NASA’s Cassini catches sunlight glinting off the oceans of Saturn’s moon!

NASA’s Cassini catches sunlight glinting off the oceans of Saturn’s moon ~  October 30, 2014.

Man, Cassini really is the best. The spacecraft, which orbits Saturn and is basically NASA’s pride and joy, keeps delivering both invaluable data and breathtaking photos. Including that one where Saturn looked like it had a creepy eye.

While it’s obviously a mosaic of several individual shots, the image above is certainly impressive. It’s the first time that one image shows both the polar seas of Titan (one of Saturn’s moons) and the aura of light caused by the sun hitting them. From NASA:

The sunglint, also called a specular reflection, is the bright area near the 11 o’clock position at upper left. This mirror-like reflection, known as the specular point, is in the south of Titan’s largest sea, Kraken Mare, just north of an island archipelago separating two separate parts of the sea.

These seas, which are made up of mostly methane and ethane, are on the planet’s poles — particularly in the north. The rest of the planet is mostly covered in sand dunes.

To the right of the yellow sunglint, the image also captures some bright methane clouds. It could be that these are producing liquid methane rain, keeping the polar seas full. And the bright outline that surrounds the sea (a “bathtub ring”) could represent the sea’s original outline, showing that it’s shrunk in size over time.

Rachel Feltman runs The Post’s Speaking of Science blog.

This near-infrared, color view from Cassini shows the sun glinting off of Titan’s north polar seas. (NASA/JPL-Caltech/University of Arizona/University of Idaho)


Two Alien Water-World Planets –“Unlike Anything in Our Solar System” ~ The Daily Galaxy.




“These planets are unlike anything in our solar system. They have endless oceans,” said lead author Lisa Kaltenegger of the Max Planck Institute for Astronomy and the CfA. “There may be life there, but could it be technology-based like ours? Life on these worlds would be under water with no easy access to metals, to electricity, or fire for metallurgy. Nonetheless, these worlds will still be beautiful, blue planets circling an orange star — and maybe life’s inventiveness to get to a technology stage will surprise us.”

These two “Water World” planets orbit the star Kepler-62. This five-planet system has two worlds in the habitable zone — the distance from their star at which they receive enough light and warmth that liquid water could theoretically exist on their surfaces. Modeling by researchers at theHarvard-Smithsonian Center for Astrophysics (CfA) suggested this past July  that both planets are water worlds, their surfaces completely covered by a global ocean with no land in sight.

Kepler-62 is a type K star slightly smaller and cooler than our sun. The two water worlds, designated Kepler-62e and -62f, orbit the star every 122 and 267 days, respectively.

They were found by NASA’s Kepler spacecraft, which detects planets that transit, or cross the face of, their host star. Measuring a transit tells astronomers the size of the planet relative to its star.

Kepler-62e is 60 percent larger than Earth, while Kepler-62f is about 40 percent larger, making both of them “super-Earths.” They are too small for their masses to be measured, but astronomers expect them to be composed of rock and water, without a significant gaseous envelope.

As the warmer of the two worlds, Kepler-62e would have a bit more clouds than Earth, according to computer models. More distant Kepler-62f would need the greenhouse effect from plenty of carbon dioxide to warm it enough to host an ocean. Otherwise, it might become an ice-covered snowball.

“Kepler-62e probably has a very cloudy sky and is warm and humid all the way to the polar regions. Kepler-62f would be cooler, but still potentially life-friendly,” said Harvard astronomer and co-author Dimitar Sasselov.

“The good news is — the two would exhibit distinctly different colors and make our search for signatures of life easier on such planets in the near future,” he added.

The discovery raises the intriguing possibility that some star in our galaxy might be circled by two Earth-like worlds — planets with oceans and continents, where technologically advanced life could develop.

“Imagine looking through a telescope to see another world with life just a few million miles from your own. Or, having the capability to travel between them on a regular basis. I can’t think of a more powerful motivation to become a space-faring society,” said Sasselov.

Kaltenegger and Sasselov’s research has been accepted for publication in The Astrophysical Journal.

The Daily Galaxy via CfA

Image Credit:



| Autumn Equinox: 5 Odd Facts About Fall!

Autumn Equinox: 5 Odd Facts About Fall ~ Jeanna Bryner, Managing Editor, Live Science.

The pools have closed and crisp temperatures and crunchy leaves are on their way. Today (Sept. 22) marks the end of summer and the beginning of fall, also called the autumn equinox, in the Northern Hemisphere.

The autumn equinox occurs today at 4:44 p.m. EDT (20:44 UTC) when the sun is directly in line with Earth’s celestial equator, or the equator projected onto the sky. Day and night last about equally long on Sunday, with about 12 hours of light and 12 hours of dark. This same phenomenon occurs on the spring equinox, which will next occur on March 20.

The date of the fall equinox (and its spring counterpart) varies slightly each year, sometimes falling on the 23rd or 24th depending on the quirks of the calendar, along with Earth’s slightly irregular orbit. Here are five surprising facts about fall and the autumn equinox.

