Tag: science

Venus’s dark stripes remain unexplained

9:50 am

The uncertainty of science: A new analysis of past data from Venus suggests that the planet’s atmospheric sulfur cannot be causing the atmosphere’s dark stripes seen in the ultraviolet.

If we look at Venus in a normal optical telescope, we see only a dull yellowish-white sphere without any other distinguishing features. However, if we capture an image in the ultraviolet range, the picture changes drastically – dark and light areas appear on the disc, reflecting the dynamics of the atmosphere. “These areas mean that somewhere in the upper cloud layer there is a substance that is absorbing UV radiation. Over the past 30 years there have been a wide range of hypotheses as to what this substance could be. Many scientists believed that sulfur particles were responsible for the absorption. But now we will have to abandon this hypothesis,” says Krasnopolsky.

It appears that the new analysis puts the sulfur too low in the atmosphere.

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Curiosity drills again

9:24 am

The Curiosity science team has paused the rover’s journey up Mt Sharp in order to drill another hole, this time on the fractured rock covering the surface of Naukluft plateau.

The drill effort was a success, and they are now gathering data from the hole and the material from it. At the same time, the drilling process drained the rover’s batteries, which means they are now taking a break from science to let them recharge.

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The methane seas of Titan

10:23 am

Scientists have used the data that Cassini has gathered in more than a hundred fly-bys of Titan to assemble a rough outline of the geology and make-up of Titan’s liquid lakes.

There are three large seas, all close to the north pole, surrounded by dozens of smaller lakes in the northern hemisphere. Just one lake has been found in the southern hemisphere. The exact make-up of these liquid reservoirs remained elusive until recently. A new study using scans from Cassini’s radar during flybys of Titan between 2007 and 2015 confirms that one of the largest seas on the moon, Ligeia Mare, is mostly liquid methane.

“We expected to find that Ligeia Mare would be mostly ethane, which is produced in abundance in the atmosphere when sunlight breaks methane molecules apart,” explains Alice Le Gall from the Laboratoire Atmosphères, Milieux, Observations Spatiales and Université Versailles Saint-Quentin, France, and lead author of the new study. “Instead, this sea is predominantly made of pure methane.”

The data is also giving them the first understanding of the weather and geology that forms the lakes, including why methane instead of ethane dominates.

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Hubble discovers moon circling Kuiper belt object

10:10 am

Worlds without end: Hubble has spotted a small moon orbiting the distant Kuiper Belt object Makemake.

The moon — provisionally designated S/2015 (136472) 1 and nicknamed MK 2 — is more than 1,300 times fainter than Makemake. MK 2 was seen approximately 13,000 miles from the dwarf planet, and its diameter is estimated to be 100 miles across. Makemake is 870 miles wide. The dwarf planet, discovered in 2005, is named for a creation deity of the Rapa Nui people of Easter Island.

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An extended Dawn mission might go to another asteroid

10:05 am

The Dawn science team is proposing that NASA extend the mission by allowing them to use the remaining fuel on the spacecraft to send it away from Ceres and towards another asteroid.

Originally mission managers had planned to park it in a stable orbit around Ceres later this summer, creating a permanent artificial satellite. They could not crash the spacecraft into Ceres, as is customary with many similar missions, because Dawn has not been sterilized in accord with planetary protection procedures. But the extra xenon has created an additional opportunity.

Scientists involved with the spacecraft say they could visit a third object in the asteroid belt. “Instead, we want to go the other way, away from Ceres, to visit yet another target,” principal investigator Chris Russell told New Scientist. Russell would not name the destination without approval of the plan from NASA, but we should learn about it in a few months.

Up until now they had said that they didn’t have enough remaining fuel to do much more than remain in orbit at Ceres. It appears now that they have saved enough fuel to give them more options.

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New Hubble image of Red Rectangle

9:13 am

The Red Rectangle

Cool image time! I think the Red Rectangle might be my favorite planetary nebula. The new image on the right, taken by the Hubble Space Telescope, is the best yet of this weirdly shaped object. And it continues to suggest, as I noted whimsically in an article about it for Sky & Telescope back in November 2014, that this is a web being spin by the universe’s largest spider.

