Tag: science

First chemical results from Rosetta

9:24 am

Spectroscopy from Rosetta has identified the make-up of a single dust grain captured by the spacecraft.

For the convenience of communications the science team had dubbed this single grain “Boris.”

[T]hese first results show that among the grain’s components are magnesium and sodium. Since 95 percent of the known observed minerals in comets resemble olivine and pyroxenes – containing a lot of magnesium – the detection of this element is not a big surprise. But, finding sodium in the dust grain, in a refractory mineral phase, has sparked our interest considerably.

The coma and tails of other comets are already known to contain sodium; it was observed in the dust samples returned from Comet Wild 2 by NASA’s Stardust mission, and a prominent example was also the sodium tail of Comet Hale-Bopp that flew past the Sun in April 1997 and which could be seen in the night sky for many weeks. However, by contrast, neither sodium nor magnesium were observed in Comet 67P/C-G dust grains before sampling the inner coma dust. But our dust grain Boris has showed off with clear sodium and magnesium mass peaks in the secondary ion mass spectra that we obtained.

Their next goal is to identify where on the surface of Comet 67P/C-G this sodium came from.

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Avalanches on an asteroid

9:12 am

A new analysis predicts that when the asteroid Apophis flies past the Earth in 2029, the close fly-by will cause avalanches on the asteroid.

If asteroids pass close to Earth, they begin to experience the effects of our planet’s gravity. Just like the moon pushes and pulls the oceans, creating the tides, asteroids are susceptible to tidal forces from our planet. To judge what effect this will have on Apophis, scientists need to know what it’s made of. Their best guess is based on photos taken by a Japanese spacecraft named Hayabusa, which took detailed pictures of an Apophis-sized asteroid named Itokawa. Those images revealed that the asteroid wasn’t a solid mass of rock spinning through space, but rather a giant clump of debris held together loosely by gravity. “You look at the [Hayabusa] pictures and you’re like, ‘Uh, that’s a pile of rocks, dude.’ It’s very likely that Apophis is similar,” says astrophysicist Derek Richardson of the University of Maryland, College Park.

To show that Earth’s gravity could cause some of these rocks to tumble, Richardson and his colleagues developed a computer model that allowed them to place virtual sand piles across the surface of a model asteroid with roughly the same dimensions as Apophis. By factoring in the gravity from the asteroid, the tidal force from Earth, centrifugal force caused by the asteroid’s rotation, inertial forces, and other effects, the team was able to predict how the particles on the surface of the asteroid would behave on approach. The results confirm that Earth’s tidal forces would be strong enough to cause tiny avalanches on the asteroid, the team reported online ahead of print in Icarus.

Need I note that there are a lot of uncertainties here? Because they are using what is known about a different asteroid, all of their assumptions about Apophis’s properties in their computer model could be very wrong.

Still, this is interesting, because it does demonstrate that an asteroid could be significantly disturbed simply by flying past a planet.

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LADEE impact site located

8:47 am

Lunar Reconnaissance Orbiter has spotted the impact crater formed when engineers sent the probe LADEE crashing into the lunar surface in April 2014.

Compared with asteroid and meteoroid impacts on the moon, LADEE was actually traveling pretty slow, ‘only’ 3,800 miles per hour (1,700 meters per second). That combined with the relatively low mass and density of the spacecraft, a fairly neat crater of only 10 feet (3 meters) across was created. The crater barely registered in LROC’s image resolution, making it a very difficult task to identify the fresh man-made divot.

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Sierra Nevada announces an X-37B version of Dream Chaser

9:29 am

The competition heats up: In a press release today, Sierra Nevada has announced plans to build a version of Dream Chaser optimized for science research.

The Dream Chaser for Science, or DC4Science, spacecraft is designed to fly independently for short and extended durations to provide customers in such fields as biotech and pharmaceuticals, biology and life science, and material and fluid science with a flexible and evolvable vehicle easily suited for individual mission requirements.

More details here.

I call this version of Dream Chaser a variation of the X-37B because that is essentially what it would be, an unmanned reusable robot vehicle capable of taking experiments into space for periods of time and then bringing them safely back to Earth on a runway.

What Sierra Nevada is doing by announcing this now, shortly after the landing of the X-37B, is selling the concept in an effort to drum up customers who will then invest in the vehicle and thus help fund its construction.

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Comet 67P/C-G smells!

5:07 pm

Instruments on Rosetta have determined that the various molecules coming off Comet 67P/C-G have a strong aroma.

You might expect a rock that spends all its time in a vacuum to be fairly inoffensive, but in fact exposure to sunlight is causing it to give off quite an aroma: hydrogen sulfide, ammonia, formaldehyde, hydrogen cyanide, and other caustic gases would make it smell “suffocating,” like a cross between a filthy barn, an embalming room, and a rotten egg.

