Tag: science

CO2 satellite overcomes design flaw

10:37 am

Despite a decade of development, including the production of two satellites, the Orbiting Carbon Observatory-2 was launched in July with a basic design flaw that was never spotted.

Scientists and engineers on the project have ridden an emotional roller coaster. In 2009, a rocket failure doomed the Orbiting Carbon Observatory, their first attempt at a carbon-mapping probe. Its replacement, OCO-2, launched successfully. But after the JPL turned on the main instrument — a trio of spectrometers that measure sunlight light reflecting off Earth’s surface — the team discovered a problem in OCO-2’s data. They eventually determined that it was caused by a design flaw that reduced the amount of light entering the instrument during one mode of operation. The problem dated to 2004 and had never been caught in testing, says JPL’s David Crisp, the science team leader of the OCO-2 mission. “It was a stupid mistake. Embarrassing to the instrument designer and to me,” he says.

This flaw was apparently in both OCO satellites and was never noticed.

Fortunately, they have improvised a work-around that is allowing the spacecraft to get its data, which interestingly shows the highest concentrations of CO2 are coming not from the U.S. and the First World but from poorer parts of Africa and South America (caused by “burning savannas and forests,” not SUVs) and from China.

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The seas of Titan

9:27 am

Thar’s black gold up thar! Data from Cassini has confirmed the presence of ocean waves on Titan’s seas, while also providing suggesting that they are made mostly of liquid methane, not ethane as had been predicted.

The maximum depth of Kraken Mare appears to be 160 meters, and Ligeia Mare could be as much as 200 meters deep, reported Marco Mastrogiuseppe of Sapienza University of Rome. The fact that the radar signals could bounce off the sea bottom suggests that the seas were more transparent than expected and thus must contain mostly methane, not ethane. Hayes says his best estimate is about 90% methane. Essam Marouf, a planetary scientist at San José State University in California, reported on the first results from a separate radar experiment that sent radar reflections to Earth instead of back to the spacecraft. Those tests provide independent evidence that the seas are dominated by methane, Marouf says, and it implies that the lakes are kept filled by precipitating methane.

As the article also notes, this methane is “55 times Earth’s oil reserves.”

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Venus Express mission ends

6:51 pm

After eight years, the European Space Agency has officially ended the Venus Express mission.

After this month of ‘surfing’ in and out of the atmosphere at low altitudes, the lowest point of the orbit was raised again through a series of 15 small thruster burns, such that by 26 July it was back up to about 460 km, yielding an orbital period of just over 22 hours. The mission then continued in a reduced science phase, as the closest approach of the spacecraft to Venus steadily decreased again naturally under gravity.

Under the assumption that there was some propellant still remaining, a decision was taken to correct this natural decay with a new series of raising manoeuvres during 23–30 November, in an attempt to prolong the mission into 2015. However, full contact with Venus Express was lost on 28 November. Since then the telemetry and telecommand links had been partially re-established, but they were very unstable and only limited information could be retrieved.

The agency has decided that further attempts to contact the spacecraft would essentially be a wasted effort, and has closed the books on this very successful mission. The spacecraft itself will soon burn up in Venus’s atmosphere when its orbit decays.

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Curiosity finds organic materials on Mars, including fluctuating levels of methane

2:53 pm

Data from Curiosity has found both organic chemicals in the surface of Mars as well as quickly changing levels of methane in the nearby atmosphere.

NASA’s Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill. “This temporary increase in methane — sharply up and then back down — tells us there must be some relatively localized source,” said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”

The organic material does not prove there is or was ever life on Mars. What it shows is that conditions on Mars could have once supported life. The methane detection, however, is a more significant finding, as it suggests that something very nearby to Curiosity is causing the spike. It could be life, or it could be chemical activity, but in either case, it means there is activity.

The one caveat is that the spike still did not amount to much, 7 parts per billion. Whatever is causing it is not really doing very much.

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Evaporating dry ice chunks create gouges on Mars

9:27 am

Scientists think they have solved the mystery of the gouges that appear seasonally on some hillsides on Mars: Chunks of dry ice that slide down the slope and then evaporate, leaving no trace.

