false colour imaging

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The discovery of Uranus

On this day, March 13, 1781,German born British astronomer discovered the planet Uranus.  He also discovered two of Uranus’s moons, Titania and Oberon and two moons of Saturn.  He is credited with the discovery of Infrared radiation, and to honor that the image above of Uranus is a 1998 false-colour near-infrared image of the planet showing cloud bands, rings, and moons obtained by the Hubble Space Telescope’s NICMOS camera.

Herschel named his discovery George, oddly enough, to commemorate his new patron, King George III.  At the time he said this:  

In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third’.

Few astronomers outside of England liked the name, however, and astronomers began proposing alternatives almost immediately.  German astronomer Johann Elert Bode called it Uranus  (Ancient Greek: Οὐρανός) after the Ancient Greek god of the sky, the logic being that as Saturn was the father of Jupiter, the new planet should be the father of Saturn.  It wasn’t until the middle of the next century that atlases dropped Herschel’s name and adopted Uranus.

All images in the public domain courtesy NASA.

Thar Desert, India

The Copernicus Sentinel-2A satellite brings us over northwest India with this false-colour image captured on 4 March 2017.

The Indian city of Bikaner is visible in the lower part of the image, surrounded by a varied landscape of agricultural structures and sand dunes.

The city lies in the Thar Desert, an arid region covering about 320 000 sq km in India and Pakistan. Most of the desert is covered by large, shifting sand dunes, some which are visible in the upper part of the image. The high winds also carry dry soils to neighbouring fertile lands, degrading them.

Archaeological evidence suggested that the region was once lush countryside, but the over-exploitation of land and water resources by humans over thousands of years drastically changed the landscape into what we see today.

In recent times, India has turned its attention to restoring the ecology and curbing the desertification of the region. For example, the Indira Gandhi Canal bringing water to the area pictured was built to keep the desert from spreading to the fertile areas, and to reclaim the land with irrigated planting projects. In this false-colour image, vegetation appears red.

Every year, 17 June marks the World Day to Combat Desertification and Drought.

ESA helps the UN Convention to Combat Desertification by providing annual global datasets on land cover and land cover changes. ESA also supports the development of operational guidelines for countries to engage in the Convention’s Land Degradation Neutrality initiative.

This image is featured on the Earth from Space video programme.

Credits: contains modified Copernicus Sentinel data (2017), processed by ESA, CC BY-SA

Space Alphabet !

(The info is under the  pics, but you can ignore them for the sake of beauty, for a moment.) 

A - Utah’s Green River doubling back on itsels a feature known as Bowknot Bend, taken from the International Space Station

B - the Arkansas River and the Holla Bend Wildlife Refuge. In the winter, it is common for the refuge to host 100,000 ducks and geese at once

C - an artificial island at the southern end of Bahrain Island. The beach sand on tropical islands is mostly made up of calcium carbonate from the shells and skeletons of marine organisms

D - the Enhanced Thematic Mapper on Landsat 7 acquired this image of Akimiski Island in James Bay

E - a phytoplankton bloom off the coast of New Zealand, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite

F - the Operational Land Imager (OLI) on Landsat 8 acquired this false-colour image of valleys and snow-covered mountain ranges in southeastern Tibet. Firn is a granular type of snow often found on the surface of a glacier before it has been compressed into ice

G - Pinaki Island, a small atoll of the Tuamotu group in French Polynesia

H - rivers running through colourful ridges in southwestern Kyrgyzstan, taken by the Operational Land Imager on Landsat 8

I - the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image of the Andaman Islands, which form an archipelago in the Bay of Bengal between India, to the west. The thin, bright rings surrounding several of the islands are coral reefs that were lifted up by a massive earthquake near Sumatra in 2004

J - Trunk Reef near Townsville, Australia, taken by the Operational Land Imager

K - glaciers at the Sirmilik National Park Pond Inlet in Mittimatalik, Canada

L - the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, captured this image of snow across the northeastern United States

