Artist's Impression of the view of the night sky from hypothetical planet in the Milky Way Galaxy 10 billion years ago

This illustration depicts a view of the night sky from a hypothetical planet within the youthful Milky Way galaxy 10 billion years ago. The heavens are ablaze with a firestorm of star birth. Glowing pink clouds of hydrogen gas harbor countless newborn stars, and the bluish-white hue of young star clusters litter the landscape. The star-birth rate is 30 times higher than it is in the Milky Way today. Our Sun, however, is not among these fledgling stars. The Sun will not be born for another 5 billion years.

Image Credit: NASA, ESA, and Z. Levay (STScI)
Explanation from: http://hubblesite.org/newscenter/archive/releases/2015/11/image/a/

Gegenschein, Total Lunar Eclipse, Milky Way Galaxy, Large Magellanic Cloud Galaxy and Small Magellanic Cloud Galaxy

Is there anything interesting to see in the direction opposite the Sun? In September 2015 ere were quite a few things. First, the red-glowing orb on the lower right of this image is the full Moon, darkened and reddened because it has entered Earth's shadow. Beyond Earth's cone of darkness are backscattering dust particles orbiting the Sun that standout with a diffuse glow called the gegenschein, visible as a faint band rising from the central horizon and passing behind the Moon. A nearly horizontal stripe of green airglow is also discernable just above the horizon, partly blocked by blowing orange sand. Visible in the distant sky as the blue dot near the top of the image is the star Sirius, while the central band of our Milky Way Galaxy arches up on the image left and down again on the right. The fuzzy light patches just left of center are the Large and Small Magellanic Clouds. Red emission nebulas too numerous to mention are scattered about the sky, but are labelled in a companion annotated image.

Namib-Naukluft National Park, Namibia

September 2015

Image Credit & Copyright: Petr Horálek
Explanation from: http://apod.nasa.gov/apod/ap151014.html

Blue Marble: Western Hemisphere

This spectacular “blue marble” image is the most detailed true-color image of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet.

Much of the information contained in this image came from a single remote-sensing device-NASA’sModerate Resolution Imaging Spectroradiometer, or MODIS. Flying over 700 km above the Earth on board the Terra satellite, MODIS provides an integrated tool for observing a variety of terrestrial, oceanic, and atmospheric features of the Earth.

The land and coastal ocean portions of these images are based on surface observations collected from June through September 2001 and combined, or composited, every eight days to compensate for clouds that might block the sensor’s view of the surface on any single day. Two different types of ocean data were used in these images: shallow water true color data, and global ocean color (or chlorophyll) data. Topographic shading is based on the GTOPO 30 elevation dataset compiled by the U.S. Geological Survey’s EROS Data Center.

MODIS observations of polar sea ice were combined with observations of Antarctica made by the National Oceanic and Atmospheric Administration’s AVHRR sensor—the Advanced Very High Resolution Radiometer. The cloud image is a composite of two days of imagery collected in visible light wavelengths and a third day of thermal infra-red imagery over the poles. Global city lights, derived from 9 months of observations from the Defense Meteorological Satellite Program, are superimposed on a darkened land surface map.

Image Credit: NASA's Earth Observatory
Explanation from: http://visibleearth.nasa.gov/view.php?id=57723

Andromeda Galaxy seen over the Alps

Monte Sella, Apuan Alps, Italy

August 12, 2015

Image Credit & Copyright: Matteo Dunchi

Galaxy Cluster IDCS 1426

This multi-wavelength image shows this galaxy cluster, called IDCS J1426.5+3508 (IDCS 1426 for short), in X-rays from the Chandra X-ray Observatory in blue, visible light from the Hubble Space Telescope in green, and infrared light from the Spitzer Space Telescope in red.

This rare galaxy cluster, which is located 10 billion light years from Earth, weighs almost 500 trillion Suns. This object has important implications for understanding how these mega-structures formed and evolved early in the Universe. Astronomers have observed IDCS 1426 when the universe was less than a third of its current age. It is the most massive galaxy cluster detected at such an early age.

