‘Supermoon’ in North America tonight


This video is called SUPERMOON TONIGHT July 12, 2014 – The 2014 Supermoon Summer!

From eNature Blog in the USA:

Don’t Miss Tonight’s Supermoon!

Posted on Saturday, July 12, 2014 by eNature

The moon that rises tonight (Saturday) is what has come to be called a “supermoon” — only hours from being perfectly full and hours from one of the year’s closest approaches to Earth.

This combination makes the moon appear bigger and somewhat brighter than usual, even for a full moon. And because the moon always looks larger as it rises, moonrise Saturday night may show off a moon that appears about as big, bright and round as the moon can get.

As the moon rises in the southeast at Saturday evening (at 8:30 or so on the East Coast) it will move west across the dark heavens through the night and early morning before setting in the southwest on Sunday morning.

Astronomers caution that without special equipment it’s difficult for the average skywatcher to assess the moon’s brightness or size. But a supermoon last year was reported to be about 15 percent larger and 30 percent brighter than the year’s run-of-the-mill full moons, and many people may consider themselves capable of spotting a 30 percent boost in brightness.

Of course, the brightness of the moon, as seen from earth, will depend, in part, on the sky’s clarity and the amount of cloud cover. If clouds do intervene, the next supermoon is not far off. There will be one in August and another in September.

More on the supermoon at Earthsky.com.

Prehistoric meteor shower and evolution of life discovery


This video is called Late Ordovician Mass Extinction (Ordovician – Silurian).

From daily The Independent in Britain:

Scientists discover fragment of ‘missing link’ asteroid that led to explosion of life on Earth

James Vincent

Thursday 03 July 2014

Scientists in Sweden have discovered a never-before seen class of meteorite that could be the ‘missing link’ between a gigantic collision in the asteroid belt 470 million years ago and the subsequent explosion of diverse life forms here on Earth.

Although it’s usually thought that meteorite impacts are disastrous for species on Earth (the classic example is the colossal impact thought to have killed off the dinosaurs 66 million years ago) there’s plenty of evidence to suggest that these events can also be beneficial to the overall diversity on the planet.

It’s thought that just such an impact – or rather, a string of them – dramatically boosted biodiversity on the planet during the Ordovician Period some 470 million years ago. It’s believed that a collision of two asteroids (or possibly an asteroid and a comet) out in space caused a shower of meteors to rain down on Earth.

Over time fragments of this meteor shower have been found around the planet and dated to 470 million years ago – but until now scientists had not found any evidence of the ‘killer’ asteroid that started this chain of events.

During the Ordovician Period most life on Earth was found in the ocean, with jawless fish, molluscs and insect-like arthropods making up the bulk of the species roll-call. However, a study from 2008 showed that the planet went through a “major phase of biodiversification” at this time shortly after “the largest documented asteroid breakup event during the past few billion years”.

The evidence for this breakup comes from the abundance of L-chondrite meteorites – the second most common meteorite type – fragments of which first started appearing on Earth around 470 million years ago.

“Something we didn’t really know about before was flying around and crashed into the L-chondrites,” said Gary Huss, co-author of the study that analysed the sample (published in Earth and Planetary Science Letters). This newly-discovered fragment is thought to be that very object – the mysterious ‘bullet’.

The composition of the fragment differs from known meteorite samples and its exposure age – the length of time it sailed through space – places it at the ‘scene of the crime’ when meteors rained down on the planet during the Ordovician Period.

“It’s a very, very strange and unusual find,” Birger Schmitz, the lead author of the study, told Live Science. “I think [it] adds to the understanding that the meteorites that come down on Earth today may not be entirely representative of what is out there.”

It’s not clear exactly why the Ordovician meteor shower led to a greater variety of life on the plane although some more far-fetched theories suggest that life itself was ‘seeded’ by organisms hitching a ride on asteroids.

A more likely explanation is that the impact craters caused by the collisions provided perfect test-beds for developing life. When meteorites hit the surface of the planet they scooped out bubbling pools of minerals and nutrients that served – in Carl Zimmer’s words – as “natural beakers that synthesized new chemicals essential for life”. However, even this is still just a theory – and the impacts might have also fostered life by creating new habitats, like restructured shorelines.