During the martian winter, carbon dioxide ice freezes over parts of the planet’s surface and sublimates back into a gas during the spring thaw. But according to the model presented here today at a meeting of the American Geophysical Union, chunks of warming dry ice may also break off from the crests of dunes and skid down slopes. This is no ordinary tumble—according to the model, the bases of the chunks are continually sublimating, resulting in a hovercraftlike motion that gouges the dune while propelling the ice down slopes. Solid ice that survives to the bottom settles into a pit before dissipating back into the atmosphere.

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The arrival of two new childhood diseases to America

10:42 am

Link here.

In the span of four months, at least 94 children in 33 U.S. states have developed a devastating form of paralysis with symptoms similar to polio. Some require a ventilator to breathe. And some of the greatest government health minds in the country say they have no idea what’s causing it. At the same time, during the past four months, at least 12 children have died after falling ill with a respiratory virus called Enterovirus D-68 (EV-D68). Again, federal health officials are at a loss to explain the origin of the epidemic.

It appears that the first, now dubbed acute flaccid myelitis (AFM), might be linked to the second.

In a November 7 alert to practitioners, the CDC noted, “the unusual clustering of acute limb weakness occurred against a background of a nationwide outbreak of severe respiratory illness among children due to enterovirus-D68 (EV-D68). Several of the patients in California and nearly half of the 11 cases identified in Colorado had tested positive for EV-D68 from nasopharyngeal (NP) swabs at the time of admission for their neurologic illness. This raised a possible association between these neurologic illnesses and the ongoing outbreak of respiratory disease due to EV-D68.”

Whether both are linked to the flood of illegal immigrant children allowed to enter the U.S. this past summer remains unclear.

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When did humans begin using fire?

10:21 am

A cave in Israel suggests that the human use of fire began around 350,000 years ago.

The researchers examined artifacts previously excavated from the site, which are mostly flint tools for cutting and scraping, and flint debris created in their manufacture. To determine when fire became a routine part of the lives of the cave dwellers, the team looked at flints from about 100 layers of sediments in the lowermost 16 meters of the cave deposits.

In layers older than roughly 350,000 years, almost none of the flints are burned. But in every layer after that, many flints show signs of exposure to fire: red or black coloration, cracking, and small round depressions where fragments known as pot lids flaked off from the stone. Wildfires are rare in caves, so the fires that burned the Tabun flints were probably controlled by ancestral humans, according to the authors. The scientists argue that the jump in the frequency of burnt flints represents the time when ancestral humans learned to control fire, either by kindling it or by keeping it burning between natural wildfires.

There are enormous uncertainties here, but the data also appears to match with what has been found in Europe. The problem however is that this date is long after humans had already migrated to colder climates, which means that they were somehow surviving for a long time in these hostile environments without fire, something that is puzzling.

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NIH panel recommends cancelling multi-billion dollar study

10:13 am

An government advisory panel has recommended the NIH cancel a controversial nationwide study to track the health of 100,000 children.

The study has already cost one billion, has had two scientists resign because they didn’t like how the study was being run, and has as yet only enrolled 4,000 children.

Update: The NIH officially cancelled the study later the same day the panel’s report was released.

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Comet 67P/C-G in color

9:49 am

Comet 67P/C-G in color

You might not believe it, but the image on the right is the first color image taken by Rosetta of Comet 67P/C-G. (Click on the link to see a full image.)

To create an image revealing 67P’s “true” colours, the scientists superposed images taken sequentially through filters centred on red, green, and blue wavelengths. However, as the comet rotated and Rosetta moved during this sequence, the three images are slightly shifted with respect to each other, and are taken from slightly different observing perspectives. Painstaking work is needed to superimpose the images accurately, which is one reason it has taken so long to come up with the first meaningful colour image of 67P/C-G.

As you can see, there really isn’t much color there. Moreover, the comet is so coal-dark that they had to brighten the images to bring out any detail.

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Global views of six Saturnian moons

9:37 am

Using images collected after ten years in orbit around Saturn, Cassini scientists have released global color maps of six of Saturn’s icy moons, Mimas, Enceladus, Tethys, Dione, Rhea and Iapetus.

These enhanced colour views have yielded several important discoveries about the icy moons. The most obvious are differences in colour and brightness between the two hemispheres of Tethys, Dione and Rhea. The dark reddish colours on the moons’ trailing hemispheres are due to alteration by charged particles and radiation in Saturn’s magnetosphere. The blander leading hemispheres, the sides that always face forward as the moons orbit Saturn, are all coated with icy dust from Saturn’s E-ring, formed from tiny particles erupting from the south pole of Enceladus.