First discovered by the Spitzer Space Telescope in 2012, IDCS 1426 was then observed using the Hubble Space Telescope and the Keck Observatory to determine its distance. Observations from the Combined Array for Millimeter Wave Astronomy indicated it was extremely massive. New data from the Chandra X-ray Observatory confirm the galaxy cluster mass and show that about 90% of the mass of the cluster is in the form of dark matter, the mysterious substance that has so far been detected only through its gravitational pull on normal matter composed of atoms.

There is a region of bright X-ray emission (seen as blue-white) near the middle of the cluster, but not exactly at the center. The location of this “core” of gas suggests that the cluster has had a collision or interaction with another massive system of galaxies relatively recently, perhaps within about the last 500 million years. This would cause the core to “slosh” around like wine in a moving glass and become offset as it appears to be in the Chandra data. Such a merger would not be surprising, given that astronomers are observing IDCS 1426 when the Universe was only 3.8 billion years old. So that an enormous structure can form so rapidly, scientists think mergers with smaller clusters would likely play a role in a large cluster’s growth.

This core, while still extremely hot, contains cooler gas than its surroundings. This is the most distant galaxy cluster where such a “cool core” of gas has been observed. Astronomers think these cool cores are important in understanding how quickly hot gas cools off in clusters, influencing the rate of stars at which stars are born. This cooling rate can be slowed down by outbursts from a supermassive black hole in the center of the cluster. Apart from the cool core, the hot gas in the cluster is remarkably symmetrical and smooth. This is another piece of evidence that IDCS 1426 formed very rapidly and quickly in the early Universe. Despite the high mass and rapid evolution of this cluster, its existence does not pose a threat to the standard model of cosmology.

Image Credit: NASA/CXC/Univ of Missouri/M.Brodwin, NASA/STScI; Infrared: JPL/CalTech
Explanation from: http://www.nasa.gov/mission_pages/chandra/images/galaxy-cluster-idcs-1426.html

Helix Nebula in the Infrared

The Helix Nebula, also known as The Helix, NGC 7293, is a large planetary nebula located in the constellation Aquarius. Discovered by Karl Ludwig Harding, probably before 1824, this object is one of the closest to the Earth of all the bright planetary nebulae. The estimated distance is about 215 parsecs (700 light-years). It is similar in appearance to the Cat's Eye Nebula and the Ring Nebula, whose size, age, and physical characteristics are similar to the Dumbbell Nebula, varying only in its relative proximity and the appearance from the equatorial viewing angle.

Image Credit: NASA/JPL-Caltech
Explanation from: https://en.wikipedia.org/wiki/Helix_Nebula

Hubble photographs grand spiral galaxy Messier 81

This is sharpest image ever taken of the large "grand design" spiral galaxy Messier 81. The image, constructed from a series of images taken with NASA/ESA Hubble Space Telescope, is among the largest ever released. Messier 81 is one of the brightest galaxies that can be seen from the Earth.

Inner bulge and nucleus of M81

Southern arm of M81
including a chain of
HII regions

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.

OB Associations in outer
northern arm of M81

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.

Bulge-disk transition in M81 and chain of HII regions

HII shell of M81 and background galaxies

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.

Southern extremity of the galaxy M81

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.

Background group of galaxies

Wide-field image showing the
Ursa Major constellation on lower right

The Hubble data was taken with the Advanced Camera for Surveys in 2004 through 2006. The colour composite measures 22,620 x 15,200 pixels and was assembled from images taken in blue, visible, and infrared light.

