Tag Archives: science

Astronomers get best and earliest view of supernovae ever

Using ground-based telescopes as well as the space telescope Kepler astronomers have obtained their best and earliest view of a Type Ia supernova.

The supernova, named SN 2018oh, was brighter than expected over the first few days. The increased brightness is an indication that it slammed into a nearby companion star. This adds to the growing body of evidence that some, but not all, of these thermonuclear supernovae have a large companion star that triggers the explosion.

Las Cumbres Observatory (LCO), based in Goleta, California, is a global network of 21 robotic telescopes that obtained some of the best data characterizing the supernova in support of the NASA mission. Wenxiong Li, the lead author of one of three papers published today on the finding, was based at LCO when much of the research was underway. Five other LCO astronomers, who are affiliated with the University of California Santa Barbara (UCSB), also contributed to two of the papers.

Understanding the origins of Type Ia supernovae is critical because they are used as standard candles to map out distances in cosmology. They were used to discover Dark Energy, the mysterious force causing the universe to accelerate in its expansion. Astronomers have long known that a supernova is the explosion of a dense white dwarf star (A white dwarf has the mass of the sun, but only the radius of the Earth; one teaspoon of a white dwarf would weigh roughly 23000 pounds) What triggers the explosion is less well understood. One theory holds that the explosions are the merger of two white dwarf stars. Another is that the second star is not a white dwarf at all, but a normal-sized or even giant star that loses only some of its matter to the white dwarf to initiate the explosion. In this theory, the explosion then smashes into the surviving second star, causing the supernova to be exceedingly bright in its early hours.

Finding that Type Ia supernovae can be brighter than previously believed throws a wrench into the results that discovered dark energy, since those results made assumptions about the brightness and thus the distance of those supernovae. If the brightness of these supernovae are not as reliable as expected, they are also less of a standard candle for estimating distance.


More ice cliffs found on Mars!

Another ice cliff

In my review of the November image download from the high resolution camera on Mars Reconnaissance Orbiter (MRO), I am, as a cave explorer and cartographer, naturally attracted to any image with “pit” in the title. The image to the right, cropped, rotated and reduced to post here, was released with the title “Pit in Mid-Latitude Mantle”. That immediately caught my eye, and in looking at it I was at first unimpressed. The three apparent collapses are interesting in that they all have south-facing sharp cliffs, but other than that I wasn’t sure why they were of interest.

Then I took at look at this image’s location. It is somewhat far south on Mars, at latitude -60 degrees, sitting south of Hellas Basin, the deepest basin on Mars. This location is in the same general area where scientists announced in January the discovery of eight cliffs with visible exposed ice layers. The white horizontal bar below Hellas Basin on the map below and to the right shows the region where seven of those ice cliffs were located. To quote the January press release:

The location of known ice scarps on Mars

These eight scarps, with slopes as steep as 55 degrees, reveal new information about the internal layered structure of previously detected underground ice sheets in Mars’ middle latitudes.

The ice was likely deposited as snow long ago. The deposits are exposed in cross section as relatively pure water ice, capped by a layer one to two yards (or meters) thick of ice-cemented rock and dust. They hold clues about Mars’ climate history. They also may make frozen water more accessible than previously thought to future robotic or human exploration missions.

Researchers who located and studied the scarp sites with the High Resolution Imaging Science Experiment (HiRISE) camera on MRO reported the findings today in the journal Science. The sites are in both northern and southern hemispheres of Mars, at latitudes from about 55 to 58 degrees, equivalent on Earth to Scotland or the tip of South America. “There is shallow ground ice under roughly a third of the Martian surface, which records the recent history of Mars,” said the study’s lead author, Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center in Flagstaff, Arizona. “What we’ve seen here are cross-sections through the ice that give us a 3-D view with more detail than ever before.”