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The geography of scientific plagiarism

10:46 am

A review of the text of hundreds of thousands of papers submitted by scientists worldwide has revealed the countries from which plagiarism is most likely.

Researchers from countries that submit the lion’s share of arXiv papers—the United States, Canada, and a small number of industrialized countries in Europe and Asia—tend to plagiarize less often than researchers elsewhere. For example, more than 20% (38 of 186) of authors who submitted papers from Bulgaria were flagged, more than eight times the proportion from New Zealand (five of 207). In Japan, about 6% (269 of 4759) of submitting authors were flagged, compared with over 15% (164 out of 1054) from Iran.

The global map illustrating this geography at the link is quite fascinating to peruse, as it generally shows the cultural roots of plagiarism. Happily, western culture does not appear to be the source.

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Solar maximum ramp down continues

10:01 am

The monthly update by NOAA of the solar cycle, showing the sunspot activity for the Sun in November, was released on December 8, just before NOAA completely revamped its website. As I have been doing every month for the past four years, I am posting it here, with annotations to give it context.

As noted in previous months, the 2009 prediction of the solar scientist community is looking better and better with time. Though there was an increase in sunspot activity in November, the overall trend continues downward very close to that prediction, though at levels that have generally been less than predicted.

November 2014 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.

Future updates will depend on whether NOAA continues to track sunspots using these same standards. After much searching I was finally able to locate the graph above at this link, suggesting that at least for now, they are holding to these standards. I note however that the links to the 2007 and the 2009 solar cycle predictions have vanished down the memory hole. Fortunately, I still have this data, and can continue to annotate the graphs to compare prediction with actual data.

That they might have removed these predictions from their webpage however is a shame. I have emailed them to ask them about this and will let you know what I learn.

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Science spending steady in proposed Congressional budget

9:18 am

The proposed budget deal announced by Congress yesterday essentially leaves level the overall spending on science.

I have a spreadsheet where I track the budgets of the various science agencies in the federal government, and from this I can say that since the Republicans took control of the House in 2010 the funding has remained very steady. Despite the partisan screams from the left that Republicans are destroying science, all these science agencies have pretty much gotten stable funding in the past four years.

Nonetheless, much of this funding could be trimmed significantly, as there is enormous featherbedding and pork among these science agencies. That won’t have a chance of happening until next year, when the Republicans control both houses of Congress. Even then, Obama and much of the Republican leadership will oppose significant cuts, Obama because he wants to see increases and the Republican leadership because they wish to maintain the status quo.

The unending growth in these budgets, routine from the 1970s through the 2000s, has definitely ceased. I also expect the political pressure to cut these budgets to grow with time. The newer Republican members of Congress tend to be much more radical than their leadership, and are much more willing to slash budgets radically.

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NOAA admits that California drought is not man-made

2:17 pm

A new study by NOAA scientists has confirmed that the recent severe California drought was not caused by the human-caused increase of carbon dioxide in the atmosphere but was instead the result of natural weather patterns.

The persistent weather pattern over the past several years has featured a warm, dry ridge of high pressure over the eastern north Pacific Ocean and western North America. Such high-pressure ridges prevent clouds from forming and precipitation from falling. The study notes that this ridge — which has resulted in decreased rain and snowfall since 2011 — is almost opposite to what computer models predict would result from human-caused climate change. [emphasis mine]

The climate models, which have all spectacularly failed to predict the lack of warming in the past 18 years, had also predicted that global warming would cause more rain in California, not less.

The article quotes both fake scientist Michael Mann and his buddy in the climategate scandal Kevin Trenberth in their effort to refute the study. They don’t provide much convincing data to explain why the models were all wrong, only loud whines about how they are right and everyone else is wrong.

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Curiosity confirms that Gale Crater was once a water filled lake.

1:31 pm

New geological data from Curiosity suggests that the interior of Gale Crater was shaped by sediments placed there by the rise and fall of a lake over millions of years.

The data also confirms that conditions on Mars were good enough for liquid water to be maintained on the surface for long periods of time. The problem is that scientists still do not understand how Mars could have maintained such kind of atmosphere and environmental conditions, based on its location and size.

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Venus Express gone?

10:06 am

Engineers have been struggling to maintain contact with Venus Express, and have only been able to establish contact for intermittent periods.