The colorful foliage of autumn

A carpet of fallen leave beneath nearly bare trees, with green grass in the background serving as a memory of summer gone by.
Credit: goran cakmazovic

The pools have closed and crisp temperatures and crunchy leaves are on their way. Today (Sept. 22) marks the end of summer and the beginning of fall, also called the autumn equinox, in the Northern Hemisphere.

The autumn equinox occurs today at 4:44 p.m. EDT (20:44 UTC) when the sun is directly in line with Earth’s celestial equator, or the equator projected onto the sky. Day and night last about equally long on Sunday, with about 12 hours of light and 12 hours of dark. This same phenomenon occurs on the spring equinox, which will next occur on March 20.

The date of the fall equinox (and its spring counterpart) varies slightly each year, sometimes falling on the 23rd or 24th depending on the quirks of the calendar, along with Earth’s slightly irregular orbit. Here are five surprising facts about fall and the autumn equinox.

1. Amazing light shows

In addition to the brilliant colors of fall leaves, the autumn equinox signals another colorful spectacle — the aurora borealis, also called theNorthern Lights. Besides the lengthening of nights and cool evening weather, which are great for stargazers, autumn truly is “aurora season,” according to NASA. That’s because geomagnetic storms are about twice as frequent as the annual average during the fall. [Aurora Photos: Northern Lights Dazzle in Night-Sky Images]

Particles that get discharged from the sun during such geomagnetic storms zip toward Earth at breakneck speed. As the particles slam into Earth’s magnetic field, they bump into atoms and molecules of oxygen, nitrogen and other elements. The result? Dazzling light shows, with hues most commonly of pink, green, yellow, blue, violet and occasionally orange and white — depending on what elements the particles collide with.

2. Animals respond, testes swell

Living things respond to the light changes that come with fall, with trees shedding their leaves and animals preparing for hibernation. Fall can bring an especially noticeable change to the high-attitude-livingmale Siberian hamster. That’s because the rodent’s testes swell up 17 times their size from short days to long; the swelling allows, in part, the animals to time reproduction properly.

Hamsters aren’t the only creatures to herald in fall in strange ways. When autumn hits, the black-capped chickadee goes gangbusters collecting seeds and hiding them in hundreds of different spots in trees and on the ground. At the same time, the tiny bird’s hippocampus balloons by 30 percent as new nerve cells pop up in this part of the brain, which is responsible for spatial organization and memory.

3. Full moon named for autumn

Autumn gets its own full moon, the Harvest Moon. From Wolf and Sturgeon to Hunter and Harvest, full moons are named for the month or season in which they rise. The Harvest Moon is the full moon closest to the autumn equinox, which occurred on the night of Sept. 18-19 this year.

Before artificial lighting, farmers took advantage of the full moon’s light to harvest their crops. In late summer and early autumn, many crops ripen all at once, making lots of work for farmers who had to stay in the fields after sundown to harvest all the goods. Such moonlight became essential to their harvest, and the Harvest Moon emerged, according to NASA.

4. Why fall leaves may fade

Climate change may dull the picture most synonymous with autumn — fall leaves. Leaves change their wardrobes in response to chilly temperatures and less light (as days begin to shorten); they stop producing chlorophyll, the green pigment that helps leaves capture sunlight to power photosynthesis. As green fades, the leave’s other pigments, such as the orange and yellow of carotenoids shine through. Vibrant red hues are the result of anthocyanins, pigments that are produced in the fall. [Photos of Turning Leaves: The Rich Colors of Fall Foliage]

These autumn colors could be some of the casualties of global warming, say scientists. Research has shown as the world warms, fall-colored leaves are delayed since their cues to change color come partly from cooling temperatures.

Fall’s cool nights and sunny days also help to trigger trees like the sugar maple to store their anthocyanins temporarily in their leaves, giving leaf peepers a show of red. But if global warming leads to warmer nights, paired with autumn’s shortening days, trees may not use their sugars to make red pigments, instead sending that fuel to twigs or burning it off, according to Howie Neufeld, a plant physiologist at Appalachian State University in North Carolina.

Climate change may also alter suitable habitats for trees like the sugar maple known to be big players in fall’s vibrant colors.

5. When is the equinox?

The autumnal equinox falls on different dates each year, usually Sept. 22, like this year, or Sept. 23; but in 1931, the equinox happened on Sept. 24. The reason: The Gregorian calendar doesn’t match up perfectly with the position of Earth in its orbit around the sun.

As Earth orbits the sun, it revolves around its axis at a 23.5-degree angle so that it is pointed directly toward the sun at the summer solstice, directly away from the sun during the winter solstice, and at a right angle with the sun on the equinoxes; that right angle means the sun shines about equal amounts of light across the Northern Hemisphere on the equinoxes. If this trek around the sun took exactly 365 days, Earth would be in its autumn equinox position on the same day each year. Since Earth takes 365.25 days to make a complete journey around the sun, the date is slightly different each year. The fall equinox won’t happen again on Sept. 24 until 2303.

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| Earth’s 6-Year Twitch Changes Day Length!

Earth’s 6-Year Twitch Changes Day Length ~ Becky Oskin, Live Science.

