Tag: science

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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Rosetta data reveals how a comet evaporates

9:57 am

Newly released Rosetta data has shown, for at least one area on the surface of Comet 67P/C-G, the process by which the surface ice is replaced by water ice from below as the comet rotates and sunlight causes the surface ice to evaporate away.

The data suggest that water ice on and a few centimetres below the surface ‘sublimates’ when illuminated by sunlight, turning it into gas that then flows away from the comet. Then, as the comet rotates and the same region falls into darkness, the surface rapidly cools again. However, the underlying layers remain warm owing to the sunlight they received in the previous hours, and, as a result, subsurface water ice keeps sublimating and finding its way to the surface through the comet’s porous interior.

But as soon as this ‘underground’ water vapour reaches the cold surface, it freezes again, blanketing that patch of comet surface with a thin layer of fresh ice. Eventually, as the Sun rises again over this part of the surface on the next comet day, the molecules in the newly formed ice layer are the first to sublimate and flow away from the comet, restarting the cycle.

They discovered this process when they noticed surface ice evaporating in this region during the comet’s 6-hour day and then getting resurfaced with ice during the comet’s 6-hour night.

Meanwhile, Rosetta is about to move as much as 1500 kilometers away from the comet for several weeks so that its scientists can study its coma more broadly.

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New Pluto images

4:07 pm

thumbnail of Pluto closeup

Cool image time! The New Horizons team has released some new images. A thumbnail of what I think is the most interesting image is shown on the right. Be sure to look at the full resolution image. It shows a flat plain of what look like frozen polygon plates with a thin layer of what appear to be dunes. In the center some rocks poke out like islands, with what looks like a wind-swept wake to the right. The wake could be caused by Pluto’s very thin atmosphere. Or maybe there are currents that slowly push the frozen plates past the harder rocks (which probably are ice, which in Pluto’s very cold environment has the structural strength of granite).

These images were posted on the New Horizons website with no accompanying press release. I think the science team has decided it will just upload them, and reserve press releases for when they have accumulated enough data to announce some intelligent conclusions. Right now, they can only speculate as wildly as I from these images. It is reasonable to give them the time to assess the data more closely before announcing any explanations. At the same time, we should also congratulate them for posting the images immediately so that others can see them.

Update: a press release was released, though it really doesn’t add much except review the images.

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Researchers push for access to confidential government records of the public

11:51 am

What could possibly go wrong? Researchers in a number of fields want access to the vast amount of private government data that is routinely gathered from the public.

In the past few years, administrative data have been used to investigate issues ranging from the side effects of vaccines2 to the lasting impact of a child’s neighbourhood on his or her ability to earn and prosper as an adult3. Proponents say that these rich information sources could greatly improve how governments measure the effectiveness of social programmes such as providing stipends to help families move to more resource-rich neighbourhoods.

But there is also concern that the rush to use these data could pose new threats to citizens’ privacy. “The types of protections that we’re used to thinking about have been based on the twin pillars of anonymity and informed consent, and neither of those hold in this new world,” says Julia Lane, an economist at New York University. In 2013, for instance, researchers showed that they could uncover the identities of supposedly anonymous participants in a genetic study simply by cross-referencing their data with publicly available genealogical information.

Read it all. It is terrifying to me how governments worldwide increasingly consider this private data their property to use as they wish. For example:

In the United States, the Census Bureau has been expanding its network of Research Data Centers, which currently includes 19 sites around the country at which researchers with the appropriate permissions can access confidential data from the bureau itself, as well as from other agencies. “We’re trying to explore all the available ways that we can expand access to these rich data sets,” says Ron Jarmin, the bureau’s assistant director for research and methodology.

I ask: What business is it of the Census Bureau to do this? The information they gather was originally intended solely to determine Congressional districts. Moreover, who gave them the right to release the confidential data to anyone? Have they asked anyone for this permission?

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Changes on the surface of Comet 67P/C-G

6:16 pm

In a science paper now accepted for publication, the Rosetta science team have described changes that have occurred on the surface of Comet 67P/C-G from May through July of this year as the comet moved closer to the Sun and activity increased.

The changes were seen in a smooth area dubbed Imhotep.

First evidence for a new, roughly round feature in Imhotep was seen in an image taken with Rosetta’s OSIRIS narrow-angle camera on 3 June. Subsequent images later in June showed this feature growing in size, and being joined by a second round feature. By 2 July, they had reached diameters of roughly 220 m and 140 m, respectively, and another new feature began to appear.

By the time of the last image used in this study, taken on 11 July, these three features had merged into one larger region and yet another two features had appeared.

Be sure to click on the link to see the images. The changes look like a surface layer is slowing evaporating away.