The spiral galaxy M81 and the neighbor galaxy M82 as seen in ground-based images from the Digitized Sky Survey 2 (DSS2). The image is a colour composite from DSS2 images. The field of view is 2.8 degrees

Image Credit: NASA, ESA and the Hubble Heritage Team STScI/AURA)
Explanation from: https://www.spacetelescope.org/news/heic0710/

Artist’s impression of a young star surrounded by a protoplanetary disc

This is an artist’s impression of a young star surrounded by a protoplanetary disc in which planets are forming. Using ALMA’s 15-kilometre baseline astronomers were able to make the first detailed image of a protoplanetary disc, which revealed the complex structure of the disc. Concentric rings of gas, with gaps indicating planet formation, are visible in this artist’s impression and were predicted by computer simulations.

Image Credit: ESO/L. Calçada
Explanation from: https://www.eso.org/public/images/eso1436f/

Moon Halo over Antarctica

Zhongshan Station, Antarctica

July 2015

Image Credit & Copyright: LI Hang

Artist’s impression of the ultracool dwarf star TRAPPIST-1 and its three planets

This artist’s impression shows an imagined view of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO’s La Silla Observatory. These worlds have sizes and temperatures similar to those of Venus and Earth and may be the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star.

In this view one of the inner planets is seen in transit across the disc of its tiny and dim parent star.

Image Credit: ESO/M. Kornmesser/N. Risinger
Explanation from: http://www.eso.org/public/images/eso1615c/

ALMA image of the protoplanetary disc around HL Tauri

This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system.

Image Credit: ALMA (ESO/NAOJ/NRAO)
Explanation from: https://www.eso.org/public/images/eso1436a/

Earth and the far side of the Moon seen by DSCOVR Observatory

A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the Moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth.

The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA).

DSCOVR, 1 million miles from Earth

July 16,, 2016

Image Credit: NASA/NOAA
Explanation from: http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=11971

Artist’s impression of the ultracool dwarf star TRAPPIST-1 from close to one of its planets

This artist’s impression shows an imagined view from close to one of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO’s La Silla Observatory. These worlds have sizes and temperatures similar to those of Venus and Earth and are the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star.

In this view one of the inner planets is seen in transit across the disc of its tiny and dim parent star.

Image Credit: ESO/M. Kornmesser
Explanation from: http://www.eso.org/public/images/eso1615b/

Aurora over Kiruna

Kiruna, Sweden

March 2005

Image Credit & Copyright: Mia Stålnacke

Earth's New Lightning Capital Revealed: Lake Maracaibo in Venezuela - about 233 flashes per square kilometer per year

Earth has a new lightning capital, according to a recent study using observations from the Lightning Imaging Sensor onboard NASA's Tropical Rainfall Measurement Mission.

Lake Maracaibo in Venezuela earned the top spot receiving an average rate of about 233 flashes per square kilometer per year, according to the study. Researchers had previously identified Africa's Congo Basin as the location of maximum lightning activity.

The research team constructed a very high resolution data set derived from 16 years of space-based LIS observations to identify and rank lightning hotspots. They described their research in the Bulletin of the American Meteorological Society.

"We can now observe lightning flash rate density in very fine detail on a global scale," said Richard Blakeslee, LIS project scientist at NASA's Marshall Space Flight Center. "Better understanding of lightning activity around the world enables policy makers, government agencies and other stakeholders to make more informed decisions related to weather and climate."

Blakeslee joined forces with lightning researchers at the University of São Paulo, the University of Maryland, the National Oceanic Atmospheric Administration and the University of Alabama in Huntsville to understand where and when most lightning occurs. Their findings will help forecasters and researchers better understand lightning and its connections to weather and other phenomena.

“Lake Maracaibo has a unique geography and climatology that is ideal for the development of thunderstorms," said Dennis Buechler with the University of Alabama in Huntsville.

Buechler noted that Lake Maracaibo is not new to lightning researchers. Located in northwest Venezuela along part of the Andes Mountains, it is the largest lake in South America. Storms commonly form there at night as mountain breezes develop and converge over the warm, moist air over the lake. These unique conditions contribute to the development of persistent deep convection resulting in an average of 297 nocturnal thunderstorms per year, peaking in September.