Earth's magnetic field

Supercomputer model of Earth’s magnetic field.

Periodic wobbles in Earth’s core change the length of a day every 5.9 years, according to a study published today (July 10) in the journal Nature.

Teasing out this subtle cycle, which subtracts and adds mere milliseconds to each day, also revealed a match between abrupt changes in the length of day and Earth’s magnetic field. During these short-lived lurches in the magnetic field intensity, events called geomagnetic jerks, Earth’s day also shifts by 0.1 millisecond, the researchers report. Since 1969, scientists have detected 10 geomagnetic jerks lasting less than a year.

Seemingly negligible, these fleeting variations are mighty to those who study the planet and its core. All of a sudden, a planet changes its spin like a figure skater open or closing her arms. The rotational effect helps scientists understand what’s happening inside theEarth’s core. Shifts in the magnetic field also provide clues to the inaccessible iron core. But their source remains a mystery.

Lead study author Richard Holme suspects a shimmy in the solid inner core that drives the 5.9-year cycle, transferring angular momentum to the outer core. But no one knows what causes geomagnetic jerks.

“I have no clue,” said Holme, lead study author and a geophysicist at the University of Liverpool in the U.K. “Something is happening at the core-mantle boundary, because you’re seeing the geomagnetic and the rotational effect at the same time, but we don’t know what’s going on,” Holme told LiveScience‘s OurAmazingPlanet.

What’s up down there?

Researchers still actively debate how the fluid outer core produces our planet’s protective magnetic field, which has weakened and flipped polarity many times in geologic history. [What if Earth’s Magnetic Poles Flip?]

Earth's layers

Scientists believe that gyrating iron fluid generates Earth’s magnetic field, like a giant dynamo. Both yearly and millennial-scale changes in the field have been attributed to the swirling, spinning outer core. Tracking changes in the magnetic field helps researchers create models of how the dynamo may work.

“Essentially, we are using the variations as a tracer for flow,” said Mathieu Dumberry, a geophysicist at the University of Alberta in Canada, who was not involved in the study.

Since geomagnetic jerks were first discovered in 1969, researchers have sought to explain and model how Earth’s dynamo produces these quick changes in the magnetic field.

Finding a connection with changes in the length of day provides a new way of thinking about the phenomenon, Holme said.

For example, the results could help modelers better understand how the core and mantle exchange angular momentum, Holme said. Perhaps electromagnetic friction creates torque, akin to an electric car battery. But the electrical conductivity of the lower mantle (or the ease with which electrical charges flow within it) can’t be too high, or it would cause a delay in the magnetic field responding to the rotational shift, Holme said. Instead, Holme and co-author Olivier de Viron of the Institut de Physique du Globe in Paris saw simultaneous geomagnetic jerks and jumps in the length of day.

“We’ve got some ideas, but it’s just me having an amused flight of fancy. I’m a data hound, and I want to propel thinking about this,” Holme said.

But Dumberry is not convinced that the study proves a link between jerks and changes in day length. “In that, it’s not such a strong story,” he said. There is a remarkable correlation between a geomagnetic jerk in 2003 and a length of day change, but earlier links aren’t as strong, he said.

Length of day oscillates

Other forces also change the planet’s spin. Since Earth formed, tugging from the sun and moon have slowed the planet’s rotation. On shorter time scales, earthquakes, melting glaciers, ocean currents and strong winds, such as the jet stream, can alter how fast the planet spins, shortening or lengthening a day by about 1 millisecond.

Holme and de Viron removed these external and planetary effects from five decades of length of day data, exposing the 5.9-year period. They then compared bumps in the cycle, which correspond to sudden jumps in the length of day, with geomagnetic jerks detected since 1969.

Dumberry praised the pair’s careful work in extracting the 5.9-year signal. “This multiyear length of day signal is the best so far,” he said.



| Curiosity’s pictures find ancient history of flowing water on Mars!

Mars pebbles prove water history ~ Jonathan Amos, Science correspondent, BBC News.

Scientists now have definitive proof that many of the landscapes seen on Mars were indeed cut by flowing water.

The valleys, channels and deltas viewed from orbit have long been thought to be the work of water erosion, but it is Nasa’s latest rover, Curiosity, that has provided the “ground truth”.

Researchers report its observations of rounded pebbles on the floor of the Red planet’s 150km-wide Gale Crater.

Their smooth appearance is identical to gravels found in rivers on Earth.

Rock fragments that bounce along the bottom of a stream of water will have their edges knocked off, and when these pebbles finally come to rest they will often align in a characteristic overlapping fashion.

Curiosity has pictured these features in a number of rock outcrops at the base of Gale Crater.

It is confirmation that water has played its part in sculpting not only this huge equatorial bowl but by implication many of the other landforms seen on the planet.

“For decades, we have speculated and hypothesised that the surface of Mars was carved by water, but this is the first time where you can see the remnants of stream flow with what are absolutely tell-tale signs,” Dr Rebecca Williams from the Planetary Science Institute, US, told BBC News.

The American space agency first announced the discovery of the pebbles in September last year, barely seven weeks after Curiosity had landed in Gale.