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New images of failed Beagle 2 on Mars

9:02 am

By carefully improving the resolution of images taken by Mars Reconnaissance Orbiter of the landing site of the 2003 European Mars lander Beagle 2, scientists think the lander might have successfully landed but failed to deploy its solar shields completely.

Showing a bright blip in dusty terrain, the new picture is four times the resolution of previous images. The image adds weight to the theory that the diminutive spacecraft – just under a metre in diameter – landed as planned on Mars in 2003, but failed to fully unfurl its solar panels. “Given the size of Beagle 2, even with super-resolution images you are not likely to see more than a series of blobs because it is so small,” said Mark Sims, of the University of Leicester and former mission manager for Beagle 2. “What it does show is that it is on the surface and it is at least partially deployed.”

The technique they have developed for improving image resolution will also be useful to tease out new details about the Martian surface.

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Fake images in biology research papers

9:38 am

The uncertainty of peer review: A new study has found that since 1995 as many as 5.5% of all biomedical research papers per year contain duplicate or faked images.

Bik, who is at Stanford University in California, spent two years looking at articles published from 1995 to 2014 in 40 different journals, hunting for instances in which identical images were used to represent different experiments within the same paper. She cross-checked the duplications that she found with her two co-authors, both microbiologists.

Overall, 4% of the inspected papers contained such images, the researchers found. But rates ranged from over 12% in the International Journal of Oncology, to 0.3% in the Journal of Cell Biology, which has since 2002 systematically scanned images in its accepted papers before publication. Journals with higher impact factors generally had lower rates of duplicated images.

…Many of the problems were probably sloppy mistakes where people selected the wrong photograph, says Bik. But half or more look deliberate — because images are flipped or rotated or the same features occur twice in the same photograph. [emphasis mine]

Essentially, a significant number of scientists in medical research are purposely faking data.

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Evidence of water on Ceres?

9:21 am

water on Ceres?

New data from Dawn suggests that there is significant water locked in surface of Ceres’s north polar regions.

These data reflect the concentration of hydrogen in the upper yard (or meter) of regolith, the loose surface material on Ceres. The color information is based on the number of neutrons detected per second by GRaND. Counts decrease with increasing hydrogen concentration. The color scale of the map is from blue (lowest neutron count) to red (highest neutron count). Lower neutron counts near the pole suggest the presence of water ice within about a yard (meter) of the surface at high latitudes.

Note that the data has not detected water. The blue areas on the image to the right suggest an increased amount of hydrogen, which could only be held to the surface if it was locked in some molecule, with water being the most likely candidate. Like the Moon, until we actual capture some samples, it will be difficult to confirm with certainty the presence of water.

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China grows mouse embryos in space

10:51 am

During a two week unmanned biology satellite mission, Chinese scientists successfully demonstrated that mouse embryos can develop in weightlessness.

The team developed an embryo culture system and placed it within a small enclosed chamber [on the spacecraft] that provides the ideal conditions for the embryos to develop in space. While the chamber was in orbit, a camera attached to the experiment took photographs of the embryos as they developed in microgravity, and sent these images back to Earth. With the aid of their imaging technology, the researchers were able to observe how the mammalian two-cell stage embryos developed into blastocysts under microgravity after four days. Blastocysts are structures formed in the very early development of mammals. In humans blastocysts begin to form five days after fertilization.

The researchers will now compare their space-developed embryos to those cultured in normal laboratory environments on Earth to see what differences there are between the two at both a cellular and molecular level.

None of this proves that life can be conceived and grow in weightlessness. It does however suggest that it might be possible.

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Liver damage from weightlessness?

11:28 pm

The uncertainty of science: Mice flown for almost two weeks on the last space shuttle mission in 2011 have shown evidence of the early symptoms of liver disease.

The mice spent time orbiting the Earth on the final space shuttle flight in 2011. Once they returned home, teams of scientists were allowed to share and study their internal organs.

