Tag: science

The Sun goes quiet! Sunspot update for November 2017

11:51 am

The past month was the most inactive month for sunspots since the middle of 2009, when the last solar minimum was just ending and the Sun was beginning its ramp up to solar maximum.

NOAA on Sunday posted its monthly update of the solar cycle, covering sunspot activity for November. As I have done every month since 2010, I have posted that graph below, with annotations.

November 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.

I have also added a straight yellow line near the bottom of the graph, indicating how the lack of activity this past month corresponds with the lack of activity in the summer of 2009, just when that unusually long and deep solar minimum was beginning to end.

November 2017 sunspot record

To get an idea how few sunspots were seen in November, the graph on the right, produced by SILSO (Sunspot Index and Long-term Solar Observations) on December 1, shows only 10 days during the entire month when any sunspots were active on the Sun’s visible hemisphere. And even those sunspot were few and weak, resulting in tiny sunspot numbers total.

Nor is December looking any different, with no sunspots recorded so far, four days into the month.

The plunge to solar minimum continues to appear to be happening faster than normal. At this pace, solar minimum will arrive in early 2018, making this one of the shortest solar cycles on record. That in itself would be unprecedented, as short cycles in the past have always accompanied very active solar maximums, not weak maximums like the maximum we have just seen.

I still expect the ramp down to solar minimum to slow down and stretch out to 2019, as would be more normal, but I also would not bet any money on this expectation, at this point.

The big question remains: Will the solar cycle continue as normal after this upcoming solar minimum, or will we instead see our first grand minimum since the Maunder Minimum in the 1600s, a period lasting for about a century with no obvious sunspots that also corresponded to the Little Ice Age?

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The fly-by anomaly returns with Juno

9:48 pm

The uncertainty of science: An orbital discrepancy between where engineers predict where Juno should be and where it actually is suggests it represents the recurrence of an anomaly that has been seen with numerous past planetary spacecraft.

During the 1970s when the Pioneer 10 and 11 probes were launched, visiting Jupiter and Saturn before heading off towards the edge of the Solar System, these probes both experienced something strange as they passed between 20 to 70 AU (Uranus to the Kuiper Belt) from the Sun.

Basically, the probes were both 386,000 km (240,000 mi) farther from where existing models predicted they would be. This came to be known as the “Pioneer anomaly“, which became common lore within the space physics community. While the Pioneer anomaly was resolved, the same phenomena has occurred many times since then with subsequent missions.

…Another mystery is that while in some cases the anomaly was clear, in others it was on the threshold of detectability or simply absent – as was the case with Juno‘s flyby of Earth in October of 2013. The absence of any convincing explanation has led to a number of explanations, ranging from the influence or dark matter and tidal effects to extensions of General Relativity and the existence of new physics.

However, none of these have produced a substantive explanation that could account for flyby anomalies.

The article describes in detail an effort to pin down the extent of Juno’s orbital anomaly, and to use that information to develop a model that would explain the phenomenon. Not surprisingly, they have not really come up with a comprehensive explanation. To me, the variability of the phenomenon suggests that it isn’t real, that it is either an unmeasured instrument effect or an ordinary component of solar system travel and orbital mechanics that programmers have not yet pinned down. For example, the gravitational effect of every planet and rock in the solar system will influence the path of a spacecraft, though with most that influence will be very small. It would not surprise me if this anomaly is simply the consequence of missing some of this influence.

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Voyager 1 fires thrusters not used in 37 years

3:30 pm

Because Voyager 1’s primary attitude thrusters are beginning to show wear (after forty years in space), engineers decided to experiment using a different set of thrusters not used since the spacecraft flew past Saturn in 1980, and found that they worked!

In the early days of the mission, Voyager 1 flew by Jupiter, Saturn, and important moons of each. To accurately fly by and point the spacecraft’s instruments at a smorgasbord of targets, engineers used “trajectory correction maneuver,” or TCM, thrusters that are identical in size and functionality to the attitude control thrusters, and are located on the back side of the spacecraft. But because Voyager 1’s last planetary encounter was Saturn, the Voyager team hadn’t needed to use the TCM thrusters since November 8, 1980. Back then, the TCM thrusters were used in a more continuous firing mode; they had never been used in the brief bursts necessary to orient the spacecraft.

…On Tuesday, Nov. 28, 2017, Voyager engineers fired up the four TCM thrusters for the first time in 37 years and tested their ability to orient the spacecraft using 10-millisecond pulses. The team waited eagerly as the test results traveled through space, taking 19 hours and 35 minutes to reach an antenna in Goldstone, California, that is part of NASA’s Deep Space Network.