If further geochemical tests on the newly discovered fragment confirm its suspected origins then scientists will have pinned down another piece of the solar system’s history – but figuring out what happened closer to home might be more difficult still.

Biggest rocky planet ever discovered


This video is called ‘Godzilla of Earths’ identified.

From daily The Guardian in Britain:

Monstrous rocky planet nicknamed ‘Godzilla of Earths’

The ‘mega-Earth’ Kepler-10c is the most massive rocky planet ever discovered and its surface may be cool enough for life

Ian Sample, science correspondent

Monday 2 June 2014 18.26 BST

A giant rocky planet roughly twice the size of Earth and with nearly 20 times as much mass has been spotted in orbit around a faraway star. The planet is the first to be classed as a “mega-Earth” – an alien world that dwarfs the other rocky planets known to exist outside the solar system.

Researchers cannot say whether the planet is hospitable to life, but if it has an atmosphere and clouds, the surface could be cool enough for life to survive.

In line with global rules for naming heavenly bodies, the planet goes by the official name of Kepler-10c. But Dimitar Sasselov, director of the Harvard Origins of Life Initiative, called it “the Godzilla of Earths”.

The discovery has surprised some astronomers because such large planets are thought to draw in hydrogen as they form and become gas giants, which is what happened for Neptune, Saturn and Jupiter.

“This is a planet that doesn’t fit the usual models of planetary formation,” said Xavier Dumusque at the Harvard Smithsonian Centre for Astrophysics.

Scientists reported their first glimpse of Kepler-10c in 2011 when Nasa’s Kepler space telescope watched the planet swing across the face of its parent star. But at that time, researchers knew only the size of the planet: around 30,000km wide.

Speaking at a meeting of the American Astronomical Society in Boston on Monday, Dumusque unveiled fresh measurements taken with instruments on the Italian National Galileo Telescope on La Palma in the Canary Islands. The readings showed that Kepler-10c has a mass a staggering 17 times greater than Earth.

The new measurements allowed Dumusque and others on the team to work out the average density of the new planet. The answer of 7 grams per centimetre cubed points to an alien world made of rock and water.

Kepler-10c circles a star much like our own sun about 560 light years from Earth in the northern constellation of Draco, the dragon. A year on the planet lasts 45 Earth days. The surface temperature is estimated to be a toasty 310C, but a cloudy sky could cool the planet considerably, Dumusuqe told the Guardian.

Another planet, Kepler-10b, orbits so fast and close to the same star that a new year unfolds every 20 hours.

Dumusque said that the next generation of space and ground-based telescopes will give astronomers the ability to analyse the atmospheres of planets outside the solar system. Those measurements could suggest which planets could be habitable and even inhabited.

The solar system containing Kepler-10c formed around 11bn years ago, or three billion years after the big bang that flung the universe into being.

“Finding Kepler-10c tells us that rocky planets could form much earlier than we thought. And if you can make rocks, you can make life,” said Sasselov.

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Oldest Dutch telescope, archaeological discovery


The anccient Delft telescope, photo by Marco Zwinkels

Translated from NOS TV in the Netherlands:

Oldest telescope found in Delft

Update: Wednesday, May 14, 2014, 13:05

In Delft, during excavations, recently the oldest telescope in the Netherlands was found. The technological marvel dates back to the early 17th century.

Archeologists found the device during the construction of a tunnel. After extensive research, scientists concluded that the telescope is older than a telescope by Christiaan Huygens in 1655. The viewer enlarged five times, enough to see mountains on the moon. The telescope is one of the highlights of the renovated museum the Prinsenhof, which re-opens this Friday.

The oldest telescope in the world dates back to 1609 and was by Galileo Galilei.

Unfortunately, in an interview archaeologist Steven Jongma said the telescope was probably not for astronomy, but for war; for spying on the enemy side.

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The sun’s sibling stars, astronomical lecture


New stars originating from cosmic 'clouds', 10 May 2014

On Saturday, 10 May, there was a lecture in the old astronomical observatory in Leiden, the Netherlands. Its subject was the “siblings” of the sun, the thousands of stars which formed about 4.6 billion years ago along with the sun. The photos in this blog post were made with a smartphone.

The lecturer was Professor Simon Portegies Zwart.