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Problems at the National Weather Service?

9:29 am

According to this news report, since Tuesday the National Weather Service has lost access to some of its satellite data.

The story is very unclear and might not be accurate. For example, it does not state where the problem is. Has a specific satellite failed? Or is the problem on the ground, preventing the NWS from processing data from any of its satellites? It also seems puzzling for such a significant failure to occur on Tuesday and only now on Thursday does anyone notice. I have seen no other news stories about this outage.

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Increasing activity at Comet 67P/C-G

8:49 am

Data from Rosetta in the past month has been showing a steady and gradual increase in dust emissions from the surface.

While images obtained a few months ago showed distinct jets of dust leaving the comet, these were limited to the ‘neck’ region. More recently, images obtained by Rosetta’s scientific imaging system, OSIRIS, show that dust is being emitted along almost the whole body of the comet. Jets have also been detected on the smaller lobe of the comet. “At this point, we believe that a large fraction of the illuminated comet’s surface is displaying some level of activity,” says OSIRIS scientist Jean-Baptiste Vincent from the Max Planck Institute for Solar System Research (MPS) in Germany.

The last two images at the link compare the same location with one image overexposed to make the jets visible. What is interesting is that the source of the jet is not evident in the other normally exposed image. It is almost as if surface material is simply heating up and then using that extra energy to simply throw itself off the surface. Why that then forms jets however is puzzling.

More info here.

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Titan’s atmosphere is unexpectedly unbalanced

5:15 pm

The uncertainty of science: New data from the ground-based telescope ALMA suggest that certain organic molecules in Titan’s atmosphere are not evenly distributed through the atmosphere as expected.

At the highest altitudes, the pockets of organic molecules were shifted away from the poles. These off-pole concentrations are unexpected because the fast-moving, east-west winds in Titan’s middle atmosphere should thoroughly mix the molecules formed there. The researchers do not have an obvious explanation for these findings yet.

I would not take these results too seriously, as the data are very sketchy. With better data many of these questions will vanish, replaced by new questions that are better based on reality.

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India begins tests of larger rocket engine

8:45 am

The competition heats up: Indian engineers have successfully completed their first tests of a new more powerful upper stage engine for their biggest launch rocket.

Taking a big step forward in the development of bigger and more powerful locally-built rocket engines, the Liquid Propulsion Systems Centre (LPSC) on Monday successfully conducted the first ‘cold flow test’ on the CE-20 cryogenic engine, which will power the upper stage of the Geosynchronous Satellite Launch Vehicle-Mk III (GSLV-Mk III). “It’s a milestone,” LPSC director Dr K Sivan told ‘Express’ here on Tuesday, confirming that the test had gone as planned at the LPSC facility in Mahendragiri, Tamil Nadu. The first ‘hot test’ – where the engine will be fired for a few seconds- will be performed in three weeks’ time, Sivan said.

In a cold test, the propellants are not ignited. On Monday, the fuel, Liquid Hydrogen (LH2), and the oxidiser, Liquid Oxygen (LOX), were injected into the chambers for the checking of various parameters.

In related news, Mangalyaan has taken another global view of Mars.

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China to launch two payloads to the Moon

9:37 am

The competition heats up: On Thursday China plans to send a capsule on a mission around the Moon and back to Earth to test its heat shield.

The rocket’s upper stage, which will also round the Moon but not return to Earth, will also carry a privately funded cubesat designed to study the radiation levels during the entire journey.

Twenty minutes after launch on October 23, (at 1:59 p.m. U.S. Eastern time), the Long March’s upper stage will separate from the test capsule, and both will continue on a trajectory that takes them around the moon. The capsule will return to re-enter Earth’s atmosphere on October 31. In early discussions with the Chinese, LuxSpace was told that the upper stage [carrying the private cubesat] would re-enter the atmosphere as well, but it’s now expected to enter a wide, looping orbit around Earth. The main battery is only designed to last 10 days, although it may go longer.

Radio receivers on Earth will be able to tune in to 4M’s signal shortly after separation, and will be able to follow it as it rounds the moon, coming as close as 7,500 miles to the surface. The payload also includes a radiation sensor that will take measurements throughout the journey into Earth-moon space. Anyone with the proper equipment will be able to receive the compressed radiation data and decode it.

Though this private mission is definitely breaking new ground by sending a small payload to lunar space for very little money, the article is incorrect when it states that this is the first privately funded Moon mission. In 1997-1998 HGS 1, a Hughes commercial communications satellite that was placed in an incorrect orbit by a Russian rocket, was sent on a wide elliptical orbit to fly past the Moon twice and thus use this sling shot effect to get the satellite into a usable orbit.

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Snowcaps of metal on Venus?

