Tag: science

The glory of Cassini’s Saturn

8:31 am

The glory of Saturn

Cool image time! The image on the right, reduced in resolution to post here, was taken by Cassini on August 17, 2017, one month before the spacecraft dived into Saturn to end its mission.

This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in green light with the Cassini spacecraft wide-angle camera on Aug. 12, 2017. Pandora was brightened by a factor of 2 to increase its visibility.

The view was obtained at a distance to Saturn of approximately 581,000 miles (935,000 kilometers) from Saturn. Image scale is 35 miles (56 kilometers) per pixel. The distance to Pandora was 691,000 miles (1.1 million kilometers) for a scale of 41 miles (66 kilometers) per pixel.

The moon Pandora can be seen in the full resolution image just beyond the outermost ring near the top of the screen.

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Iranian scientist sentenced to death

8:13 am

An Iranian judge has sentenced an Iranian scientist to execution in 20 days.

The scientist, who appears to have mostly worked in Sweden, was convicted of spying for Israel. He in turn says he was railroaded because he refused to spy on his colleagues for the Iranian intelligence service.

What baffles me here is that he was arrested when returned to Iran for a short visit. He must have known that going back was going to put him in great risk. Why do it?

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NASA instrument for European space telescope flawed and must be rebuilt

5:29 pm

The NASA instrument for Europe’s Euclid optical/near-infrared space telescope has been found defective and must be rebuilt, thus delaying the launch of the telescope by at least one year.

What interested me about this telescope is its goals and specifications:

Euclid is a two-ton space telescope selected by ESA in 2011 as a medium-class mission in its Cosmic Vision program of space science missions. The spacecraft features a 1.2-meter telescope with visible and near-infrared instruments to study dark energy and dark matter, which combined account for about 95 percent of the universe. Euclid will operate at the Earth-sun L-2 Lagrange point, 1.5 million kilometers from Earth, that is used by other infrared astronomy missions.

With a mirror about half the size of Hubble’s, this telescope will act as a partial replacement and back up for it. In fact, it will likely make numerous ground-breaking discoveries, as every optical telescope placed above the atmosphere has so far done.

Meanwhile, the article provided no information on the flaws, who built the flawed instrument, and who will pay for the delays its failure will cause.

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Juno’s first hints of Jupiter’s interior

5:17 pm

Data from Juno not only suggests that the gas giant has a small fuzzy core, its storms appear to extend thousands of miles into the interior.

By studying Jupiter’s gravitational field, researchers can probe thousands of kilometres into the planet. On each close fly-by, Juno measures the planet’s complex gravitational tug. These observations have already revealed that Jupiter has a small, ‘fuzzy’, poorly defined core.

The latest results show that Jupiter’s gravitational field is askew, with different patterns in its northern and southern hemispheres, said Tristan Guillot, a planetary scientist at the Observatory of the Côte d’Azur in Nice, France. That suggests that its hydrogen-rich gas is flowing asymmetrically deep in the planet. “This is something that was not expected,” Guillot said at the meeting. “We were not sure at all whether we would be able to see that.”

Another clue to the structure of Jupiter’s interior came from how the gravity field varies with depth. Theoretical studies predict that the bigger the gravity signal, the stronger the flow of gas deep down. That information is important for teasing out whether all of Jupiter’s interior is rotating as a single solid body, or whether different layers spin separately from one another, like a set of nesting Russian dolls moving within each other.

Juno detected a gravity signal powerful enough to indicate that material is flowing as far down as 3,000 kilometres. “We’re just taking the clouds and the winds and extending them into the interior,” Kaspi said. Future work could help to pinpoint how strong the flow is at various depths, which could resolve whether Jupiter’s interior really resembles Russian dolls.

What is especially fascinating is that this first study of Jupiter shows it to appear so very different than Cassini’s first look at Saturn. Their polar regions are completely different, their storms are different, even their horizontal bands behave and look different. As I’ve said numerous times, the one given in planetary exploration is that every single planetary object we look at will be completely different from every other object.

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NASA extends Dawn’s mission orbiting Ceres

2:11 pm

NASA has decided to extend the Dawn mission again, but have that extension remain in orbit around Ceres.

A priority of the second Ceres mission extension is collecting data with Dawn’s gamma ray and neutron spectrometer, which measures the number and energy of gamma rays and neutrons. This information is important for understanding the composition of Ceres’ uppermost layer and how much ice it contains.