In an email correspondence today with Dr. Dundas, he confirmed that the image to the right was of ice cliffs not included in the January paper. The image was a follow-up of an earlier MRO image and was taken to confirm the ice cliff’s existence.

What I noticed in reviewing the January paper was that these three new ice scarps were actually outside the white bar on the map above, located at -60.7 degrees latitude, 83.5 degrees longitude.
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Analysis of InSight’s landing site

Link here. It appears they landed within a small crater filled with sand.

InSight landed in what’s called a hollow, a crater that has been filled in with soil and leveled flat. In images taken from the elbow of the lander’s stowed robotic arm, the edge of the crater is visible. Once the team determines the diameter of the crater—it could be meters, maybe tens of meters—researchers can infer its depth and the amount of sand blown into it. Either way, this bodes well for the heat probe instrument, called HP3, which should penetrate the material with ease. “This is about as good news for HP3 as you could possibly hope,” he says.

Landing in the hollow was fortunate for another reason. InSight didn’t quite hit the bull’s-eye of its target landing zone, and ended up in terrain that, overall, is rockier than desired. But the hollow is mostly devoid of rocks. One, about 20 centimeters across, sits close to the lander’s feet, whereas three smaller ones lie farther away—but none poses a threat to placing the instruments. The hollow is flat and lacks sand dunes, and small pebbles indicate a surface dense enough to support the weight of the instruments. “We won’t have any trouble whatsoever,” Golombek says.

They still need to pin down exactly where the lander is, on the surface. They know, within a few kilometers, but it will take more work to narrow that down to a precise location.


The lava tubes and canyons of Cerberus Fossae

Cerberus Fossae rock falls

Cool image time! In the November image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO) I found the image on the right (cropped to post here), dubbed “Possible Rock Falls on Steep Slopes in Cerberus Fossae.” You can see the full image by clicking on the photo on the right.

The cropped section focuses on the steep cliffs of this deep canyon, formed when lava flowed down from the giant volcano Elysium Mons almost like water, following the faults created by the bulging volcanoes to carve a long series of parallel canyons more seven hundred miles in length. Not only can individual boulders be seen piled up on the base of the canyon, you can see on the lower right a large section of cliff that has broken off and partly fallen, propped now precariously on the cliff’s steep slope. I would not want to be hiking below it at the base of this canyon.

Elysium Mons and Cereberus Fossae

This photograph itself made me more interested in looking at other MRO images of Cerberus Fossae. The context map on the right shows that MRO has taken numerous images along the length of these faults, indicated by the red boxes. The location of the above image is shown by the white cross, at the western end where the canyons tend to be steep, deep, and pronounced. In taking a look at the many images of Cerberus Fossae, I found a variety of canyons, plus pit chains, lava tube skylights, and one especially intriguing image, posted below, that shows what appears to be an extended collapse along the length of what was once an underground lava tube.
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Scientists to pollute atmosphere to stop global warming

The coming dark age: In order to stop global warming a team of scientists plan a first test of a method designed to block sunlight by injecting aerosols (the scientific term for pollution) into the upper atmosphere.

If all goes as planned, the Harvard team will be the first in the world to move solar geoengineering out of the lab and into the stratosphere, with a project called the Stratospheric Controlled Perturbation Experiment (SCoPEx). The first phase — a US$3-million test involving two flights of a steerable balloon 20 kilometres above the southwest United States — could launch as early as the first half of 2019. Once in place, the experiment would release small plumes of calcium carbonate, each of around 100 grams, roughly equivalent to the amount found in an average bottle of off-the-shelf antacid. The balloon would then turn around to observe how the particles disperse.

The test itself is extremely modest. Dai, whose doctoral work over the past four years has involved building a tabletop device to simulate and measure chemical reactions in the stratosphere in advance of the experiment, does not stress about concerns over such research. “I’m studying a chemical substance,” she says. “It’s not like it’s a nuclear bomb.”