Jonscher’s team found that spaceflight resulted in increased fat storage in the liver, comparing pair-fed mice on Earth to those on the shuttle. This was accompanied by a loss of retinol, an animal form of Vitamin A, and changes to levels of genes responsible for breaking down fats. As a result, mice showed signs of nonalcoholic fatty liver disease (NAFLD) and potential early indicators for the beginnings of fibrosis, which can be one of the more progressive consequences of NAFLD. “It generally takes a long time, months to years, to induce fibrosis in mice, even when eating an unhealthy diet,” Jonscher said. “If a mouse is showing nascent signs of fibrosis without a change in diet after 13 ½ days, what is happening to the humans?”

This result doesn’t prove that weightlessness causes liver damage. It only suggests that more research is needed, though the data from six month to year long missions suggest that the liver harm to humans is either non-existent or temporary.

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Problems with attitude system doomed Hitomi

12:48 am

A series of failures in the attitude system on Japan’s X-ray space telescope Hitomi led to its destruction.

The problem started when the satellite’s inertial reference unit detected Hitomi was rotating around its Z-axis at 21.7 degrees per hour. The spacecraft was actually stable at the time, mission managers from the Japan Aerospace Exploration Agency said Friday. The satellite’s attitude control system commanded Hitomi’s reaction wheels, rapidly-spinning devices which control the pointing of the spacecraft with momentum, to counteract the spin. The action caused the satellite to rotate in the opposite direction as the faulty inertial reference unit indicated, officials said. Momentum accumulated inside the reaction wheel system, and magnetic torquers aboard the satellite were unable to unload the building momentum, which neared the reaction wheels’ design limit.

Hitomi’s computers recognized the dangerous situation and put the satellite into safe hold a few hours later. The satellite tried to stabilize using the craft’s hydrazine-fueled rocket thrusters to aim its solar panels toward the sun. But the trouble was not over, and the spacecraft’s solar sensor was unable to find the sun. Struggling to correct the growing spin rate, small rocket firings inadvertently caused Hitomi to rotate faster due to a bad setting in the thruster system, JAXA officials said.

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Tetanus boosters can work for almost thirty years

9:17 am

The uncertainty of science: A new study has found that tetanus vaccine booster shots might last three times longer than previously believed.

The study looked for tetanus antibodies in 546 adults who had received the tetanus vaccine at some point in the past. Of those 546 adults, the researchers found that 97 percent still had sufficient antibodies to fight off tetanus. Since tetanus boosters are also designed to fight diphtheria, the same percentage also had antibodies to fight off that disease.

The researchers then looked at the amount of antibodies present in each individual compared to the amount of time that had passed since they received their vaccines. The result was that the study determined the half-life of a tetanus booster to be about 14 years, which means that the average person should be able to go about 28 years between boosters, or almost three times as long as the current CDC recommendation.

The half-life for diphtheria immunity was found to be even longer, at about 27 years, or roughly 54 years between boosters.

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An update on Philae

8:21 am

Link here. No big news. The lander remains silent, and has not yet been precisely located on the surface, though they have a pretty good idea where it is. They expect to get images of it on the surface sometime before September, when Rosetta’s mission will end with its own attempted touchdown on Comet 67P/C-G.

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The asteroid didn’t do it all

12:34 am

The uncertainty of science: A new study adds weight to the theory that the dinosaurs were already in decline when the asteroid hit 65 million years ago.

While some have argued that dinosaurs began petering out some 5 million or 10 million years before their final doom, the new paper suggests it started happening much earlier, maybe 50 million years before the asteroid catastrophe. In terms of species, “they were going extinct faster than they could replace themselves,” said paleontologist Manabu Sakamoto of the University of Reading in England. He led a team of British scientists who analyzed three large dinosaur family trees, looking for evidence of when extinctions began to outnumber the appearances of new species.

They found that starting to happen about 50 million years before the asteroid for most groups of dinosaurs. Two other groups showed increases rather than declines; if their results are included, the overall time for the start of dinosaur decline shrinks to 24 million years before the final demise.