Africa remains the continent with the most lightning hotspots, according to the study, home to six of the world's top ten sites for lightning activity. The majority of the hotspots were by Lake Victoria and other lakes along the East African Rift Valley, which have a similar geography to Lake Maracaibo.

The study also confirmed earlier findings that concentrated lightning activity tends to happen over land and reduced lightning activity over oceans and that continental lightning peaks generally in the afternoon.

"Our research using LIS observations in new ways is a prime example of how NASA partners with scientists all over the world to better understand and appreciate our home planet," said Blakeslee.

Developed at Marshall, LIS detects the distribution and variability of total lightning – cloud-to-cloud, intracloud, and cloud to ground – that occurs in the tropical regions of the globe. LIS uses a specialized, high-speed imaging system to look for changes in the optical output caused by lightning in the tops of clouds. By analyzing a narrow wavelength band around 777 nanometers -- which is in the near-infrared region of the spectrum – the sensors can spot brief lightning flashes even under bright daytime conditions that swamp out the small lightning signal.

The team at Marshall that created LIS in the mid-1990s built a spare -- and now that second unit is stepping up to contribute, as well. The sensor is scheduled to launch on a Space Exploration Technologies rocket to the International Space Station in August 2016.

Explanation from: https://www.nasa.gov/centers/marshall/news/news/releases/2016/earths-new-lightning-capital-revealed.html

Three Potentially Habitable Worlds Found Around Nearby Ultracool Dwarf Star - Currently the best place to search for life beyond the Solar System

This artist’s impression shows an imagined view from the surface one of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO’s La Silla Observatory. These worlds have sizes and temperatures similar to those of Venus and Earth and are the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star. In this view one of the inner planets is seen in transit across the disc of its tiny and dim parent star.

Astronomers using the TRAPPIST telescope at ESO’s La Silla Observatory have discovered three planets orbiting an ultracool dwarf star just 40 light-years from Earth. These worlds have sizes and temperatures similar to those of Venus and Earth and are the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star. The new results will be published in the journal Nature on 2 May 2016.

A team of astronomers led by Michaël Gillon, of the Institut d’Astrophysique et Géophysique at the University of Liège in Belgium, have used the Belgian TRAPPIST telescope to observe the star 2MASS J23062928-0502285, now also known as TRAPPIST-1. They found that this dim and cool star faded slightly at regular intervals, indicating that several objects were passing between the star and the Earth. Detailed analysis showed that three planets with similar sizes to the Earth were present.

TRAPPIST-1 is an ultracool dwarf star — it is much cooler and redder than the Sun and barely larger than Jupiter. Such stars are both very common in the Milky Way and very long-lived, but this is the first time that planets have been found around one of them. Despite being so close to the Earth, this star is too dim and too red to be seen with the naked eye or even visually with a large amateur telescope. It lies in the constellation of Aquarius (The Water Carrier).

Emmanuël Jehin, a co-author of the new study, is excited: “This really is a paradigm shift with regards to the planet population and the path towards finding life in the Universe. So far, the existence of such ‘red worlds’ orbiting ultra-cool dwarf stars was purely theoretical, but now we have not just one lonely planet around such a faint red star but a complete system of three planets!”

Michaël Gillon, lead author of the paper presenting the discovery, explains the significance of the new findings: "Why are we trying to detect Earth-like planets around the smallest and coolest stars in the solar neighbourhood? The reason is simple: systems around these tiny stars are the only places where we can detect life on an Earth-sized exoplanet with our current technology. So if we want to find life elsewhere in the Universe, this is where we should start to look."

Astronomers will search for signs of life by studying the effect that the atmosphere of a transiting planet has on the light reaching Earth. For Earth-sized planets orbiting most stars this tiny effect is swamped by the brilliance of the starlight. Only for the case of faint red ultra-cool dwarf stars — like TRAPPIST-1 — is this effect big enough to be detected.