Nevertheless, the experiment will be the first to fly under the banner of solar geoengineering. And so it is under intense scrutiny, including from some environmental groups, who say such efforts are a dangerous distraction from addressing the only permanent solution to climate change: reducing greenhouse-gas emissions. The scientific outcome of SCoPEx doesn’t really matter, says Jim Thomas, co-executive director of the ETC Group, an environmental advocacy organization in Val-David, near Montreal, Canada, that opposes geoengineering: “This is as much an experiment in changing social norms and crossing a line as it is a science experiment.” [emphasis mine]

The number of stupid and ill-documented conclusions mentioned in this article are so many it would be hard to list them all. For one, it assumes the climate is warming in a disastrous manner, an assumption that remains entirely unproven. For another, the last paragraph in the quote above illustrates how much politics dominates this scientific field. Science has nothing to do with this experiment.

Third, the risks involved in doing this kind of geoengineering are impossible to measure. They very easily could be very negative, for us and the environment. Fourth, the only objections to this experiment quoted in the article come from activist groups who believe in global warming, but would rather impose political restrictions on freedom and property rights than do geoengineering. Skepticism of the global warming theory is merely mentioned as an aside, coming from “the occasional conspiracy theorist.”

I could go on. The worst part of this article and the scientists proposing this work is their utter refusal to consider the gigantic amounts of research that has shown the many benefits of increased atmospheric carbon dioxide and warming for agriculture and plant growth. Global warming, should it happen, could have negative consequences, but the data so far is very far from conclusive.

Let me add one more side note: The same environmentalists who generally support geoengineering to halt global warming are also likely to agree with this infantile op-ed: Richard Branson and Elon Musk threaten the purity of space.

Despite all the money the US and Russia have spent attempting to show who has the biggest balls, space remains pure. But, while Nasa re-engages and fuels up for another go, so-called space pioneers and entrepreneurs are already selling seats.

I don’t know about you, but I don’t want space to be commercialised, owner [sic] by Richard Branson or Elon Musk. For me, this would ruin something very special.

I’d suggest you read it all, but I would fear your level of education and ability to think will be seriously damaged.

For these anti-human environmentalists, manipulating the Earth’s atmosphere, based on weak scientific theories, is perfectly okay. Having humans and private enterprise in space, however, is evil and must be prevented at all costs.

The empty-headed lack of thought and ignorance required to come to these conclusions, simultaneously, boggles my mind.


InSight’s solar panels have opened

InSight engineers have now reported that solar panels have opened and are functioning properly.

NASA’s InSight has sent signals to Earth indicating that its solar panels are open and collecting sunlight on the Martian surface. NASA’s Mars Odyssey orbiter relayed the signals, which were received on Earth at about 5:30 p.m. PST (8:30 p.m. EST). Solar array deployment ensures the spacecraft can recharge its batteries each day. Odyssey also relayed a pair of images showing InSight’s landing site.

“The InSight team can rest a little easier tonight now that we know the spacecraft solar arrays are deployed and recharging the batteries,” said Tom Hoffman, InSight’s project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California.

This was the last major event in the landing sequence, and with it they can now shift to the slow deployment of instruments over the next few weeks. Results from this spacecraft will not be sudden or spectacular. It is going to take time to get the spectrometer placed and than time to gather quake data.


Quasars that shut off

The uncertainty of science: Astronomers have discovered a class of quasars that suddenly turn off, something that no theory had predicted possible.

LaMassa, an astronomer now at the Space Telescope Science Institute, was mystified. Until that moment in 2014, she, like so many others, had expected quasars to be relatively stagnant. “Then you see these drastic changes within a human lifetime, and it’s pretty cool,” she said.

Confusion turned into excitement, and a hunt began to find more of these oddities. Although less luminous examples had already been seen, astronomers wanted to know if changes as dramatic as the one LaMassa discovered were common. It was no straightforward task, given that surveys tend not to go back and look at objects they have previously observed. But astronomers searched through archived data and discovered 50 to 100 more of what became known as “changing-look quasars.” Some of these have dimmed substantially more than LaMassa’s first example. Others have transitioned in the space of a month or two. And others, after disappearing, have reappeared again.

