Tag: science

Pluto in 3D

9:09 am

The New Horizons science team has released its first 3D image of the surface of Pluto.

You need red/blue stereo glasses to view it.

The image shows an ancient, heavily cratered region of Pluto, dotted with low hills and cut by deep fractures, which indicate extension of Pluto’s crust. Analysis of these stereo images shows that the steep fracture in the upper left of the image is about 1 mile (1.6 kilometers) deep, and the craters in the lower right part of the image are up to 1.3 miles (2.1 km) deep. Smallest visible details are about 0.4 miles (0.6 kilometers) across.

My impression of the image, using the glasses, makes me wonder if they have exaggerated the vertical depth so that it would stand out. The craters look more like pits than craters. And if they didn’t exaggerate the vertical depth, then that means that impacts on Pluto produce craters that are very different than those seen in the inner solar system.

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Mysterious piece of space junk to hit Earth

8:34 am

A piece of unidentified space junk, discovered in a long elliptical orbit going out far beyond the Moon, has been calculated to hit the Earth over the Indian Ocean on November 13.

WT1190F was detected by the Catalina Sky Survey, a program aimed at discovering asteroids and comets that swing close to Earth. At first scientists didn’t know what to make of this weird body. But they quickly computed its trajectory, after collecting more observations and unearthing 2012 and 2013 sightings from telescope archives, says independent astronomy software developer Bill Gray, who has been working to track the debris with NASA’s Jet Propulsion Laboratory in Pasadena, California.

WT1190F travels a highly elliptical orbit, swinging out twice as far as the Earth-Moon distance, Gray says. Gray’s calculations show that it will hit the Earth at 6:20 UTC, falling about 65 kilometres off the southern tip of Sri Lanka. Much if not all of it will burn up in the atmosphere, but “I would not necessarily want to be going fishing directly underneath it,” Gray says.

What makes the object interesting is that they don’t know when it was launched or how it got in the orbit it is in. It could even be something from the Apollo lunar missions.

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The largest astronomical image ever

8:44 am

Astronomers have assembled the largest single image of the entire Milky Way ever taken.

It is 46 billion pixels across.

The amazing view of the Milky Way was built out of 268 individual views of the galaxy that includes the sun and the Earth, captured night after night over the course of five years with telescopes in Chile’s Atacama Desert. Astronomers at Ruhr-Universität Bochum used the data to examine stars whose brightness changes over time — and the image portrays more than 50,000 new objects with variable brightness that have never been recorded before.

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Another Pluto Moon revealed

8:16 am

Kerberos

The uncertainty of science: The New Horizons science team has released their best image of Pluto’s moon Kerberos, finding it to be nothing like what they expected.

Before the New Horizons encounter with Pluto, researchers had used Hubble Space Telescope images to “weigh” Kerberos by measuring its gravitational influence on its neighboring moons. That influence was surprisingly strong, considering how faint Kerberos was. They theorized that Kerberos was relatively large and massive, appearing faint only because its surface was covered in dark material. But the small, bright-surfaced, Kerberos now revealed by these new images show that that idea was incorrect, for reasons that are not yet understood.

Instead, Kerberos is much smaller than expected, and its surface is bright, suggesting it is covered by relatively clean ice. It is also double lobed, kind of like Comet 67P/C-G.

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Earth might be one of the universe’s first habitable planets

9:57 pm

The uncertainty of science: An analysis of data from the Hubble Space Telescope and Kepler suggests that the Earth might be one of the first planets in the universe to harbor life.

I label this result uncertain because it is based on what I consider to be a very poor sampling of exoplanets as seen by Kepler. Kepler might have found a lot of exoplanets, but the numbers are still small and skewed by the limited types of suns observed and the short time frame of its observations. Moreover, the data from Hubble is rich, but also quite small, leaving great uncertainties for all of these conclusions.

At the same time, this conclusion might help explain why, after almost a half century of looking, we have yet to detect any evidence of radio communications from any other civilizations. You would think we would have detected something by now. Maybe they don’t exist, and we are the first.

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200 new lunar impact craters discovered

9:18 am

In a paper [pdf] presented this week at a lunar science conference, scientists announced the identification of more than 200 new impact craters on the Moon from Lunar Reconnaissance Orbiter (LRO).

As of 1 May 2015, we have scanned and classified changes in 14,182 NAC temporal pairs using our automated change detection tool leading to the discovery over 200 impact craters ranging in size from 1.5 to 43 m. In addition, we also identified thousands of other surface changes, including about 44,000 low reflectance splotches, 3,500 high reflectance splotches, 850 mixed reflectance splotches, [and] 1 Chinese lander/rover.