The spacecraft also will take visible-light images of Ceres’ surface geology with its camera, as well as measurements of Ceres’ mineralogy with its visible and infrared mapping spectrometer.

The extended mission at Ceres additionally allows Dawn to be in orbit while the dwarf planet goes through perihelion, its closest approach to the Sun, which will occur in April 2018. At closer proximity to the Sun, more ice on Ceres’ surface may turn to water vapor, which may in turn contribute to the weak transient atmosphere detected by the European Space Agency’s Herschel Space Observatory before Dawn’s arrival. Building on Dawn’s findings, the team has hypothesized that water vapor may be produced in part from energetic particles from the Sun interacting with ice in Ceres’ shallow surface.Scientists will combine data from ground-based observatories with Dawn’s observations to further study these phenomena as Ceres approaches perihelion.

They aim to get as close as 120 miles of the surface during this extension, half as close as the previous closest approach.

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NASA and Australia sign extension of space-tracking agreement

8:39 am

NASA and Australia have signed an extension of the treaty that allowed for the construction and operation of antennas in Australia used by NASA’s Deep Space Network.

Australia’s ambassador to the US, Joe Hockey, signed the Space Tracking Treaty on behalf of Australia, with the acting administrator of NASA, Robert Lightfoot, signing on behalf of the US, at a ceremony at the Australian Embassy in Washington DC.

The treaty covers civil space facilities owned by NASA and located within Australia, including the Canberra Deep Space Communication Complex at Tidbinbilla, as well as facilities in Western Australia and the Northern Territory.

That the treaty signing was turned into a photo-op, something that previous signings did not require, suggests to me that Australia’s politicians are planning bigger things for their future space program.

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Thirty mile cave on the Moon?

8:34 am

A new analysis of data from Japan’s Kaguya lunar orbiter suggests that one of the cave pits it found could be an entrance to a lava tube 30 miles long.

In 2009, the Kaguya probe found a large shaft with an opening about 50 meters in diameter in the Marius Hills area. The shaft descends about 50 meters beneath the surface.

The JAXA team analyzed data obtained from a lunar radar sounder on the probe that indicated an underground structure extended west from the shaft. The study confirmed that the cavern, likely created by volcanic activity, has not collapsed, and there is the possibility of ice or water existing in rocks within the cave, the team said.

Do a search on Behind the Black using the search terms “cave” and “moon” and you will see many images of this pit, taken by Lunar Reconnaissance Orbiter as a follow-up to the Kaguya mission.

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Astronomers reduce estimate of still undiscovered dangerous asteroids

11:49 am

Astronomers have now reduced [pdf] their estimate of the number of still undiscovered dangerous Near Earth Asteroids (NEAs) that could impact the Earth from 100 to less than 40.

Observers have been cataloging potentially hazardous asteroids for decades. Based on the number of finds, the area of sky explored, and the limiting brightness our telescopes and cameras can reach, researchers can estimate what fraction of the NEA population has been detected so far and how many more objects lurk undiscovered. Harris has published numerous such estimates over the years. Recently he realized that his estimates have been plagued by a seemingly innocuous but nonetheless consequential round-off error. Once corrected, the estimated number of large (diameter > 1 kilometer) NEAs remaining to be discovered decreases from more than 100 to less than 40.

To put it mildly, there is a lot of uncertainty here. This also reminds me of the cavers’ joke question: “How many miles of unexplored passages does this cave have?”

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Nearby asteroid orbits both the Earth and the Sun

11:42 am

Worlds without end: Astronomers have determined that a recently discovered object with a weird solar orbit that also has it loop around the Earth each year is an asteroid, not space junk.

The asteroid is dubbed 2016 HO3. What is most interesting about this story to me however was this tidbit:

“Of the near-Earth objects we know of, these types of objects would be the easiest to reach, so they could potentially make suitable targets for exploration,” said Veillet, director of the LBT Observatory. “With its binocular arrangement of two 8.4-meter mirrors, coupled with a very efficient pair of imagers and spectrographs like MODS, LBT is ideally suited to the characterization of these Earth’s companions.”