“It’s clear that the reason we weren’t finding these objects before is that we weren’t looking for them,” said Eric Morganson, an astronomer at the University of Illinois.

The article does a fine job of explaining the whole problem, including outlining the theories now being posited to explain these events. Bottom line: the universe is always more complicated that expected by initial observations.


Bennu from 85 miles

Bennu at 85 miles

The OSIRIS-REx science team today released a new image of Bennu, taken by the spacecraft from only 85 miles on November 16, two weeks ago Its contrast has been increased to bring out the details.

The asteroid continues to remind me of Ryugu, a rubble pile of boulders with few smooth spots. I suspect the OSIRIS-REx engineers are going to struggle as much as the Hayabusa-2 engineers are in an effort to find a safe spot to grab a sample. The advantage however for OSIRIS-REx is that the main body of the spacecraft doesn’t have to get as close to the surface as with Hayabusa-2. They will come down only close enough for the robot arm to touch down.

Rendezvous is set for December 3.


Present and future landing sites on Mars

With InSight’s landing on Mars set for 11:54 am (Pacific) this coming Monday, November 26, 2018, I decided to put together a map of Mars showing the location of all the successful landers/rovers, adding the landing sites for the planned landers/rovers through 2020. This will give some context to InSight’s landing site.

Landing sites on Mars

The map does not show the landing sites for the failed Soviet, American, and British landers.

As I noted in describing the Mars2020 landing site, the location of the bulk of these landing sites, along the transition zone from the southern highlands and the northern lowlands, demonstrates the areas of the planet that interest geologists the most. It is here that we find many shoreline features, suggestive of the ocean that many scientists theorize existed intermittently in the northern lowlands. It is here that planetary scientists can quickly gather the most information about Martian geological history. And it is here that they have the opportunity to study the widest range of rock types.

From an explorer’s perspective, however, this approach has its limits. It does not provide us a look at a wide variety of locations. It is not directly aimed at finding lower latitude locations where ice might actually exist. And it is decidedly not focused in studying the planet from the perspective of future colonists. I am sometimes frustrated that we have as yet no plans to send any rovers into Marineris Valles, or to the western slopes of Arsia Mons, the southern most volcano in the chain of three giant volcanoes where there are indications that ice might exist underground, or to any of the places where caves are known to exist where a colony could be built more easily. In fact, the caves on the slopes of Arsia Mons seems a prime exploration target.

Eventually these locations will be explored, likely by private landers aimed at scouting out locations for future private settlements. I am just impatient.


India wants international instruments for its Venus mission

The new colonial movement: India has requested science instruments proposals from the international community for its planned Venus orbiter, set to launch in 2023.

ISRO has already selected 12 instruments, proposed by Indian scientists, including cameras and chemical analyzers to study the atmosphere. Now, it’s hoping other scientists will join. “Planetary exploration should be all about global partnerships,” says Kailasavadivoo Sivan, a rocket scientist and ISRO’s chair. (The deadline for submitting proposals is 20 December.)

For me, the big news with this article is that it is the very first I have seen that actually spells out Sivan’s first name. Since he became head of ISRO in January 2018, he has only been listed as “K. Sivan” in every single article, even those describing his background when he was appointed. Now that I have learned what a tongue-twister that first name is, I can understand why they abbreviate it.

On a more serious note, this article indicates the growing maturity of India’s space effort. They not only are planning a mission to Venus, they will fly missions to the Moon in January and Mars in 2022, and intend to launch their first manned mission in that same time period.


Another star found that dims strangely like Tabby’s Star

Astronomers have found a second star that dims in an inexplicable manner, like Tabby’s Star.