Lo and behold, on Wednesday, Nov. 29, they learned the TCM thrusters worked perfectly — and just as well as the attitude control thrusters.

They figure these back-up thrusters will allow them to extend the mission by two or three years. The test also went so well that they now plan to do the same test on Voyager 2, which has still not entered interstellar space.

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Baby stars at center of galaxy

2:40 pm

New observations of the region surrounding Sagittarius A* (Sgr A*), the super-massive black hole at the center of the Milky Way, has confirmed earlier research by finding what appears to be eleven newly formed baby stars.

Prior observations of the region surrounding Sgr A* by Zadeh and his team had revealed multiple massive infant stars but the finding was not conclusive. These objects, known as proplyds, are common features in more placid star-forming regions, like the Orion Nebula. The new measurements provide more conclusive evidence for young star formation activity. Though the galactic center is a challenging environment for star formation, it is possible for particularly dense cores of hydrogen gas to cross the necessary threshold and forge new stars.

The new ALMA observations, however, revealed something even more remarkable, signs that 11 low-mass protostars are forming within one parsec – a scant three light-years – of the galaxy’s central black hole. Zadeh and his team used ALMA to confirm that the masses and momentum transfer rates – the ability of the protostar jets to plow through surrounding interstellar material – are consistent with young protostars found throughout the disk of our galaxy. “This discovery provides evidence that star formation is taking place within clouds surprisingly close to Sagittarius A*,” said Al Wootten with the National Radio Astronomy Observatory in Charlottesville, Virginia, and co-author on the paper.

They have several theories on how new stars could coalesce in such a violent and turbulent region, but none appears that convincing. Essentially, this is a mystery that does not yet have an answer. It does tell us however that star formation can occur almost anywhere.

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The organic dust of Comet 67P/C-G

11:36 am

A study of the dust released by Comet 67P/C-G and captured by Rosetta shows that carbon molecules appear to comprise the comet’s largest component, and that this material is found in the form of very large macromolecules.

As the study shows, organic molecules are among those ingredients at the top of the list. These account for about 45 percent of the weight of the solid cometary material. “Rosetta’s comet thus belongs to the most carbon-rich bodies we know in the solar system,” says MPS scientist and COSIMA team member Dr. Oliver Stenzel. The other part of the total weight, about 55 percent, is provided by mineral substances, mainly silicates. It is striking that they are almost exclusively non-hydrated minerals i.e. missing water compounds. “Of course, Rosetta’s comet contains water like any other comet, too,” says Hilchenbach. “But because comets have spent most of their time at the icy rim of the solar system, it has almost always been frozen and could not react with the minerals.” The researchers therefore regard the lack of hydrated minerals in the comet’s dust as an indication that 67P contains very pristine material.

…The current findings also touch on our ideas of how life on Earth came about. In a previous publication, the COSIMA team was able to show that the carbon found in Rosetta’s comet is mainly in the form of large, organic macromolecules. Together with the current study, it becomes clear that these compounds make up a large part of the cometary material. Thus, if comets indeed supplied the early Earth with organic matter, as many researchers assume, it would probably have been mainly in the form of such macromolecules.

Organic here does not mean life, but is instead used as chemists use it, to mean the molecule includes the element carbon. The results do suggest however that the early solar system had a lot of carbon available, and that much of it was in a relatively pure form available to interact with other elements.

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Chinese space probe detects possible dark matter signal

8:56 am

The uncertainty of science: A Chinese space probe designed to measure cosmic rays has detected a pattern that could be evidence of the existence of dark matter.

Researchers launched the spacecraft from the Jiuquan Satellite Launch Center in the Gobi Desert, about 1600 kilometers west of Beijing, in December 2015. Its primary instrument—a stack of thin, crisscrossed detector strips—is tuned to observe the incoming direction, energy, and electric charge of the particles that make up cosmic rays, particularly electrons and positrons, the antimatter counterparts of electrons. Cosmic rays emanate from conventional astrophysical objects, like exploding supernovae in the galaxy. But if dark matter consists of WIMPs, these would occasionally annihilate each other and create electron-positron pairs, which might be detected as an excess over the expected abundance of particles from conventional objects.

