Hidden Unseen

Catatumbo Lightning

You must have heard that lightening doesn’t strike the same place twice. Say that to the natives of Venezuela and they will ride you down to the mouth of river Catatumbo and let you watch the spectacular lightening show of your life. The Catatumbo Lightning is one of the coolest natural phenomenon on earth. It occurs strictly in an area located over the mouth of the Catatumbo River where it empties into Lake Maracaibo. Over this relatively small area powerful flashes of lightening more than 5 km in height strike at surprising frequency - during 140 to 160 nights a year, 10 hours per day and up to 280 times per hour.

The Catatumbo Lightning is likely to be caused by ionised gases - specifically the methane created by the decomposition of organic matter in the marshes - rising from a swamp to meet cooler air descending from the Andes Mountains. The meeting of the two currents creates an electrical charge that is discharged as lightening. The lightning is seen most often in the afternoons, when evaporation is greatest.

This phenomenon, also known with the popular name of the Lighthouse of Maracaibo, is easy to be seen from hundreds of miles away. These thunderstorms have a beneficial effect on the earth’s ecosystem too because they produce a high percentage of all the ozone production worldwide. The Catatumbo lightning can be considered a major regenerator of the planet's ozone layer, as it produces approximately 1,176,000 kW of atmospheric electricity.

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Stunning New Images Of The Eagle Nebula - As Never Seen Before

Space-based observatories such as ESA's Herschel and XMM-Newton help to peel back that veil and see the full beauty of the Universe across the electromagnetic spectrum.

With regions like the Eagle Nebula, combining all of these observations helps astronomers to understand the complex yet amazing lifecycle of stars. Don't miss these stunning new images of the beautiful Eagle nebula!

In 1995, the Hubble Space Telescope's 'Pillars of Creation' image of the Eagle Nebula became one of the most iconic images of the 20th century. Now, two of ESA's orbiting observatories have shed new light on this enigmatic star-forming region.

The Eagle Nebula is 6500 light-years away in the constellation of Serpens. It contains a young hot star cluster, NGC6611, visible with modest back-garden telescopes, that is sculpting and illuminating the surrounding gas and dust, resulting in a huge hollowed-out cavity and pillars, each several light-years long.

The Hubble image hinted at new stars being born within the pillars, deeply inside small clumps known as 'evaporating gaseous globules' or EGGs. Owing to obscuring dust, Hubble's visible light picture was unable to see inside and prove that young stars were indeed forming.

Combining almost opposite ends of the electromagnetic spectrum, this composite of the Herschel in far-infrared and XMM-Newton’s X-ray images shows how the hot young stars detected by the X-ray observations are sculpting and interacting with the surrounding ultra-cool gas and dust, which, at only a few degrees above absolute zero, is the critical material for star formation itself. Both wavelengths would be blocked by Earth’s atmosphere, so are critical to our understanding of the lifecycle of stars

The ESA Herschel Space Observatory's new image shows the pillars and the wide field of gas and dust around them. Captured in far-infrared wavelengths, the image allows astronomers to see inside the pillars and structures in the region. In parallel, a new multi-energy X-ray image from ESA's XMM-Newton telescope shows those hot young stars responsible for carving the pillars.

Combining the new space data with near-infrared images from the European Southern Observatory's (ESO's) Very Large Telescope at Paranal, Chile, and visible-light data from its Max Planck Gesellschaft 2.2m diameter telescope at La Silla, Chile, we see this iconic region of the sky in a uniquely beautiful and revealing way.

This 1995 Hubble Space Telescope image of the ‘Pillars of Creation’ is probably the most famous astronomical image of the 20th Century. Taken in visible light using a combination of SII/H-alpha and OIII filters, it shows a part of the Eagle Nebula where new stars are forming. The tallest pillar is around 4 light-years high

In visible wavelengths, the nebula shines mainly due to reflected starlight and hot gas filling the giant cavity, covering the surfaces of the pillars and other dusty structures.