Known as VVV-WIT-07, the star appears to be much older and redder than our sun, although the amount of interstellar dust between our solar system and the star’s home closer to the galactic center makes exact classification and distance measurements very difficult. What is certain is that in the summer of 2012, the object’s brightness faded slightly for 11 days, then plummeted over the following 48 days, suggesting that something blocked more than three quarters of the star’s light streaming toward Earth. But what could that “something” be?

According to Eric Mamajek, an astrophysicist at the University of Rochester unaffiliated with the VVV survey, such a profound degree of dimming suggests that a staggeringly large object or group of objects is blocking the light. “It’s got to be over a million kilometers wide, and very dense to be able to block that much starlight,” he says. Mamajek should know: He led the team that discovered J1407, another strange star periodically eclipsed by a planet-sized object thought to boast a massive ring system some 200 times broader than that of Saturn. In this latest case, he says, the strange signals from VVV-WIT-07 could arise from clumps or clouds of material passing between Earth and the star, though he cautioned that the data were preliminary and more observations are required.

Tabetha Boyajian agrees. Boyajian, an astronomer at Louisiana State University, was the lead author for the 2015 paper announcing the strange dimming of KIC 8462852, also known as Tabby’s Star, an unusual object first spotted by NASA’s Kepler Space Telescope. VVV-WIT-07 would have to harbor “a very peculiar kind of dust cloud to make these kinds of dips,” Boyajian says. Boyajian’s study helped spark a surge of public interest in Tabby’s Star because the star’s unusual dimming could be seen as evidence of an alien civilization building an artificial structure that soaked up the star’s light. More conventional explanations include a swarm of comets or fragments from a shattered planet, both of which would create significant clouds of dust and debris that could also occlude the star’s light. But, so far, no simple single explanation fits the complexities of the dimming seen around the star; researchers remain stymied in their attempts to understand the true nature of the strange dimming of Tabby’s Star.

As is usually the case in these cases, the explanation will not be aliens. That it could be, however, is what makes it so intriguing.


A young lunar impact crater

Lunar crater

Cool image time! The science team from Lunar Reconnaissance Orbiter (LRO) today released a new image, taken on November 3, 2018, of a relatively young small crater not easily seen from Earth.

The unnamed crater, just 1.8 kilometers across, is too small to see from Earth with unaided eyes. It is in the Moon’s wild west, just past Oceanus Procellarum and close to the line dividing the nearside from the farside, so it would be hard to glimpse in any case. If you stood on the crater rim, you would see the Earth forever slowly bobbing up, down, and sideways close to the eastern horizon.

The image above is a cropped and reduced-in-resolution section of the released image. If you click on it you can see this section at full resolution.

What I find fascinating about this crater are the black streaks that appear to only run down the outside slopes of the eastern rim, but nowhere else. At first glance it looks like prevailing winds, blowing from the west, caused this, but of course that’s wrong because the Moon has no atmosphere. The website explains:
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The soft landslides of Mars

A soft avalanche on Mars

Context image of landslide

The light gravity of Mars, combined with different materials, a lot of dust, and a geological history different from Earth, produces events that — though reminiscent of similar geological events on Earth — are definitely not the same.

The image above, cropped and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and was one of the many uncaptioned images released in the November archive. If you click on the image you can see the full resolution version. It shows the tongue of a landslide inside a crater located in the planet’s southern highlands.

You can immediately see why I call it a soft landslide. The craters on its top are barely visible, as if they hit a soft surface that absorbed most of the impact. The grooves spreading southward in the slide suggest that this solid material flowed almost like mud. And the soft, smooth surface head of the slide suggests an almost liquid-like flow. As far as I can tell, this landslide had few large boulders. It was made up instead of small particles of about the same size.