In its first 530 days of scientific observations, DAMPE detected 1.5 million cosmic ray electrons and positrons above a certain energy threshold. When researchers plot of the number of particles against their energy, they’d expect to see a smooth curve. But previous experiments have hinted at an anomalous break in the curve. Now, DAMPE has confirmed that deviation. “It may be evidence of dark matter,” but the break in the curve “may be from some other cosmic ray source,” says astrophysicist Chang Jin, who leads the collaboration at the Chinese Academy of Science’s (CAS’s) Purple Mountain Observatory (PMO) in Nanjing. [emphasis mine]

I must emphasize the large uncertainty here. They have not detected dark matter. Not even close. What they have detected is a pattern in how the spacecraft is detecting cosmic rays that was predicted by the existence of dark matter. That pattern however could have other causes, and the consistent failure of other efforts to directly find dark matter strengthens the possibility that this break is caused by those other causes.

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“Yeti” DNA found to come from bears and dogs

8:59 am

Scientists analyzing DNA samples said to come from either the legendary yeti in the Himalayas or sasquatch in North America have found that all come from known ordinary animals, mostly bears.

Of the nine “yeti” samples, eight turned out to be from bears native to the area, the researchers report today in the Proceedings of the Royal Society B. The other sample came from a dog. Similar studies of hair samples supposedly related to North America’s big hairy hominid, the sasquatch (aka Bigfoot), have revealed that those fibers came from bears, horses, dogs, and a variety of other creatures—even a human.

Debunking aside, the new study also yielded lots of scientifically useful info, Lindqvist says. The analyses generated the first full mitochondrial genomes for the Himalayan brown bear (Ursus arctos isabellinus) and the Himalayan black bear (Ursus thibetanus laniger), for example. That could help scientists figure out how genetically different these rare subspecies are from more common species, as well as the last time these groups shared maternal ancestors in the past.

While we must always recognize the uncertainties of science, we must also recognize when it provides us clarity. This is an example of the latter.

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Wind eating away the Martian terrain

9:44 am

Yardangs on Mars

Cool image time! The Mars Reconnaissance Orbiter (MRO) image on the right, cropped and reduced in resolution to post here, shows the transition zone between the lower flat plain to the north and the higher but rougher region to the south. What makes it interesting is the north-south aligned mesas. These are yardangs, a geological feature that actually acts like a weather vane.

Yardangs are composed of sand grains that have clumped together and have become more resistant to erosion than their surrounding materials.

As the winds of Mars blow and erode away at the landscape, the more cohesive rock is left behind as a standing feature. (This Context Camera image shows several examples of yardangs that overlie the darker iron-rich material that makes up the lava plains in the southern portion of Elysium Planitia.) Resistant as they may be, the yardangs are not permanent, and will eventually be eroded away by the persistence of the Martian winds.

For scientists observing the Red Planet, yardangs serve as a useful indicator of regional prevailing wind direction. The sandy structures are slowly eroded down and carved into elongated shapes that point in the downwind direction, like giant weathervanes. In this instance, the yardangs are all aligned, pointing towards north-northwest. This shows that the winds in this area generally gust in that direction.

Crater splash

The wind comes from the southeast and blows to the northwest, and is slowly wearing down the southern rougher terrain. Why some of these yardangs are surrounded by dark material remains a mystery, as noted I noted in a previous post.

Meanwhile, the northern plain is not as boring as it seems. Only a short distance to the north is an unusual crater, cropped from the full image to show here on the right. To my eye, when this impact occurred it literally caused a splashlike feature of compressed and more resistant material. Over time, the prevailing wind has eroded away the surrounding less resistant regolith to better reveal that splash, leaving behind a mesa with a crater in its center.

Why the impact created this splash tells us something about the density and make-up of the plain. It suggests to me a surface that was once muddy and soft that over time has hardened like sandstone.

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Worms on Mars!

9:09 am

Scientists growing plants on Earth using a simulated Martian soil have found that earthworms like it.

These slimy invertebrates play a key role in making Earth soil healthy by digesting dead organic matter and excreting a potent fertilizer that helps release nutrients like nitrogen and phosphorus. Their constant burrowing also helps lighten up the soil, allowing air and water to seep through better.

That’s an important improvement for the simulated Mars soil, which water struggled to soak through in previous tests. Altogether, the tests showed that the combination of worms and pig slurry helped the plants grow in Martin soil, and the worms not only thrived but reproduced. “Clearly the manure stimulated growth, especially in the Mars soil simulant, and we saw that the worms were active,” says Wamelink. “However, the best surprise came at the end of the experiment when we found two young worms in the Mars soil simulant.”