They think the splotches are created from impacts too small to see with LRO.

Hat tip James Fincannon.

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New cheap way to turn sea water drinkable?

8:25 am

Egyptian researchers have developed what they think could be a cheap and easy way to desalinate sea water.

In a paper published last month in the journal, Water Science & Technology, researchers Mona Naim, Mahmoud Elewa, Ahmed El-Shafei and Abeer Moneer announced that they have developed a new way to purify sea water using materials that can be manufactured easily and cheaply in most countries, and a method that does not rely on electricity.

The technology uses a method of separating liquids and solids called pervaporation. Pervaporation is a simple, two-step process – the first step involves filtering the liquid through a ceramic or polymeric membrane, while the second step requires vaporizing and collecting the condensed water. Pervaporation is faster, cleaner and more energy efficient than conventional methods, not least because the heat required for the vaporization stage does not necessarily have to be electrically generated.

The technology is not yet proven, but if it bears fruit, many of the world’s water problems will soon vanish.

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Study questions scientific dating method

8:32 am

The uncertainty of science: A new study has raised questions about the methods scientists have used to date the late heavy bombardment in the early solar system.

A study of zircons from a gigantic meteorite impact in South Africa, now online in the journal Geology, casts doubt on the methods used to date lunar impacts. The critical problem, says lead author Aaron Cavosie, a visiting professor of geoscience and member of the NASA Astrobiology Institute at the University of Wisconsin-Madison, is the fact that lunar zircons are “ex situ,” meaning removed from the rock in which they formed, which deprives geoscientists of corroborating evidence of impact. “While zircon is one of the best isotopic clocks for dating many geological processes,” Cavosie says, “our results show that it is very challenging to use ex situ zircon to date a large impact of known age.”

The problem is that the removal of the zircon from lunar rocks changes the data enough to make the dating unreliable. The method might work on Earth, but the dating done on Apollo samples can be questioned. This means that much of the supposed history of the solar system, centered on what planetary scientists call the late heavy bombardment, a period 4 billion years ago when the planets were being hit by innumerable impacts as they cleared the solar system of its dusty debris disk, might not have happened as dated from lunar samples. If so, our understanding of when that bombardment ended and life began to form on Earth might be considerably incorrect.

The solution? Get to the planets in person, where you can obtain many samples in situ and thus gather a much deeper understanding of the geology.

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Fractures on Enceladus’s north pole

6:02 pm

Enceladus's North Pole

The Cassini science team has released the first image from Wednesday’s flyby of the Saturn moon Enceladus.

Scientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images from the Voyager mission, but the new high-resolution Cassini images show a landscape of stark contrasts. “The northern regions are crisscrossed by a spidery network of gossamer-thin cracks that slice through the craters,” said Paul Helfenstein, a member of the Cassini imaging team at Cornell University, Ithaca, New York. “These thin cracks are ubiquitous on Enceladus, and now we see that they extend across the northern terrains as well.”

To see more you can browse the raw images here.

The next flyby later this month will be especially interesting as they will dip to within 30 miles of the surface.

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More evidence of giant flash floods on Mars

9:45 am

Mangala Valles

A newly released image from ESA’s Mars Express orbiter shows that catastrophic flooding — caused by ice melted from volcanic activity — created the Mangala Valles channels on Mars.

The perspective image on the right shows the topography of the region, with low points indicated in blue and high points by red. The channel along the right side of the image is Mangala Valles itself, though you can also see additional flood channels to the left of it passing around and through a large crater whose floor now stands above the surrounding terrain caused by the erosion of the rim plus the deposit of sediment inside the crater during the flooding.

I have a soft spot for Mangala Valles. When it was first photographed by the first orbiter missions to Mars in the early 1970s I was struck by its river-like appearance and striking topography. I therefore placed my Martian colony here in one of my efforts at science fiction writing. I figured it a good location for colonization, as there would likely be water and, by roofing over the deep canyon, a colony could be built relatively easily.

Better locations on Mars have since been found, but the location still intrigues me.

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Real clam digging

6:01 pm

An evening pause: Rocco had suggested this short video about the joys of going out and digging clams. I prefer the video below, of a real clam doing its own digging, because it shows us something we normally don’t see and that is really amazing. Who would have thought that a clam could bury itself so quickly, with a single digging foot?