Follow-up observations with larger telescopes, including the HAWK-I instrument on ESO’s 8-metre Very Large Telescope in Chile, have shown that the planets orbiting TRAPPIST-1 have sizes very similar to that of Earth. Two of the planets have orbital periods of about 1.5 days and 2.4 days respectively, and the third planet has a less well determined period in the range 4.5 to 73 days.

"With such short orbital periods, the planets are between 20 and 100 times closer to their star than the Earth to the Sun. The structure of this planetary system is much more similar in scale to the system of Jupiter’s moons than to that of the Solar System," explains Michaël Gillon.

Although they orbit very close to their host dwarf star, the inner two planets only receive four times and twice, respectively, the amount of radiation received by the Earth, because their star is much fainter than the Sun. That puts them closer to the star than the habitable zone for this system, although it is still possible that they possess habitable regions on their surfaces. The third, outer, planet’s orbit is not yet well known, but it probably receives less radiation than the Earth does, but maybe still enough to lie within the habitable zone.

"Thanks to several giant telescopes currently under construction, including ESO’s E-ELT and the NASA/ESA/CSA James Webb Space Telescope due to launch for 2018, we will soon be able to study the atmospheric composition of these planets and to explore them first for water, then for traces of biological activity. That's a giant step in the search for life in the Universe," concludes Julien de Wit, a co-author from the Massachusetts Institute of Technology (MIT) in the USA.

This work opens up a new direction for exoplanet hunting, as around 15% of the stars near to the Sun are ultra-cool dwarf stars, and it also serves to highlight that the search for exoplanets has now entered the realm of potentially habitable cousins of the Earth. The TRAPPIST survey is a prototype for a more ambitious project called SPECULOOS that will be installed at ESO’s Paranal Observatory.

Image Credit: ESO/M. Kornmesser
Explanation from: http://www.eso.org/public/news/eso1615/

The Pencil Nebula

The Pencil Nebula is pictured in this image from ESO’s La Silla Observatory in Chile. This peculiar cloud of glowing gas is part of a huge ring of wreckage left over after a supernova explosion that took place about 11 000 years ago. This detailed view was produced by the Wide Field Imager on the MPG/ESO 2.2-metre telescope.

Despite the tranquil and apparently unchanging beauty of a starry night, the Universe is far from being a quiet place. Stars are being born and dying in an endless cycle, and sometimes the death of a star can create a vista of unequalled beauty as material is blasted out into space to form strange structures in the sky.

This new image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile shows the Pencil Nebula against a rich starry background. This oddly shaped cloud, which is also known as NGC 2736, is a small part of a supernova remnant in the southern constellation of Vela (The Sails). These glowing filaments were created by the violent death of a star that took place about 11 000 years ago. The brightest part resembles a pencil; hence the name, but the whole structure looks rather more like a traditional witch’s broom.

The Vela supernova remnant is an expanding shell of gas that originated from the supernova explosion. Initially the shock wave was moving at millions of kilometres per hour, but as it expanded through space it ploughed through the gas between the stars, which has slowed it considerably and created strangely shaped folds of nebulosity. The Pencil Nebula is the brightest part of this huge shell.

This new image shows large, wispy filamentary structures, smaller bright knots of gas and patches of diffuse gas. The nebula's luminous appearance comes from dense gas regions that have been struck by the supernova shock wave. As the shock wave travels through space, it rams into the interstellar material. At first, the gas was heated to millions of degrees, but it then subsequently cooled down and is still giving off the faint glow that was captured in the new image.

By looking at the different colours of the nebula, astronomers have been able to map the temperature of the gas. Some regions are still so hot that the emission is dominated by ionised oxygen atoms, which glow blue in the picture. Other cooler regions are seen glowing red, due to emission from hydrogen.

The Pencil Nebula measures about 0.75 light-years across and is moving through the interstellar medium at about 650 000 kilometres per hour. Remarkably, even at its distance of approximately 800 light-years from Earth, this means that it will noticeably change its position relative to the background stars within a human lifetime. Even after 11 000 years the supernova explosion is still changing the face of the night sky.

