Tag: science

More data says no alien civilization at KIC 8462852

9:32 am

New observations of the star KIC 8462852 to see if an alien civilization had produced laser signals has produced a null result, reinforcing the conclusion that the erratic dimming of the star is not caused by alien megastructures.

On six nights between October 29 and November 28, 2015, scientists searched for pulses as short as a billionth of a second at the Boquete Optical SETI Observatory in Panama, using a 0.5 m Newtonian telescope. The observatory’s relatively small telescope uses a unique detection method having enhanced sensitivity to pulsed signals. If any hypothetical extraterrestrials had beamed intentional laser pulses in the visible spectrum toward Earth, the Boquete observatory could have detected them so long as they exceeded the observatory’s minimum detectable limit.

KIC 8462852 has puzzled astronomers because it shows irregular dimming unlike anything seen for another star. The anomalous light curve was measured using NASA’s Kepler telescope, as part of its search for exoplanets. However, even though a planet the size of Jupiter would cause dimming of approximately 1%, the dimming observed for KIC 8462852 was far greater – up to 22%. Just as strange, the dimming didn’t follow the regular pattern of a planet orbiting a star, but instead was unpredictable. The best explanation to date is that the dimming may have been caused by cometary fragments in a highly elliptical orbit around KIC 8462852, intercepting starlight at the same time the Kepler mission was observing it.

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Sunspots continue predicted decline

4:30 pm

On Sunday NOAA posted, as it does each month, its monthly update of the solar cycle, showing the Sun’s sunspot activity in November. And as I have done every month since 2010, I am posting it here, with annotations to give it context.

Though sunspot activity in November was just slightly higher than in October, the increase was so small that it is insignificant. Essentially, the overall decline in sunspot count continues, matching almost perfectly the ramp down predicted by the 2007 low prediction. Solar activity continues to be far weaker then anything seen in a century. Whether this suggests a coming Grand Minimum, however, is not known. Solar activity could continue to decline as we move into the next solar cycle, or it could recover. Our understanding of what causes the sunspot cycle remains somewhat fuzzy, which means our ability to predict what will happen next is as fuzzy..

November 2015 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

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A new technique for creating diamonds

8:54 am

In discovering a new solid state for carbon scientists have also discovered that it is a relatively inexpensive way to produce diamonds.

Professor Jay Narayan of North Carolina State University is the lead author of three papers describing the work that sees Q-carbon join the growing list of carbon solids, a list that includes graphite, graphene, fullerene, amorphous carbon and diamond. He has suggested that the only place Q-carbon might be found in the natural world is in the core of certain planets.

The researchers created Q-carbon by starting with a thin plate of sapphire (other substrates, such as glass or a plastic polymer, will also work). Using a high-power laser beam, they coated the sapphire with amorphous carbon, a carbon form with no defined crystalline structure. They then hit the carbon with the laser again, raising its temperature to about 4,000 Kelvin, and then rapidly cooled, or quenched, the melted carbon. This stage of quenching is where “Q” in Q-carbon comes from.

The researchers have found that, depending on the substrates, tiny diamonds will form within the Q-carbon, suggesting to me that they have actually discovered how diamonds are formed deep below the Earth. The hot high pressure environment there allows Q-carbon to naturally form, and in the process of its solidification diamonds are a byproduct.

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Success at last for Akatsuki

8:45 am

Five years after the Japanese Venus probe Akatsuki’s main engines failed while trying to put it into orbit, the spacecraft today fired its attitude thrusters and was successfully inserted into orbit.

This is a singular achievement by the Japanese engineers running the mission. They improvised a plan using the thrusters, which were designed to adjust the spacecraft orientation, not its course, and were able to get Akatsuki in an solar orbit that brought it back to Venus.

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New spectacular images of Pluto

3:01 pm

Pluto's mountainous shoreline

Many cool images! The New Horizons science team has today released new images from the spacecraft’s close fly-by of Pluto.