10:32 am

A new look at old data of Venus has added weight to the theory that the planet’s higher elevations are coated with a frost of heavy metals.

The research not only confirmed a radar brightening at higher altitudes, thus suggesting a frost coating of some kind, it also showed many dark spots whose cause remains completely unknown. As the article notes,

Years ago it was proposed that some sort of ferro-electric compound might be the cause of the brightening and the dark spots, but so far no specific compound has been identified which does the trick. Then again, with the surface of Venus being at almost 900 °F (500 °C) under more than 90 times the air pressure of Earth’s atmosphere at sea level, with occasional showers of acid, it’s not easy to test the properties of materials under Venusian conditions. “No one knows what explains the sudden darkness,” said Harrington, who will be presenting the work at the meeting of the Geological Society of America in Vancouver, B.C., on Monday, Oct. 20.

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Ebola’s rate of growth

8:49 am

The journal Science provides a detailed analysis of the infection rate of ebola, as well a reasonable estimate of the present and future number of cases.

The article makes two key points. First, the trends “…clearly show that the number of cases has roughly doubled every 3 to 4 weeks and that this trend is continuing. If underreporting gets worse, however, it may be even more difficult to discern such trends.”

Second, there is some good news in the worst effected countries.

The number of new cases in some areas at the epicenter of the outbreak– Kenema and Kailahun districts in Sierra Leone and Liberia’s Lofa county–has been dropping, and that’s not a result of underreporting, says Dye. “It has happened for a sufficiently large number of weeks now that we are confident that it’s a real reduction in incidence on the ground, probably related to control measures,” he says. “Our colleagues working on the ground believe it is too.”

One important factor has been the increase in safe burials, Dye says. (The bodies of Ebola victims are very infections.) People in the affected areas have resisted abandoning traditional burial practices that carry a high risk of infection, but in these three areas, local leaders, supported by WHO and others, have come to advocate a change. If that happens elsewhere, says Dye, “we expect to be able to cut out a substantial amount of infection in the community.”

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Comet 67P/C-G at 2 feet per pixel

9:58 am

New images from Rosetta, now about 6 miles from the surface of Comet 67P/C-G, show details as small as 2 feet across.

Go to the link to see some images. If you were hiking there, these images would see you.

In related news, the Rosetta team is asking the public to help name the landing site for its Philae lander.

As the location of the first soft landing of a human-made object on a comet, the site, currently identified as Site J, deserves a meaningful and memorable name that captures the significance of the occasion. The rules are simple: any name can be proposed, but it must not be the name of a person. The name must be accompanied by a short description (up to 200 words) explaining why this would make the ideal name for such an historic location. A jury comprising members of the Philae Steering Committee will select the best name from the entries, and the winning proposer will be invited to follow the landing in person from ESA’s mission control centre in Darmstadt, Germany on 12 November.

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The mysterious interior of Saturn’s moon Mimas

9:47 am

Mimas

The uncertainty of science: Using data from Cassini scientists have found that Saturn’s weird moon Mimas might have either an underground ocean or a misshapen inner core.

Tajeddine and his team relied on pictures taken by NASA’s Cassini spacecraft, which has been exploring the Saturn system since 2004. They built a 3D model of the moon and found that it rotates with an extra wobble, like a misshapen top spinning slightly askew. Because Mimas is nearly spherical, the wobble hinted that something lumpy, or perhaps sloshy, lay beneath the surface. The scientists tested several models of the moon’s interior to see what might give rise to the observed wobble.

It could be the core is lumpy and not spherical. It could be that there is a liquid ocean under the crust that sloshes about as the moon moves through space. Or it could be that a massive impact, the one that produced Mimas’s Death Star look with its one gigantic single crater, could have caused the wobble.

At the moment the data is not sufficient to favor any of these theories. I guess we will just have to go there to find out.

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G2 survives fly-by of Milky Way’s supermassive black hole

9:02 am

The uncertainty of science: The mysterious object G2, thought by astronomers to be either a cloud or a star, has survived its close fly-by of Sagittarius A* (pronounced A-star), the supermassive black hole at the center of the Milky Way, without telling scientists whether it is a cloud or a star.

Not only do astronomers still not know clearly what G2 is, the Milky Way’s supermassive black hole continues to behave in ways that baffle them.

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Three potential post-Pluto targets for New Horizons

9:01 am

After completing a deep search using the Hubble Space Telescope, scientists have identified three Kuiper Belt Objects (KBO) that New Horizons can actually reach after it flies past Pluto next year.

The KBOs Hubble found are each about 10 times larger than typical comets, but only about 1-2 percent of the size of Pluto. Unlike asteroids, KBOs have not been heated by the sun and are thought to represent a pristine, well preserved deep-freeze sample of what the outer solar system was like following its birth 4.6 billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto.