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Kepler finds a star no one can explain

3:56 pm

Observations using Kepler have uncovered a star whose light fluctuations can only be explained in two ways.

First,

If another star had passed through the unusual star’s system, it could have yanked a sea of comets inward. Provided there were enough of them, the comets could have made the dimming pattern. But that would be an extraordinary coincidence, if that happened so recently, only a few millennia before humans developed the tech to loft a telescope into space. That’s a narrow band of time, cosmically speaking.

Second? Maybe the star’s light is being blocked by a swarm of megastructures built by an alien civilization. They intend to look for radio emissions from the star in wavelengths associated with technology to see if this theory has any possibility.

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New global maps of Titan

11:23 am

Titan's North Pole

The Cassini science team has released new maps of Titan, including new maps of both poles, assembled from images taken during the 100 flybys that the spacecraft has made of the moon since it arrived in orbit around Saturn.

The scale is rough, just less than a mile at best, and there is no topographic information because the thick atmosphere allows for no strong sunlight or shadows. The images show differences in surface brightness, which does tell us where Titan’s dark methane lakes are.

This is likely the best we will get of Titan for decades, until another spacecraft is sent there.

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Cassini’s last flybys of Enceladus

2:04 pm

As Cassini approaches the end of its decade-long mission at Saturn it will begin its last series of flybys of the moon Enceladus starting October 14.

Images will arrive a day or two afterward. The last two flybys will take place in late October and then in December, with the second October flyby getting closest, only 30 miles from the surface.

Beginning next year they will shift the spacecraft’s orbit so that it can get a better look at Saturn’s poles during its last two years. In that orbit flybys of the moons cannot be done.

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New weather maps of Jupiter

1:27 pm

Using the Hubble Space Telescope astronomers have compiled a new set of maps of Jupiter, showing changes in the gas giant’s bands and spots, including the Giant Red Spot.

The scientists behind the new images took pictures of Jupiter using Hubble’s Wide Field Camera 3 over a ten-hour period and have produced two maps of the entire planet from the observations. These maps make it possible to determine the speeds of Jupiter’s winds, to identify different phenomena in its atmosphere and to track changes in its most famous features.

The new images confirm that the huge storm, which has raged on Jupiter’s surface for at least three hundred years, continues to shrink, but that it may not go out without a fight. The storm, known as the Great Red Spot, is seen here swirling at the centre of the image of the planet. It has been decreasing in size at a noticeably faster rate from year to year for some time. But now, the rate of shrinkage seems to be slowing again, even though the spot is still about 240 kilometres smaller than it was in 2014.

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Solar ramp down jumps slightly

9:56 am

My original post about NOAA’s October update to its monthly tracking of the Sun’s sunspot cycle contained an incorrect graph. For reasons I do not understand, the first graph they posted did not include the data for September, thus creating for me the illusion that little had changed in September. I am now posting the correct graph here, below the fold, with annotations to give it context.

In September numbers showed a slight jump in sunspot activity, though once again nothing so significant as to change the overall trends. Moreover, the correction doesn’t change what I wrote previously in any way: the rate of decline seems to have transitioned down from the 2009 prediction (red curve) to the 2007 weak prediction (lower green curve). This doesn’t real mean much, as the sunspot number can still vary up and down considerable before we reach solar minimum in two or three years.

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Getting India’s first space telescope working

9:12 am

A moment of terror: During the first week of successful operation, there was an initial moment of terror when the engineers checking out Astrosat, India’s first space telescope, thought the spacecraft was unable to point at its target accurately.

During the first orbit, there was a difficulty in detecting this Crab Nebula as the satellite happened to pass through the South Atlantic Anomaly (SAA) region when Crab was in the field of view. SAA avoidance zone was deliberately kept wide to protect the instruments, and detectors were switched OFF in this interval during the initial days of Astrosat operation. When all the data were systematically analysed and data were selected based on the availability of Crab in the detector field of view, one could see the Crab emerging from Earth’s shadow (Fig 3).

Using the Crab Nebula as Astrosat’s first target, the check-out has been proceeding well, with full research operations expected to begin in the next few weeks.

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Back from a weekend underground

9:22 pm

Bob Zimmerman underground

The picture on the right will explain why I have been silent posting since Friday. I have just returned with five friends from three days of caving in New Mexico, doing some wild caving plus my first visit to Carlsbad Caverns since 1992, guided by a local caver who has been helping me with my cave survey project in Arizona.