Obviously, we do not know yet how the worms would respond to the lower Martian gravity, but it sure would be a significant experiment to see them reproduce there.

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Russia astronauts have found bacteria living on the outside of ISS

8:42 am

Russia astronauts have found bacteria that was not intentionally brought into space living on the outside of ISS.

They are being studied on Earth but most likely they don’t pose any sort of danger, Russian cosmonaut Anton Shkaplerov told TASS on Monday. According to him, during spacewalks from the International Space Station under the Russian program, the cosmonauts took samples with cotton swabs from the station’s external surface. In particular, they took probes from places where the accumulation of fuel wastes were discharged during the engines’ operation or at places where the station’s surface is more obscure. After that, the samples were sent back to Earth.

“And now it turns out that somehow these swabs reveal bacteria that were absent during the launch of the ISS module. That is, they have come from outer space and settled along the external surface.”

I suspect it is a bit of hyperbole to say the bacteria came from outer space. It more likely came from either the station itself, or later spacecraft docking with the station. At the same time, the article is vague about what has been discovered. For example, it says nothing about the bacteria itself.

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A mission to interstellar object Oumuamua?

11:31 am

A private company and a volunteer group dedicated to promoting interstellar travel have written a paper [pdf] exploring the possibility of launching a mission to fly past the interstellar object Oumuamua, now speeding out of our solar system.

As they note in the paper’s abstract,

Can such objects be intercepted? The challenge of reaching the object within a reasonable timeframe is formidable due to its high heliocentric hyperbolic excess velocity of about 26 km/s; much faster than any vehicle yet launched. This paper presents a high-level analysis of potential near-term options for such a mission. Launching a spacecraft in a reasonable timeframe of 5-10 years requires a hyperbolic solar system excess velocity between 33 to 76 km/s for mission durations between 30 to 5 years. Different mission durations and their velocity requirements are explored with respect to the launch date, assuming direct impulsive transfer to the intercept trajectory. Several technology options are outlined, ranging from a close solar Oberth Maneuver using chemical propulsion, and the more advanced options of solar and laser sails. To maximize science return decelerating the spacecraft at ’Oumuamua is highly desirable, due to the minimal science return from a hyper-velocity encounter. It is concluded that although reaching the object is challenging, there seem to be viable options based on current and near-term technology.

The paper even considers the use of SLS or SpaceX’s Big Falcon Rocket.

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Nobel laureates demand Iran release scientist sentenced to death

8:57 am

Seventy-five Nobel laureates have written and signed a letter to the Iranian government demanding it release the Iranian scientist who it convicted of espionage and sentenced to death.

The group wrote to Gholamali Khoshroo, the Iranian ambassador to the United Nations, on 17 November, and the letter was made public on 21 November. The Nobel laureates express their concern for the conditions of Djalali’s detention; they deem his trial “unfair” and “flawed”, and they urge the Iranian authorities to let him return to Sweden, where he lived.

The list includes prominent names such as Harold Varmus, a former director of the US National Institutes of Health, now at the Weill Cornell Medicine institute in New York, and Andre Geim, a physicist based at the University of Manchester, UK. They wrote: “As members of a group of people and organizations who, according to the will of Alfred Nobel are deeply committed to the greatest benefit to mankind, we cannot stay silent, when the life and work of a similarly devoted researcher as Iranian disaster medicine scholar Ahmadreza Djalali is threatened by a death sentence.”

The scientist, Ahmadreza Djalali, lived in Sweden and was accused by Iran of spying for Israel. He in turn said the conviction was revenge for his refusal to spy for Iran.

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A spot on Mars, as seen by different orbiters over the past half century

9:29 am

Mars as seen over the past half century

The science team of Mars Reconnaissance Orbiter (MRO) have assembled a collection of images of the same location on Mars that were taken by different Martian orbiters, beginning with the first fly-by by Mariner 4 in 1965 and ending with MRO’s HiRise camera. The image on the right, reduced in resolution to post here, shows these images superimposed on that location, with resolutions ranging from 1.25 kilometers per pixel (Mariner 4) down to 50 meters per pixel (MRO).

This mosaic essentially captures the technological history of the first half century of space exploration in a single image. Mariner 4 was only able to take 22 fuzzy pictures during its fly-by. Today’s orbiters take thousands and thousands, with resolutions so sharp they can often identify small rocks and boulders.