I wrote a science article on this subject back in 1999, and even then the science was far from settled, with most paleontologists strongly arguing that the asteroid was only the final blow and that many other factors, including the big volcano eruption in India about that time, also contributed to the dinosaur’s extinction. That journalists and the planetary science community have pushed the asteroid as the sole factor in that extinction has been a disservice to science. The science has never been that certain.

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Funds needed to identify “Wow!” signal

9:52 am

An astronomer who thinks the “Wow!” radio signal was not from aliens but caused by two comets that were not known at the time is trying to crowd-source the funds he needs to obtain radio telescope time to prove his theory.

Comet 266P/Christensen will pass the Chi Sagittarii star group again on 25 January 2017, while 335P/Gibbs will make its passage on 7 January 2018. Paris plans to observe these events to look for a recurrence of the mystery signal. But time is not on his side for using an existing radio telescope – they are all booked out.

So, he has launched a crowdfunding campaign on gofundme to raise the $13,000 he needs to buy a radio telescope to make the observation. Donations are rolling in and he is already most of the way to his target. “I would like to [be fully funded] in May, order the stuff so that I can have it by October,” he says. This would give him time to construct the dish, test it and prepare for the January encounter.

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More Obamacare exchanges expected to fail

4:30 pm

Finding out what’s in it: Eight of the remaining eleven Obamacare co-op exchanges are expected to default or go out of business before the end of the year, according to a new analysis.

Data compiled by TheDCNF based on the co-op 2015 annual reports suggest eight are likely to default and only four of them will be in business by year’s end. The co-op documents obtained by TheDCNF were annual reports filed before state insurance regulators. The reports must accurately depict the financial health of the co-ops and are current through the end of calendar year 2015. The annual reports became available to the public in mid-March.

More than half of the original 23 co-ops have already gone out of business, leaving hospitals and doctors with millions of dollars of unpaid bills.

Obviously, we must elect Clinton or Sanders, because they want to use the government to do more1

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NOAA plans use of private weather data

9:56 am

The competition heats up: Mandated by Congress to use commercial weather data obtained from privately launched weather satellites, NOAA has announced its first plan for doing so.

The first Commercial Weather Data Pilot, or CWDP, will kick off this summer with a solicitation for GPS radio occultation data of the sort NOAA and Eumetsat have been using for years to improve weather forecasts. GPS radio occultation receivers that have flown on a handful of research satellites and the U.S.-Taiwanese COSMIC constellation obtain highly detailed temperature and humidity soundings by observing tiny distortions of U.S. Air Force GPS signals as they pass through the atmosphere. While the U.S. and Taiwan are preparing to replace the six original COSMIC satellites with the first six of 12 planned satellites slated to launch on a SpaceX Falcon Heavy perhaps late this year, meteorologists would like to see scores of additional GPS radio occultation satellites in orbit.

Several companies, including GeoOptics, PlanetiQ and Spire, have announced plans to address that demand by deploying constellations of dozens to hundreds of small satellites equipped with GPS radio occultation receivers. Spire launched its first four operational satellites last September.

If this goes as I hope, private companies will launch enough satellites to provide the data, at a far lower cost than NOAA spends to build and launch its own satellites, so that eventually it will not pay for the government to do it anymore. Just as private space is replacing NASA in supplying crew and cargo to ISS, private space can do the same for NOAA.

And like NASA initially, NOAA’s managers have been very reluctant to allow this to happen, as it will eventually take the business from them and give it to others. Since they, like NASA, can’t do it very efficiently, however, they can’t really argue their case very well, which is why Congress has been forcing their hand.

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Japanese Venus probe sends back first science data

9:26 am

In a triumph of engineering, the salvaged Japanese Venus probe Akatsuki has beamed back to Earth its first science data.

After an unplanned five-year detour, Japan’s Venus probe, Akatsuki, has come back to life with a bang. On 4–8 April, the Japan Aerospace Exploration Agency (JAXA) presented the first scientific results from the spacecraft since it was rescued from an errant orbit around the Sun and rerouted to circle Venus, four months ago. These include a detailed shot of streaked, acidic clouds and a mysterious moving ‘bow’ shape in the planet’s atmosphere.