New Mexico probably has the largest concentration of truly large and spectacularly decorated caves in the entire world. I’ve caved there previously, but this was my first trip driving from Arizona. We went to two wild caves, one of which I had never visited before and a second that I had seen during my 1992 trip. The picture shows me in the latter, standing above a large clear pool near the back of the cave with some giant flowstone speleothems all around me.

The new cave contained a room dubbed Speleogasm, because every formation there, of which there are too many to count, is completely festooned with helectites and sodastraws in a mad protrusion that no geologist can as yet explain. Nor is there any way to describe it adequately or photograph it successfully. To witness it you need to go, requiring the specialized caving skills that include the techniques and equipment required to rappel and climb a 40 foot rope.

As always, the advantages of learning how to do this successfully is the reward of seeing things that few ever see. It is why engineers and scientists strive so hard to get planetary probes to distant planets. And why humans want to travel to the planets. For me, getting inside a remote and beautifully decorated cave will just have to do.

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3D image of Comet 67P/C-G

9:06 am

Do you own red-blue 3-D glasses? Get them out and go to this link. Rosetta scientists have created a 3-D image of Comet 67P/C-G, including the jets of material shooting out from its surface.

[C]reating a 3d anaglyph of dynamic events like this is notoriously difficult: often the jets are too faint or their duration is too short to find two high-quality images taken several minutes apart that are suitable to pair together to create this type of view. However, the OSIRIS team got lucky with this particular event, capturing two images separated by about two-and-a-half minutes.

The image shows a bright, collimated jet embedded in a broader emission structure. The three dimensional perspective also reveals the conical shape of the jet and that the collimated feature is emitted towards the observer.

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Sunlight rolled the rocks on an asteroid

8:53 am

Scientists studying the rounded rocks on the surface of the asteroid 25143 Itokawa, photographed by the Japanese probe Hayabusa, have concluded that sunlight combined with the asteroid’s tiny gravity caused them move and thus erode themselves.

As sunlight bounced off the orbiting boulders, photons provided a tiny push. As they radiated back outward as heat, they triggered a recoil effect that added a gentle spin. Over time, these slowly spinning boulders bumped into each other with enough force to wear their edges into smooth surfaces.

Warning! This is only a model, and thus could very well be wrong. It is reasonable however and worth considering as a factor in studying the early formation history of asteroids.

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More confirmation from Curiosity of past lakes in Gale Crater

2:25 pm

New data from Curiosity has now provided further confirmation that the deeper sedimentary layers seen in Gale Crater were likely formed far in the past by flowing water.

“Paradoxically, where there is a mountain today there was once a basin, and it was sometimes filled with water,” said John Grotzinger, the former project scientist for Mars Science Laboratory at the California Institute of Technology in Pasadena, and lead author of the new report. “We see evidence of about 250 feet (75 meters) of sedimentary fill, and based on mapping data from NASA’s Mars Reconnaissance Orbiter and images from Curiosity’s camera, it appears that the water-transported sedimentary deposition could have extended at least 500 to 650 feet (150 to 200) meters above the crater floor.”

Furthermore, the total thickness of sedimentary deposits in Gale Crater that indicate interaction with water could extend higher still, perhaps up to one-half mile (800 meters) above the crater floor.

Above 800 meters, Mount Sharp shows no evidence of hydrated strata, and that is the bulk of what forms Mount Sharp. Grotzinger suggests that perhaps this later segment of the crater’s history may have been dominated by dry, wind-driven deposits, as was once imagined for the lower part explored by Curiosity.

This was always the reason to go and climb Mount Sharp. As Curiosity heads uphill it begins to map out the geological history of Mars, first as a wet place with liquid water, then as a dry place in which the water is gone.

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Ice and blue skies on Pluto

11:59 am

New data downloaded from New Horizons has confirmed the presence of ice on the planet’s surface, as well as suggesting that the planet’s sky might actually be colored blue.

The haze particles themselves are likely gray or red, but the way they scatter blue light has gotten the attention of the New Horizons science team. “That striking blue tint tells us about the size and composition of the haze particles,” said science team researcher Carly Howett, also of SwRI. “A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins.”

Scientists believe the tholin particles form high in the atmosphere, where ultraviolet sunlight breaks apart and ionizes nitrogen and methane molecules and allows them to react with each other to form more and more complex negatively and positively charged ions. When they recombine, they form very complex macromolecules, a process first found to occur in the upper atmosphere of Saturn’s moon Titan. The more complex molecules continue to combine and grow until they become small particles; volatile gases condense and coat their surfaces with ice frost before they have time to fall through the atmosphere to the surface, where they add to Pluto’s red coloring.