M - the Operational Land Imager (OLI) on Landsat 8 captured this image of glaciers in the Tian Shan mountains in northeastern Kyrgyzstan. The trail of brown sediment in the middle of the uppermost glacier is a medial moraine, a term glaciologists use to describe sediment that accumulates in the middle of merging glaciers

N - the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite, captured this image of ship tracks over the Pacific. Ship emissions contain small particles that cause the clouds to form

O - the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on the Terra satellite, captured this image of Tenoumer meteorite crater in Mauritania. The meteorite struck Earth between 10,000 and 30,000 years ago

P - the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor on the Terra satellite, captured this false-color image of the Mackenzie River Delta in Canada

Q - the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, acquired this image of Lonar Crater in India. Shocked quartz minerals with an unusual structure that can only form under intense pressure, offering a clue that the lake was formed by a large meteorite

R - the Operational Land Imager (OLI) on Landsat 8, captured this image of Lago Menendez in Argentina

S - the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite, acquired this image of clouds swirling over the Atlantic Ocean

T - the Operational Land Imager (OLI) on Landsat 8, captured this image of development along two roads in the United Arab Emirates

U - the Ikonos satellite captured this image of Gooseneck State Park in Utah

V - the Operational Land Imager (OLI) on Landsat 8, acquired this image of ash on the snow around Shiveluch- one of the largest and most active volcanoes on Russia’s Kamchatka Peninsula

W - the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, captured this image of dust blowing over the Red Sea

X - the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, captured this false-colour image of the northwest corner of Leidy Glacier in Greenland

Y - the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s. Terra satellite captured this false-colour image of the Ugab River in Namibia

Z - the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite, captured this image of wildfire smoke over Canada 

Earth Observatory has tracked down images resembling all 26 letters of the English alphabet using only NASA satellite imagery and astronaut photography. Science writer for the Nasa Earth Observatory, Adam Voiland, said: “A few years ago, while working on a story about wildfires, a V appeared to me in a satellite image of a smoke plume over Canada. That image made me wonder: could I track down all 26 letters of the English alphabet using only NASA satellite imagery and astronaut photography?” "With the help of readers and colleagues, I started to collect images of ephemeral features like clouds, phytoplankton blooms, and dust clouds that formed shapes reminiscent of letters. Some letters, like O and C, were easy to find. Others-A, B, and R-were maddeningly difficult. Note that the A above is cursive. And if you can find a better example of any letter (in NASA imagery), send us an email with the date, latitude, and longitude.“ 

Adam Voiland explains that when he finally tracked down all the letters and it was time write captions, he had just become a new dad & deep into a Dr. Seuss reading phase with my son. 

"The Seuss-inspired ABC gallery above is the result. To add some education to the fun.”

IMAGE: Cancer in colour || Bettina Weigelin and Peter Friedl, Radboud Univ. Nijmegen

This false-colour image shows yellow melanoma cells invading skin tissue, amid cyan nerve and fat cells, green muscle, and red blood vessels.

Researchers are increasingly turning to video in order to truly understand how cancer spreads.  You can see a ten second video clip in this Nature News Feature …

SOURCE: Images of the month: Nature News & Comment

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Today is the birthday of William Herschel (15 November 1738 – 25 August 1822) a German born British astronomer known today as the discoverer of the planet Uranus in March of 1781.  He also discovered two of Uranus’s moons, Titania and Oberon and two moons of Saturn.  He is also credited with the discovery of Infrared radiation, and to honor that the image above of Uranus is a 1998 false-colour near-infrared image of the planet showing cloud bands, rings, and moons obtained by the Hubble Space Telescope's NICMOS camera.

Herschel named his discovery George, oddly enough, to commemorate his new patron, King George III.  At the time he said this:  

In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third’.