Baby picture of the sun's family, 10 May 2014

Stars were born and are born throughout the universe, he said. Sometimes, 100 together. Sometimes 100 million together. Usually, somewhere between 1000 and 10,000 together, as probably happened when the sun arose.

Stars, 10 May 2014

These many stars very probably have many planets; called ‘exoplanets‘, as they are outside our solar system. So far, about 1000 exoplanets are known, thanks to the Hubble telescope and other recent research. It is far easier to discover a new star than a new exoplanet; as a planet’s light, compared to a star, is like a firefly’s light near a lighthouse. At least some exoplanets have exomoons.

So, new dots in the sky get planet status. On the other hand, a solar planet recently lost planet status: Pluto. Most astronomers were in favour of changing Pluto from planet to dwarf planet. Many United States astronomers were against; probably, Professor Portegies Zwart said, because Pluto was the only planet discovered in the USA. The congress deciding on Pluto was in Prague, a relatively easy place to get the demotion of Pluto accepted.

Why did astronomers no longer want to accept Pluto as a planet? Mainly, the lecturer said, because of its eccentric and highly inclined orbit. While “real” planets go around the sun in similar orbits, close to a flat reference plane called the ecliptic, Pluto clearly differs.

Sibling star approaches sun, 10 May 2014

The eccentric orbit of Pluto may have been caused by a sibling star approaching the sun, creating chaos.

Circle of 1,6pc, 10 May 2014

This may have happened when ten stars were together within a circle of 1,6. parsec.

Andromeda galaxy, 10 May 2014

On a much bigger scale than planetary systems, there are galaxies. Like the Andromeda galaxy, with probably over a trillion stars; more than ‘our’ Milky Way, which together with Andromeda and about 50 smaller galaxies forms the Local Group. The Local Group, again, is part of the Virgin Supercluster; or Local Supercluster.

Earth's position in the universe

The lecturer showed an animation about how the sun and its sibling stars were close together shortly after their origin.

Sun in the Milky Way, 10 May 2014

Then, they started orbiting through the Milky Way. Differences in their speed, orbits, etc. made them drift further and further apart.

HD 28676, 10 May 2014

Which stars are siblings of the sun? That is not an easy question. Astronomers need complex calculations with complex computers for that. Star HD 28676 may be a good candidate. The solar sibling stars, according to recent research, are still fairly close together. “Close” in a cosmic sense, with, measured by planet Earth standards, still enormous distances between them.

Spiral, 10 May 2014

Milky Way’s Fattening Behind Revealed : DNews: here.

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New earth-like planet discovery


Kepler-186F and earth

Translated from NOS TV in the Netherlands:

Planet like Earth found

Thursday 17 April 2014, 16:00 (Update: 17-04-14, 16:19)

Astronomers have found a planet which looks like Earth. Kepler-186F is rocky, only 10 percent larger than Earth and is the right distance from its star. Scientists call it a major discovery in the search for extraterrestrial life.

The planet was found in March 2009 with the space telescope Kepler. From minor fluctuations in the light of a star, scientists infer that there is a planet circling beyond the star, they write in the scientific journal Science. In this galaxy four other planets were discovered earlier this way.

Thanks to Kepler in this way a total of almost 2000 exoplanets have been discovered. That also included earth-like planets, but none of them looks so much like our earth as Kepler-186F.

Goldilocks zone

The distance of the planet from the star is just right to make liquid water possible. The planet is on the edge of the so-called Goldilocks zone. Like in the fairy tale of the three bears, it is not so hot there that water evaporates and not so cold that it freezes.

Whether anything actually lives on the planet, astronomers cannot say. The star around which the planet orbits may be a spoilsport.

For Kepler-186F orbits around a different kind of star than our sun, being a red dwarf. Such a star is smaller than our sun, but also more active. This might expose the planet to too much radiation to make life possible.

More time

The chances of life are improved on the other hand by dwarf stars living longer than their larger counterparts. This would give more time to develop life. Also maybe on the planet there is an atmosphere filtering the radiation.

The planet is 500 light years away from our solar system in the constellation Cygnus. It turns around its star once every 130 days.

Most Earth-like planet yet discovered: here.

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Total lunar eclipse in North America


This video from the USA is called NASA – Skywatchers’ Delight – Multiple Lunar Eclipses expected in April 2014.

