Tag: science

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).

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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.
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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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The Earth has a lot of trees!

9:32 am

The uncertainty of science: A new estimate of the number of trees on Earth has increased that estimate seven-fold, from about 400 billion to 3 trillion.

The previously accepted estimate of the world’s tree population, about 400 billion, was based mostly on satellite imagery. Although remote imaging reveals a lot about where forests are, it does not provide the same level of resolution that a person counting trunks would achieve.

Crowther and his colleagues merged these approaches by first gathering data for every continent except Antarctica from various existing ground-based counts covering about 430,000 hectares. These counts allowed them to improve tree-density estimates from satellite imagery. Then the researchers applied those density estimates to areas that lack good ground inventories. For example, survey data from forests in Canada and northern Europe were used to revise estimates from satellite imagery for similar forests in remote parts of Russia.

That these same scientists can, in this same story, also claim with almost certainty that the number of trees on Earth has declined precisely 46% since homo sapiens appeared 12,000 years ago illustrates the difficulty humans have to remain skeptical. How do they get this precise number for the tree count 12,000 years ago? It appears to me that they have allowed the modern environmental agenda of blaming the evil destruction of the environment on humanity to cloud their thinking.

If scientists have discovered a seven-fold error in their count today, I am sure the margin of error for an estimate for 12,000 years ago will be much higher.

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High res radar instrument fails on Earth observation satellite

9:18 am

Only seven months after launch one of the two instruments on NASA’s Soil Moisture Active Passive (SMAP) Earth observation satellite has failed.

Launched on Jan. 31, the Soil Moisture Active Passive spacecraft’s objective is to map global soil moisture and to detect whether soils are frozen or thawed. It is the first mission where scientists have attempted to collect high-resolution, high-accuracy soil moisture data, said Kent Kellogg, SMAP’s JPL-based project manager.

NASA budgeted $916 million for the mission and has been working on it for the past eight years. “We do a lot of testing on the ground to make sure the designs will be built properly and will last in the environment,” Kellogg said. “But space is a very unforgiving place, and we can have these kinds of problems where despite our best efforts with design and vigorous testing, something surprises us. It’s very uncommon, but these things can happen occasionally.”

SMAP’s two scientific tools are an active radar and a passive radiometer. They complement each other, making up for the other’s measurement limitations. The broken radar collected soil moisture and freeze-thaw measurements at a higher resolution of up to 1.9 miles. The still functioning radiometer generates more accurate measurements but its resolution is lower at about 25 miles. [emphasis mine]

I am not satisfied by the explanation for the failure expressed above. NASA spent a lot of money for this science satellite over almost a decade. In addition, we have been launching instruments like this for almost half a century, and have by now learned quite well the engineering necessary to keep them operating under the conditions in low Earth orbit. I suspect a screw-up somewhere, which we might or might not ever identify.

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Apollo lunar samples crumbling to dust

9:08 am

The uncertainty of science: A comparison between the average particle size of 20 Apollo moon soil samples has discovered that their size has decreased by more than half in the past 40 years.

The differences between the two datasets are stark. For example, the median particle diameter has decreased from 78 microns (0.0031 inches) to 33 microns (0.0013 inches). And in the original sieve data, 44 percent of soil particles were between 90 and 1,000 microns (0.0035 to 0.039 inches) wide; today, just 17 percent of the particles are that large.

The most likely explanation for the degradation is damage caused by water vapor, the scientists say. “Leaching by water vapor causes the specific surface area of a lunar soil sample to multiply, and a system of pores develops,” they wrote in the study, which was published online last week in the journal Nature Geoscience. “These structural changes may be attributed to the opening of existing, but previously unavailable, pore structure or the creation of new surfaces through fracturing of cement or dissolution of amorphous particles.”

I was surprised that in the article above the scientists made no mention of gravity as a factor. These particles were originally formed under lunar gravity, 1/6 that of Earth. I would have thought that their structural strength was partly determined by this, and once brought to Earth’s heavier gravity would have thus slowly deteriorated over time.

Either way, the study illustrates why saving these samples for future researchers was a foolish mistake. Time changes all things, and that change has made these samples no longer a good representation of the Moon. The NASA scientists and managers who decided to store these samples instead of distributing them all for immediate study forgot this basic fact.

The scientists who did this study appear to have not learned this lesson as well. They suggest future samples be stored off-Earth, in a place like ISS. I say, we should instead go to the Moon so often we don’t need to store any samples. When we want a sample, we go and get one.