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New findings from Cassini’s final months

11:49 am

Link here. Among a bunch of other interesting results, this one I found the most tantalizing:

The spacecraft’s Ion and Neutral Mass Spectrometer (INMS) returned a host of first-ever direct measurements of the components in Saturn’s upper atmosphere, which stretches almost to the rings. From these observations, the team sees evidence that molecules from the rings are raining down onto the atmosphere. This influx of material from the rings was expected, but INMS data show hints of ingredients more complex than just water, which makes up the bulk of the rings’ composition. In particular, the instrument detected methane, a volatile molecule that scientists would not expect to be abundant in the rings or found so high in Saturn’s atmosphere.

The results generally leave behind more questions than answers, but that is exactly why exploring the universe is so much fun.

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Europe’s Trace Gas Orbiter detects clouds over Martian volcano

9:31 am

Europe’s Trace Gas Orbiter (TGO) has detected clouds over the western slopes of the giant Martian volcano Arsia Mons.

This is not a new discovery, merely a confirmation of many past observations, all of which suggest that water-ice glaciers once flowed down those western slopes, and that some of that ice remains trapped in underground caves and lava tubes there. Undeniably this region appears at present to be the most valuable real estate on Mars. It has caves where the first colonies can be more easily built. Those caves likely have water in them. And the location is near the equator, which is easier to reach and also makes the environment somewhat less hostile.

TGO is presently slowly aerobraking itself down to its planned science orbit, which it is expected to reach in 2018.

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Astronomers detect neutron star merger in both light and gravitational waves

9:00 am

Big news! Astronomers from dozens of telescopes on the ground and in space have observed for the first time the light burst caused by the merger of two neutron stars because earlier observations of the merger’s gravitational wave and gamma ray burst told them where to look in the sky.

On 17 August 2017 the NSF’s Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States, working with the Virgo Interferometer in Italy, detected gravitational waves passing the Earth. This event, the fifth ever detected, was named GW170817. About two seconds later, two space observatories, NASA’s Fermi Gamma-ray Space Telescope and ESA’s INTErnational Gamma Ray Astrophysics Laboratory (INTEGRAL), detected a short gamma-ray burst from the same area of the sky.

The LIGO–Virgo observatory network positioned the source within a large region of the southern sky, the size of several hundred full Moons and containing millions of stars. As night fell in Chile many telescopes peered at this patch of sky, searching for new sources. These included ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA) and VLT Survey Telescope (VST) at the Paranal Observatory, the Italian Rapid Eye Mount (REM) telescope at ESO’s La Silla Observatory, the LCO 0.4-meter telescope at Las Cumbres Observatory, and the American DECam at Cerro Tololo Inter-American Observatory. The Swope 1-metre telescope was the first to announce a new point of light. It appeared very close to NGC 4993, a lenticular galaxy in the constellation of Hydra, and VISTA observations pinpointed this source at infrared wavelengths almost at the same time. As night marched west across the globe, the Hawaiian island telescopes Pan-STARRS and Subaru also picked it up and watched it evolve rapidly.

Press releases today from numerous other observatories are too numerous to link here, and most essentially say the same thing. The key facts so far gleaned however are intriguing:

Distance estimates from both the gravitational wave data and other observations agree that GW170817 was at the same distance as NGC 4993, about 130 million light-years from Earth. This makes the source both the closest gravitational wave event detected so far and also one of the closest gamma-ray burst sources ever seen

This event also highlights the advantages of observing the universe in as many ways as possible. Some phenomenon get to us sooner, and thus provide us clues on where to look with other tools. Without the gravitational wave and gamma ray burst detectors, on Earth and in space, the other optical and infrared telescopes would have almost certainly not have recorded this merger.

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Storms on Titan dump a lot of liquid methane, quickly

3:16 pm

A new climate model for Titan that suggests the planet’s methane rainstorms occur about once a Saturn year (29.5 years) and at about 60 degree latitude correlates with Cassini surface data that found a high concentration of alluvial fans at that latitude.

“The most intense methane storms in our climate model dump at least a foot of rain a day, which comes close to what we saw in Houston from Hurricane Harvey this summer,” said Mitchell, the principal investigator of UCLA’s Titan climate modeling research group.

Sean Faulk, a UCLA graduate student and the study’s lead author said the study also found that the extreme methane rainstorms may imprint the moon’s icy surface in much the same way that extreme rainstorms shape Earth’s rocky surface. On Earth, intense storms can trigger large flows of sediment that spread into low lands and form cone-shaped features called alluvial fans. In the new study, the UCLA scientists found that regional patterns of extreme rainfall on Titan are correlated with recent detections of alluvial fans, suggesting that they were formed by intense rainstorms.