The mosaic also illustrates well the uncertainty of science. When Mariner 4 took the first pictures some scientists thought that there might be artificially built canals on Mars. Instead, the probe showed a dead cratered world much like the Moon. Later images proved that conclusion to be wrong as well, with today’s images showing Mars to be a very complex and active world, with a geological history both baffling and dynamic. Even now, after a half century of improved observations, we still are unsure whether life there once existed, or even if exists today.

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New study says recurring dark streaks on Mars are from flowing sand, not water

9:49 am

The uncertainty of science: A new study has concluded that the recurring dark streaks on Martian slopes are caused not from flowing seeps of water but from small sand avalanches.

Continuing examination of these still-perplexing seasonal dark streaks with a powerful camera on NASA’s Mars Reconnaissance Orbiter (MRO) shows they exist only on slopes steep enough for dry grains to descend the way they do on faces of active dunes.

The findings published today in Nature Geoscience argue against the presence of enough liquid water for microbial life to thrive at these sites. However, exactly how these numerous flows begin and gradually grow has not yet been explained. Authors of the report propose possibilities that include involvement of small amounts of water, indicated by detection of hydrated salts observed at some of the flow sites.

The results do not exclude the possibility that water plays a part, but do suggest it plays a much smaller part, or none at all.

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Arecibo gets a backer to keep it running

10:59 pm

The National Science Foundation has found at least one backer to pick up the majority of the cost for running the Arecibo Observatory in Puerto Rico, thus keeping it operational.

For about a decade, the National Science Foundation, which owns the observatory and supplies about two-thirds of its $12 million budget, had been mulling downsizing or even shuttering the telescope to free up funds for other projects. Instead, the NSF will continue scientific operations at the facility in collaboration with an unnamed partner organization, according to a Record of Decision signed this week.

Arecibo sustained $4 million to $8 million in damage during the hurricane, according James Ulvestad, acting assistant director for the agency’s mathematical and physical sciences directorate. Some scientists worried that would weaken the case for keeping the observatory operational.

But Ulvestad said the agency’s Record of Decision reflects that it has received viable partnership proposals from one or more collaborators — though he would not provide details about those proposals. This announcement allows the NSF to move forward with negotiations on a new management contract.

Under the new plan, the agency will reduce its annual contribution to the observatory from about $8.2 million to $2 million over the next five years. It is also committed to funding any repairs required to restore Arecibo to its pre-hurricane condition, Ulvestad said.

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Mars rover update: November 16, 2017

10:17 am

Summary: Curiosity does drill tests, crosses Vera Rubin Ridge. Opportunity finds evidence of either ice or wind scouring on rocks in Perseverance Valley.

Curiosity

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Curiosity looks up Vera Rubin Ridge, Sol 1850

Since my last update on September 6, Curiosity has continued its travels up and across Vera Rubin Ridge, a geological bedding plain dubbed the Hematite Unit. The panorama above, created by reader Phil Veerkamp, shows the view looking up the ridge slope. If you click on it you can see the full resolution image, with lots of interesting geological details.

The panorama below, also created by Veerkamp, shows the view on Sol 1866, two weeks later, as the slope begins to flatten out and the distant foothills of Mount Sharp become visible. (If you click on the image you can see a very slightly reduced version of the full resolution panorama.) This image also shows the next change in geology. From orbit the Hematite Unit darkens suddenly at its higher altitudes, and Curiosity at this point was approaching that transition. The rover is now, on Sol 1876, sitting on that boundary, where they will spend a few days making observations before moving on.

Curiosity on the Hematite Unit, Sol 1866

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The image on the right shows Curiosity’s approximate position, about halfway across the Hematite Unit and with the rover’s approximate future route indicated, as shown in this October 3, 2016 press release.

In the two months since my last rover update the Curiosity engineering team has spent a lot of time imaging and studying the Hematite Unit. They have also spent a considerable amount of time doing new tests on the rover’s drill in an effort to get around its stuck feed mechanism in order to drill again. Only yesterday they took another series of close-up images of the drill in this continuing effort.

As indicated by the October 3 2016 press release, the rover still has a good way to go before it begins entering the distant canyons and large foothills. While they should leave the Hematite Unit and enter the Clay Unit beyond in only a few more months, I expect it will be at least a year before they pass through the Clay Unit and reach the much more spectacular Sulfate Unit, where the rover will explore at least one deep canyon as well as a recurring dark feature on a slope that scientists think might be a water seep.

Opportunity

For the context of Opportunity’s recent travels along the rim of Endeavour Crater, see my May 15, 2017 rover update.
» Read more

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Another LIGO black hole merger detected

8:47 am

Astronomers have announced another black hole merger detected by the LIGO gravitational wave observatory.

