Tag: science

Nothing for New Horizons after Pluto

8:57 am

As New Horizons begins its final shake-down in advance of its July 2015 flyby of Pluto, scientists have so far failed to find any Kuiper Belt objects in the right place for it to fly past after Pluto.

They haven’t given up hope, however. The search continues. As for the Pluto flyby,

The hibernating spacecraft will send weekly status beacons back to Earth, with wakeup scheduled for Dec. 7 to begin the final phase of its approach to Pluto. New Horizons will stay awake for two years to prepare for the encounter, fly by Pluto, and downlink science data. The craft’s appointment with Pluto is set for July 14, 2015, when it will zoom about 6,200 miles from the icy world’s unmapped surface for a one-shot chance to explore Pluto’s geology and atmosphere.

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Opportunity to get a reboot

9:32 am

Because of an increasing number of computer resets on the Mars rover Opportunity, engineers plan to reformat the rover’s computer.

The resets, including a dozen this month, interfere with the rover’s planned science activities, even though recovery from each incident is completed within a day or two.

Flash memory retains data even when power is off. It is the type used for storing photos and songs on smart phones or digital cameras, among many other uses. Individual cells within a flash memory sector can wear out from repeated use. Reformatting clears the memory while identifying bad cells and flagging them to be avoided.

Obviously there is a risk, though small, that this action will not work and the mission will end here. Stay tuned.

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Spitzer spots asteroid collision

11:57 am

A monitoring program of a young star by the Spitzer Space Telescope has paid off with evidence of a major collision between asteroids in the debris disk that surrounds the star.

Scientists had been regularly tracking the star, called NGC 2547-ID8, when it surged with a huge amount of fresh dust between August 2012 and January 2013. “We think two big asteroids crashed into each other, creating a huge cloud of grains the size of very fine sand, which are now smashing themselves into smithereens and slowly leaking away from the star,” said lead author and graduate student Huan Meng of the University of Arizona, Tucson.

While dusty aftermaths of suspected asteroid collisions have been observed by Spitzer before, this is the first time scientists have collected data before and after a planetary system smashup. The viewing offers a glimpse into the violent process of making rocky planets like ours.

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Rosetta’s camera zooms in

9:10 am

67P/C-G on August 23, 2014
Comet 67P/C-G as seen on August 23, 2014 from 38 miles.
Click on image for uncropped version.

The Rosetta team has begun releasing more close-up images of Comet 67P/C-G taken by the spacecraft. The image to the right was taken by the navigation camera, but rather than capture the entire nucleus in a single image the camera is now zoomed in and taking a mosaic of four images. This picture is one quarter of that mosaic.

Note the boulders and the sharp peaks in the image. The boulders are important to map for planning Philae’s landing site. The sharp peaks suggest recent outgassing.

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Natural methane plumes found on the sea floor

9:26 am

The uncertainty of science: Scientists have discovered hundreds of natural methane sea-floor seeps that had not been predicted by theory.

The bubble streams showed up on sonar scans of the sea floor taken between September 2011 and August 2013 during oceanographic expeditions ranging from Cape Hatteras in North Carolina to Georges Bank off Cape Cod. Altogether, researchers analysed data covering a 94,000-square-kilometre arc (an area about the size of Indiana or Hungary) that includes the edge of the continental shelf and the steep slope just seaward of it, says co-author Adam Skarke, a geologist at Mississippi State University in Starkville. Within a distance of about 950 kilometres, the team found about 570 bubble plumes — an astounding number considering that scientists had previously reported only a handful in the region, he notes.

The article’s first two paragraphs breathlessly attempt to link these plumes to human-caused global warming, noting that there is theory that a warming ocean could produce such methane seeps. Worse, the article adds, once this methane is released it will accentuate warming, as methane is a very powerful greenhouse gas.

The article’s last paragraph, however, finally tells us the real story. Hard data gathered by remote robot vehicles that have actually visited these kinds of plumes instead suggests that the plumes have been there for more than a thousand years and thus could have nothing to do with human-caused global warming. In fact, their natural existence is a significant problem for most climate theories, as they now have to account for this additional greenhouse gas, naturally produced.

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Russia to continue on ISS past 2020?

9:03 am

A Russian news story today suggests that they are leaning strongly to continuing their partnership with the United States on ISS beyond 2020.

“The issue of Russia’s participation at the ISS after 2020 remains open, but there is a 90-percent chance that the state’s leadership will agree to participate in the project further,” [Izvestia] wrote, citing a source at Russia’s Federal Space Agency Roscosmos.