Image Credit: ESO
Explanation from: http://www.eso.org/public/images/eso1236a/

Total Lunar Eclipse and Lightning Storm

Ibiza, Spain

September 2015

Image Credit & Copyright: Jose Antonio Hervás

Four-Panel Zoom into the Galactic Center

This four-panel graphic zooms into the Hubble Space Telescope view of the galactic core. The first panel shows a wide view of the Milky Way in visible light. The second panel, which zooms into the boxed area in the first panel, shows interstellar dust obscuring much of the view of the core. The third panel zooms in yet again, but the view shifts to infrared light that penetrates the dust and exposes the core. Finally, the fourth panel is a close-up of the galactic core as seen in infrared by the Hubble Space Telescope. The locator mark in the middle designates the galaxy's nucleus, which is home to a central, supermassive black hole.

Image Credit: NASA, ESA, and Z. Levay (STScI), A. Fujii, Digitized Sky Survey (DSS), STScI/AURA, Palomar/Caltech, UKSTU/AAO, NASA/JPL-Caltech/S. Stolovy (Spitzer Science Center/Caltech), the Hubble Heritage Team (STScI/AURA), T. Do and A. Ghez (UCLA), and V. Bajaj (STScI)
Explanation from: http://hubblesite.org/newscenter/archive/releases/2016/11/image/b/

The most powerful laser guide star system in the world sees first light at the Paranal Observatory

On 26 April 2016 ESO’s Paranal Observatory in Chile hosted an event to mark the first light for the four powerful lasers that form a crucial part of the adaptive optics systems on ESO’s Very Large Telescope. Attendees were treated to a spectacular display of cutting-edge laser technology against the majestic skies of Paranal. These are the most powerful laser guide stars ever used for astronomy and the event marks the first use of multiple laser guide stars at ESO.

ESO staff were present for the event, along with senior representatives of the companies that have manufactured the different components of the new system.

The Four Laser Guide Star Facility (4LGSF) shines four 22-watt laser beams into the sky to create artificial guide stars by making sodium atoms in the upper atmosphere glow so that they look just like real stars. The artificial stars allow the adaptive optics systems to compensate for the blurring caused by the Earth’s atmosphere and so that the telescope can create sharp images. Using more than one laser allows the turbulence in the atmosphere to be mapped in far greater detail to significantly improve the image quality over a larger field of view.

The Four Laser Guide Star Facility is an example of how ESO enables European industry to lead complex research and development projects. The fibre laser used by the 4LGSF is also one of the most successful transfers of ESO technology to industry.

TOPTICA, the German main contractor, was responsible for the laser system and provided the oscillator, the frequency doubler, and the system control software. Wilhelm Kaenders, president of TOPTICA, said: “TOPTICA has enjoyed the collaboration with ESO tremendously. It is not only the personal thrill of being engaged with astronomy, an old passion, again, and working with very clever ESO technologists; it is also the inspiration that we have received for our own commercial product development.”

MPBC of Canada provided the fibre laser pumps and Raman amplifiers, which are based on an ESO licensed patent. Jane Bachynski, President of MPB Communications Inc. said: “MPBC is proud to have worked with ESO in the development of Raman fibre amplifiers to much higher powers, allowing MPBC to bring this technology to the stars. This event marks the culmination of many years of hard work on behalf of all involved.”

TNO in the Netherlands manufactured the optical tube assemblies, which expand the laser beams and direct them into the sky. Paul de Krom, CEO of TNO, said: “TNO valued the cooperative working environment during the development of the optical tube assemblies and looks forward to the opportunity to work with ESO and the other partners in the 4LGSF project in the future.”

The 4LGSF is part of the Adaptive Optics Facility on Unit Telescope 4 of the VLT, designed specifically to provide the adaptive optics systems GALACSI/MUSE and GRAAL/HAWK-I with four sodium laser guide stars. With this new facility, Paranal Observatory continues to have the most advanced and the largest number of adaptive optics systems in operation today.