Dubbed GW170608, the latest discovery was produced by the merger of two relatively light black holes, 7 and 12 times the mass of the sun, at a distance of about a billion light-years from Earth. The merger left behind a final black hole 18 times the mass of the sun, meaning that energy equivalent to about 1 solar mass was emitted as gravitational waves during the collision.

This event, detected by the two NSF-supported LIGO detectors at 02:01:16 UTC on June 8, 2017 (or 10:01:16 pm on June 7 in US Eastern Daylight time), was actually the second binary black hole merger observed during LIGO’s second observation run since being upgraded in a program called Advanced LIGO. But its announcement was delayed due to the time required to understand two other discoveries: a LIGO-Virgo three-detector observation of gravitational waves from another binary black hole merger (GW170814) on August 14, and the first-ever detection of a binary neutron star merger (GW170817) in light and gravitational waves on August 17.

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Petroglyphs found depicting the earliest leashed dogs?

8:43 am

Archaeologists have found petroglyphs in Saudi Arabia that could be the earliest depiction of dogs being held by leashes.

Carved into a sandstone cliff on the edge of a bygone river in the Arabian Desert, a hunter draws his bow for the kill. He is accompanied by 13 dogs, each with its own coat markings; two animals have lines running from their necks to the man’s waist.

The engravings likely date back more than 8000 years, making them the earliest depictions of dogs, a new study reveals. And those lines are probably leashes, suggesting that humans mastered the art of training and controlling dogs thousands of years earlier than previously thought.

The dating however remains uncertain. The carvings could be much younger.

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Haze on Pluto lowers its global climate temperature 54º F

8:32 am

Using data collected during New Horizons’ fly-by, scientists have found that the planet’s atmosphere is 54º F colder than predicted, and from this they theorize that the presence of haze in that atmosphere is what cools it.

Pluto’s atmosphere is made mostly of nitrogen, with smaller amounts of compounds such as methane. High in the atmosphere — between 500 and 1,000 kilometres above the surface — sunlight triggers chemical reactions that transform some of these gases into solid hydrocarbon particles.

The particles then drift downward and, at around 350 kilometres above Pluto’s surface, clump with others to form long chemical chains. By the time they reach 200 kilometres’ altitude, the particles have transformed into thick layers of haze, which the New Horizons spacecraft saw dramatically blanketing Pluto.

Zhang and his colleagues compared the heating and cooling effects of the atmosphere’s gas molecules to those of its haze particles. Earlier studies have suggested that the presence of gas molecules, such as hydrogen cyanide, could help explain why Pluto’s atmosphere is so cold. But Zhang’s team found that including haze was the only way to get their model to match the temperatures that New Horizons measured as it flew by the dwarf planet.

This theory remains unproven. Moreover, there are other explanations proposed for the cold atmosphere by other scientists. It will take new instruments and future probes to resolve the question.

The post has been corrected. My math in calculating the conversion from Celsius to Fahrenheit was initially faulty. Thanks to reader Kirk for spotting the error.

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Interstellar object resembles asteroid

6:43 pm

Astronomers who have been observing the interstellar object that zipped past the Sun last month have concluded that it mostly resembles asteroids seen in our own solar system.

From its changing brightness, the team inferred that U1 is highly elongated with rough dimensions 30m x 30m x 180m. About twice the height of the Statue of Liberty, the 6:1 aspect ratio of U1 is “similar to the proportions of a fire extinguisher — although U1 is not as red as that,” says David Jewitt (UCLA), the first author of the study.

“With such an elongated shape, U1 probably needs a little cohesive strength to hold it together. But that’s not really unusual,” remarked study coauthor Jayadev Rajagopal (National Optical Astronomy Observatory). Commenting on its size, rotation, and color, Rajagopal mused that, “the most remarkable thing about U1 is that, except for its shape, how familiar and physically unremarkable it is.”

I wonder if they are still tracking it.

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Astronomers find habitable Earth-mass planet 11 light years away

9:15 am

Worlds without end: Astronomers have found an Earth-mass planet 11 light years away, orbiting a quiet red dwarf star in the habitable zone.

Unlike Proxima Centauri, which periodically has large flares which make its Earth-sized planet less hospitable to life, this red dwarf, Ross 128, is more stable.

Many red dwarf stars, including Proxima Centauri, are subject to flares that occasionally bathe their orbiting planets in deadly ultraviolet and X-ray radiation. However, it seems that Ross 128 is a much quieter star, and so its planets may be the closest known comfortable abode for possible life.