This report gives a better overview of the debate going on with Russia’s government and space agency. If they abandon ISS the work they have already done on new modules for the station will have to be written off, and it appears assembling their own station from those modules will be too expensive and take too long.

It also looks like NASA offered them a second year long mission if they stuck around.

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Rosetta’s comet landing sites

8:48 am

67P/C-G landing sites

The Rosetta science team has narrowed the choices for Philae landing sites on Comet 67P/C-G to five, three on the smaller lobe and two on the larger lobe.

The smaller lobe sites, being on the outside surface of the lobe, don’t provide as good a view of the rest of the comet, while the larger lobe sites are on its inside surface, looking down at the neck and the smaller lobe. In addition, the terrain for the larger lobe sites looks to me more interesting.

Being on the inside surface, however, the larger lobe sites are going to be more difficult to land on.

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Cooking the climate numbers in Australia

4:59 pm

A comparison of the raw climate data with the adjusted numbers released by Australia’s Bureau of Meteorology shows that the adjustments have routinely turned the trends from cooling to warming.

This is the same finding that Steven Goddard and others in the U.S. found when they did the same comparison of NASA and NOAA numbers. In every case the adjustments either cooled the past or warmed the present in order to accentuate the appearance of a warming trend, sometimes in complete contradiction of numbers that had been accepted by scientists for decades.

So, does this mean the climate isn’t warming? No. What it means is we haven’t the slightest idea what’s happening, since the data has now been corrupted so badly that it is almost meaningless.

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Picking a comet landing site

9:05 am

67P/C-G on August 22, 2014
Comet 67P/C-G as seen on August 22, 2014
from 40 miles. Click on image for full resolution.

Engineers have begun the landing site selection for Rosetta’s Philae lander.

This week, up to ten possible sites are being laid on the table for a first round of dedicated discussions and for the LCC and the SONC to carry out a technical analysis on each site, ready to be presented at the weekend meeting. Participants of the LSSG will then review the results from the technical analysis and discuss the scientific merits of the candidate sites. By the end of the weekend meeting, as many as five sites could be selected for further detailed investigation.

They will announce the five finalist sites on Monday.

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Confirmed: Life in buried Antarctic lake

6:50 pm

American scientists have confirmed that water samples from the buried Antarctic Lake Whillans, first obtained in January 2013, contained almost 4,000 different species of life.

Samples from the lake show that life has survived there without energy from the Sun for the past 120,000 years, and possibly for as long as 1 million years. And they offer the first look at what may be the largest unexplored ecosystem on Earth — making up 9% of the world’s land area. “There’s a thriving ecosystem down there,” says David Pearce, a microbiologist at Northumbria University, UK, who was part of a team that tried, unsuccessfully, to drill into a different subglacial body, Lake Ellsworth, in 2013.

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A problem with drilling on Mars

9:07 am

In drilling a new hole while scientists considered Curiosity’s future route to Mount Sharp, the drill cut off operations prematurely.

Engineers think that the rock might have shifted during drilling, causing the robot rover to abort. They have ordered the rover to take a lot of pictures of the situation so they can figure out what happened.

I should note that engineers take a large risk every time they use Curiosity’s drill, as the design of the rover’s electrical system is such that the drill might short everything out while it operates. Thus, when I see a story about a problem with any drilling operation, I become very concerned. In this case, however, it appears to not be a problem with the rover itself.

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The weight of Comet 67P/C-G

10:26 am

Scientists, using radio and orbital data from Rosetta, have made their first estimate of the mass of Comet 67P/C-G.

For the Rosetta mission, this task comes under the umbrella of the Radio Science Investigation (RSI). Using 80 hours worth of tracking data between 6 August, since arriving at the comet, and up to 9 August, the RSI team made a first estimate of the comet’s mass as approximately 1×10^13 kg +/-10%, or about 10 trillion kilograms.

This is very much a preliminary number which will be refined significantly as the spacecraft continues its travels with the comet.

More here. This mass, when considered in conjunction with the nucleus’s size, suggests a very low density. If you could find an ocean large enough it would float.

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Curiosity retreats from Hidden Valley

3:27 pm

Finding its sandy floor slipperier than expected, engineers have backed Curiosity out of Hidden Valley to drill some holes while they reassess the rover’s route.