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Technical problems for cosmic ray detector on ISS

9:53 am

The failure of a second of four cooling pumps on the Alpha Magnetic Spectrometer on ISS threatens the science instrument’s ability to continue its observations.

The AMS continues to gather science data using the three remaining pumps. They are part of a liquid carbon dioxide cooling system that is meant to dissipate heat as the AMS, which is on the outside of the space station, cycles in and out of sunlight during each 90-minute orbit of Earth Only one pump is needed at any given time. One failed in February 2014 and at least one of the other three is showing possible signs of trouble.

Since the 8.5-tonne AMS began operating in 2011, it has tracked more than 69 billion cosmic rays flying through its detectors. Its goal is to search for antimatter and dark matter. In 2013, AMS scientists reported measuring numbers and energies of positrons that hinted at, but did not confirm, the existence of dark matter.

The news article suggests that the instrument is now working with only one reliable pump. It also is possible that repairs might be done by astronauts on ISS during a spacewalk.

Some background: AMS cost $2 billion and about 20 years to build. It only got launched because Congress ordered NASA to launch one more shuttle mission to ISS to get it there.

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Curiosity spots a spoon on Mars!

9:04 am

The spoon on Mars

Very cool image time! In one of Curiosity’s recent images of the Martian surface on the slopes of Mount Sharp appears what looks like a long thin spoon jutting horizontally out of the ground.

The shadow below the feature is strong evidence that that this almost certainly a real object, shaped exactly as we see it. However, it is not an artificially created spoon. If you look at both the full raw image as well as zoom in on the feature itself, you will see that it is something that formed naturally due to Mars’ low gravity and the geology here. The spoon is a thin prong of harder material that has remained intact as the ground below it has been slowly eroded away by the ever-present but very weak Martian wind. If you look close you can see that harder material extend back into the rock behind the spoon.

Some of that erosion might also have been caused by flowing water sometime in the past, but to confirm this will take additional geological research.

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Data from New Horizons does not match what is seen from Earth

9:10 am

The uncertainty of science: Planetary geologists are presently baffled by a conflict in the atmospheric data between New Horizons and data gathered from Earth.

On 29 June, a few weeks before the fly-by, Young organized astronomers across New Zealand and Australia to watch Pluto as it passed in front of a distant star. Tracking how the star’s light faded during the passage provided information on how much gas is in Pluto’s atmosphere. Using the same method, planetary scientists have seen the atmosphere grow denser since 1988 — and analysis of the 29 June observations shows that the trend remains intact. Young calculates that the current atmospheric pressure at Pluto’s surface is 22 microbars (0.022 pascals), or 22-millionths the pressure at sea level on Earth.

But on 14 July, New Horizons measured Pluto’s surface pressure as much lower than that ­— just 5 microbars. “How we link the two, we’re still working on,” says Cathy Olkin, a deputy project scientist for New Horizons at SwRI.

The difference could simply be that Pluto’s atmosphere is not smooth, that some regions are dense while others are thin, and New Horizons happened to look at a thin place. The Earth observations don’t have the resolution to separate the two.

There are other proposals to explain the problem. Regardless, the answer is likely hidden in the data from New Horizons that has still not been downloaded back to Earth. In a few months, all might very well become clear.

Or not, as is the natural state of science.

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New Horizons team picks its next Kuiper Belt target

3:07 pm

The New Horizons science team has picked its next Kuiper Belt fly-by target beyond Pluto.

New Horizons will perform a series of four maneuvers in late October and early November to set its course toward 2014 MU69 – nicknamed “PT1” (for “Potential Target 1”) – which it expects to reach on January 1, 2019. Any delays from those dates would cost precious fuel and add mission risk. “2014 MU69 is a great choice because it is just the kind of ancient KBO, formed where it orbits now, that the Decadal Survey desired us to fly by,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado. “Moreover, this KBO costs less fuel to reach [than other candidate targets], leaving more fuel for the flyby, for ancillary science, and greater fuel reserves to protect against the unforeseen.”

The press release includes some silly gobbly-gook about how the science team can’t announce this as its official target because they still have to write up a proposal to submit to NASA, which then must ponder their decision and decree it valid. We all know this is ridiculous. Will NASA sit and ponder and make them miss their target? I doubt it.

The fly-by itself will be really exciting, because this object will truly be the most unusual we will have ever gotten a close look at, as it has spent its entire existence far out in the dim reaches of the solar system.