These latest pictures are part of a sequence taken near New Horizons’ closest approach to Pluto, with resolutions of about 250-280 feet (77-85 meters) per pixel – revealing features less than half the size of a city block on the diverse surface of the distant planet. In these new images, New Horizons captured a wide variety of spectacular, cratered, mountainous and glacial terrains.

I have cropped and lowered the resolution of the image above to fit it here. Make sure you click on the link to see it and the other images. As they note,

In this highest-resolution image from NASA’s New Horizons spacecraft, great blocks of Pluto’s water-ice crust appear jammed together in the informally named al-Idrisi mountains. Some mountain sides appear coated in dark material, while other sides are bright. Several sheer faces appear to show crustal layering, perhaps related to the layers seen in some of Pluto’s crater walls. Other materials appear crushed between the mountains, as if these great blocks of water ice, some standing as much as 1.5 miles high, were jostled back and forth. The mountains end abruptly at the shoreline of the informally named Sputnik Planum, where the soft, nitrogen-rich ices of the plain form a nearly level surface, broken only by the fine trace work of striking, cellular boundaries and the textured surface of the plain’s ices (which is possibly related to sunlight-driven ice sublimation).

Today’s release also includes a short animation of a faint distant Kuiper Belt object, assembled by four images taken by New Horizons. The images don’t show much more than a streak of light, but the feat of imaging this object by a spacecraft billions of miles away in this manner is breath-taking.

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India wins contract to launch private weather satellites

8:39 am

The competition heats up: The first two satellites in the first private weather satellite constellation will be launched on India’s PSLV rocket.

With 12 satellites on orbit, PlanetiQ will collect approximately 34,000 “occultations” per day, evenly distributed around the globe with high-density sampling over both land and water. Each occultation is a vertical profile of atmospheric data with very high vertical resolution, comprised of measurements less than every 200 meters from the Earth’s surface up into the ionosphere. The data is similar to that collected by weather balloons, but more accurate, more frequent and on a global scale.

“The world today lacks sufficient data to feed into weather models, especially the detailed vertical data that is critical to storm prediction. That’s why we see inaccurate or ambiguous forecasts for storms like Hurricane Joaquin, which can put numerous lives at risk and cost businesses millions of dollars due to inadequate preparation or risk management measures,” McCormick said. “Capturing the detailed vertical structure of the atmosphere from pole to pole, especially over the currently under-sampled oceans, is the missing link to improving forecasts of high-impact weather.”

This project is a win-win for aerospace. Not only will this weather constellation help shift ownership of weather satellites from government to private ownership, the company’s decision to use India’s PSLV rocket increases the competition in the launch industry.

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Beaver dams centuries old

8:28 am

Using a map from the first major study of beavers from 150 years ago, scientists have found that beaver dams can last centuries.

The researcher who produced the original map, Lewis Henry Morgan, had himself theorized that beaver dams were long-lived. This study proves it. Then again, it makes sense, since geography is going to limit the right locations for a dam. The right place is always going to be the right place, and thus the new study proves that generations of beavers go back to the best locations repeatedly.

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LRO finds lunar impact site for Apollo rocket stage

10:03 pm

Lunar Reconnaissance Orbiter has located the impact site for the Apollo 16 rocket booster that, like four other boosters, had been deliberately crashed on the surface so the Apollo seismometers could use the vibrations to study the Moon’s interior.

The other impact sites had been found already, but Apollo 16 was harder to pin down because contact with the booster had ended prematurely so its location was less well known.

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Oblique view of Ceres’s bright spots

3:58 pm

Occator Crater on Ceres

Cool image time! The image above is a newly released image of Occator Crater on Ceres, the location of the dwarf planet’s double bright spots, taken by Dawn in October.

I have cropped the image to focus on the crater and the bright spots. Unlike most previous images, this one is taken from an angle to bring out the topography, which also confirms what other data had shown, that the bright spots are not on top of any peaks. If anything, they appear to be located at low spots in the crater, as that previous data had suggested.

Though the spots are not really very bright, they are very bright relative to the dark surface of Ceres. This is why it is difficult to get a good image of them. Either you have to over-expose the spots to see the surface details around them, or under-expose the surface around them to see some detail in the spots. This image tries to find a middle ground.