To the right is an image showing the wider context of the above image, taken by Mars Odyssey and cropped and annotated by me to post here. The white box shows the entire area photographed by the full resolution image of the landslide, with the tongue of the landslide at the bottom of the box. If you look at the floor of this crater, you can see what looks like the ghost of a past smaller impact, seemingly buried in either a field of lava or soft dusty regolith. The smoothness of the crater floor also suggests a material softness, allowing it to settle into a pondlike featureless flat plain.
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New Wolf-Rayet star discovered 8,000 light years away

Astronomers have discovered a Wolf-Rayet star — the kind of star thought to eventually cause major explosions — 8,000 light years away.

The binary star system, containing a pair of massive ‘Wolf-Rayet’ stars, has been discovered by an international team of researchers, including Professor Paul Crowther from the University of Sheffield, and published in Nature Astronomy.

Wolf-Rayet stars are amongst the hottest stars in the Universe, blast out powerful winds of hot gas, and represent the last stage in the evolution of the most massive stars prior to exploding as a supernova.

Located around 8,000 light years away – half a billion times further away than our Sun – the binary system is surrounded by a gigantic dust cloud. The collision between the winds of the two stars can form dust, which takes on elegant spiral pinwheel shapes as the stars orbit each other.

Expect to see a number of news articles hinting at how this system is a deadly threat to Earth. It is not. For one thing, it is too far away for any supernovae or gamma ray burst to cause serious harm here. Second, it will be a long time before any of that is going to happen.

Wolf-Rayet stars however are rare, and being able to study them helps astronomers better understand the life and death of stars. Having another so relatively close is a boon to astronomers.


Parker reports in

Scientists have received confirmation from the Parker Solar Probe that it successfully survived its first close fly-by of the Sun and that all its instruments were able to gather data.

All Parker Solar Probe systems are operating well and as designed. The solid state recorder on the spacecraft indicated that, as planned, the four instrument suites had recorded a significant amount of data, which is scheduled to be downloaded to Earth via the Deep Space Network over several weeks starting Dec. 7. In addition to helping scientists begin to explore fundamental questions about the physics of our star, the data from this initial perihelion — collected closer to the Sun than any before — will help instrument teams calibrate Parker Solar Probe’s instruments and plan future observations.

Parker will repeat this many times over the next seven years. And while it will provide us a ton of new knowledge about the Sun, it will also be proving out technology that future solar system travelers will use to get closer such hostile environments.


NASA picks Mars 2020 landing site: Jezero Crater

Jezero Crater

NASA has picked Jezero Crater has the landing site for its as yet unnamed 2020 Mars rover.

Jezero Crater is located on the western edge of Isidis Planitia, a giant impact basin just north of the Martian equator. Western Isidis presents some of the oldest and most scientifically interesting landscapes Mars has to offer. Mission scientists believe the 28-mile-wide (45-kilometer) crater, once home to an ancient river delta, could have collected and preserved ancient organic molecules and other potential signs of microbial life from the water and sediments that flowed into the crater billions of years ago.

Jezero Crater’s ancient lake-delta system offers many promising sampling targets of at least five different kinds of rock, including clays and carbonates that have high potential to preserve signatures of past life. In addition, the material carried into the delta from a large watershed may contain a wide variety of minerals from inside and outside the crater.

The geologic diversity that makes Jezero so appealing to Mars 2020 scientists also makes it a challenge for the team’s entry, descent and landing (EDL) engineers. Along with the massive nearby river delta and small crater impacts, the site contains numerous boulders and rocks to the east, cliffs to the west, and depressions filled with aeolian bedforms (wind-derived ripples in sand that could trap a rover) in several locations.

The red dot on the map of Mars below shows this location. The blue dot is Gale Crater where Curiosity landed. The purple dot is the landing site for the European ExoMars rover. The yellow dot is where Opportunity has been roving, and the black dot is Spirit’s location.
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Computer model suggests universe has innumerable exomoons

A supercomputer simulation has shown that ice-giant planets like Uranus and Neptune can have their own dust disk during formation, thus allowing these kinds of planets to also form moons.