I think it remarkable that in the vastness beyond Pluto they were able to find any objects that also happen to be within the narrow path that New Horizons must fly after it passes Pluto in July.

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Democrats oppose an ebola travel ban

10:07 pm

Incompetence: Congressional Democrats have expressed strong opposition to any travel bans from ebola infected countries.

Remember, these are the same people who conceived, wrote, and passed Obamacare, without really reading it or even considering the concerns expressed by many people about the law (all of which have turned out to be true). Thus, it is not surprising they don’t have the brains now to recognize that a quarantine is exactly the right approach to handle ebola at this time, We have a very infectious disease that hasn’t yet broken out into the general populace which we can still keep confined to a small area, where we can more effectively fight it. A quarantine, enforced by a travel ban, will accomplish this.

But these Democrats care! So what they don’t have the ability to think? Let’s vote for them again!

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A reviving solar maximum

12:32 pm

Last week NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in September. As I do every month, I am posting it here, below the fold, with annotations to give it context.

As much as I am always willing to point out the errors and foibles of scientists when they get something wrong or overstate their conclusions, I also believe it right to give credit when credit is due. I have been saying for several years now that the prediction of the solar scientist community, indicated by the red curve in the graph below the fold, had seriously overstated the Sun’s sunspot production during this solar maximum.

Well, it now appears that, as the solar cycle continues to run its course, that their May 2009 prediction is becoming increasingly correct.
» Read more

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Ice photographed in Mercury’s permanently shadowed craters?

12:08 pm

Kandinsky Crater on Mercury

Using Messenger, scientists think they have obtained optical images of the ice that is thought to exist in the permanently shadowed craters of Mercury.

Although the polar deposits are in permanent shadow, through many refinements in the imaging, the WAC [Messenger’s camera] was able to obtain images of the surfaces of the deposits by leveraging very low levels of light scattered from illuminated crater walls. “It worked in spectacular fashion,” said Chabot.

The team zeroed in on Prokofiev, the largest crater in Mercury’s north polar region found to host radar-bright material. “Those images show extensive regions with distinctive reflectance properties,” Chabot said. “A location interpreted as hosting widespread surface water ice exhibits a cratered texture indicating that the ice was emplaced more recently than any of the underlying craters.” In other areas, water ice is present, she said, “but it is covered by a thin layer of dark material inferred to consist of frozen organic-rich compounds.” In the images of those areas, the dark deposits display sharp boundaries. “This result was a little surprising, because sharp boundaries indicate that the volatile deposits at Mercury’s poles are geologically young, relative to the time scale for lateral mixing by impacts,” said Chabot. [emphasis mine]

The image on the right is of the crater Kandinsky, and shows a very intriguing bright area on the crater’s central peak.

I highlighted that one word in the the scientist’s quote above to emphasize how preliminary these conclusions are. The images are intriguing, but I would not at this time bet a lot of money on these conclusions. Ice might be the best explanation for this data, at this time, but I would not be surprised at all if later research finds this conclusion to be false.

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First results back from the U.S. MAVEN Mars probe

9:13 am

Scientists have released the first results from NASA’s MAVEN probe orbiting Mars, designed to study that planet’s upper atmosphere.

As expected, the spacecraft has quickly found evidence of the Martian atmosphere leaking away into space.

Hydrogen appears to be leaving the planet’s atmosphere in clumps and streams that reach about 10 Mars radii into space, said Mike Chaffin, a MAVEN scientist also at the University of Colorado, who discussed the results at a 14 October news briefing. The hydrogen comes from water vapour that breaks apart in the upper atmosphere; because hydrogen is so much lighter than oxygen, it escapes into space relatively easily. “That’s effectively removing water from the Martian atmosphere,” says Chaffin.

Other images show oxygen and carbon drifting away from the planet, although these heavier atoms cluster closer to Mars than hydrogen. Deep within the atmosphere, oxygen forms ozone molecules that accumulate near Mars’s south pole.

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Finding a meteorite 20 years after it hit the ground

8:32 am

By reanalyzing the data that had recorded the fireball twenty years ago, a team of meteorite hunters in the Czech Republic have finally located the remains of a meteorite that landed in 1991 but could not be found.

What is most interesting scientifically about their find is that the pieces they found were from different types of meteorites.

[T]hese four meteorites are of three different mineralogical types. This means that the Benešov meteoroid was heterogeneous and contained at least three different types of material. After the Almahata Sitta fall, this is the second time that such a heterogeneous composition has been found. It raises the possibility that a significant fraction of all asteroids are heterogeneous and that they were strongly reprocessed by collisions with other asteroids in the main belt.

In other words, the meteorite had been a conglomerate of different geological types, which were created in different environments and were later smashed together to form this one rock.

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