At near-infrared wavelengths, the dust becomes almost transparent and the pillars practically vanish.

In far-infrared, Herschel detects this cold dust and the pillars reappear, this time glowing in their own light.

Intricate tendrils of dust and gas are seen to shine, giving astronomers clues about how it interacts with strong ultraviolet light from the hot stars seen by XMM-Newton.

XMM-Newton’s images of the Eagle Nebula region in X-rays, which here is colour-coded to show different energy levels (red: 0.3–1 keV, green: 1–2 keV and blue: 2–8 keV) is helping astronomers to investigate a theory that the Eagle Nebula is being powered by a hidden supernova remnant. The researchers are looking for signs of very diffuse emission and how far this extends around the region. They believe that an absence of this X-ray emission beyond that found by previous orbiting space telescopes (Chandra and Spitzer) would support the supernova remnant theory. The work on this is continuing

In 2001, Very Large Telescope near-infrared images had shown only a small minority of the EGGs were likely to contain stars being born.

However, Herschel's image makes it possible to search for young stars over a much wider region and thus come to a much fuller understanding of the creative and destructive forces inside the Eagle Nebula.

Messier 16 is a diffuse emission nebula that contains the young open cluster NGC6611. The iconic ‘Pillars of Creation’ image taken with the Hubble Space Telescope in 1995 is captured in near-infrared by the VLT, which penetrates straight through the obscuring gas and dust, rendering them almost invisible. The pillars are only a small portion of the extensive nebulous region imaged in far-infrared by ESA’s Herschel Space Observatory, which shows cool dust and gas tendrils being carved away by the hot stars seen in the X-ray image from XMM-Newton. The wide-field optical image from the ESO MPG telescope puts the pillars into context against the full scale of the nebula, which is over 75 light-years across

The 8.2m-diameter VLT’s ANTU telescope imaged the famous Pillars of Creation region and its surroundings in near-infrared using the ISAAC instrument. This enabled astronomers to penetrate the obscuring dust in their search to detect newly formed stars. The research into the ‘evaporating gaseous globules’ (EGGs), which were first detected in the Hubble images, needed the near-infrared capabilities and resolution of the VLT to peel back the layers of dust and detect the low-mass young stars cocooned within the EGG shells. The near-infrared results showed that 11 of the 73 EGGs detected possibly contained stars, and that the tips of the pillars contain stars and nebulosity not seen in the Hubble image

This Herschel image of the Eagle Nebula, colour coded to 70 microns for blue and 160 microns for green using the PACS (Photodetector Array Camera) and 250 microns for red using the SPIRE (Spectral and Photometric Imaging Receiver) shows the self-emission of the intensely cold nebula’s gas and dust as never seen before. Each colour shows a different temperature of dust, from around 10 degrees above absolute zero (10K) for the red, up to around 40K for the blue. In the far–infrared, the nebula shows its intricate tendril nature, with vast cavities forming an almost cave-like surrounding to the famous pillars, which take on an ethereal ghostly appearance. The gas and dust provide the material for the star formation that is still under way inside this enigmatic nebula

Up to 1998 the ESA ISO (Infrared Space Observatory) was the most sensitive mid infrared telescope ever built. ISO observations were performed at 7 microns (and 15 microns, not shown) aiming to detect embedded sources in the pillars

Earlier mid-infrared images from ESA's Infrared Space Observatory and NASA's Spitzer, and the new XMM-Newton data, have led astronomers to suspect that one of the massive, hot stars in NGC6611 may have exploded in a supernova 6000 years ago, emitting a shockwave that destroyed the pillars. However, because of the distance of the Eagle Nebula, we won't see this happen for several hundred years yet.

Powerful ground-based telescopes continue to provide astonishing views of our Universe, but images in far-infrared, mid-infrared and X-ray wavelengths are impossible to obtain owing to the absorbing effects of Earth's atmosphere.