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The FDA and its regulation of genetic data purchased by Americans

11:46 am

Link here. The article is a detailed history of the company 23andMe, which offers individuals a way to get their personal genetic data. The company was growing and flourishing, providing data to its customers, until the FDA stepped in.

In 2009, the FDA started asking 23andme for evidence that the company’s products worked as advertised and wouldn’t harm customers. The agency was worried that people might take drastic medical measures on the basis of their test results, such as deciding to change the dosage of their medications without consulting a doctor or undergoing unnecessary surgery, such as a mastectomy, or treatment based on false positives. Regulators demanded evidence that the tests were accurate, and that customers were well informed what the results meant.

The next years were difficult ones for 23andme. It communicated with the agency on a few occasions and promised in January 2013 that data would be forthcoming. According to the FDA, it then ceased communicating with regulators entirely in May, even as it started a new advertising campaign. Fed up, the agency sent [Anne] Wojcicki [company CEO] a strongly worded warning letter on 22 November 2013 ordering her company to stop marketing its product.

It was a self-inflicted wound for the company. “There was a bit of arrogance,” says Richard Scheller, who was an executive at Genentech at the time. As a result, 23andme was forced to drastically cut its customer offerings, threatening its viability.

Wojcicki was stunned. “It became clear that we had pissed them off,” she says. “I really didn’t know that we had done so many things that angered them.”

Soon after the letter arrived, Wojcicki called Kathy Hibbs, a lawyer then working for Genomic Health, a gene-testing company in nearby Redwood City, California. “Can I get my whole company back in one year?” Wojcicki asked Hibbs.

“You can get it back, but it will take years,” Hibbs replied. And to get there, she counselled, Wojcicki would have to cooperate with regulators.

It was a tough adjustment for Wojcicki; she didn’t think that the FDA should be able to stop customers from learning their own genetic information. But Hibbs and others convinced her that capitulating to the FDA’s demands was the fastest way to rescue her company. [emphasis mine]

The FDA’s high and mighty attitude here really offends me. It appears that before and after their demands, nothing really changed. All that had happened was that a government agency took control of a private company’s operation, coming between it and its customers. Right now it limits the data that the company can release to its customers, the people that pay for the service in order to obtain their own genetic data.

In other words, the FDA doesn’t think ordinary people are smart enough to see their own data. If that doesn’t capture the arrogance of government, I don’t know what does.

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Astronomers discover ring around object beyond Neptune

10:14 am

Observations of the trans-Neptunian object Haumea has revealed that not only is is shaped like a football due to its fast rotation, it has a ring.

Haumea is an interesting object: it rotates around the Sun in an elliptic orbit which takes it 284 years to complete (it presently lies fifty times further from the Sun than the Earth), and it takes 3.9 hours to rotate around its axis, much less than any other body measuring more than a hundred kilometers long in the entire Solar System. This rotational speed causes it to flatten out, giving it an ellipsoid shape similar to a rugby ball. The recently published data reveal that Haumea measures 2.320 kilometers in its largest axis – almost the same as Pluto – but lacks the global atmosphere that Pluto has.

“One of the most interesting and unexpected findings was the discovery of a ring around Haumea. Until a few years ago we only knew of the existence of rings around the giant planets; then, recently, our team discovered that two small bodies situated between Jupiter and Neptune, belonging to a group called centaurs, have dense rings around them, which came as a big surprise. Now we have discovered that bodies even farther away than the centaurs, bigger and with very different general characteristics, can also have rings,” says Pablo Santos-Sanz, another member of the IAA-CSIC team.

The more we see of these distant objects beyond Neptune the more I suspect that they are going to be puffy, not very dense, and surrounded by miscellaneous objects. The gravity and environment that far from the Sun simply allows them to not coalesce as happened in the inner solar system.