From eNature Blog in the USA:

Watch The Moon Disappear Before Your Eyes—Don’t Miss Tonight’s Total Lunar Eclipse!

Posted on Monday, April 14, 2014 by eNature

There’s a total lunar eclipse happening across all of North America LATE tonight and early tomorow morning (the 15th). A total lunar eclipse occurs when the full Moon passes through the dark inner core of the Earth’s shadow, which is called the umbra.

North America hasn’t experienced a total eclipse of the Moon since 2011. But that dearth ends in the early morning hours of April 15th (or late on April 14th for the West Coast), when the full Moon passes through the umbra and all but disappears. In fact, we’re due to see three more eclipses over the next two years, a bounty of lunar eclipses that won’t occur again until 2032.

While it may be happening a little late for folks on the East Coast, you’ll find that a total eclipse is worth staying up for.

The eclipse will start to be noticeable around 1:00 AM ET when the Moon’s leading edge enters Earth’s penumbra, the outer portion of its shadow.

Initially the affect is not especially noticeable — you won’t start to see a dusky fringe along the Moon’s leading edge (known to astronomers as its “celestial east”) until the the moon intrudes about halfway across the penumbra. As the Moon glides deeper into the penumbra and approaches the umbra, the shading effect of the Earth’s shadow on the appearance of the moon becomes much more obvious.

The total eclipse begins at 3:07 AM ET when the moon is completely within the Earth’s shadow. From the Moon’s perspective, the Sun remains completely hidden for 1 hour 18 minutes. From Earth’s perspective, the lunar disk isn’t completely blacked out but instead remains dimly lit by a deep orange or red glow— but it’s easy to think the moon’s completely missing if you don’t look closely.

You can do the math and see the timing is a little more friendly for folks on the west coast.

Regardless of how late the hour, you’ll not regret staying up to catch one of nature’s best shows!

Sky and Telescope magazine provided much of the info in this entry and has LOTS more great detail about the eclipse.

‘Blood Moon’ Eclipse: Best Pictures Of Amazing Sight Above America: here.

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Cosmos, science and media from Carl Sagan to today


This video is called Cosmos: A SpaceTime Odyssey (Part 1).

By Bryan Dyne in the USA:

Cosmos reboot falls short of the mark

14 April 2014

Cosmos: A Spacetime Odyssey (Cosmos) is a remake of the 1980 series Cosmos: A Personal Voyage, hosted by astronomer Carl Sagan. Hosted by Neil deGrasse Tyson, the new series comes after three and a half decades of scientific advances—sequencing of the human genome, discovery of the Higgs boson, quantification of conditions in the first moments of the Big Bang, and detailed spacecraft exploration of parts of the solar system. Yet, beyond some scientific generalities, little of this enormous progress would be apparent from watching the new series.

Alongside Tyson, the new series is being produced by Seth MacFarlane in collaboration with Ann Druyan (Sagan’s widow) and astronomer Steven Soter, both of whom worked on the original Cosmos series. It is being aired on ten 21st Century Fox networks and on the National Geographic Channel and being distributed across 170 countries and in 45 languages—one of the widest television distributions to date. So far, six out of 13 episodes have been aired, with an estimated 27 million viewers in the US.

In itself, the production of this new Cosmos is a welcome development. Almost without exception, US television is dominated by series promoting the police and military, the occult and mystical, and sometimes all of them at the same time. In contrast, Cosmos sets as its task the socially progressive work of portraying the world as it is objectively, examining natural laws before a mass audience, and placing human society within the context of the development of the universe.

This video is called Cosmos: A Personal Voyage – Episode 1 (Carl Sagan).

The original Cosmos derived much of its strength from its seriousness and the internal consistency and fidelity to the scientific method which the show promoted and defended. At times, the new series follows the original in that respect. The second episode features a wonderful sequence showing the development of the eye, as part of its discussion on natural selection. Using a split-screen technique, viewers see ocean life evolve over hundreds of millions of years on the left and a view of what those creatures actually saw on the right, starting with patches of light and dark and slowly getting clearer as each modification of the eye came along. Throughout the segment, Tyson explains that by tracing these developments through the fossil record, we can rule out claims of an “intelligent designer” for the eye. It evolved.