“So far it was believed that Uranus and Neptune are too light to form such a disk,” says the astrophysicist. Therefore, it was considered that the moons of Uranus could have formed after a cosmic collision – like our own moon, also a relatively infrequent event as the capture. Now the researchers who are also members of the NCCR PlanetS were able to refute this previous idea. Their extremely complex computer simulations reveal that in fact Uranus and Neptune were making their own gas-dust disk while they were still forming. The calculations generated icy moons in-situ, that are very similar in composition with the current Uranian satellites. From the simulations performed by the supercomputer called “Mönch” at CSCS it is clear that Neptune originally also was orbited by a Uranus-like, multiple moon system, but this must have been wiped out during the capture of Triton.

The new study has a much wider impact on moons in general, than only on our Solar System formation history. “If ice giants can also form their own satellites, that means that the population of moons in the Universe is much more abundant than previously thought,” summarizes Dr.Szulágyi.Ice giants and mini-Neptune planets are often discovered by exoplanet surveys, so this planet mass category is very frequent. “We can therefore expect many more exomoon discoveries in the next decade,” the astrophysicist says.

I actually don’t believe the assumption posited here that scientists previously believed Uranus and Neptune were too light to form disks. I think many astronomers might have believed that, while many others remained unsure, since it is more intuitive to expect such disks to form as these gas giants formed.

Either way, this computer model lends weight to those who believe the universe is littered with planets and moons, everywhere, many of which will exist in the habitable zones of all kinds of stars. These planets and moons might not have life, but they will be places we could live, when we begin colonizing interstellar space.


Sunset/sunrise on Mars

The sun on Mars's horizon

Cool image time! The image on the right, reduced to post here, was taken by Curiosity during a photo campaign this week to monitor Mars’s atmosphere. It looks out to the horizon at the Sun. I think the view is eastward, at Mount Sharp, as the Sun rises, but I am not sure. It might be looking west across the crater rim at sunset.

If you click on the image you can see it at full resolution. The haziness in the atmosphere might be left over from this summer’s global dust storm, but probably not, as I have read numerous reports in connection with Opportunity saying the storm is completely over and the atmosphere has now cleared. More likely it is from the windy conditions that are simply present these days at Gale Crater.

Regardless, it is quite cool because it illustrates how far we have come since the first planetary missions half a century ago. We can now routinely watch a sunset on Mars.


Looking at the south pole of the Milky Way

Link here. The link provides instructions for finding the spot in the sky that corresponds to the south pole of the galaxy, pointing in a perpendicular direction away from its center.

No star marks the position. It sits in the faint southern constellation of Sculptor, the sculptor’s studio, hence its identification is intellectual rather than sensorial.

This is the case of the dog that did not bark. The reason there is little to see there is that you will be looking down out of the plane of the galaxy, in a direction with the fewest stars to see. The view is therefore looking out of our galaxy, at intergalactic space, vast and empty.


OSIRIS-REx unfolds its robot arm

In preparation for its December 3 rendezvous with the asteroid Bennu OSIRIS-REx successfully unfolded its robot arm for the first time since launch this week.

The website has a nice short video showing how the arm will grab its samples. Very innovative, and not what you would expect. The technique had to be clever because Bennu is so small and has such a tiny gravity.


The fractured floor of Komarov Crater

Fractured floor of Komarov Crater

Cool image time! The Lunar Reconnaissance Orbiter (LRO) oblique image on the right, reduced significantly from the original to post here, shows the deeply fractured floor of Komarov Crater on the Moon’s far side. As noted at the image link,

The spectacular fractures that cut across the floor of Komarov crater [about 85 kilometers or 50 miles diameter] were formed when magma rose from the mantle, uplifting and fracturing the crater in the process. In this case the magma did not erupt to the surface, thus the fractures remain visible.