Researchers have since been studying the robot’s pictures in more detail and have now written up a report for Science magazine – the first scholarly paper from the surface mission to make it into print; and the study reinforces the initial interpretation.

Link The team only has pictures from the rover’s main cameras. Attempts will be made to get close-up, high-resolution imagery of Gale’s conglomerates in the weeks ahead using the Mahli “hand lens”.

It describes the nature of the outcrops, and estimates the probable conditions in which their sediments were laid down.

The pebbles range in size from about two to 40mm in diameter – too big to have been blown along by the wind.

These clasts, as scientists will often call them, are cemented together in a sandy matrix to make a rock type referred to as a conglomerate.

In many places, the clasts are touching each other, and the pictures show examples of so-called imbrication – an arrangement where elongated pebbles stack like a row of toppled dominos. It is a classic sign of past river activity.

Precisely dating landforms on Mars is not possible, but the rock outcrops seen by the rover are almost certainly more than three billion years old.

Curiosity’s pictures have enabled the team to make some informed statements about the speed and depth of the water that once flowed across the crater floor.

Reull Vallis
So many surface features look from orbit to have been cut by flowing water.

“We estimate that the flow velocities were walking pace, approximately – it’s not something we can absolutely reconstruct, but it gives us a rough idea, and these are minimum values,” explained Prof Sanjeev Gupta from Imperial College London, UK.

“And we can also say that the water depths ranged from ankle-deep to waist-deep.

“This is the first time we’ve been able to do this quantification [on the Red Planet]. It is routine to do this on Earth, but to do it on Mars by looking at ancient rocks is just remarkable.”

River gravelsAncient river deposits on Earth. Note the predominantly sandy layers. These indicate there was a drop in the speed of the water, meaning only the smallest particles could be carried and deposited downstream.

The pebbles come in a variety of dark and light shades, further indicating that they have been eroded from different rock types and transported from different locations.

Using its Chemcam remote-sensing laser, the rover was able to detect feldspar in the lighter toned clasts.

Feldspar is a common mineral on Earth that weathers quickly in the presence of water.

This suggests past conditions were not overly wet and that the pebbles were carried only a relatively short distance – probably no more than 10-15km.

This fits with satellite observations of what appears to be a nearby network of old rivers or streams spreading away from the mouth of a channel that cuts through the northern rim of Gale Crater.

This valley – or Peace Vallis as it is known – is the probable route down which the water flowed and later dumped its load of rounded gravels.

Curiosity is due to drive back on itself in the coming weeks as it makes for the big peak, Mount Sharp, at the centre of the crater.

Scientists hope this will take the vehicle past similar rock outcrops so that additional pictures can be obtained.

“What’s exciting is that when we made this discovery our highest resolution camera – the hand-lens camera, Mahli – hadn’t even been commissioned. It has now. So, if we find similar rocks on the way to Mount Sharp, we will be able to get much better images with fantastic detail,” said Prof Gupta.

Sanjeev Gupta will be discussing the explorations and discoveries of the Curiosity rover on Mars with astrobiologist Lewis Dartnell at next week’sTimes Cheltenham Science Festival on Sunday 9 June. A huge panorama of Mount Sharp built from Curiosity pictures is going on display at the Visions of the Universe exhibition at the National Maritime Museum in London from Friday 7 June.

Gale Crater


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| Planck satellite: Maps detail Universe’s oldest light!

Planck satellite: Maps detail Universe’s ancient light ~ Jonathan AmosScience correspondent, BBC News, Paris.


A map tracing the “oldest light” in the sky has been produced by Europe’s Planck Surveyor satellite. Its pattern confirms the Big Bang theory for the origin of the Universe but subtle, unexpected details will require scientists to adjust some of their ideas.

A spectacular new map of the “oldest light” in the sky has just been released by the European Space Agency.

Scientists say its mottled pattern is an exquisite confirmation of our Big-Bang model for the origin and evolution of the Universe.

But there are features in the picture, they add, that are unexpected and will require ideas to be refined.

The map was assembled from 15 months’ worth of data acquired by the 600m-euro (£515m) Planck space telescope.

It details what is known as the cosmic microwave background, or CMB – a faint glow of microwave radiation that pervades all of space.

Its precise configuration, visible in the new Planck data, is suggestive of a cosmos that is slightly older than previously thought – one that came into existence 13.82 billion years ago.

This is an increase of about 50 million years on earlier calculations.

The map’s pattern also indicates a subtle adjustment is needed to the Universe’s inventory of contents.

It seems there is slightly more matter out there (31.7%) and slightly less “dark energy” (68.3%), the mysterious component thought to be driving the cosmos apart at an accelerating rate.

“I would imagine for [most people] it might look like a dirty rugby ball or a piece of modern art,” said Cambridge University’s George Efstathiou, presenting the new picture here at Esa headquarters in Paris.

“But I can assure you there are cosmologists who would have hacked our computers or maybe even given up their children to get hold of this map, we’re so excited by it.”

Planck is the third western satellite to study the CMB. The two previous efforts – COBE and WMAP – were led by the US space agency (Nasa). The Soviets also had an experiment in space in the 1980s that they called Relikt-1.