William Herschel

In another animated sequence, viewers are introduced to astronomer William Herschel (1738-1822), who observationally described binary stars in apparent orbit about one another, generalizing Newton’s theory of gravity from the movement of bodies within the Solar System to all celestial bodies. This was one of the critical demonstrations that established that natural laws discovered on Earth can be extrapolated to areas of the universe beyond direct human experience.

Another sequence worth noting revolved around the life of Giordano Bruno, who was burned at the stake by the Catholic Church. The Church has always asserted that this was for his heretical theology. Cosmos, on the other hand, explains that the true reason for Bruno’s execution was his ideas about scientific inquiry and how to understand the world. His methods led him to expand on Copernicus’ idea that the Earth revolved around the Sun, to say that the Sun and all the stars were the same, that the stars also had planets and that those planets could have life. To this day, Bruno’s writings are still on the Vatican’s list of forbidden texts.

But beyond a few such exceptions, the show is largely lacking in describing the development of science as a social process, or even in providing concrete examples of momentous discoveries and how they came about. A segment describing the development of Newton’s theory of gravity took as its focus petty personal frictions between Newton, Robert Hooke and Edmund Halley, rather than the vast upheavals of Enlightenment Europe, or the meticulous work of Tycho Brahe and Johannes Kepler in acquiring the observational data which could be unified by Newton into a single theoretical framework.

Albert Einstein is discussed equally ahistorically, but in the opposite way: rather than his inspiration coming from conflicts, he is presented as the isolated genius who arrives at his unifying idea by virtue of his alienation. In reality, Einstein’s work temporarily sealed a rupture in physics which had erupted in the 1860s and which attracted work from many of its best minds. Taking as his point of departure the surprising results of Michelson and Morley in 1887 that the speed of light appeared to be the same to both stationary and moving observers, Einstein worked out the implications of a fixed speed of light using mathematics developed by Riemann, Lorentz, Poincare, and Weyl. That his most productive years occurred in Europe between 1905 and 1917, spanning a World War and two Russian revolutions, should be worthy of notice, but the news Cosmos makes no reference to this background.

Christiaan Huygens by Bernard Vaillant, Museum Hofwijck, Voorburg

In contrast, the original series depicted Christiaan Huygens, one of the foremost astronomers of the 1600s, as a product of his time. While viewers were given a glimpse of his work, such as early (and quite accurate) initial estimates of the distances from Earth to nearby stars, the focus was on the time and place in which he lived. One got a flavor of Huygens’ contemporaries, the character of 17th century Holland, the proliferation of free thought, the science and technology being done, the architecture, i.e. the culture as a whole.

The production also includes segments which are factually incorrect, misleading or empty. Tyson describes the proteins that help DNA to operate as “creatures” rather than molecules, which is what they actually are. His “ship of the imagination” dodges rocks in the asteroid belt per the science-fiction norm. Rather than discussing what is known about how life developed, Tyson blithely states that the origins of life are unknown, as if the decades of research into this topic have produced nothing. And the momentous imagery produced by robotic probes throughout the solar system (Voyager, Cassini, Galileo, numerous Mars missions, etc.) is by and large dispensed with in favor of computer graphics manufactured to order.

Tyson’s career may play a role in these weaknesses. He is not a full-time scientific researcher and has published little, serving mainly as a media popularizer involved in publishing books, TV appearances, the Hayden Planetarium and sitting on science panels for the Bush and Obama administrations. He seems somewhat disconnected from the science he once practiced. However, it is not simply that Tyson the media figure is missing something essential compared to Sagan the working scientist. Rather, there has been a shift in intellectual life over the past 35 years, particularly among the liberal intelligentsia. No longer is Western society, and science along with it, flush with resources and expanding at a high rate. American capitalism is on the decline, and this is felt in the official treatment of science. The new Cosmos had a chance to challenge its audience, seeking to raise popular understanding of science. Instead, Tyson largely appeals to the lowest common denominator.

One of the many ways this has manifested is in the exposition of the scientific method. To the show’s credit, Cosmos explains the relationship between observations and theories that model those observations and make predictions. In the third episode, it shows how the observations of comets over centuries transformed them in common understanding from harbingers of doom to predictable celestial phenomena, based on the work of Halley, Hooke and Newton.