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First discoveries from China’s FAST radio telescope

8:58 am

Astronomers using China’s new FAST radio telescope have announced its first discoveries, the identification of two pulsars,

The new pulsars PSR J1859-01 and PSR J1931-02, also referred to as FAST pulsar #1 and #2 (FP1 and FP2), were detected on August 22 and 25, and were confirmed by the Parkes telescope in Australia on September 10. “FP1 is a pulsar with a spin period of 1.83 second and an estimated distance of 16 thousand light-years, and FP2, is a pulsar with a spin period of 0.59 second and an estimated distance of 4,100 light years,” said Li Di, Deputy Chief Engineer of FAST Project at the National Astronomical Observatories (NAOC), on Tuesday.

FAST’s gigantic size will allow it to pinpoint many similar astronomical objects previously beyond the resolution of radio telescopes.

Note that there is still no word on whether China has found a scientist to head FAST operations.

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The mysterious dark splotches of Mars

11:58 am

The dark splotches of Mars

Cool image time! The image on the right, cropped and reduced in resolution to post here, shows one particular dark splotch in a region with several similar dark areas.

Geologists aren’t quite sure what to make of the dark splotch in the middle of this image, one of several similar dark splotches that extend east and west for over 100 kilometers. From measurements made in infrared, this and other dark splotches have what we call “high thermal inertia,” meaning that it heats up and cools down slowly. Scientists use thermal inertia to assess how rocky, sandy, or dusty a place is. A higher thermal inertia than the surrounding area means it’s less dusty.

The image below the fold shows at full resolution the area indicated by the white box. It provides me no clue as to the cause for the darker color. I think we can speculate all we want, but the truth is that we simply don’t have enough information. We need a closer look, including boots on the ground, to figure this out.
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Sunspot update for September 2017

9:38 am

On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for September. That graph is posted below, with annotations.

September 2017 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.

Last month saw the strongest amount of sunspot activity in a year, thus helping to bring the pace in the decline of sunspot activity back towards the low prediction from April 2007. This also suggests that the ramp down to solar minimum will continue through 2019, with minimum not occurring before then, at the earliest. At the same time, the increase in sunspot activity seen in September seems to have eased in October, with the return of a blank Sun this past week.

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Mars Odyssey makes its first observations of Phobos

2:37 pm

Sixteen years after entering Mars orbit Mars Odyssey finally made its first observations of the Martian moon Phobos last week.

Since Odyssey began orbiting the Red Planet in 2001, THEMIS has provided compositional and thermal-properties information from all over Mars, but never before imaged either Martian moon. The Sept. 29 observation was completed to validate that the spacecraft could safely do so, as the start of a possible series of observations of Phobos and Deimos in coming months.

In normal operating mode, Odyssey keeps the THEMIS camera pointed straight down as the spacecraft orbits Mars. In 2014, the spacecraft team at Lockheed Martin Space Systems, Denver; and NASA’s Jet Propulsion Laboratory, Pasadena, California; and the THEMIS team at Arizona State University, Tempe, developed procedures to rotate the spacecraft for upward-looking imaging of a comet passing near Mars. The teams have adapted those procedures for imaging the Martian moons.

The data from this particular observation is less significant than the fact that the spacecraft can now do it. Expect some new results about the Martian moons in the coming months.

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Nobel Prize for Physics awarded to three LIGO scientists

10:20 am

The 2017 Nobel Prize for Physics has been awarded to three scientists involved in the development of the Laser Interferometer Gravitational-wave Observatory (LIGO), which detected the first gravitational waves in 2015.

While some of the recent Nobel Prizes have been absurd (such as the Peace award to Obama), this award is absolutely deserved and appropriate. Until LIGO detected that gravitational wave they were merely a theory. The detection proved the theory to be real.

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Database of presumed human-caused earthquakes created

9:52 am

The uncertainty of science: Geologists have assembled a database of more than 700 earthquakes they think might have been caused by human activity.

The Human-Induced Earthquake Database, or HiQuake, contains 728 examples of earthquakes (or sequences of earthquakes) that may have been set off by humans over the past 149 years. Most of them were small, between magnitudes 3 and 4. But the list also includes several large, destructive earthquakes, such as the magnitude-7.8 quake in Nepal in April 2015, which one paper linked to groundwater pumping.

Miles Wilson, a hydrogeologist at Durham University, UK, and his colleagues describe the database in a paper set to be published on October 4 in Seismological Research Letters2. The scientists say that HiQuake is the biggest, most up-to-date public listing of human-caused quakes ever made. By bringing the data together in this way, they hope to highlight how diverse induced quakes can be — and help society to understand and manage the future risk.

