxy clusters like the Coma cluster. So the question now is, ‘Is this the tip of an iceberg?' Maybe there are more monster black holes out there that don't live in a skyscraper in Manhattan, but in a tall building somewhere in the Midwestern plains."

The researchers also were surprised to discover that the black hole is 10 times more massive than they had predicted for a galaxy of this mass. Based on previous Hubble surveys of black holes, astronomers had developed a correlation between a black hole's mass and the mass of its host galaxy's central bulge of stars — the larger the galaxy bulge, the proportionally more massive the black hole. But for galaxy NGC 1600, the giant black hole's mass far overshadows the mass of its relatively sparse bulge. "It appears that that relation does not work very well with extremely massive black holes; they are a larger fraction of the host galaxy's mass," Ma said.

Ma and her colleagues are reporting the discovery of the black hole, which is located about 200 million light-years from Earth in the direction of the constellation Eridanus, in the April 6 issue of the journal Nature. Jens Thomas of the Max Planck Institute for Extraterrestrial Physics, Garching, Germany, is the paper's lead author.

One idea to explain the black hole's monster size is that it merged with another black hole long ago when galaxy interactions were more frequent. When two galaxies merge, their central black holes settle into the core of the new galaxy and orbit each other. Stars falling near the binary black hole, depending on their speed and trajectory, can actually rob momentum from the whirling pair and pick up enough velocity to escape from the galaxy's core. This gravitational interaction causes the black holes to slowly move closer together, eventually merging to form an even larger black hole. The supermassive black hole then continues to grow by gobbling up gas funneled to the core by galaxy collisions. "To become this massive, the black hole would have had a very voracious phase during which it devoured lots of gas," Ma said.

The frequent meals consumed by NGC 1600 may also be the reason why the galaxy resides in a small town, with few galactic neighbors. NGC 1600 is the most dominant galaxy in its galactic group, at least three times brighter than its neighbors. "Other groups like this rarely have such a large luminosity gap between the brightest and the second brightest galaxies," Ma said.

Most of the galaxy's gas was consumed long ago when the black hole blazed as a brilliant quasar from material streaming into it that was heated into a glowing plasma. "Now, the black hole is a sleeping giant," Ma said. "The only way we found it was by measuring the velocities of stars near it, which are strongly influenced by the gravity of the black hole. The velocity measurements give us an estimate of the black hole's mass."

The velocity measurements were made by the Gemini Multi-Object Spectrograph (GMOS) on the Gemini North 8-meter telescope on Mauna Kea in Hawaii. GMOS spectroscopically dissected the light from the galaxy's center, revealing stars within 3,000 light-years of the core. Some of these stars are circling around the black hole and avoiding close encounters. However, stars moving on a straighter path away from the core suggest that they had ventured closer to the center and had been slung away, most likely by the twin black holes.

Archival Hubble images, taken by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), support the idea of twin black holes pushing stars away. The NICMOS images revealed that the galaxy's core was unusually faint, indicating a lack of stars close to the galactic center. A star-depleted core distinguishes massive galaxies from standard elliptical galaxies, which are much brighter in their centers. Ma and her colleagues estimated that the amount of stars tossed out of the central region equals 40 billion suns, comparable to ejecting the entire disk of our Milky Way galaxy.

Image Credit: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel
Explanation from: http://hubblesite.org/newscenter/archive/releases/2016/12/image/a/ and http://hubblesite.org/newscenter/archive/releases/2016/12/full/

The NGC 5408 Galaxy

The NGC 5408 Galaxy

Most galaxies possess a majestic spiral or elliptical structure. About a quarter of galaxies, though, defy such conventional, rounded aesthetics, instead sporting a messy, indefinable shape. Known as irregular galaxies, this group includes NGC 5408, the galaxy that has been snapped here by the NASA/ESA Hubble Space Telescope.

John Herschel recorded the existence of NGC 5408 in June 1834. Astronomers had long mistaken NGC 5408 for a planetary nebula, an expelled cloud of material from an aging star. Instead, bucking labels, NGC 5408 turned out to be an entire galaxy, located about 16 million light-years from Earth in the constellation of Centaurus (The Centaur).

In yet another sign of NGC 5408 breaking convention, the galaxy is associated with an object known as an ultraluminous X-ray source, dubbed NGC 5408 X-1, one of the best studied of its class. These rare objects beam out prodigious amounts of energetic X-rays. Astrophysicists believe these sources to be strong candidates for intermediate-mass black holes. This hypothetical type of black hole has significantly less mass than the supermassive black holes found in galactic centers, which can have billions of times the mass of the sun, but have a good deal more mass than the black holes formed when giant stars collapse.