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More data tampering at NOAA

3:18 pm

The uncertainty of science: An analysis of the 2015 climate data released by NOAA suggests that they continue to adjust the data on a yearly basis to cool the past and warm the present so as to create the false illusion of global warming,.

More here. There is no justification for these adjustments. None. Worse, the NOAA scientists don’t even bother to try to explain the changes, even the changes to past data from 2014 to 2015.

The most damning aspect is that the adjustments only shift things in one direction — increasing the illusion that the climate is warming. This strongly suggests that these changes are political and not scientific, and that there is fraud and corruption at NOAA.

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Global warming advocates call for the prosecution of scientists who disagree with them

11:31 pm

Fascists: Twenty global warming scientists have written a public letter to President Obama demanding he prosecute those who challenge their claim that humans are causing the climate to warm.

We appreciate that you are making aggressive and imaginative use of the limited tools available to you in the face of a recalcitrant Congress. One additional tool – recently proposed by Senator Sheldon Whitehouse – is a RICO (Racketeer Influenced and Corrupt Organizations Act) investigation of corporations and other organizations that have knowingly deceived the American people about the risks of climate change, as a means to forestall America’s response to climate change.

The very fact that these global warming scientists find it necessary to demand their opponents be prosecuted proves that their claims are invalid. If they had the facts on their side, there would be no need for them to call for the government to prosecute and possibly imprison those who disagree with them. They could simply cite the facts, using a willing press to spread the news, and the opposition of this small minority of skeptics would make little difference. The public would pay the skeptics no mind.

The public however is not stupid and has been following this story with great interest. They might not be convinced that the skeptics are right, but the public is also very doubtful about the claims of the global warming advocates. Instead, the public is aware that the science of the climate is very uncertain, and that more facts are required before they will be convinced about anything.

What this letter does prove, beyond a shadow of a doubt, is that many important members of the global warming community are downright fascists, and do not believe in freedom and the first amendment.

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Philomena Cunk’s Moments of Wonder: Time

6:01 pm

An evening pause: This hilarious parody of BBC science documentaries, which are not much different than many American PBS science documentaries, captures perfectly the typical empty-headed interviewers that I myself have sometimes had to deal with during too many of my television and radio appearances. They are not only often ignorant of some basic science, they are also ignorant of their own ignorance. They think they know a lot, and thus are easily confused and defensive when suddenly confronted with that ignorance.

I especially like her description of “the famous Greenwich Marillion line.”

Hat tip to Danae.

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New images from Pluto

3:32 pm

Mountains and glaciers on Pluto

Cool image time! As expected, the New Horizons team has made its weekly press announcement, though on Thursday instead of Friday, releasing new images taken by the spacecraft during its July 14 flyby.

The image above has been cropped and reduced by me to fit. Make sure you look at the full resolution image.

Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured a near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto’s tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 230 miles (380 kilometers) across.

The mountains are made of ice, the glacier flows of nitrogen.

The main takeaway so far is that Pluto might have a “hydrological” cycle like Earth’s, but instead of water cycling from ice to water to gas to rain, it appears it is nitrogen and other strange materials.

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Giant global ocean inside Saturn’s moon Enceladus

1:53 pm

Using data from seven years of flybys by Cassini of Enceladus scientists now think they have confirmed the existence of a global ocean of liquid water beneath the moon’s icy crust.

Cassini scientists analyzed more than seven years’ worth of images of Enceladus taken by the spacecraft, which has been orbiting Saturn since mid-2004. They carefully mapped the positions of features on Enceladus — mostly craters — across hundreds of images, in order to measure changes in the moon’s rotation with extreme precision. As a result, they found Enceladus has a tiny, but measurable wobble as it orbits Saturn. Because the icy moon is not perfectly spherical — and because it goes slightly faster and slower during different portions of its orbit around Saturn — the giant planet subtly rocks Enceladus back and forth as it rotates.

The team plugged their measurement of the wobble, called a libration, into different models for how Enceladus might be arranged on the inside, including ones in which the moon was frozen from surface to core. “If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be,” said Matthew Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a co-author of the paper. “This proves that there must be a global layer of liquid separating the surface from the core,” he said.

Previous data had suggested a lens-shaped ocean under the south pole. This new data suggests the ocean in global.

As always, the possibility of liquid water suggests the possibility of life. None has been found, but with water and energy it is certainly possible.

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Rivers and lakes on Pluto?

8:49 am

Cool image time! Though the New Horizons science team will likely not issue their next press release until Friday, they appear to be posting new images on their website on a daily basis. From those images I pulled out the one below, which to fit I have cropped and reduced slightly in size. Be sure to go to the full image.

Do you see what I see? It appears that there are meandering braided dry streambeds on Pluto, draining into what appears to be a large basin.

Rivers and lakes on Pluto?