The rover’s wheels slipped more in Hidden Valley’s sand than the team had expected based on experience with one of the mission’s test rovers driven on sand dunes in California. The valley is about the length of a football field and does not offer any navigable exits other than at the northeastern and southwestern ends. “We need to gain a better understanding of the interaction between the wheels and Martian sand ripples, and Hidden Valley is not a good location for experimenting,” said Curiosity Project Manager Jim Erickson of JPL. …

Curiosity reversed course and drove out of Hidden Valley northeastward. On the way toward gaining a good viewpoint to assess a possible alternative route north of the valley, it passed over the pale paving stones on the ramp again. Where a rover wheel cracked one of the rocks, it exposed bright interior material, possibly from mineral veins.

More and more, the journey to Mount Sharp appears to be increasingly adventurous for the rover.

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Did Stardust capture stardust?

4:19 pm

Scientists now believe that the spacecraft Stardust captured seven particles from interstellar space during its seven year journey.

Inside the canister, a tennis racket-like sample collector tray captured the particles in silica aerogel as the spacecraft flew within 149 miles (about 240 kilometers) of a comet in January 2004. An opposite side of the tray holds interstellar dust particles captured by the spacecraft during its seven-year, three-billion-mile journey.

Scientists caution that additional tests must be done before they can say definitively that these are pieces of debris from interstellar space. But if they are, the particles could help explain the origin and evolution of interstellar dust. The particles are much more diverse in terms of chemical composition and structure than scientists expected. The smaller particles differ greatly from the larger ones and appear to have varying histories. Many of the larger particles have been described as having a fluffy structure, similar to a snowflake. [emphasis mine]

It appears that for these seven particles, the scientists conclude they are likely interstellar particles because of the speed in which they were traveling when captured as well as their make-up. Both suggest an origin outside the solar system.

However, we should be cautious about this. The data still remains tenuous and preliminary. More work obviously needs to be done to pin this down definitively. More information here.

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Michael Mann’s court suit under attack

10:17 am

Good news: Groups from across the political spectrum are expressing their opposition to Michael Mann’s court suit against his critics.

On Monday, The Reporters Committee for the Freedom of the Press — along with 26 other groups including The Washington Post, Bloomberg and Fox News — filed an “amici curiae,” or “friend of the court,” brief with the D.C. Court of Appeals. An amici curiae is a brief submitted to a court to raise additional points of view to sway a court’s decision.

“While Mann essentially claims that he can silence critics because he is ‘right,’ the judicial system should not be the arbiter of either scientific truth or correct public policy,” the brief states, adding that “a participant in the ‘rough-and-tumble’ of public debate should not be able to use a lawsuit like this to silence his critics, regardless of whether one agrees with Mann or defendants.”

Just as Mark Steyn and Rand Simberg said it, I will say it also: Michael Mann is a fraud. He has no idea what it means to be a scientist, and should have been fired by his university after his climategate emails were uncovered. Instead, his university’s investigation was a whitewash and as much a fraud as Mann is.

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It ain’t gravity holding this asteroid together

1:14 pm

Astronomers have discovered that near Earth asteroid 1950DA is spinning so fast that gravity can’t hold it together. Instead, it is kept whole by cohesive forces called van der Waals forces, predicted but never detected before on an asteroid.

This is the coolest factoid from the article, however:

“We found that 1950 DA is rotating faster than the breakup limit for its density,” said Rozitis. “So if just gravity were holding this rubble pile together, as is generally assumed, it would fly apart. Therefore, interparticle cohesive forces must be holding it together.”

In fact, the rotation is so fast that at its equator, 1950 DA effectively experiences negative gravity. If an astronaut were to attempt to stand on this surface, he or she would fly off into space unless he or she were somehow anchored.

The important take away from this discovery is that it will be very easy to break this kind of asteroid up, turning a large and big threat into a collection of small but harmless rocks.

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Rosetta detects its first dust grains

8:57 am

67P/C-G on August 12, 2014

The Rosetta science team announced today that the spacecraft’s Grain Impact Analyser and Dust Accumulator (GIADA) has captured its first dust grains from Comet 67P/C-G.

Earlier this month, GIADA detected the first four dust grains in its Impact Sensor. The first detection was made on 1 August, when Rosetta was 814 km from 67P/C-G, and about 543 million kilometres from the Sun. Further impacts from three more dust grains were detected on 2, 4, and 5 August, at distances of 603, 286, and 179 km from the comet, respectively.