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Comet 67P/C-G goes boom!

7:48 am

Outburst on Comet 67P/C-G

Cool image time! On August 22, just days after its closest approach to the sun, Rosetta caught the outburst, image above, from the larger lobe on Comet 67P/C-G.

The image scale is 28.6 m/pixel and the image measures 29.3 km across. Although the activity is extraordinarily bright even in the original (below), the image above has been lightly enhanced to give a better view of the outline of the nucleus in the lower part of the image, as well as to show the full extent of the activity.

The most interesting images, I think, will actually come later, when the activity dies down and they can bring Rosetta in closer again. We will then be able to compare the nucleus both before and after this outburst, getting a sense of how the comet changes with each close pass to the sun.

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More than half of published psychology papers cannot be replicated

11:51 am

The uncertainty of science: An attempt to replicate 98 different psychological research studies has found that significantly less than half could be replicated.

In the biggest project of its kind, Brian Nosek, a social psychologist and head of the Center for Open Science in Charlottesville, Virginia, and 269 co-authors repeated work reported in 98 original papers from three psychology journals, to see if they independently came up with the same results. The studies they took on ranged from whether expressing insecurities perpetuates them to differences in how children and adults respond to fear stimuli, to effective ways to teach arithmetic.

According to the replicators’ qualitative assessments, as previously reported by Nature, only 39 of the 100 replication attempts were successful. … There is no way of knowing whether any individual paper is true or false from this work, says Nosek. Either the original or the replication work could be flawed, or crucial differences between the two might be unappreciated. Overall, however, the project points to widespread publication of work that does not stand up to scrutiny. [emphasis mine]

None of this surprises me. The focus of much science research, especially in the soft sciences like psychology, is statistical in nature and easily manipulated. In fact, most of it isn’t science at all, but an attempt to use mere statistics to prove a point. Science would instead try to find out why something happens, not just demonstrate through statistics that it does.

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IAU balks at some Pluto names picked by New Horizons team

9:12 am

Irritated that the New Horizons team did not consult with the International Astronomical Union (IAU) before it announced its proposed names for many Pluto features, IAU officials are now threatening to reject them once submitted.

“Frankly, we would have preferred that the New Horizons team had approached us before putting all these informal names everywhere,” said Rosaly Lopes, a senior research scientist at NASA’s Jet Propulsion Laboratory who is a member of the IAU’s Working Group for Planetary System Nomenclature.

The group’s chair, Rita Schulz of the European Space Agency, said the New Horizons team has not yet submitted a formal proposal for naming features on Pluto and its moons. “Usually, there are always some features for which this process goes rather fast, some for which more checks and balances are required (which then takes a bit longer) and there are usually also some names or descriptors that cannot be approved and need to be replaced by others,” she told GeekWire in an email.

There has been a conflict between the IAU and the principal investigator for New Horizons, Alan Stern, for years now. Stern also runs the private company Uwingu, which offers citizens the ability to name unnamed craters on Mars for a fee, without asking the IAU. Stern, like myself, believes that the IAU’s claim that it is the only authority that can approve names for every object not on Earth is hogwash. Stern also strongly objects to the IAU’s decision to demote Pluto’s planetary status to a dwarf planet.

These comments by IAU officials suggest that they are being somewhat petty and are threatening to reject the New Horizons names to get back at Stern.

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New Hubble image of Twin Jet Nebula

8:27 am

Twin Jet Nebula

Astronomers using the Hubble Space Telescope have taken a new image of the Twin Jet Nebula, a planetary nebula officially called PM M2-9.

The M in this name refers to Rudolph Minkowski, a German-American astronomer who discovered the nebula in 1947. The PN, meanwhile, refers to the fact that M2-9 is a planetary nebula. The glowing and expanding shells of gas clearly visible in this image represent the final stages of life for an old star of low to intermediate mass. The star has not only ejected its outer layers, but the exposed remnant core is now illuminating these layers — resulting in a spectacular light show like the one seen here. However, the Twin Jet Nebula is not just any planetary nebula, it is a bipolar nebula.

The bipolar nature of the nebula is thought to be caused by the interaction of a binary star system. I like to say that the orbiting stars act like the blades in a blender, mixing the ejected layers of material to produce the jets and shapes that make planetary nebula so beautiful.

Hubble first imaged this nebula in 1997. This image, using the telescope’s newer instruments, is important because it shows the complex layers within each jet, suggesting multiple ejection events in the past.

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