Despite the probe’s tumble around the Solar System, its instruments are working “almost perfectly”, Akatsuki project manager Masato Nakamura, a planetary scientist at JAXA’s Institute of Space and Astronautical Science in Sagamihara, Japan, announced at the Inter­national Venus Conference in Oxford, UK. And if another small manoeuvre in two years’ time is successful, he said, the spacecraft might avoid Venus’s solar-power-draining shadow, and so be able to orbit the planet for five years, rather than the two it was initially assigned.

The timing is also good, since Akatsuki is now the only probe circling Venus, and will be for a number of years, until someone else approves, builds, and launches a mission.

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Russian billionaire backs interstellar project

9:00 am

The competition heats up: A Russian billionaire has announced a $100 million investment in an effort to use lasers to propel cellphone-sized spacecraft on an interstellar voyage to Alpha Centauri.

Called Breakthrough Starshot, the programme is based on an idea that has been around for decades: the solar sail. The theory is that a lightweight space sail could harness the momentum carried by photons in order to travel without fuel.

The Breakthrough Starshot team is betting that a burst of concentrated lasers, fired from the ground, could rapidly accelerate a mobile-phone-sized device equipped with microelectronics and a tiny sail — providing much more energy than could be harnessed from the Sun. Whereas NASA’s plutonium-powered New Horizons spacecraft took nine years to reach Pluto, the “nanocraft” envisioned by Breakthrough Starshot would pass by the dwarf planet and exit the Solar System in three days.

The project’s initial US$100-million budget covers only research and development of such a spacecraft. But Breakthrough Starshot’s ultimate goal is to demonstrate proof of concept for an international programme that would send a fleet of nanocraft into space. Doing so would require the group to surmount enormous scientific and engineering challenges in developing the necessary laser technology, materials and communications systems.

This technology is related though not identical to an earlier story about using lasers to power spacecraft.

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Universe’s expansion rate contradicts dark energy data

8:42 am

The uncertainty of science: New measurements of the universe’s expansion rate, dubbed the Hubble constant, contradict theoretical predictions based on previous data.

For their latest paper, Riess’s team studied two types of standard candles in 18 galaxies using hundreds of hours of observing time on the Hubble Space Telescope. “We’ve been going gangbusters with this,” says Riess.

Their paper, which has been submitted to a journal and posted on the arXiv online repository on 6 April, reports that they measured the constant with an uncertainty of 2.4%, down from a previous best result2 of 3.3%. They find the speed of expansion to be about 8% faster than that predicted based on Planck data, says Riess. [emphasis mine]

I highlight the number of galaxies used to get this data because I think these scientists, are being a bit over-confident about the uncertainty of their data. The universe has untold trillions of galaxies. To say they have narrowed their uncertainty down to only 2.4% based on 18 is the height of silliness.

But then, the lead scientist, Adam Riess, recognizes this, as he is also quoted in the article saying “I think that there is something in the standard cosmological model that we don’t understand.”

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Kepler in trouble

9:29 am

Engineers report that the Kepler space telescope went into safe mode about two days ago.

During a scheduled contact on Thursday, April 7, mission operations engineers discovered that the Kepler spacecraft was in Emergency Mode (EM). EM is the lowest operational mode and is fuel intensive. Recovering from EM is the team’s priority at this time.

The mission has declared a spacecraft emergency, which provides priority access to ground-based communications at the agency’s Deep Space Network. Initial indications are that Kepler entered EM approximately 36 hours ago, before mission operations began the maneuver to orient the spacecraft to point toward the center of the Milky Way for the K2 mission’s microlensing observing campaign.

This brief report does not look good. If the spacecraft is in a “fuel intensive” mode, it means it is using extra fuel to survive. This suggests that if they don’t recover it soon it might run out of the fuel and be lost forever.

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Update on Dawn at Ceres

10:07 am

Link here. Though the story initially focuses on the possibility that the mission might be extended a few extra months until the spacecraft’s fuel runs out, it also gives a good summary of what has been learned so far about the dwarf planet, including the theory that Ceres was once an “ocean world.”