Many of these quakes were likely caused by human activity. Many however might not have been. The jury is still out, as the article reluctantly admits near the end.

All possible instances of induced quakes were included “without regard to plausibility”, writes the team, because of the difficulty involved in deciding what constitutes absolute proof that an earthquake was caused by human activity. But that could mislead people about the real hazard from induced quakes, says Raphaël Grandin, a geophysicist at the Institute of Earth Physics in Paris. “When you put a dot in the database, and a scientific reference behind it, then you may lead the non-expert to think that the earthquake was caused by humans,” he says. Such a listing might hide scientific uncertainty, as with the Chinese quake: despite the paper linking it to reservoir filling, many seismologists do not believe it was triggered by human activity.

In other words, they included every quake that had the slightest suggestion it was connected to human activity, without noting the uncertainties. This makes this database to me somewhat suspect. Rather than identify the known reliable links between human activity and quakes in order to learn what causes them, this database seems more designed as a political propaganda tool aimed at limiting future human activity. It certainly doesn’t clarify our knowledge on this subject, but instead muddies the water significantly.

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Testing underwater interplanetary robots on the cheap

6:54 pm

This article describing a test of an underwater robot by JPL scientists in the interior of a glacier warmed the cockles of my heart when I read this paragraph:

Klesh and Leicty’s recent expedition relied on a commercial grade submersible and a “homemade” glacial probe. The latter was built using off-the-shelf and 3-D printed parts. They did all their own wiring and programming.

NASA test projects like this are often gold-plated. I like how these scientists took a more practical approach, getting their data without spending a fortune in time and money. Moreover, they gained some engineering knowledge that can be applied practically in future probes, both here on Earth and on other planets.

Hat tip Jim Mallamace.

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Solar storm activates global aurora on Mars

12:00 pm

The strong solar flare that occurred earlier this month was strong enough to activate a global aurora on Mars.

The solar event on Sept. 11, 2017 sparked a global aurora at Mars more than 25 times brighter than any previously seen by the MAVEN orbiter, which has been studying the Martian atmosphere’s interaction with the solar wind since 2014. It produced radiation levels on the surface more than double any previously measured by the Curiosity rover’s Radiation Assessment Detector, or RAD, since that mission’s landing in 2012. The high readings lasted more than two days.

Strangely, it occurred in conjunction with a spate of solar activity during what is usually a quiet period in the Sun’s 11-year sunspot and storm-activity cycle. This event was big enough to be detected at Earth too, even though Earth was on the opposite side of the Sun from Mars.

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Webb Space Telescope delayed again

11:32 pm

NASA announced today that they are further delaying the launch of the James Webb Space Telescope from October 2018 to late spring 2019.

NASA’s James Webb Space Telescope now is planning to launch between March and June 2019 from French Guiana, following a schedule assessment of the remaining integration and test activities. Previously Webb was targeted to launch in October 2018. “The change in launch timing is not indicative of hardware or technical performance concerns,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at Headquarters in Washington. “Rather, the integration of the various spacecraft elements is taking longer than expected.”

As part of an international agreement with the ESA (European Space Agency) to provide a desired launch window one year prior to launch, NASA recently performed a routine schedule assessment to ensure launch preparedness and determined a launch schedule change was necessary. The careful analysis took into account the remaining tasks that needed to be completed, the lessons learned from unique environmental testing of the telescope and science instruments at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the current performance rates of integrating the spacecraft element.

Webb’s original launch date was supposed to be 2011, making its launch now verging on a decade late. The original budget for the telescope was supposed to be $1 billion. It is now expected to cost more than $9 billion. Like SLS/Orion, this project more resembles feather-bedding, providing NASA employees and the contractors involved a steady paycheck, regardless of whether they ever get anything done. In fact, both Webb and SLS/Orion seemed designed to encourage failure. The project never gets cancelled no matter what goes wrong. Instead, more money gets poured in.

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Hubble spots most distance active comet yet

11:13 am

Comet C/2017 K2

Using the Hubble Space Telescope astronomers have imaged a comet that is sublimating material at a distance from the Sun farther than any previously known comet, out beyond Saturn.