There is still too little data to come to any firm conclusions about the density and make-up of the coma, but this announcement confirms that the instrument is working as designed. When the comet zips past the Sun at its closest point on August 13, 2015, this instrument will then be able to give us a very good assessment of this particular comet’s behavior as it slowly evaporates.

Meanwhile, the images keep coming. The picture at the top of the post was taken on August 12 from about 64 miles.

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Giant Greek tomb discovered

3:49 pm

Archeologists have uncovered the largest tomb ever discovered in Greece and think it is linked to the reign of Alexander the Great.

The tomb, dating to around 300 BC, may have held the body of one of Alexander’s generals or a member of his family. It was found beneath a huge burial mound near the ancient site of Amphipolis in northern Greece. Antonis Samaras, Greece’s prime minister, visited the dig on Tuesday and described the discovery as “clearly extremely significant”.

A broad, five-yard wide road led up to the tomb, the entrance of which was flanked by two carved sphinxes. It was encircled by a 500 yard long marble outer wall. Experts believe a 16ft tall lion sculpture previously discovered nearby once stood on top of the tomb.

The excavations began in 2012, and by this month hope to identify who actually was buried there.

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The weather is finally changing on Titan

2:14 pm

New Cassini images of Titan have spotted the appearance of clouds above the planet’s northern seas, suggesting the overdue onset of the summer storms that climate models have predicted.

For several years after Cassini’s 2004 arrival in the Saturn system, scientists frequently observed cloud activity near Titan’s south pole, which was experiencing late summer at the time. Clouds continued to be observed as spring came to Titan’s northern hemisphere. But since a huge storm swept across the icy moon’s low latitudes in late 2010, only a few small clouds have been observed anywhere on the icy moon. The lack of cloud activity has surprised researchers, as computer simulations of Titan’s atmospheric circulation predicted that clouds would increase in the north as summer approached, bringing increasingly warm temperatures to the atmosphere there.

“We’re eager to find out if the clouds’ appearance signals the beginning of summer weather patterns, or if it is an isolated occurrence,” said Elizabeth Turtle, a Cassini imaging team associate at the Johns Hopkins University Applied Physics Lab in Laurel, Maryland. “Also, how are the clouds related to the seas? Did Cassini just happen catch them over the seas, or do they form there preferentially?”

Any conclusions drawn at this time about the seasonal weather patterns of Titan must be considered highly uncertain, since we only have been observing the planet for a period that only covers one very short portion of its very long 30 year-long year.

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A blue flask of viruses

9:00 am

The story of the discovery of Ebola.

The next day—September 29—the package arrived: a cheap plastic thermos flask, shiny and blue. I settled down with Guido Van Der Groen—a shy, funny, fellow Belgian aged about thirty, a few years older than I—and René Delgadillo, a Bolivian postdoc student, to open it up on the lab bench. Nowadays it makes me wince just to think of it. Sure, we were wearing latex gloves—our boss insisted on gloves in the lab but we used no other precautions, no suits or masks of any kind.

We didn’t even imagine the risk we were taking. Indeed, shipping those blood samples in a simple thermos, without any kind of precautions, was an incredibly perilous act. Maybe the world was a simpler, more innocent place in those days, or maybe it was just a lot more reckless.

Unscrewing the thermos, we found a soup of half-melted ice: it was clear that subzero temperatures had not been constantly maintained. And the thermos itself had taken a few knocks, too. One of the test tubes was intact, but there were pieces of a broken tube—its lethal content now mixed up with the ice water—as well as a handwritten note, whose ink had partially bled away into the icy wet.

Read it all. The excerpt is from a book length memoir that looks to me to be a very worthwhile read.

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The Milky Way’s most distant stars

11:18 pm

Astronomers have discovered the two most distant stars of the Milky Way.

Both stars are red giants, aging suns that shine so brightly observers can see them from afar. One star is about 890,000 light-years from Earth in the constellation Pisces—33 times farther from the Milky Way’s center than we are and well beyond the edge of the galactic disk. The only other Milky Way member at a comparable distance is a small galaxy named Leo I, which orbits ours at a distance of 850,000 light-years. If the star in Pisces revolves on a circular path as fast as we do, it takes some eight billion years to complete a single orbit around the galaxy. That’s more than half the age of the universe.

The other newfound star is about 780,000 light-years distant in the constellation Gemini and more than a million light-years from the other star. For comparison, the previous record-breaking individual star was only about half a million light-years from Earth.

Both stars are so far outside the galaxy’s disk that it is quite possible that they are not part of the Milky Way at all.

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