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Amazing Murmurations of Starlings

Every year during autumn, thousands of starlings put on a spectacular dance show just before dusk over the sky in Scotland (and other countries in the temperate regions), in a breathtaking phenomenon called murmurations. This is when a huge flock of migratory birds form a magical shape-shifting flight pattern in the sky. Murmaration is common among starlings, a small to medium-sized passerine birds in the family Sturnidae, commonly called mynas in Asia. Flocking starlings are one of nature’s most extraordinary sights.

Scientists aren’t sure how they do it. Even complex algorithmic models haven’t yet explained the starlings’ acrobatics, which rely on the tiny bird’s quicksilver reaction time of under 100 milliseconds to avoid aerial collisions—and predators—in the giant flock. The birds tend to flock together for protection and can reach speeds of up to 20 mph.

Vimeo user Sophie Windsor Clive was recently canoeing on the River Shannon in Ireland when she witnessed the beautiful phenomenon.

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Salar de Uyuni: World’s Largest Salt Flat

Salar de Uyuni (or Salar de Tunupa), located in southwest Bolivia, near the crest of the Andes, is one of the most visually captivating place in South America. Photographers flock here everyday to capture the stunning landscape created by amazing geological formations, geothermal springs and brine lakes. Covering an area of 10,582 square kilometers, it is the world's largest salt flat. Salar de Uyuni is estimated to have a reserve of 10 billion tons of salt.

Some 30 to 40 thousand years ago, this area was part of a giant prehistoric lake called Lake Minchin. The lake underwent a series of transformation between several vast lakes, and when it dried, it left behind two modern lakes, Poopó Lake and Uru Uru Lake, and two major salt deserts, Salar de Coipasa and the larger Salar de Uyuni.

In the dry season, the salt planes are completely flat expanses of dry salt, but during the wet season, the neighboring Lake Poopó overflows and floods Salar De Coipasa and Salar de Uyuni covering both deserts with a thin sheet of water that looks magnificent under the vast open sky.

Underneath the surface of the Salar is a lake of brine 2 to 20 meters deep. The lake is covered with a solid salt crust with a thickness varying between tens of centimeters to a few meters. The center of the Salar contains a few "islands", which are the remains of the tops of ancient volcanoes which were submerged during the era of lake Minchin. They include unusual and fragile coral-like structures and deposits that often consist of fossils and algae.

The Land Rover G4 Challenge of 2006 staged in Salar de Uyuni

In the wet season, the Poopó Lake overflows into Salar de Uyuni turning it into the worlds largest mirror.

The Salar contains large amounts of sodium, potassium, lithium and magnesium as well as borax. With estimated 5,400,000 tonnes, Bolivia holds about half of the world's lithium reserves, most of those are located in the Salar de Uyuni. Despite the large reserve, there is currently no mining plant at the site, as the Bolivian government doesn't want to allow exploitation by foreign corporations. Instead, it intends to build its own pilot plant with a modest annual production by 2012.

Salar de Uyuni is estimated to contain 10 billion tonnes of salt, of which less than 25,000 tonnes is extracted annually.

Salt Hotels
Salar de Uyuni attracts tourists from around the world. As it is located far from the cities, a number of hotels have been built for accommodation. Due to lack of conventional construction materials, many of them are almost entirely built with salt blocks cut from the Salar - including walls, roof and furniture. The first such hotel, Hotel de Sal Playa, was erected in 1993-1995 in the middle of the salt flat, and soon became a popular tourist destination. Many more hotels and hostels made out of salt were constructed later.

The Salar is virtually devoid of any wild life and vegetation, except by giant cacti that grow at a rate of about 1 centimeter per year to a length of about 12 meters. A few shrubs and bushes are scattered along the plains.

Salar de Uyuni is also the breeding grounds for pink South American flamingos, their color presumably originating from feeding on pink algae. There are about 80 of other bird species present, including the horned coot, the Andean goose and the Andean Hillstar.

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