Eventually they will move Dawn in very close to try to get higher resolution images of the spots alone. At that time we might finally be able to get a better understanding of what causes them.

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Hawaii’s Supreme Court kills TMT

8:53 am

The coming dark age: As I expected the Hawaiian Supreme Court today ruled that the construction permit given to the builders of the Thirty Meter Telescope (TMT) is invalid, putting all construction on Mauna Kea on hold indefinitely.

It is very clear that the very liberal government of Hawaii is on the side of the protesters and is doing what it can to stop construction. Will the builders of TMT recognize this and try to find a new site for the telescope, or will they continue the legal battle to build it in Hawaii? I think they stand no chance of winning in Hawaii, but they might not have any other choice.

I also ask: What about the decisions to decommission other telescopes to make room for TMT? Do those telescopes still get removed, even if TMT isn’t built?

All in all, this decision probably puts an end to new cutting-edge science in Hawaii. Like the Catholic Church’s attack on Galileo (which essentially killed the Renaissance in Italy), astronomers, and in fact all scientists, will likely go elsewhere now to find a friendly haven for the search for knowledge.

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Lisa Pathfinder lifts off

8:42 am

Lisa Pathfinder, an experimental probe to test the technologies for measuring gravity waves in space, was successfully launched today by Arianespace’s Vega rocket.

At its core is a pair of free-floating, identical 46 mm gold–platinum cubes separated by 38 cm, which will be isolated from all external and internal forces acting on them except one: gravity. “LISA Pathfinder will put these test masses in the best free-fall ever produced in space and monitor their relative positions to unprecedented precision,” says Karsten Danzmann, who also is the Co-Principal Investigator for the LISA Pathfinder Technology Package, the scientific heart of the satellite. “This will lay the foundations for future gravitational-wave observatories in space such as eLISA.”

It is important to point out that this probe will not measure gravity waves. It doesn’t have the sensitivity to do it. Instead it is testing the engineering, as described above, for building a later probe that will have sensitivity. To gain that sensitivity the floating cubes must be much farther apart, and likely will require several independent satellites flying in formation.

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More than half Kepler planet candidates false positives

9:40 am

The uncertainty of science: In attempting to confirm the giant exoplanet candidates in the Kepler telescope database a team of scientists has found that more than half are not planets at all but false positives.

An international team1 led by Alexandre Santerne from Instituto de Astrofísica e Ciências do Espaço (IA), made a 5-year radial velocity campaign of Kepler’s giant exoplanet candidates, using the SOPHIE spectrograph (Observatory of Haute-Provence, France), and found that 52,3% were actually eclipsing binaries, while 2,3% were brown dwarfs. Santerne (IA & University of Porto), first author of this paper commented: “It was thought that the reliability of the Kepler exoplanets detection was very good – between 10 and 20% of them were not planets. Our extensive spectroscopic survey, of the largest exoplanets discovered by Kepler, shows that this percentage is much higher, even above 50%.

The news article above is unclear about the number of candidates total this study actually looked at and pinned down. It appears they began looking at the full database of almost 9,000 candidates, but then narrowed it to 125. Were 50% of the 9,000 false positives, or of the 125? The article is unclear.

At first glance, this study appears to tell us that there might be fewer giant Jupiter-sized exoplanets out there than previously thought. Then again, the data is uncertain enough that this conclusion could easily be wrong. The real take-away is that the science of exoplanets has only just begun, and that sweeping generalizations about the nature of solar systems in the galaxy are exceedingly unreliable. We simply don’t know enough yet.

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The first Ceres atlas

3:46 pm

Ceres's first atlas

Using data during Dawn’s first orbit of Ceres German scientists have compiled a global atlas of the dwarf planet.

The images used for this are the wide angle survey images, which won’t show the smallest objects because they were taken from about 2,700 miles above the surface. Nonetheless, this atlas gives scientists a baseline for studying the giant asteroid.

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Scientists begin another attempt to drill through the Earth’s crust

9:26 am

An expedition to the Indian Ocean is about to begin an effort to drill a core down through the Earth’s crust and into its mantle.