How Planck’s view hints at new physics

Planck anomalies graphic
  • The CMB’s temperature fluctuations are put through a number of statistical analyses
  • Deviations can be studied as a function of their size on the sky – their angular scale
  • When compared to best-fit Big Bang models, some anomalies are evident
  • One shows the fluctuations on the biggest scales to be weaker than expected
  • Theorists will need to adjust their ideas to account for these features

The CMB is the light that was finally allowed to spread out across space once the Universe had cooled sufficiently to permit the formation of hydrogen atoms – about 380,000 years into the life of the cosmos.

It still bathes the Earth in a near-uniform glow at microwave frequencies, and has a temperature profile that is just 2.7 degrees above absolute zero.

But it is possible to detect minute deviations in this signal, and these fluctuations – seen as mottling in the map – are understood to reflect the differences in the density of matter when the light parted company and set out on its journey all those years ago.

The fluctuations can be thought of as the seeds for all the structure that later developed in the cosmos – all the stars and galaxies.

Scientists subject the temperature deviations to a range of statistical analyses, which can then be matched against theoretical expectations.

This allows them to rule in some models to explain the origin and evolution of the cosmos, while ruling out a host of others.

The team that has done this for Planck’s data says the map is an elegant fit for the standard model of cosmology – the idea that the Universe started in a hot, dense state in an incredibly small space, and then expanded and cooled.

At a fundamental level, it also supports an “add-on” to this Big Bang theory known as inflation, which postulates that in the very first moments of its existence the Universe opened up in an exponential manner – faster than light itself.

But because Planck’s map is so much more detailed than anything previously obtained, it is also possible to see some anomalies in it.

Temperature anomalies in Planck data
Planck has confirmed the north/south differences and a “cold spot” in the data

One is the finding that the temperature fluctuations, when viewed across the biggest scales, do not match those predicted by the standard model. Their signal is a bit weaker than expected.

Continue reading the main story

Planck’s new numbers

  • 4.9% normal matter – atoms, the stuff from which we are all made
  • 26.8% dark matter – the unseen material holding galaxies together
  • 68.3% dark energy – the mysterious component accelerating cosmic expansion
  • The number for dark energy is lower than previously estimated
  • The new age – 13.82 billion years – results from a slower expansion
  • This is described by value known as the Hubble Constant
  • It also has been recalculated at at 67.15 km per second, per megaparsec

There appears also to be an asymmetry in the average temperatures across the sky; the southern hemisphere is slightly warmer than the north.

A third significant anomaly is a cold spot in the map, centred on the constellation Eridanus, which is much bigger than would be predicted.

These features have been hinted at before by Planck’s most recent predecessor – Nasa’s WMAP satellite – but are now seen with greater clarity and their significance cemented.

A consequence will be the binning of many ideas for how inflation propagated, as the process was first introduced in the 1980s as a way to iron out such phenomena.

The fact that these delicate features are real will force theorists to finesse their inflationary solutions and possibly even lead them to some novel physics on the way.

“Inflation doesn’t predict that it should leave behind any kind of history or remnant, and yet that’s what we see,” Planck project scientist Dr Jan Tauber told BBC News.

Continue reading the main story

CMB – The ‘oldest light’ in the Universe

Detail of CMB data
  • Theory says 380,000 years after the Big Bang, matter and light “decoupled”
  • Matter went on to form stars and galaxies; the light spread out and cooled
  • The light – the CMB – now washes over the Earth at microwave frequencies
  • Tiny deviations from this average glow appear as mottling in the map (above)
  • These fluctuations reflect density differences in the early distribution of matter
  • Their pattern betrays the age, shape and contents of the Universe, and more


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| NASA Vid [4m] debunks Maya doom theory: Why the world won’t end on Dec. 21, 2012!

Why the World Didn’t End Yesterday! ~ NASA.

NASA is so sure the world won’t come to an end on Dec. 21, 2012, they have already released this news item for the day after.

Dec. 22, 2012: If you’re reading this story, it means one thing:

The World Didn’t End Yesterday.

According to media reports of an ancient Maya prophecy, the world was supposed to be destroyed on Dec. 21, 2012.

Apparently not.

“The whole thing was a misconception from the very beginning,” says Dr. John Carlson, director of the Center for Archaeoastronomy.  “The Maya calendar did not end on Dec. 21, 2012, and there were no Maya prophecies foretelling the end of the world on that date.”

The truth, says Carlson, is more interesting than fiction.

Yesterday (splash)

A new ScienceCast video explores what the Maya really thought about Dec. 21, 2012. 

Carlson is a hard-nosed scientist–a radio astronomer who earned his degree studying distant galaxies.  He became interested in the 2012 phenomenon in the early 70s  when he attended a meeting of the American Association for the Advancement of Science and learned about the lost civilization of the Maya.

Where the rain forests of Mesoamerica now stand, a great civilization once flourished. The people of Maya society built vast cities, ornate temples, and towering pyramids. At its peak around 800 A.D., the population numbered more than 2,000 people per square mile in the cities — comparable to modern Los Angeles County.  The Maya mastered astronomy, developed an elaborate written language, and left behind exquisite artifacts.

