Tag: science

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.

» Read more

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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.
» Read more

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IPPC replaces head with economist

2:34 pm

The politics of climate science: The IPCC has selected an economist, Hoesung Lee, to replace the disgraced railroad engineer, Rajendra Pachauri, who had previously been its leader.

That neither Pachauri nor Lee is an actual climate scientist, nor have they ever even done any climate science, tells us all we need to know about the IPCC. It is a political body, designed to push the political agenda of the advocates of human-caused global warming regardless of the scientific evidence. And that political agenda has nothing to do with science or climate, but using science and climate as a tool to impose Marxist fascist rule on everyone.

And if you doubt me, read this article in the science journal Nature describing the possible directions the IPCC will take under Lee’s leadership.

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Ramp down in sunspots continues

12:59 pm

Correction! For reasons I do not understand, the graph below, originally posted on the NOAA website, was incorrect and was changed several days after I posted my piece below. See this post for the correct graph and analysis.

The uncertainty of science: On Monday NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in September. Once again I post it here, below the fold, with annotations to give it context.

For the third month in a row the sunspot count dropped a tiny amount, lingering at about the same number as the previous two months. Moreover, 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.

» Read more

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Curiosity’s future path

9:07 am

Looking up Mt Sharp

Cool image time! The Curiosity science team has produced another panorama of Mount Sharp and the regions that the rover will soon traverse.

This composite image looking toward the higher regions of Mount Sharp was taken on September 9, 2015, by NASA’s Curiosity rover. In the foreground — about 2 miles (3 kilometers) from the rover — is a long ridge teeming with hematite, an iron oxide. Just beyond is an undulating plain rich in clay minerals. And just beyond that are a multitude of rounded buttes, all high in sulfate minerals. The changing mineralogy in these layers of Mount Sharp suggests a changing environment in early Mars, though all involve exposure to water billions of years ago. The Curiosity team hopes to be able to explore these diverse areas in the months and years ahead. Further back in the image are striking, light-toned cliffs in rock that may have formed in drier times and now is heavily eroded by winds.

They have adjusted the colors, adding blue, so that things look as they would on Earth, in order to help the geologists understand what they are looking at.

Be sure and click on the link. The full resolution image is quite amazing. Like mountains on Earth, from a distance things look a lot simpler than they do once you get there. The slopes of Mount Sharp are complex and rugged, and will be a big challenge for Curiosity to traverse.

Moreover, this rough terrain illustrates that the Martian surface has, like Earth, been significantly shaped by erosion. The surface we see here is not the surface produced by the impact that produced the crater. It has been reshaped and eroded over many eons by many later processes, including wind and water.

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It wasn’t just an asteroid that killed the dinosaurs

11:49 am

Scientists have now obtained enough solid data to confirm that the large extinction of the dinosaurs 65 million years ago was caused not just by the Yucatan asteroid impact but also by the gigantic volcanic event in India called the Deccan Traps.

The researchers said the asteroid strike occurred 66.04 million years ago, plus or minus about 30,000 years. They said eruptions in a region called the Deccan Traps were already underway at a lower intensity but dramatically accelerated after the asteroid strike as if the powerful impact triggered it. The dating method they used found this acceleration began within 50,000 years of the impact, but it could have been in the mere days, months or years afterward. “Within measurement error, they’re simultaneous,” said volcanologist Loÿc Vanderkluysen of Philadelphia’s Drexel University. “The two processes in tandem caused the extinctions,” added Paul Renne, director of the Berkeley Geochronology Center and a University of California, Berkeley geologist, who led the study in the journal Science.

Though many planetary scientists have discounted the Deccan Traps for decades, paleontologists have tended to favor it as a major factor in the extinction. This new study suggests that both were involved, which was the theory held by most of the more reasonable scientists in both fields. While many liked to push one or the other theory in the press, the better scientists considered both a possible factor and have been working to determine this possibility.

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Comet 67P/C-G was formed by a soft collision

9:04 am

Scientists, using data from Rosetta, have concluded that Comet 67P/C-G’s double lobed shape was caused by the slow-motion collision of two distinct comets.

By using high-resolution images taken between 6 August 2014 and 17 March 2015 to study the layers of material seen all over the nucleus, they have shown that the shape arose from a low-speed collision between two fully fledged, separately formed comets. “It is clear from the images that both lobes have an outer envelope of material organised in distinct layers, and we think these extend for several hundred metres below the surface,” says Matteo Massironi, lead author from the University of Padova, Italy, and an associate scientist of the OSIRIS team. “You can imagine the layering a bit like an onion, except in this case we are considering two separate onions of differing size that have grown independently before fusing together.”

While erosion continues to eat away at the comet’s surface, changing its shape, the two lobes formed separately, though in much the same way.

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India launches its first space observatory

8:46 am

The competition heats up: India today successfully launched Astrosat, its first space telescope.

ASTROSAT, with a mission life of five years, is armed with telescopes that will simultaneously study the space in visible light, ultraviolet (UV) rays and low- and high-energy X-rays, plus an X-ray scanning sky monitor to detect transient X-ray emissions and γ-ray bursts. The observatory aims to study star-birth regions and high-energy processes, including binary star systems of neutron stars and black holes.

This space observatory fills several gaps that have existed in astronomical research since the shut down of NASA’s Rossi X-Ray Timing Explorer in 2012 as well as the International Ultraviolet Explorer in 1996.

The launch also put six other small satellites into orbit, demonstrating once again the reliability of India’s smaller Polar Satellite Launch Vehicle (PSLV).

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Using fish to study bone loss in weightlessness

9:04 pm

A Japanese experiment on ISS, comparing the development of fish in weightlessness with those on the ground, has provided` scientists more information about bone density loss in weightlessness.

Akira Kudo at Tokyo Institute of Technology, together with scientists across Japan, have shown that medaka fish reared on the International Space Station for 56 days experienced increased osteoclast activity – bone cells involved in the re-absorption of bone tissue – likely leading to a subsequent reduction of bone density. They also found several genes that were upregulated in the fish during the space mission. The team generated fish with osteoclasts that emit a fluorescent signal. They sent 24 fish into space as juveniles, and monitored their development for 56 days under microgravity. The results were compared with a fish control group kept on Earth.

Kudo and his team found that bone mineral density in the pharyngeal bone (the jaw bone at the back of the throat) and the teeth of the fish reduced significantly, with decreased calcification by day 56 compared with the control group. This thinning of bone was accompanied by an increase in the volume and activity of osteoclasts. The team conducted whole transcriptome analysis of the fish jaws, and uncovered two strongly upregulated genes (fkbp5 and ddit4), together with 15 other mitochondria-related genes whose expression was also enhanced. Reduced movement under microgravity also has an influence. The fish began to exhibit unusual behavior towards the latter stages of their stay in space, showing motionless at day 47.

What the data mostly confirms is that long-term weightlessness is a bad thing for the development of bones, and not just in humans. Whether scientists can use these results to counter these harmful effects is not clear, however.

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