Geologists have been trying to drill through the contact between the crust and the mantle, called the Moho, since the 1960s, with no success. Either the projects have gone way over budget and been shut down, have failed due to engineering problems, or were stopped by the geology itself. This last issue is maybe the most interesting.

Expeditions have come close before. Between 2002 and 2011, four holes at a site in the eastern Pacific managed to reach fine-grained, brittle rock that geologists believe to be cooled magma sitting just above the Moho. But the drill could not punch through those tenacious layers. And in 2013, drillers at the nearby Hess Deep found themselves similarly limited by tough deep-crustal rocks

This new project hopes to learn from these past problems to obtain the first rock samples from below the Earth’s crust.

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The jets of Enceladus

9:09 am

Enceladus's jets

Cool image time! The image above, taken in June by Cassini, shows the night side of Saturn’s moon Enceladus, framed by Saturn’s rings, and faintly showing the jets of water coming from its south pole. To show it here I have cropped it and reduced it somewhat, as well as brightened the jets to make them more visible.

The release notes how the image compares the frozen water of Saturn’s rings and the liquid activity of Enceladus’s jets. I note how the image is simply beautiful. Be sure to click on the link to see the full resolution image.

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The blackballing of Judith Curry

9:18 am

Link here. Curry is a climate scientists who believes carbon dioxide is warming the planet, but she is also a good scientist who is not afraid of data that counters her beliefs, and who also recognizes what she herself calls “the large uncertainties” in our knowledge of the climate.

The article is worth reading at length, as it outlines quite well the close-minded approach to climate science that permeates the global warming crowd. This quote, describing Curry’s experience, sums it up well:

Curry’s independence has cost her dear. She began to be reviled after the 2009 ‘Climategate’ scandal, when leaked emails revealed that some scientists were fighting to suppress skeptical views. ‘I started saying that scientists should be more accountable, and I began to engage with skeptic bloggers. I thought that would calm the waters. Instead I was tossed out of the tribe. There’s no way I would have done this if I hadn’t been a tenured professor, fairly near the end of my career. If I were seeking a new job in the US academy, I’d be pretty much unemployable. I can still publish in the peer-reviewed journals. But there’s no way I could get a government research grant to do the research I want to do. Since then, I’ve stopped judging my career by these metrics. I’m doing what I do to stand up for science and to do the right thing.’ [emphasis mine]

Curry makes it very clear who is blackballing who. If you don’t toe the global warming line, your career as a climate scientists is squelched.

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A developing new astronomical mystery

8:58 am

Radio astronomers in Australia have recently detected a number of new mysterious radio bursts, dubbed fast radio bursts because of their nature, coming from outside our galaxy whose cause presently has no clear explanation.

An unprecedented double burst recently showed up along with four more of these flashes, researchers report online November 25 at arXiv.org.

Fast radio bursts, first detected in 2007, are bright blasts of radio energy that last for just a few milliseconds and are never seen again. Until now, astronomers had cataloged nine bursts that appeared to originate well outside the Milky Way. Yet, follow-up searches with nonradio telescopes for anything that might be pulsing or exploding keep coming up empty.

This mystery is similar to that of gamma ray bursts (GRBs), which were first discovered in the 1960s. About once a day there would be a short burst of gamma ray energy coming from scattered random directions in the sky, but no other radiation in any other wavelength. For decades astronomers didn’t know if the GRBs were coming from just outside our atmosphere or from billions of light years away. Finally, in the 1990s they pinned their location to the deaths of stars in distant other galaxies. As noted by one scientist at a conference, “GRBs signal the daily formation of a new black hole.”

Fast radio bursts are more intriguing. Because of their wavelengths and random locations on the sky, astronomers seem confident that they are occurring outside the Milky Way. However, in the eight years since their discovery only a handful have been detected, making it extremely difficult to study them. Nonetheless, they are significant because they signal some cataclysmic event far away, likely the death of a star in a way not yet understood or predicted. Finding out what that event is will produce important information about the evolution of our universe.

It just might take decades for this new mystery to be solved. Stay tuned!

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