Image Credit: ESA/Hubble & NASA, Judy Schmidt
Explanation from: https://www.nasa.gov/image-feature/goddard/2016/hubble-spies-a-rebel

April 11, 2016

Meteor and the Milky Way Galaxy seen over Mount Rainier

Meteor and the Milky Way Galaxy over Mount Rainier

A meteor can be seen piercing through the darkness as the Milky Way towers above the 4,392m peak of Mount Rainier in Washington, USA. The white lights dotted across the rocky paths of the mountain’s face are the headlamps of hikers ascending to the peak

Image Credit & Copyright: Brad Goldpaint
Explanation by: Royal Observatory Greenwich

Piton de la Fournaise Volcano Eruption

Piton de la Fournaise Volcano Eruption

Réunion, Indian Ocean
May 17, 2015

Image Credit: Richard Bouhet

The Rite of Spring

Saturn Cassini

Of the countless equinoxes Saturn has seen since the birth of the solar system, this one, captured here in a mosaic of light and dark, is the first witnessed up close by an emissary from Earth … none other than our faithful robotic explorer, Cassini.

Seen from our planet, the view of Saturn’s rings during equinox is extremely foreshortened and limited. But in orbit around Saturn, Cassini had no such problems. From 20 degrees above the ring plane, Cassini’s wide angle camera shot 75 exposures in succession for this mosaic showing Saturn, its rings, and a few of its moons a day and a half after exact Saturn equinox, when the sun’s disk was exactly overhead at the planet’s equator.

The novel illumination geometry that accompanies equinox lowers the sun’s angle to the ring plane, significantly darkens the rings, and causes out-of-plane structures to look anomalously bright and to cast shadows across the rings. These scenes are possible only during the few months before and after Saturn’s equinox which occurs only once in about 15 Earth years. Before and after equinox, Cassini’s cameras have spotted not only the predictable shadows of some of Saturn’s moons, but also the shadows of newly revealed vertical structures in the rings themselves.

Also at equinox, the shadows of the planet’s expansive rings are compressed into a single, narrow band cast onto the planet as seen in this mosaic.

The images comprising the mosaic, taken over about eight hours, were extensively processed before being joined together. First, each was re-projected into the same viewing geometry and then digitally processed to make the image “joints” seamless and to remove lens flares, radially extended bright artifacts resulting from light being scattered within the camera optics.

At this time so close to equinox, illumination of the rings by sunlight reflected off the planet vastly dominates any meager sunlight falling on the rings. Hence, the half of the rings on the left illuminated by planetshine is, before processing, much brighter than the half of the rings on the right. On the right, it is only the vertically extended parts of the rings that catch any substantial sunlight.

With no enhancement, the rings would be essentially invisible in this mosaic. To improve their visibility, the dark (right) half of the rings has been brightened relative to the brighter (left) half by a factor of three, and then the whole ring system has been brightened by a factor of 20 relative to the planet. So the dark half of the rings is 60 times brighter, and the bright half 20 times brighter, than they would have appeared if the entire system, planet included, could have been captured in a single image.

The moon Janus (179 kilometers, 111 miles across) is on the lower left of this image. Epimetheus (113 kilometers, 70 miles across) appears near the middle bottom. Pandora (81 kilometers, 50 miles across) orbits outside the rings on the right of the image. The small moon Atlas (30 kilometers, 19 miles across) orbits inside the thin F ring on the right of the image. The brightnesses of all the moons, relative to the planet, have been enhanced between 30 and 60 times to make them more easily visible. Other bright specks are background stars. Spokes -- ghostly radial markings on the B ring -- are visible on the right of the image.

This view looks toward the northern side of the rings from about 20 degrees above the ring plane.

The images were taken on Aug. 12, 2009, beginning about 1.25 days after exact equinox, using the red, green and blue spectral filters of the wide angle camera and were combined to create this natural color view. The images were obtained at a distance of approximately 847,000 kilometers (526,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 74 degrees. Image scale is 50 kilometers (31 miles) per pixel.

Image Credit: NASA/JPL/Space Science Institute
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA11667

Oxycomanthus Bennetti

Oxycomanthus Bennetti

Oxycomanthus bennetti, common name Bennett's feather star, is a species of crinoids belonging to the family Comasteridae

Crinoids are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 metres (20,000 ft). Sea lilies refer to the crinoids which, in their adult form, are attached to the sea bottom by a stalk. Feather stars or comatulids refer to the unstalked forms.