Few astronomers outside of England liked the name, however, and astronomers began proposing alternatives almost immediately.  German astronomer Johann Elert Bode called it Uranus  (Ancient Greek: Οὐρανός) after the Ancient Greek god of the sky, the logic being that as Saturn was the father of Jupiter, the new planet should be the father of Saturn.  It wasn’t until the middle of the next century that atlases dropped Herschel’s name and adopted Uranus

All images in the public domain.

Magnetar discovered close to supernova remnant Kesteven 79

Massive stars end their life with a bang, exploding as supernovas and releasing massive amounts of energy and matter. What remains of the star is a small and extremely dense remnant: a neutron star or a black hole.

Neutron stars come in several flavours, depending on properties such as their ages, the strength of the magnetic field concealed beneath their surface, or the presence of other stars nearby. Some of the energetic processes taking place around neutron stars can be explored with X-ray telescopes, like ESA’s XMM-Newton.

This image depicts two very different neutron stars that were observed in the same patch of the sky with XMM-Newton. The green and pink bubble dominating the image is Kesteven 79, the remnant of a supernova explosion located about 23,000 light-years away from us.

From the properties of the hot gas in Kesteven 79 and from its size, astronomers estimate that it is between 5000 and 7000 years old. Taking account of the time needed for light to travel to Earth, this means that the supernova that created it must have exploded almost 30,000 years ago. The explosion left behind a a young neutron star with a weak magnetic field, which can be seen as the blue spot at the centre of Kesteven 79.

Beneath it, a blue splotch indicates an entirely different beast: a neutron star boasting an extremely strong magnetic field, known as a magnetar. Astronomers discovered this magnetar, named 3XMM J185246.6+003317, in 2013 by looking at images that had been taken in 2008 and 2009. After the discovery, they looked at previous images of the same patch of the sky, taken before 2008, but did not find any trace of the magnetar. This suggests that the detection corresponded to an outburst of X-rays released by the magnetar, likely caused by a dramatic change in the structure of its magnetic field.

While the neutron star in the supernova remnant is relatively young, the magnetar is likely a million years old; the age difference means that it is very unlikely that the magnetar arose from the explosion that created Kesteven 79, but must have formed much earlier. This false-colour image is a composite of 15 observations performed between 2004 and 2009 with the EPIC MOS camera on board XMM-Newton. The image combines data collected at energies from 0.3 to 1.2 keV (shown in red), 1.2 to 2 keV (shown in green) and 2 to 7 keV (shown in blue).

Image credit: ESA/MPS

A cosmic trick of the eye

Stars of different masses end their lives in different ways. While truly massive stars go out in a blaze of glory, intermediate-mass stars — those between roughly one and eight times the mass of the Sun — are somewhat quieter, forming cosmic objects known as planetary nebulas.

Named because of their vague resemblance to planets when seen through early, low-resolution telescopes, planetary nebulas are created when a dying star flings off its outer layers of gas into space. This cloud forms an expanding shell around the central star, while the star itself slowly cools to become a white dwarf. This is what has happened in this NASA/ESA Hubble Space Telescope image, taken in 2007, which shows a planetary nebula known as NGC 2371.

NGC 2371 resides 4300 light-years away from us, in the constellation of Gemini. It is one of the largest planetary nebulas known, measuring roughly three light-years across. Its progenitor star can be seen here as a pinprick of orange–-red light, surrounded by a green, blue and aqua-tinged puff of gas. This shell appears to have a regular, elliptical shape that is sliced in half by a dark lane running through the nebula, which also encompasses the central star.

This dark feature misled astronomers when NGC 2371 was initially catalogued because the two lobes visually resembled two objects, not one. As a result of this confusion, the nebula has two names in William Herschel’s New General Catalogue: NGC 2371 and 2372 (often combined as NGC 2371/2 or NGC 2371-2).

Two prominent pink patches are also visible on either side of the central star. These features are thought to be knots of gas, most likely jets, thrown off by the star at some point in the past. Their pink colour indicates that they are cooler and denser than their surroundings.