But rather than asserting the growing superiority of science over religion in explaining how the world works, the show muddles the two. There are constant concessions to religious language. The highly accurate predictions of the astronomers are referred to constantly in the program as “prophecies.” In the fourth episode, Tyson similarly refers to the fact that the speed of light is always constant as a “commandment” of the universe, rather than explaining the underlying physics.

Given the advances since 1980, it is long past time for the presentation of what has been learned and the process of how this has been learned to a mass audience. Sadly, the weaknesses of the new Cosmos in this respect overshadow its strengths.

The author also recommends:

Carl Sagan (1934-1996): An appreciation
[13 January 1997]

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Polar aurora lights on planet Saturn


This video says about itself:

Dance of Saturn’s Auroras

11 Feb 2014

Ultraviolet and infrared images from NASA’s Cassini spacecraft and Hubble Space Telescope show active and quiet auroras at Saturn‘s north and south poles.

Saturn’s auroras glow when energetic electrons dive into the planet’s atmosphere and collide with hydrogen molecules. Sometimes a blast of fast solar wind, composed of mostly electrons and protons, creates an active aurora at Saturn, as occurred on April 5 and May 20, 2013.

The first set of images, as seen in the ultraviolet part of the spectrum by Hubble, shows an active aurora dancing around Saturn’s north pole on April 5. The movie then shows a relatively quiet time between April 19 to 22 and between May 18 and 19. The aurora flares up again in Hubble images from May 20. This version, shown in false-color, has been processed to show the auroras more clearly.

A second set of ultraviolet images shows a closer view of an active north polar aurora in white. This set comes from Cassini ultraviolet imaging spectrograph observations on May 20 and 21.

The last set of images, in the infrared, shows a quiet southern aurora (in green) in observations from Cassini‘s visual and infrared mapping spectrometer on May 17. Saturn’s inner heat glows in red, with dark areas showing where high clouds block the heat.

Image credit: NASA/JPL-Caltech/University of Colorado/Central Arizona College and NASA/ESA/University of Leicester and NASA/JPL-Caltech/University of Arizona/Lancaster University.

From Sci-News.com:

Hubble, Cassini See Auroras on Saturn

Feb 15, 2014

Detailed images of auroras at Saturn’s north and south poles have been captured by astronomers using NASA’s Hubble Space Telescope and Cassini spacecraft.

Saturn’s auroras glow when energetic electrons dive into the planet’s atmosphere and collide with hydrogen molecules.

Sometimes a blast of fast solar wind, composed of mostly electrons and protons, creates an active aurora at the sixth planet from the Sun.

“The auroras at Saturn are some of the planet’s most glamorous features – and there was no escaping NASA’s paparazzi-like attention,” said Dr Marcia Burton from NASA’s Jet Propulsion Laboratory in Pasadena, California.

“Saturn’s auroras can be fickle – you may see fireworks, you may see nothing,” said team leader Dr Jonathan Nichols from the University of Leicester, UK.

Dr Nichols and his colleagues used Hubble telescope to observe the northern auroras in ultraviolet wavelengths and NASA’s Cassini spacecraft to capture images of the north and south in infrared, visible-light and ultraviolet wavelengths.

While the curtain-like auroras we see at Earth are green at the bottom and red at the top, NASA's Cassini spacecraft has shown astronomers similar auroras at Saturn that are red at the bottom and purple at the top. Image credit: NASA / JPL-Caltech / SSI

The Hubble and Cassini images help shed light on an unsolved mystery about the atmospheres of giant outer planets.

“Scientists have wondered why the high atmospheres of Saturn and other gas giants are heated far beyond what might normally be expected given their distance from the Sun,” said Dr Sarah Badman from Lancaster University.

“We know there must be other energy interactions going on to cause this heating, but we can’t yet say for sure what they are.”

“From the Earth, we can only see part of the picture, but by looking at these amazing new movies from the vantage points of both Cassini and the Hubble Space Telescope, we can see exactly where the aurora is heating Saturn’s atmosphere and for how long.”

“Being able to track the aurora all around Saturn’s poles is vital if we are to discover how its atmosphere is heated.”

The new images also help astronomers figure out the colors of Saturn’s auroras.