Most compelling to Carlson was the Maya’s expansive sense of time. “The times Mayas used dwarf any time scales currently used by modern astronomers,” he explains. “According to our science, the Big Bang occurred 13.7 billion years ago.

There are dates and time references in Mayan ruins that stretch back a billion billion times farther than that.”

The Maya Long Count Calendar was designed to keep track of such long intervals. “It is the most complex calendar system ever developed by people anywhere.”

Written using modern typography, the Long Count Calendar resembles the odometer in a car.  It’s a modified base-20 system in which rotating digits represent powers of 20 days. Because the digits rotate, the calendar can “roll over” and repeat itself; this repetition is key to the 2012 phenomenon.

Yesterday (ruins, 200px)

What caused the fall of the Maya? Using NASA data, one archeologist believes he has found the answer.

According to Maya theology, the world was created 5125 years ago, on a date modern people would write “August 11, 3114  BC.”  At the time, the Maya calendar looked like this:

On Dec. 21, 2012, it is exactly the same:

In the language of Maya scholars, 13 Bak’tuns or 13 times 144,000 days elapsed between the two dates.   This was a significant interval in Maya theology, but, stresses Carlson, not a destructive one.  None of the thousands of ruins, tablets, and standing stones that archeologists have examined foretell an end of the world.

Modern science agrees. NASA experts recently gathered in a Google hangout to review their own findings with the public.

Don Yeomans, head of NASA’s Near-Earth Object Program, stated that no known asteroids or comets are on a collision course with Earth.

Neither is a rogue planet coming to destroy us. “If there were anything out there like a planet headed for Earth,” said NASA astrobiologist David Morrison, “it would already be [one of the] brightest objects in the sky. Everybody on Earth could see it. You don’t need to ask the government, just go out and look.  It’s not there.”

Lika Guhathakurta, head of NASA’s Living with a Star Program, says the sun is not a threat, either. “The sun has been flaring for billions of years–long before the Maya even existed–and it has never once destroyed the world.”

“Right now the sun is approaching the maximum of its 11-year activity cycle,” she added, “but this is the wimpiest solar cycle of the past 50 years. Reports to the contrary are exaggerated.”

What would an ancient Maya think about all this hoopla?  Carlson believes he knows the answer.

“If we could time warp a Maya to the present day, they would say that Dec. 21, 2012, is a very important date.  Many Maya believed that their gods who created the world 5125 years ago would return.  One of them in particular, an enigmatic deity named Bolon Yokte’ K’uh, would conduct old rites of passage, to set space and time in order, and to regenerate the cosmos.”  The world would be refreshed, not destroyed.

“I have been waiting to experience this day for more than 30 years,” he says.

For him, “experiencing Dec. 21, 2012” means visiting the Maya homeland in the Yucatan, and thinking back to the height of Maya civilization, when ancient humans contemplated expanses of time orders of magnitude beyond modern horizons.

And, of course, appreciating the fact that The World Didn’t End Yesterday.
Author: Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit: Science@NASA



| X-37B Orbital Test Vehicle: Boeing-made mystery spacecraft launched!

Boeing-made mystery spacecraft launched ~ Seattle Times.

The military’s small, top-secret version of the space shuttle rocketed into orbit Tuesday for a repeat mystery mission, two years after making the first flight of its kind.

CAPE CANAVERAL, Fla. — The military’s small, top-secret version of the space shuttle rocketed into orbit Tuesday for a repeat mystery mission, two years after making the first flight of its kind.

The space plane, dubbed the X-37B Orbital Test Vehicle, was launched into orbit hidden atop an Atlas V rocket Tuesday for a classified Air Force mission that could last more than nine months.

This is the third time the Air Force will send an X-37B into orbit. It resembles a miniature space shuttle, is 29 feet long with a wingspan of 15 feet, and draws solar power for energy using unfolding panels.

The X-37B vehicles were built by Boeing in Huntington Beach, Calif. Engineering work was done at the company’s facilities in Huntington Beach and Seal Beach, Calif. Components also came from Boeing’s satellite-making plant in El Segundo, Calif.

While the Air Force has said the space plane is designed to stay in orbit for 270 days, it hasn’t said much about the overall mission. It has said only that the vehicle provides a way to test new technologies in outer space. In fact, launch commentary ended 17 minutes into the flight, and a news blackout followed.

The first X-37B was launched in April 2010 and landed 224 days later on a 15,000-foot airstrip at Vandenberg Air Force Base, northwest of Santa Barbara, Calif. The second X-37B spent 469 days in space.

These high-tech mystery machines are about one-quarter the size of NASA’s old space shuttles and can land automatically on a runway. The two previous touchdowns occurred in Southern California; this one might end on NASA’s three-mile-long runway once reserved for space shuttles.

Jonathan McDowell, of the Harvard-Smithsonian Center for Astrophysics, speculates the space plane is carrying sensors designed for spying and likely is serving as a test bed for future satellites. He dismisses rumors of “exotic ideas” for the X-37B, such as weaponry or shadowing a Chinese satellite.