The 4LGSF lasers were developed by ESO with industry and have already been procured, among others, by the Keck Observatory (which contributed to the industrial laser development cost along with the European Commission) and the Subaru Telescope. In the future these industrial lasers will also feature on the telescopes at the Gemini Observatory and will be the preferred choice for several other observatories and extremely large telescope projects.

The new techniques developed for the Four Laser Guide Star Facility pave the way for the adaptive optics system of the European Extremely Large Telescope (E-ELT), the world’s biggest eye on the sky.

Image Credit: ESO/F. Kamphues
Explanation from: http://www.eso.org/public/news/eso1613/

Earth and the Moon seen by DSCOVR Observatory

A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the Moon as it moved in front of the sunlit side of Earth in July 2015. The series of test images shows the fully illuminated “dark side” of the Moon that is never visible from Earth.

The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA).

EPIC maintains a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere. Once EPIC begins regular observations next month, the camera will provide a series of Earth images allowing study of daily variations over the entire globe. About twice a year the camera will capture the Moon and Earth together as the orbit of DSCOVR crosses the orbital plane of the Moon.

These images were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the Moon moving over the Pacific Ocean near North America. The North Pole is in the upper left corner of the image, reflecting the orbital tilt of Earth from the vantage point of the spacecraft.

The far side of the Moon was not seen until 1959 when the Soviet Luna 3 spacecraft returned the first images. Since then, several NASA missions have imaged the lunar far side in great detail. The same side of the Moon always faces an earthbound observer because the Moon is tidally locked to Earth. That means its orbital period is the same as its rotation around its axis.

In May 2008 NASA’s Deep Impact spacecraft captured a similar view of Earth and the Moon from a distance of 31 million miles away. The series of images showed the Moon passing in front of our home planet when it was only partially illuminated by the sun.

EPIC’s “natural color” images of Earth are generated by combining three separate monochrome exposures taken by the camera in quick succession. EPIC takes a series of 10 images using different narrowband spectral filters -- from ultraviolet to near infrared -- to produce a variety of science products. The red, green and blue channel images are used in these color images.

Combining three images taken about 30 seconds apart as the Moon moves produces a slight but noticeable camera artifact on the right side of the Moon. Because the Moon has moved in relation to the Earth between the time the first (red) and last (green) exposures were made, a thin green offset appears on the right side of the Moon when the three exposures are combined. This natural lunar movement also produces a slight red and blue offset on the left side of the Moon in these unaltered images.

The lunar far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side. The largest far side features are Mare Moscoviense in the upper left and Tsiolkovskiy crater in the lower left. A thin sliver of shadowed area of Moon is visible on its right side.

“It is surprising how much brighter Earth is than the Moon," said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. "Our planet is a truly brilliant object in dark space compared to the lunar surface.”

Once EPIC begins regular observations next month, NASA will post daily color images of Earth to a dedicated public website. These images, showing different views of the planet as it rotates through the day, will be available 12 to 36 hours after they are acquired.

DSCOVR is a partnership between NASA and NOAA with the primary objective of maintaining the nation’s real-time solar wind monitoring capabilities, which are critical to the accuracy and lead time of space weather alerts and forecasts from NOAA.

Image Credit: NASA/NOAA
Explanation from: http://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth

Artist's Impression of the Protoplanetary Disk

This illustration shows a star surrounded by a protoplanetary disk. Material from the thick disk flows along the star's magnetic field lines and is deposited onto the star' surface. When material hits the star, it lights up brightly.

The star's irregular illumination allows astronomers to measure the gap between the disk and the star by using a technique called "photo-reverberation" or "light echoes." First, astronomers look at how much time it takes for light from the star to arrive at Earth. Then, they compare that with the time it takes for light from the star to bounce off the inner edge of the disk and then arrive at Earth. That time difference is used to measure distance, as the speed of light is constant.

Image Credit: NASA/JPL-Caltech
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA20645