Although it is currently 11 light-years from Earth, Ross 128 is moving towards us and is expected to become our nearest stellar neighbour in just 79 000 years — a blink of the eye in cosmic terms. Ross 128 b will by then take the crown from Proxima b and become the closest exoplanet to Earth!

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Zwicky Transient Facility sees first light

10:54 am

Astronomers announced today that the Zwicky Transient Facility at the Palomar Observatory in California has seen first light, and will begin full operations in 2018.

When fully operational in 2018, the ZTF will scan almost the entire northern sky every night. Based at the Palomar Observatory in southern California and operated by Caltech, the ZTF’s goal is to use these nightly images to identify “transient” objects that vary between observations — identifying events ranging from supernovae millions of light years away to near-Earth asteroids.
an image of stars and the night sky

In 2016, the UW Department of Astronomy formally joined the ZTF team and will help develop new methods to identify the most “interesting” of the millions of changes in the sky — including new objects — that the ZTF will detect each night and alert scientists. That way, these high-priority transient objects can be followed up in detail by larger telescopes, including the UW’s share of the Apache Point Observatory 3.5-meter telescope.

By producing new high resolution images of the entire northern sky every night, this telescope instrument is going to discover gobs of new transients, from supernovae to binaries to novae to things we haven’t even seen before.

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Exploring one of Mars’ giant volcanoes

10:42 am

Master index

For the past two weeks JPL’s image site has been releasing a string of images taken by Mars Odyssey of the smallest of Mars’ four giant volcanoes.

Pavonis Mons is one of the three aligned Tharsis Volcanoes. The four Tharsis volcanoes are Ascreaus Mons, Pavonis Mons, Arsia Mons, and Olympus Mars. All four are shield type volcanoes. Shield volcanoes are formed by lava flows originating near or at the summit, building up layers upon layers of lava. The Hawaiian islands on Earth are shield volcanoes. The three aligned volcanoes are located along a topographic rise in the Tharsis region. Along this trend there are increased tectonic features and additional lava flows. Pavonis Mons is the smallest of the four volcanoes, rising 14km above the mean Mars surface level with a width of 375km. It has a complex summit caldera, with the smallest caldera deeper than the larger caldera. Like most shield volcanoes the surface has a low profile. In the case of Pavonis Mons the average slope is only 4 degrees.

The image on the right is the context image, annotated by me to show where all these images were taken. The images can accessed individually below.

Each of these images has some interesting geological features, such as collapses, lava tubes, faults, and flow features. Meanwhile, the central calderas are remarkable smooth, with only a few craters indicating their relatively young age.

The most fascinating geological fact gleaned from these images is that they reveal a larger geological trend that runs through all of the three aligned giant volcanoes to the east of Olympus Mons.

The linear and sinuous features mark the locations of lava tubes and graben that occur on both sides of the volcano along a regional trend that passes thru Pavonis Mons, Ascreaus Mons (to the north), and Arsia Mons (to the south).

This trend probably also indicates the fundamental geology that caused all three volcanoes to align as they have.

Arsia Mons is of particular interest in that water clouds form periodically above its western slope, where there is also evidence of past glaciation. Scientists strongly suspect that there is a lot of water ice trapped underground here, possibly inside the many lava tubes that meander down its slopes. These facts also suggest that this might be one of the first places humans go to live, when they finally go to live on Mars.

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Billionaire Yuri Milner considering funding mission to Enceladus

9:21 pm

Capitalism in space: Billionaire Yuri Milner, who already funds several astronomy projects aimed at interstellar travel, is now considering funding a planetary probe to the Saturn moon Enceladus.

At the moment all he is doing is holding workshops with scientists and engineers to see if such a mission can be done for an amount he can afford. Considering that Elon Musk’s first concept to send a private probe to Mars, before SpaceX existed, was stopped because of high launch costs, thus becoming the inspiration for SpaceX itself in order to lower those costs, Milner’s private effort might actually be affordable now.

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Sacrificing Scientific Skepticism

10:59 am

Phil Berardelli, who periodically comments here and who is a veteran science journalist who worked for the journal Science for a number of years, has written a very cogent four part essay on the subject of climate change for the think tank Capital Research Center.

Berardelli very carefully outlines the uncertainties that dominate our knowledge of the Earth’s climate, while explaining clearly why consensus is never what good science relies upon. As he notes,

Science is not primarily about proof; science is about disproof. Nothing in science, absolutely nothing, should ever be taken at face value. This view isn’t new; it’s age old.