Assuming my guess of what this is is correct, this is obviously not a streambed created by water. Earlier images showed nitrogen ice flows and glacier-like geology. It is possible this new image is observing evidence of past nitrogen riverbeds and nitrogen lakes.

Expect a very interesting press release from New Horizons later this week.

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Astronomers find no evidence of nearby alien civilizations

8:33 am

New observations of the best candidate galaxies now suggests that very advanced civilizations are very rare or don’t exist in the local universe.

They looked at several hundred nearby galaxies that emitted a high amount of mid-infrared radiation, which could possibly be produced as the waste heat from civilizations using energy on galactic scales.

Professor Michael Garrett (ASTRON & University of Leiden) has used radio measurements of the very best candidate galaxies and discovered that the vast majority of these systems present emission that is best explained by natural astrophysical processes. In particular, the galaxies as a sample, follow a well-known global relation that holds for almost all galaxies – the so-called “Mid-Infrared Radio correlation”. The presence of radio emission at the levels expected from the correlation, suggests that the mid-IR emission is not heat from alien factories but more likely emission from dust – for example, dust generated and heated by regions of massive star formation.
As Professor Garrett explains: “the original research at Penn State has already told us that such systems are very rare but the new analysis suggests that this is probably an understatement, and that advanced Kardashev Type III civilisations basically don’t exist in the local Universe. In my view, it means we can all sleep safely in our beds tonight – an alien invasion doesn’t seem at all likely!”.

Joking aside, Professor Garrett is still looking at a few candidate galaxies that lie off of the astrophysical correlation: “Some of these systems definitely demand further investigation but those already studied in detail turn out to have a natural astrophysical explanation too. It’s very likely that the remaining systems also fall into this category but of course it’s worth checking just in case!”

Obviously, the uncertainty of these results is quite high. Nonetheless, the results indicate that either humanity really is the only intelligent species in this part of the universe, or advanced civilizations are far more efficient in their use of energy than is reasonable to assume.

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Decline to solar minimum

9:17 am

Last week NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in August. As I have done every month since 2010, I am posting it here, below the fold, with annotations to give it context.

The sunspot count continued its decline, though dropping only a small amount. Regardless, the decline continues at a rate far faster than predicted or is usual during the ramp down from solar maximum. If this rate of decline should continue, we will reach solar minimum sometime late in 2017, two years earlier than predicted (as indicated by the red curve).

» Read more

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Whiskey tastes strange after being aged in space

12:08 pm

Whiskey that was aged for three years on ISS was taste-tested this past week in Scotland, and the testers all found the taste “completely unlike anything they have ever tasted before.”

The space whiskey had a much smokier quality, with flavors akin to cherries, prunes, raisins, and cinnamon, he said. He also noted that the whiskey’s aftertaste was “pungent, intense, and long, with hints of wood, antiseptic lozenges, and rubbery smoke.” This was in contrast to the Earth-aged whiskey, which had richer flavors more characteristic of whiskey drinks. The space whiskey still had strong flavor, but they were strange, Lumsden said — and not particularly good. He still has yet to figure out why. “That I haven’t been able to work out yet,” he said.

This is not the same Japanese whiskey that was recently sent up to ISS. That is a second experiment, along the same lines.

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CDC expands investigation into military handling of dangerous disease samples

10:46 am

Does this make you feel safer? The Centers for Disease Control (CDC) has now expanded its investigation of the Defense Department’s handling of dangerous infectious disease samples.

The Centers for Disease Control and Prevention is expanding its investigation into possible mishandling and improper shipment by Defense Department laboratories of organisms that cause deadly diseases, including plague and encephalitis, U.S. officials said Thursday. Concerns about the handling of those samples led the Army to announce a moratorium on production, shipping and handling of toxins at nine labs last week. But officials did not acknowledge until Thursday that plague and encephalitis samples were involved.

When asked why the Pentagon didn’t disclose the new concerns about plague and encephalitis last week, Pentagon press secretary Peter Cook said that officials were trying to be as forthcoming as possible “without alarming the public.” [emphasis mine]

In other words, the Defense Department withheld critical information because it made them look bad and illustrated how dangerous their mishandling of dangeous diseases has been.

Other than that, all is well!

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A detailed update on the efforts to contact Philae

9:29 am

Link here.

The story is fascinating because the lander’s behavior and response to commands has been quite puzzling. They have had about a half dozen short contacts of varying length, all interspersed with a lot of intermittencies. At the moment they have not entirely given up on Philae, since based on what they know of its location and condition it could remain functional through the end of this year. They also recognize that re-establishing contact is becoming increasingly unlikely. The big hope is that once the comet moves farther away from the sun and becomes less active, they will be able to move Rosetta in closer, when the chances of contact will improve.