The nebula’s central star was once similar to the Sun, but is now only a shadow of its former self. It is slowly cooling after energetically shedding most of its gas, but has a long way to go yet. It currently boasts a scorching surface temperature of over 130 000ºC – some 25 times hotter than the surface of the Sun – and glows with the luminosity of at least 700 Suns.

The hot ultraviolet radiation streaming outwards into the nebula energises the gas it touches, causing NGC 2371 to glow in the beautiful aquamarine colours seen in this image.

This picture was taken in November 2007 by Hubble’s Wide Field Planetary Camera 2. It is a false-colour image created with a combination of filters to detect light coming from sulphur and nitrogen (shown in red), hydrogen (green) and oxygen (blue). The observations were gathered as part of the Hubble Heritage project.

Copyright NASA/ESA/Hubble Heritage Team (STScI/AURA)

The Himalayan Mountains - ESA

This Envisat image captures Asia’s diverse topography, altitude and climate with the snow-sprinkled Himalayan Mountains marking the barrier between the peaks of the Tibetan Plateau [top] in Central Asia and the plains of Nepal, Buthan and India in the Indian subcontinent. In this false-colour image, lush or green vegetation appears bright red.

Cold Gas in the Milky Way

SPIRE infrared image of a reservoir of cold gas in the constellation of the Southern Cross. The region is located about 60° from the Galactic Centre, thousands of light-years from Earth. The images cover an area of 2°x2° on the sky. The images taken on 3 September 2009 reveal structure in cold material in our Galaxy, as we have never seen it before. Even before a detailed analysis, scientists have gleaned information on the quantity of the material, its mass, temperature, composition and whether it is collapsing to form new stars.

That a dark, cool area such as this would be bustling with activity, was unexpected. But the images reveal a surprising amount of turmoil: the interstellar material is condensing into continuous and interconnected filaments glowing from the light emitted by new-born stars at various stages of development. Ours is a tireless Galaxy constantly forging new generations of stars. Stars form in cold, dense environments, and in these images it is easy to locate the star-forming filaments that would be very difficult to isolate in a single-wavelength image.

Traditionally, in a crowded region like this, situated in the plane of our Galaxy and containing many molecular clouds along the line of sight, astronomers have had a difficult time resolving details. But Herschel’s sophisticated infrared instruments made short work of the task, seeing through the dust that is opaque to visible light, and seeing the glow from the dust itself. These observations are not possible from ground. The result is a view of an incredible network of filamentary structures, and features indicating a chain of near-simultaneous star-formation events, glittering like strings of pearls deep in our Galaxy. The image was constructed by colour-coding the different observing wavelengths, and creating composite false-colour images. Cyan denotes 70 microns and red 160 microns emission.

Image Credit: ESA AND THE SPIRE CONSORTIUM

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William Herschel and a Planet named GEORGE

Today is the birthday of William Herschel (15 November 1738 – 25 August 1822) a German born British astronomer known today as the discoverer of the planet Uranus in March of 1781.  He also discovered two of Uranus’s moons, Titania and Oberon and two moons of Saturn.  He is also credited with the discovery of Infrared radiation, and to honor that the image above of Uranus is a 1998 false-colour near-infrared image of the planet showing cloud bands, rings, and moons obtained by the Hubble Space Telescope‘s NICMOS camera.

Herschel named his discovery George, oddly enough, to commemorate his new patron, King George III.  At the time he said this:  

In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third’.

Few astronomers outside of England liked the name, however, and astronomers began proposing alternatives almost immediately.  German astronomer Johann Elert Bode called it Uranus  (Ancient Greek: Οὐρανός) after the Ancient Greek god of the sky, the logic being that as Saturn was the father of Jupiter, the new planet should be the father of Saturn.  It wasn’t until the middle of the next century that atlases dropped Herschel’s name and adopted Uranus.

All images in the public domain.