Europe’s Venus Express was launched in November 2005 and got to the second planet from the Sun in April 2006, on what was originally a two-year mission. Since then it has sent data streaming back from its polar orbit.

But the probe’s days are numbered, and last month the flight control team at the European Space Operations Centre (ESOC) at Darmstadt, Germany, reported loss of contact with it. According to ESA’s Venus Express blog, it is possible that the remaining fuel on board the spacecraft was exhausted during recent manoeuvres and that the spacecraft is no longer in a stable attitude (the spacecraft’s high-gain antenna must be kept pointed toward Earth to ensure reliable radio contact).

They have been able to get bits of telemetry from the craft, but since its fuel supply is almost gone the possibility of keeping it operating much longer is limited.

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New Horizons awakes

9:55 am

After almost nine years of travel the American New Horizons probe has been successfully awakened in preparation for its July fly-by of Pluto.

Since launching on January 19, 2006, New Horizons has spent 1,873 days — about two-thirds of its flight time — in hibernation. Its 18 separate hibernation periods, from mid-2007 to late 2014, ranged from 36 days to 202 days in length. The team used hibernation to save wear and tear on spacecraft components and reduce the risk of system failures. “Technically, this was routine, since the wake-up was a procedure that we’d done many times before,” said Glen Fountain, New Horizons project manager at APL. “Symbolically, however, this is a big deal. It means the start of our pre-encounter operations.”

By mid-May we will begin to see images of Pluto and its moons that are better than any images ever before taken.

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Europe approves construction of giant telescope

9:17 am

Europe has approved the construction of the European Extremely Large Telescope (E-ELT), which when completed will be the largest ground-based telescope.

The E-ELT will have a mirror 39 meters across, almost four times bigger than the world’s largest telescope today.

A word to the wise: This very month Sky & Telescope’s cover article, written by yours truly, describes the many difficulties the world’s present generation of giant telescopes have faced. Four out of five have not produced the science promised. Two of the four were dogged by so many technical problems that they required complete reconstruction. The builders of E-ELT will face even greater engineering challenges. Do not be surprised if this telescope does not get completed by 2025 as promised, and even if it does, do not be surprised if it takes another half decade or more before the engineers work out all the kinks.

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Human etchings half a million years old?

3:39 pm

The uncertainty of science: Did an ancestor of humanity etch zig-zags on a shell half a million years ago?

This story is a fascinating illustration of the difficulties of pinning down facts in the field of science. The researchers do an impeccable job of checking all possibilities, and finish by cheerfully admitting that their conclusions could be wrong. If right, however, the discovery is significant, as it tells us that 500,000 years ago an ancestor of the human race was capable of drawing an abstract design on the surface of a shell.

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Organic material from Mars?

12:55 pm

The uncertainty of science: Scientists theorize that the carbon material found in a 2011 meteorite could be Martian biological material.

Ejected from Mars after an asteroid crashed on its surface, the meteorite, named Tissint, fell on the Moroccan desert on July 18, 2011, in view of several eyewitnesses. Upon examination, the alien rock was found to have small fissures that were filled with carbon-containing matter. Several research teams have already shown that this component is organic in nature. But they are still debating where the carbon came from.

Chemical, microscopic and isotope analysis of the carbon material led the researchers to several possible explanations of its origin. They established characteristics that unequivocally excluded a terrestrial origin, and showed that the carbon content were deposited in the Tissint’s fissures before it left Mars.

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Chinese spacecraft reaches L2

10:13 am

The service module for China’s test lunar probe, that circled the Moon before returning to Earth, has reached L2 as planned.

As of Friday, the service module had been flying for 28 days, and was 421,000 kilometers away from Earth and 63,000 km from the moon. All experiments are going well. The service module was separated from the return capsule of China’s test lunar orbiter, which returned to Earth on Nov. 1 after circling the moon in its eight-day mission launched on Oct. 24.

…After two orbital transfers, the service module re-entered the elliptical orbit with an apogee of 540,000 km and a perigee of 600 km. During the flight, the service module again performed orbital transfer actions twice, and flew along the pre-set Earth-moon transfer orbit. On Nov. 23, it reached the perilune and with the lunar gravity it was able to undertake the orbit maneuver to fly to the L2 point.

This is brilliant management. They not only test return-to-Earth capability, they practice flying a robot ship in deep space, doing complex orbital maneuvers. In addition, depending on the equipment on the service module, they get a cheap unmanned probe for observing the near lunar environment.

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