While acknowledging he does not know what the space plane is carrying, McDowell said onboard sensors could be capable of imaging or intercepting electronic transmissions from terrorist training sites in Afghanistan or other hot spots.

The beauty of a reusable space plane is that it can be launched on short notice, McDowell said.

What’s important about this flight is that it is the first reflight.

“ That’s something that has only really been done with the shuttle,” he said.

The two previous secret X-37B flights were in 200-plus-mile-high orbits, circling at roughly 40-degree angles to the equator, as calculated by amateur satellite trackers.


X-37B Orbital Test Vehicle1

| NASA X-rays the Moon + gets a Theory of Life on Mars!

Via the Moon, a Theory of Life on Mars ~ The Atlantic.

NASA captures, quite literally, gravity’s rainbow.


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A gravitational map of the moon, depicting newly quantified lunar mass: Red indicates more massive areas and blue indicates less mass (NASA/JPL-Caltech/MIT/GSFC)

Scientists care about the moon in part because it is the moon — our moon. But they care about it, also, because its body is in some ways a proxy for our Earth’s: Its surface, like ours, bears the scars of a long existence in our little corner of the Milky Way. And new research suggests that that existence might have been much more violent — and perhaps more hospitable to life — than we humans initially believed. Yes.

The story begins, officially, around five years ago. In 2007, the Japanese lunar satellite Kaguya released two small probes into orbit around the moon. Those satellites, working in tandem, created the first gravity map of the far side of the moon — a chart that showed, in color-coded detail, the variations in mass on our nearest planetary neighbor.

The same year, NASA announced plans for a similar mission: the launch of twin spacecraft that would spend several months doing their own moon-mapping work, measuring the lunar gravity field in unprecedented detail. In late 2011, NASA began that mission, sending a pair of spacecraft — collectively known as GRAIL (Gravity Recovery and Interior Laboratory) — to orbit the lunar surface. The pair of satellites (named, awesomely, Ebb and Flow) fly in formation around the moon, sending each other — and Earth — microwave measurements of our only natural satellite. The twin vehicles, each about the size of a washing machine, work by detecting tiny changes in the distance between them — variations caused by lunar mountains, craters, and subsurface mass concentrations.

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An artist’s rendering of GRAIL’s twin spacecraft, flying in tandem orbits around the moon (NASA/JPL)

The GRAIL satellites and their operators use a technique pioneered by GRACE, the Gravity Recovery and Climate Experiment, launched in 2002 and run jointly by NASA and the German Aerospace Center. The Grace satellites have been taking detailed measurements of Earth’s gravity field — tracking, in particular, gravity changes related to the movement of mass within Earth (like, say, the melting of ice at its poles and changes in its ocean circulations). GRAIL has been applying the lessons of GRACE to our planetary neighbor — helped along by the fact that the moon lacks an atmosphere, which allows the satellites to orbit wonderfully close to its surface: between 10 and 30 miles above the lunar crust. (The ESA’s GOCE satellite, which does gravitational mapping of Earth, has to stay 10 times farther away from its target to avoid atmospheric drag.)

So. Between March and May of 2012, the Ebb and Flow satellites essentially X-rayed the moon, assessing our nearest planetary neighbor both from and beyond its surface. Scientists took measurements from the moon’s crust to its core to reveal both the moon’s subsurface structures and — indirectly — its thermal history. And partial results of that work are reflected in the amazing graphic shown above, which is, GRAIL says, the highest-resolution map of this kind ever generated for a celestial body. The colors in question represent the variations in the moon’s structure, with red indicating more massive areas and blue representing less-massive.

And here, along those lines, is a map depicting the bulk density of the lunar highlands on both the near (left) and far (right) sides of the moon — generated using both gravity data from the GRAIL mission and topography data from NASA’s Lunar Reconnaissance Orbiter. Solid circles correspond to prominent impact basins. White denotes regions that contain mare basalts (thin lines) and that were not analyzed; red corresponds to higher than average densities; and blue corresponds to lower than average densities.

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A graphic depicting the bulk density of the lunar highlands on the near and far sides of the moon. (NASA/JPL-Caltech/ IPGP)

So what do these maps actually mean? Well, first, consider the craters. The color-coding suggests that the moon was pummeled by impacts that were much more violent than previously assumed. The moon’s crust is pretty much covered by craters — and, if those impacts were caused by asteroids and other space debris, it would stand to reason that Earth, along with Mercury, Venus, and Mars — our nearest neighbors — once endured similar punishment. As Maria Zuber, GRAIL’s principal investigator, put it in a press conference announcing the findings: The discovery “really opens a window to this early stage of just what a violent place the surfaces of all terrestrial planets were early in their history.”

The data also suggest that the moon’s crust is thinner than previously thought — just 21 to 27 miles. (Earlier estimates had it ranging from 30 to 40 miles deep.) And underneath that crust, Ebb and Flow detected several large, linear structures — structures, composed of solidified magma, that can run for up to 300 miles. Those lunar “dikes” are covered by craters, which would suggest that they predate most of the moon’s violent impacts. And they could have formed, most interestingly, only if the moon’s crust were extending — only if the moon’s interior were heating up and expanding.