While the curtain-like auroras we see at Earth are green at the bottom and red at the top, Cassini’s imaging cameras have shown us similar curtain-like auroras at Saturn that are red at the bottom and purple at the top

The color difference occurs because auroras on our planet are dominated by excited nitrogen and oxygen molecules, and Saturn’s auroras are dominated by excited hydrogen molecules.

“While we expected to see some red in Saturn’s aurora because hydrogen emits some red light when it gets excited, we also knew there could be color variations depending on the energies of the charged particles bombarding the atmosphere and the density of the atmosphere. We were thrilled to learn about this colorful display that no one had seen before,” explained team member Dr Ulyana Dyudina from the California Institute of Technology in Pasadena, California.

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Whales counted from space


This video is called Breeding Southern Right Whales – Attenborough – Life of Mammals – BBC.

From the BBC:

12 February 2014 Last updated at 23:04 GMT

Scientists count whales from space

By Jonathan Amos, Science correspondent, BBC News

Scientists have demonstrated a new method for counting whales from space.

It uses very high-resolution satellite pictures and image-processing software to automatically detect the great mammals at or near the ocean surface.

A test count, reported in the journal Plos One, was conducted on southern right whales in the Golfo Nuevo on the coast of Argentina.

The automated system found about 90% of creatures pinpointed in a manual search of the imagery.

This is a huge improvement on previous attempts at space-borne assessment, and could now revolutionise the way whale populations are estimated.

Currently, such work is done through counts conducted from a shore position, from the deck of a ship or from a plane. But these are necessarily narrow in scope.

An automated satellite search could cover a much larger area of ocean and at a fraction of the cost.

“Our study is a proof of principle,” said Peter Fretwell from the British Antarctic Survey.

“But as the resolution of the satellites increases and our image analysis improves, we should be able to monitor many more species and in other types of location.

“It should be possible to do total population counts and in the future track the trajectory of those populations,” he told the Inside Science programme on BBC Radio 4.

The breakthrough is in part down to the capability of the latest hi-res satellites.

In this study, Mr Fretwell and colleagues used DigitalGlobe’s WorldView-2 platform.

This is among the most powerful commercial Earth observation platforms in operation today, and can see surface features down to 50cm in size in its panchromatic mode (black and white).

The team selected as their test area a 113-sq-km segment of the Golfo Nuevo on the Peninsula Valdes, a location famed for its gatherings of calving southern right whales.

Even though these are large animals, they still only take up a few pixels in the satellite picture.

Nonetheless, a manual search of the scene found 55 probable whales, 23 possible whales and 13 sub-surface features.

Several automated methods where then trialled, with the best results coming from a combination of the very hi-res panchromatic view and a narrow band of wavelengths in the violet part (400-450 nanometres) of the light spectrum.

This coastal band, as it is known, penetrates 15m or so into the water column in good conditions.

The automated approach found 89% of probable whales identified in the manual count.

Different bands

WorldView-2 has spectral bands that allow scientists to pull out specific information in the imagery

Mr Fretwell cautions that there are limitations to the technique. For example, rough seas or murky waters will confound a search. But he believes, on the basis of the trial study, that satellite counting can become a very useful conservation tool.

“In this type of automated analysis you have to balance two types of errors – errors where you miss whales, and errors where you misidentify whales. If you push too hard one way, like trying to catch all the whales, you’ll increase the number of false positives. With our 90%, we had almost no misidentifications,” the researcher explained.

Southern right whales were a very appropriate target for the study.

These animals were driven to near-extinction in the early 20th Century. Recognised as slow, shallow swimmers, they were the “right” whales to hunt.

Their numbers have seen something of a recovery, but without the means to carry out an accurate census, it is hard to know their precise status.

Concern has also been raised of late because of the sightings of many dead calves in the nursery grounds around the Peninsula Valdes.

Prof Vicky Rowntree from the University of Utah is the director of the Ocean Alliance’s Southern Right Whale Program, and has spent many years studying the Valdes whales.

She said the new method would be a huge boon to her field of research.

“It’s going to be absolutely amazing. The other dimension of it is that many marine mammal researchers have been killed flying in small planes while surveying whales. So my great desire is to get us out of small planes circling over whales and to be able to do it remotely. Satellite data is wonderful.”

To hear more about southern right whales and satellite counting, listen to Inside Science with Lucie Green on BBC Radio 4 on Thursday at 1630 GMT.

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