“K2 is so far from the Sun and so cold, we know for sure that the activity — all the fuzzy stuff making it look like a comet — is not produced, as in other comets, by the evaporation of water ice,” said lead researcher David Jewitt of the University of California, Los Angeles. “Instead, we think the activity is due to the sublimation [a solid changing directly into a gas] of super-volatiles as K2 makes its maiden entry into the solar system’s planetary zone. That’s why it’s special. This comet is so far away and so incredibly cold that water ice there is frozen like a rock.”

Based on the Hubble observations of K2’s coma, Jewitt suggests that sunlight is heating frozen volatile gases – such as oxygen, nitrogen, carbon dioxide, and carbon monoxide – that coat the comet’s frigid surface. These icy volatiles lift off from the comet and release dust, forming the coma. Past studies of the composition of comets near the Sun have revealed the same mixture of volatile ices.

The significance here is that by studying the comet’s activity scientists will be able to identify some of these volatile gases, which in turn will tell them something about the make-up of the outermost fringes of the solar system.

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Status of Arecibo radio observatory

9:16 am

It appears that, while Puerto Rico itself suffered devastating damage from Hurricane Maria, the Arecibo Observatory came through relatively unscathed.

The surface of the dish was largely unscathed, and the observatory’s most vulnerable component, the instrument platform suspended high above the dish by cables strung from three towers, each more than 80 meters tall, was still in place and seemed undamaged, says Schmelz. She is based at the Columbia, Maryland, headquarters of one of Arecibo’s operators, the Universities Space Research Association, and spoke with staff in Puerto Rico who first used a ham radio and then a single working satellite phone. But the roofs on some observatory buildings were blown off, the sinkhole under the dish was flooded, and other equipment was damaged by rain and fallen trees. Most significantly, a large portion of a 29-meter-long antenna—the 430-megahertz line feed used for studying the upper atmosphere—appears to have broken off and fallen from the platform into the dish. Mathews estimates a bill of several million dollars to replace the line feed alone.

Because of the significant infrastructure damage across the island, there will be significant delays in getting any of this fixed. Since the telescope is already being considered for shut down due to budget issues, these delays could lead to that shut down.

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One last image from Rosetta

8:17 am

Rosetta's last image

Engineers reviewing the last bits of telemetry that was transmitted back to Earth by Rosetta just before it crashed on Comet 67P/C-G have discovered one last image of the comet’s surface.

That image is on the right. It is slightly blurred because of the limitations of Rosetta’s camera at this short range, and the incompleteness of the data received.

The image covers an area about a meter across, with a resolution of about two millimeters per pixel.

I imagine this surface is relatively soft, since the gravity holding the comet together is so slight. If you wanted to dig down, you would find it easy digging.

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Gravitational waves from black hole collision detected

10:47 am

Three Earth gravitational wave observatories have detected the waves coming from the same collision of two black holes.

The collision was observed Aug. 14 at 10:30:43 a.m. Coordinated Universal Time (UTC) using the two National Science Foundation (NSF)-funded Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors located in Livingston, Louisiana, and Hanford, Washington, and the Virgo detector, funded by CNRS and INFN and located near Pisa, Italy.

The detection by the LIGO Scientific Collaboration (LSC) and the Virgo collaboration is the first confirmed gravitational wave signal recorded by the Virgo detector.

Based on the data obtained, they estimate that the two black holes 25 and 31 times the mass of the Sun and are about 1.8 billion light years away.

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Dark energy might not exist

6:22 pm

The uncertainty of science: A new model for the universe that omits dark energy produces a better fit to what is know than previous theories that included it.

The new theory, dubbed timescape cosmology, includes the known lumpiness of the universe, while the older traditional models that require dark energy do not.

Timescape cosmology has no dark energy. Instead, it includes variations in the effects of gravity caused by the lumpiness in the structure in the universe. Clocks carried by observers in galaxies differ from the clock that best describes average expansion once variations within the universe (known as “inhomogeneity” in the trade) becomes significant. Whether or not one infers accelerating expansion then depends crucially on the clock used. “Timescape cosmology gives a slightly better fit to the largest supernova data catalogue than Lambda Cold Dark Matter cosmology,” says Wiltshire.

He admits the statistical evidence is not yet strong enough to definitively rule in favour of one model over the other, and adds that future missions such as the European Space Agency’s Euclid spacecraft will have the power to distinguish between differing cosmology models.

Both models rely on a very weak data set, based on assumptions about Type 1a supernovae that are likely wrong. It is thus likely that neither explains anything, as neither really has a good picture of the actual universe.

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