Crinoids are characterised by a mouth on the top surface that is surrounded by feeding arms. They have a U-shaped gut, and their anus is located next to the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, most crinoids have many more than five arms. Crinoids usually have a stem used to attach themselves to a substrate, but many live attached only as juveniles and become free-swimming as adults.

There are only about 600 extant crinoid species, but they were much more abundant and diverse in the past. Some thick limestone beds dating to the mid- to late-Paleozoic are almost entirely made up of disarticulated crinoid fragments.

Image Credit: Hectonichus via wikipedia.org
Explanation from: https://en.wikipedia.org/wiki/Crinoid

Artist's Impression of the Icy Exoplanet

Icy Exoplanet

Using a network of telescopes scattered across the globe, including the Danish 1.5-m telescope at ESO La Silla (Chile), astronomers discovered a new extrasolar planet significantly more Earth-like than any other planet found so far. The planet, which is only about 5 times as massive as the Earth, circles its parent star in about 10 years. It is the least massive exoplanet around an ordinary star detected so far and also the coolest. The planet most certainly has a rocky/icy surface. Its discovery marks a groundbreaking result in the search for planets that support life.

The planet, designated by the unglamorous identifier of OGLE-2005-BLG-390Lb, orbits a red star five times less massive than the Sun and located at a distance of about 20,000 light years, not far from the centre of our Milky Way galaxy.

Image Credit: ESO
Explanation from: https://www.eso.org/public/images/eso0603a/

April 10, 2016

Aurora over Kiruna

Aurora over Kiruna

Kiruna, Lapland, Sweden

Image Credit & Copyright: Antony Spencer

Star formation in the constellation of Carina

Star formation in the constellation of Carina

This wide-field image, based on data from Digitized Sky Survey 2, shows the whole region around the cosmic factory NGC 3603, located about 20 000 light-years away. This region contains many star formation regions featuring huge clouds of glowing gas.

Image Credit: ESO/Digitized Sky Survey 2
Explanation from: http://www.eso.org/public/images/eso1005b/

2015 Mount Etna Volcano Eruption

Mount Etna Volcano Eruption

Mount Etna, Sicily, Italy
December 3, 2015

Image Credit: Marco Restivo/Demotix/Corbis

Hubble photographs grand spiral galaxy Messier 81

Messier 81

The beautiful galaxy Messier 81 is tilted at an oblique angle on to our line of sight, giving a "birds-eye view" of the spiral structure. The galaxy is similar to our Milky Way, but our favourable view provides a better picture of the typical architecture of spiral galaxies. Though the galaxy is 11.6 million light-years away, the vision of the NASA/ESA Hubble Space Telescope is so sharp that it can resolve individual stars, along with open star clusters, globular star clusters, and even glowing regions of fluorescent gas.

The spiral arms, which wind all the way down into the nucleus, are made up of young, bluish, hot stars formed in the past few million years. They also host a population of stars formed in an episode of star formation that started about 600 million years ago. The greenish regions are dense areas of bright star formation. The ultraviolet light from hot young stars are fluorescing the surrounding clouds of hydrogen gas. A number of sinuous dust lanes also wind all the way into the nucleus of Messier 81.

The galaxy's central bulge contains much older, redder stars. It is significantly larger than the Milky Way's bulge. The central black hole is 70 million solar masses, or 15 times the mass of the Milky Way's black hole. Previous Hubble research shows that the size of the central black hole in a galaxy is proportional to the mass of a galaxy's bulge.

Messier 81 may be undergoing a surge of star formation along the spiral arms due to a close encounter it may have had with its nearby spiral galaxy NGC 3077 and a nearby starburst galaxy (Messier 82) about 300 million years ago. Astronomers plan to use the Hubble image to study the star formation history of the galaxy and how this history relates to the neutron stars and black holes seen in X-ray observations of Messier 81 with NASA's Chandra X-ray Observatory.

Messier 81 is one of the brightest galaxies that can be seen from the Earth. It is high in the northern sky in the constellation Ursa Major, the Great Bear. At an apparent magnitude of 6.8 it is just at the limit of naked-eye visibility. The galaxy's angular size is about the same as that of the Full Moon.

Image Credit: NASA, ESA and the Hubble Heritage Team STScI/AURA), A. Zezas and J. Huchra (Harvard-Smithsonian Center for Astrophysics)
Explanation from: https://www.spacetelescope.org/news/heic0710/