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An artist’s rendering of a planetary collision near the star Vega: The Moon may have formed from the debris of this kind of impact between Earth and a Mars-sized body. (NASA)

This gives more evidence in favor of the Giant Impact hypothesis, the leading theory for the moon’s origin — a theory suggesting that the moon was formed from the fragments of Earth that gathered after a Mars-size body smashed into our planet about 4.5 billion years ago. A warmer-on-the-inside/cooler-on-the-outside moon would be consistent with that kind of coalescent lunar formation. As GRAIL guest scientist Jeff Andrews-Hanna noted in the team’s press conference: “This had been predicted theoretically a long time ago, but there was no direct observational evidence to support this period of early lunar expansion until this GRAIL data.”

And! Finally! The new information about the moon also suggests some evidence for a theory of how life might exist, or have existed, on other rocky planets. Because the cracks on the moon’s surface could provide a pathway for fluids — which might explain what happened to the ocean that some scientists believe once existed on the surface of, yes, Mars. As Zuber noted, “that ocean could well be underground.” As the Martian surface dried out, the sub-surface water could have provided a hospitable environment for any microbes that were living on the planet’s surface. Microbes, Zuber said, “could have gone very deep within the crust of Mars.”


| Space: A galaxy takes a bullet to the heart!

A Galaxy Takes a Bullet to the Heart ~ , Slate.

Hubble and Chandra composite view of NGC 922

NGC 922, shot through the heart. Click to grab the giant 3300 x 3300 version.
Image credit: NASA, ESA, CXC

Space is big. In fact, that’s why we call it space.

OK, duh. But in general, most objects are small compared to the space around them. The distance from Earth to Venus, the nearest planet, is still thousands of times longer than the size of the Earth. The distance to the nearest star is 30 million times the Sun’s size. That’s like living in a house where your next-door neighbor is as far away as the Moon.

But galaxies are different. The distance to the nearest big galaxy, Andromeda, is less than 30 times the size of our galaxy. On a cosmic scale, galaxies are actually pretty crowded together. And that means they sometimes get in each other’s way … and sometimes that means they collide.

NGC 922 is one such galaxy. It’s located about 140 million light years away, which is close enough to give us a great view of it. And that’s cool, because about 300 million years ago, a smaller galaxy collided with and shot right through NGC 922, leaving behind chaos.

The image at the top of this post shows NGC 922. It’s a combination of shots taken by the Hubble Space Telescope and the Chandra X-Ray Observatory. You can tell NGC 922 is a spiral, or at least it’s trying to be. But it’s a mess. The collision with the smaller galaxy was like a gravitational stone thrown into a pond, creating a ripple that expanded outwards from the center, compressing vast clouds of gas and dust, and triggering massive amounts of star formation in a lopsided ring tens of thousands of light years across. You can see that ring in pinkish-red, the color of hydrogen clouds being heated by newborn stars within them. It’s a tell-tale sign that something big happened, which is as obvious to an astronomer as a siren going off.

The folks at Hubble put together a nice video explaining the disaster that shaped NGC 922:

That ring tells us a lot about how events went down. For example, we know the collision took the smaller galaxy only a little off dead-center through NGC 922. Collisions that are well off-center stretch out the galaxies, and even if the bullet had passed through the disk halfway to the edge the galaxy would be more distorted. Because that ring is so close to being a circle, the bullet must have passed very nearly through the heart of NGC 922.

The interloper was moving fast enough to blow right through NGC 922, and it can be seen in wider-field images quite some distance from its victim. Weirdly, though, while these two galaxies physically passed through each other, the chance that there was even a single collision between stars is pretty low. As I said, stars are far apart compared to their size, so when galaxies collide the stars go right on past one another. It’s an odd thought.

Cartwheel galaxy

The Cartwheel galaxy, victim of a cosmic collision. 
Image credit: Kirk Borne (STScI), and NASA

But gravity knows no such isolation. The pull of each galaxy strongly affected the other, whipping up NGC 922 into this frenzy of star birth. We’ve seen this before in galaxies like the Cartwheel (shown here). In that case, the collision was more recent, and the bullet galaxy (the lower, bluer of the two smaller galaxies you see) is still pretty close. Eventually it will pull away, heading out into intergalactic space, its damage done.

The fate of NGC 922 is that the ring will likely break up into clumps as the material orbits the galactic center. The gas and dust will get sloshed around, and the galaxy will eventually lose its spiral structure, becoming a more or less featureless disk. Those kinds of galaxies, called lenticulars, are common in galaxy clusters where collisions are frequent. That’s no coincidence.

And just in case you think this is all very esoteric and has nothing to do with us, think again. The massive Andromeda Galaxy, every bit the Milky Way’s equal, is on a collision course with us. The two galaxies are destined to collide—a train wreck on a cosmic scale—and merge. Of course, this won’t happen for about another four billion years. So don’t lose any sleep over it. But given the sheer beauty and coolness of NGC 922 and the Cartwheel, I think I’d kinda like to witness that. What a sight that would be!