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New Pluto images!

7:27 pm

Chaos region

Cool image time! The first of what will likely be weekly image releases for the next few months from New Horizons was made public today, and shows Pluto’s surface to be incredibly complex and confusing.

New close-up images of Pluto from NASA’s New Horizons spacecraft reveal a bewildering variety of surface features that have scientists reeling because of their range and complexity. “Pluto is showing us a diversity of landforms and complexity of processes that rival anything we’ve seen in the solar system,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI), Boulder, Colorado. “If an artist had painted this Pluto before our flyby, I probably would have called it over the top — but that’s what is actually there.”

The image above only shows one cropped section. Make sure you look at the full image. In the section I’ve cropped we can see nitrogen ice flowing around chunks of some darker harder material, probably water ice. On the left, near the small crater, is what appears to be a canyon formed by flowing liquid. Other images show what appear to be dunes!

It appears, as is typical of scientific exploration, that we are going to be left with more questions from the New Horizons’ data than we had before the fly-by occurred.

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Martian floods regional, not global

5:52 pm

Using the data accumulated from various modern Mars orbiters scientists now think that many of the Martian floods were caused by regional circumstances rather than a single global event.

“The flooding is due to regional processes, not global processes,” said Rodriguez, a Senior Scientist at the Planetary Science Institute and lead author of “Martian outflow channels: How did their source aquifers form, and why did they drain so quickly?” that appears in a Nature Scientific Report. “Deposition of sediment from rivers and glacial melt filled giant canyons beneath a primordial ocean contained within the planet’s northern lowlands. It was the water preserved in these canyon sediments that was later released as great floods, the effects of which can be seen today.”

The canyons filled, the Martian ocean disappeared, and the surface froze for approximately 450 million years. Then, about 3.2 billion years ago, lava beneath the canyons heated the soil, melted the icy materials, and produced vast systems of subterranean rivers extending hundreds of kilometers. This water erupted onto the now-dry surface in giant floods.

This theory suggests that Mars still has a great deal of trapped frozen water held in large underground reserves, available for future colonists. I like the fact that it also suggests that there were “vast systems of subterranean rivers extending hundreds of kilometers” where this frozen water was once stored and, having now melted, has left behind gigantic underground caverns.

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New human species found?

10:34 am

The uncertainty of science: Scientists in South Africa think they have found fossils of a new human species.

In the end, the work of more than 60 researchers yielded a picture of “a relatively tall, skinny hominid with long legs, humanlike feet, with a core and shoulder that is primitive,” Berger says. Some body parts have come into sharper focus than others. In an analysis of the remarkably complete hands, paleoanthropologist Tracy Kivell of the University of Kent in the United Kingdom found that bones in the wrist were shaped like those in modern humans, suggesting that the palm at the base of the thumb was quite stiff. That would allow forces to dissipate over a larger area of the hand than in more primitive humans—a trait associated with tool use. At the same time, H. naledi had a weird thumb and long, curving fingers, as if it still spent a lot of time climbing.

The story of the discovery is interesting in that the fossils were found in a cave in a room that is very difficult to access, so difficult that the scientists themselves have never seen the site. Instead, they have sent very small cavers inside to do the fossil gathering.

There are many caveats to this story. The 15 skeletons appear different than humans, but to then create a whole human species from this single location is a bit risky.

I think the biggest mystery about this find involves its location. How the heck did these 15 individuals get trapped in this room at the back of a cave that requires you to squeeze down a vertical 100-foot chute only about 8 inches wide to enter?

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Closing in on Ceres’s bright spots

9:33 am

Ceres's bright spots

Cool image time! The Dawn science team has released a new close-up of Ceres’s Double Bright Spot.

The new up-close view of Occator crater from Dawn’s current vantage point reveals better-defined shapes of the brightest, central spot and features on the crater floor. Because these spots are so much brighter than the rest of Ceres’ surface, the Dawn team combined two different images into a single composite view — one properly exposed for the bright spots, and one for the surrounding surface.

They have also released a detailed topographic map of the crater as well as a fly-around video, which I have posted below the fold. The interesting take-away from this new data is that, while the bright spots look at first glance remarkably like the snow-cap on a mountain-top, they are actually at the low spots in the crater. This suggests that they are instead material that has either bubbled up from below, or flowed downward to the crater bottom.

Be sure you click on the link and look at the full resolution image.
» Read more

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Venus probe about to rise from the dead

9:07 am

Five years after it failed to enter Venus orbit as planned, the Japanese probe Akatsuki is about to try again, in December.

The article provides an interesting and detailed explanation of what had gone wrong in 2010, and then describes the amazing things engineers have done to make this second attempt even possible. If they succeed it will be one of the most brilliant achievements in the history of space exploration.

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