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Government admits whole milk was always good for you

4:06 pm

The uncertainty of science: A new study has found that whole milk not only does not increase heart disease, it might even help prevent it.

The most significant part of this story however is that when the federal government made the original recommendation that people stop drinking whole milk to avoid fats, the science behind that recommendation was flawed and inconclusive.

But even as a Senate committee was developing the Dietary Goals, some experts were lamenting that the case against saturated fats was, though thinly supported, was being presented as if it were a sure thing. “The vibrant certainty of scientists claiming to be authorities on these matters is disturbing,” George V. Mann, a biochemist at Vanderbilt’s med school wrote in the New England Journal of Medicine. Ambitious scientists and food companies, he said, had “transformed [a] fragile hypothesis into treatment dogma.”

As Morrissey says at the link, “Golly, doesn’t that sound … familiar?”

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Ozone-destroying gas suddenly decreases for no reason

11:49 am

The uncertainty of science: Scientists are baffled by the sudden drop in one kind of atmospheric hydrochlorofluorocarbon (HCFC) gas that is thought to help create the hole in the ozone layer above the south pole.

New measurements show that after a rapid increase of the compound in the atmosphere of the Northern Hemisphere from 0.13 parts per trillion (ppt) in 2000 to 0.50 ppt in 2013, the concentration suddenly dropped to about 0.44 ppt by early 2015. This drop in concentration is equivalent to a 50 percent decline in global emissions percent of the gas: from 3,000 metric tons (3,300 US tons) in 2011 to about 1,500 metric tons (1,700 tons) in 2014, according to the new study.

Now for the kicker: They not only don’t know why this HCFC suddenly declined, they also don’t know where it is coming from. This gas is not one of the gases that were restricted decades ago to save the ozone hole. Until last year, scientists hadn’t even known it existed. And though the article claims it is human-caused, they haven’t yet identified how humans cause it. They hope its sudden decline in the atmosphere will help them pin down its source.

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A planet-forming disk with mysterious ripples

11:40 am

cropped image of dust disk and ripples

The mysteries of science: Astronomers have detected ripples and blobs moving outward through the dust disk surrounding a nearby star, and have no idea what is causing them.

The images reveal a train of wave-like arches, resembling ripples in water. After spotting the features in the SPHERE data the team turned to earlier Hubble images of the disk, taken in 2010 and 2011. The wave-like nature of some of these features were not recognized in the initial Hubble observations. But once astronomers reprocessed the Hubble images they not only identified the features but realized that they had changed over time. The researchers report that these ripples are moving — and they are moving very fast. “We ended up with enough information to track the movement of these strange features over a 3- to 4-year period,” explained team member Christian Thalmann of the Swiss Federal Institute of Technology in Zurich, Switzerland. “By doing this, we found that the arches are racing away from the star at speeds of up to 10 kilometers per second (22,000 miles per hour)!” Co-investigator Carol Grady of Eureka Scientific in Oakland, California, added, “Because nothing like this has been observed or predicted in theory we can only hypothesize when it comes to what we are seeing and how it came about.”

The one theory that is still not refuted is that the star’s flaring activity, which is significant, causes the ripples somehow.

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An avalanche on Mars, as it happens

4:49 pm

Avalanche on Mars

Cool image time! In their routine monitoring for avalanches at the layered deposits at the Martian north pole, the Mars Reconnaissance Orbiter science team captured the avalanche on the right, as it happened.

This picture managed to capture a small avalanche in progress, right in the color strip. … The small white cloud in front of the brick red cliff is likely carbon dioxide frost dislodged from the layers above, caught in the act of cascading down the cliff. It is larger than it looks, more than 20 meters across, and (based on previous examples) it will likely kick up clouds of dust when it hits the ground.

They note that avalanches in this area of Mars are common in the spring when things are warming, and have been documented previously, but possibly not so dramatically.

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Guess where?

3:12 pm

Pluto lake

I found the image on the right while trolling about on the various raw image sites for NASA’s planetary missions. No press release yet, and maybe there never will be one. I do know the scientists involved in this particular mission are right now drooling over the details available in the full resolution image, which I have cropped and reduced to fit on the right. Take a look and you will drool as well.

Want to know where this is? I bet you have already guessed, but if you need help, click on the “read more” link below, where I have also added some comments.
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