[Carol Raymond, Dawn’s deputy principal investigator,] said Ceres appears to be a former ocean world and could have once been similar to Europa or Enceladus, the icy moons of Jupiter and Saturn. “One of the things that we anticipated about Ceres before getting there is that it’s a former ocean world,” Raymond said. “We’re so interested in going to Europa and Enceladus, and these other interesting objects in the outer solar system because we think they harbor subsurface oceans at present, and possible habitable environments, and possibly even locations where there’s extant life.

“Ceres appears to have been one of those objects in the past, when it was younger and hotter,” Raymond said. “What we’re looking at now is, we believe, the remnant of a frozen ocean. The salt is left over from the brines that were concentrated as the ocean froze out, so it’s all a fairly consistent story that Ceres is a former ocean (world) where the ocean froze, and now we’re interrogating the chemistry, essentially, of that ocean-rock interface through the subsurface layers that we’re detecting on Ceres.”

The data has found the high latitudes to have lots of hydrogen, suggesting water-ice on or near the surface. The bright salt patches also suggest frozen water below the surface that left behind the salt when it reached the surface and evaporated away.

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The changing color of Comet 67P/C-G

9:12 am

Data from Rosetta has found that Comet 67P/C-G has changed color and brightness since the spacecraft’s arrival.

Even when Rosetta first rendezvoused with the comet far from the Sun, ices hidden below the surface were being gently warmed, sublimating into gas, and escaping, lifting some of the surface dust away and contributing to the comet’s coma and tail. VIRTIS shows that as the ‘old’ dust layers were slowly ejected, fresher material was gradually exposed. This new surface was both more reflective, making the comet brighter, and richer in ice, resulting in bluer measurements.

On average, the comet’s brightness changed by about 34%. In the Imhotep region, it increased from 6.4% to 9.7% over the three months of observations

The changes are similar to those found on the Moon when the surface there is disturbed. The old surface is very dark. When hit by a meteorite or scrapped by an astronaut’s foot, it brightens. In the case of Comet 67P, the underlying ice pushes outward when heated, the dust is removed, and the surface gets brighter.

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The supernovae that fertilized the Earth

5:45 pm

A new study has pinned down the dates of two recent supernovae that showered the Earth with the heavier elements that make life here possible.

Many mainstream articles about this story have been implying that this research has discovered the existence of supernovae near the primordial Earth. This is false. Scientists have had evidence of these early supernovae for decades, from asteroids, in isotopes on Earth, and in the existence of the Local Bubble in which the Sun is presently traveling. What this study has done is narrow the location and the time of at least two of these supernovae, a significant discovery, though not the one much of the ignorant press is pushing.

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The sunspot decline continues

11:18 am

NOAA’s monthly update of the solar cycle was released today, showing the Sun’s sunspot activity in March. It is annotated and posted below.

March 2016 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.

For the fourth month in a row the change in the graph is so small you almost need a magnifying glass to see it. Despite this, the decline remains remarkably steady, tracking precisely the decline predicted by the low prediction of the 2007 predictions (indicated by the smaller green line curve).

Recently the number of sunspots has dropped enough that I suspect we are not far the moment when we will once again begin to see days where the Sun is blank of sunspots, a situation last seen in 2010 near the end of the previous solar minimum. When that happens, it will herald the beginning of the next solar minimum.

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WISE completes another year of asteroid hunting

9:08 am

After being mothballed in space and then reactivated, NASA’s WISE infrared telescope (renamed NEOWISE for no good reason) has now completed its second year of observations, looking for near-Earth objects (NEOs).

NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE) mission has released its second year of survey data. The spacecraft has now characterized a total of 439 NEOs since the mission was re-started in December 2013. Of these, 72 were new discoveries. Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of the giant planets in our solar system into orbits that allow them to enter Earth’s neighborhood. Eight of the objects discovered in the past year have been classified as potentially hazardous asteroids (PHAs), based on their size and how closely their orbits approach Earth. [emphasis mine]

Unfortunately, the press release does not provide any details about those eight potentially hazardous asteroids.

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