Read it all, especially if you are one of the people who reads my writing and questions my skepticism about much of what I see in the climate field, especially coming from NASA and NOAA. Berardelli illustrates how doubt and skepticism are the hallmarks of science, and should always be honored, not denigrated with slurs like “denier.”

Full disclosure: Phil Berardelli was also my editor when I did a weekly column for UPI called Space Watch for six months in 2005.

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A storm on Jupiter

10:09 am

A storm of Jupiter

Cool image time! The image above, reduced in resolution to post here, was taken during Juno’s ninth close fly-by of Jupiter in late October, and shows one particular storm swirl in the gas giant’s southern hemisphere.

The Juno team today highlighted an image taken during this fly-by of Jupiter’s entire southern hemisphere, but I find this close-up more interesting. Be sure to check out the full resolution version. It appears to me that the white swirls have risen up above the gold and blue regions, casting shadows down upon them.

Unfortunately, I cannot tell you the scale of this storm, as the release does not give any details, including where in the full hemisphere image it is located. I suspect, however, that it is large enough to likely cover the Earth.

Both the full hemisphere image and the image above were processed by citizen scientists Gerald Eichstädt and Seán Doran.

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Physicists shrink their next big accelerator

9:52 am

Because of high costs and a refocus in research goals, physicists have reduced the size of their proposed next big particle accelerator, which they hope will be built in Japan.

On 7 November, the International Committee for Future Accelerators (ICFA), which oversees work on the ILC, endorsed halving the machine’s planned energy from 500 to 250 gigaelectronvolts (GeV), and shortening its proposed 33.5-kilometre-long tunnel by as much as 13 kilometres. The scaled-down version would have to forego some of its planned research such as studies of the ‘top’ flavour of quark, which is produced only at higher energies.

Instead, the collider would focus on studying the particle that endows all others with mass — the Higgs boson, which was detected in 2012 by the Large Hadron Collider (LHC) at CERN, Europe’s particle-physics lab near Geneva, Switzerland.

Part of the reason for these changes is that the Large Hadron Collider has not discovered any new particles, other than the Higgs Boson. The cost to discover any remaining theorized particles was judged as simply too high. Better to focus on studying the Higgs Boson itself.

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Physicists once again fail to detect dark matter

9:25 am

The uncertainty of science: The most sensitive detector yet created by physicists has once again failed to detect dark matter, casting strong doubt on all present theories for its existence.

The latest results from an experiment called XENON1T at the Gran Sasso National Laboratory in Italy, published on 30 October, continue a dry spell stretching back 30 years in the quest to nab dark-matter particles. An attempt by a Chinese team to detect the elusive stuff, the results of which were published on the same day, also came up empty-handed. Ongoing attempts by space-based telescopes, as well as at CERN, the European particle-physics laboratory near Geneva, Switzerland, have also not spotted any hints of dark-matter particles.

The findings have left researchers struggling for answers. “We do not understand how the Universe works at a deeper and more profound level than most of us care to admit,” says Stacy McGaugh, an astrophysicist at Case Western Reserve University in Cleveland, Ohio.

The process here has been a good demonstration of the scientific method. Observers detect a phenomenon that does not make sense, which in this case was that the outer regions of galaxies rotate so fast that they should fly apart. Theorists then come up with a hypothesis to explain the phenomenon, which here was dark matter, subatomic particles that have weight but do not generally interact with the rest of the universe except by their mass, which acts to hold the galaxies together. Observers than try to prove the hypothesis by finding these theorized particles.

When the particles are not found, the theorists begin to rethink their theories. Maybe dark matter does not exist. Maybe (as is mentioned near the end of the article) a rethinking of the nature of gravity itself might be necessary. Or possibly the unseen matter is not subatomic, but ordinary matter not yet detected.

If only the climate field would apply this basic scientific method to its work. There, scientists found that carbon dioxide is increasing in the atmosphere. Some theorists posited an hypothesis that said that this increase might cause the climate to warm, and created numerous (almost a hundred) models to predict this warming. After more than thirty years, however, none of those models has successfully worked. The climate has not warmed as predicted, which suggests the hypothesis is flawed, and needs rethinking. Sadly, the leaders in the climate field refuse to do this rethinking. Instead, they appear willing to adjust and change their data to make it fit, sometimes in ways that are downright fraudulent.

This is not how science is done, and it is doing a terrible disservice to both science and society in general.

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