The Komarov fractures are quite large, the major left-to-right fracture that cuts across the center of the scene is over 500 meters deep [1,600 feet] and 2500 meters wide [1.5 miles]. When did they form? The large number of craters superimposed on the floor and fractures testifies to their ancient ages. Likely they are of the same vintage (>2.6 billion years) as the Mare Moscoviense lava plains just to the north

An overview of Komarov Crater as well as other LRO images of it can be found here.

The question that comes to my mind is the relative rarity of craters with such large fractures on their floors. I have noted this for Mars as well. It is expected that there is melt on the floor of all large impact craters. Why do a few produce such pronounced fractures, while most do not? This website posits one explanation, but its complexity leaves me unsatisfied. It also doesn’t explain why it happens only rarely.


Movie of Juno’s October 29, 2018 Jupiter fly-by

Cool movie time! Citizen scientist Gerald Eichstädt has created a time lapse movie using the images taken by Juno during its sixteenth close fly-by of Jupiter on October 29, 2018.

The movie is embedded below the fold. Quite spectacular. The colors are enhanced to bring out the details, and begins looking down at Jupiter’s north hemisphere at night.
» Read more


Escape velocity on Phobos changes a lot depending on location

A new computer analysis of the shape of the gravitational field of the Martian moon Phobos suggests that the escape velocity varies significantly, depending on where you are on the moon’s surface.

Phobos is an odd duck among our solar system’s moons. It’s tiny (a fraction of a percent the size of our own moon) and is shaped like a potato; that weird shape draws gravity to different places, depending on where you are.

All these features make Phobos a challenge to travel on, researchers report in Advances in Space Research. In some places, moving any faster than 5 kilometers per hour would be enough to free you from the moon’s meager gravitational pull, sending you off into space where you’d likely be captured by Mars’s gravity and end up orbiting the Red Planet. The fastest you could travel anywhere on Phobos would be about 36 kilometers per hour, or a little faster than a golf cart, the team finds.

Obviously, this must be recognized for any mission trying to land and explore the moon.


Astronomers identify first progenitor star for Type 1C supernovae

Astronomers have for the first time identified a progenitor star for a Type 1C supernovae.

[The search for supernovae progenitor stars has found] a few pre-supernova stars. But the doomed stars for one class of supernova have eluded discovery: the hefty stars that explode as Type Ic supernovas. These stars, weighing more than 30 times our Sun’s mass, lose their hydrogen and helium layers before their cataclysmic death. Researchers thought they should be easy to find because they are big and bright. However, they have come up empty. Finally, in 2017, astronomers got lucky. A nearby star ended its life as a Type Ic supernova. Two teams of researchers pored through the archive of Hubble images to uncover the putative precursor star in pre-explosion photos taken in 2007. The supernova, catalogued as SN 2017ein, appeared near the center of the nearby spiral galaxy NGC 3938, located roughly 65 million light-years away.

An analysis of the candidate star’s colors shows that it is blue and extremely hot. Based on that assessment, both teams suggest two possibilities for the source’s identity. The progenitor could be a single star between 45 and 55 times more massive than our Sun. Another idea is that it could have been a binary-star system in which one of the stars weighs between 60 and 80 times our Sun’s mass and the other roughly 48 solar masses. In this latter scenario, the stars are orbiting closely and interact with each other. The more massive star is stripped of its hydrogen and helium layers by the close companion, and eventually explodes as a supernova.

As can be seen by the quote above, identifying the star that exploded still leaves much unknown, including whether the star is a single or a binary. Still, they finally have some idea what kind of star erupts in a Type IIC supernovae, which will help constrain the theories for explaining the cause of these explosions.

Note also that this identification will not be confirmed until the supernova itself completely fades in about two years. They might find when that happens that the candidate progenitor is still there, meaning it was not the progenitor of the supernova at all.


Scientists admit to many errors in ocean warming paper

The uncertainty of science: The scientists who wrote a much heralded paper a few weeks ago claiming that the oceans are retaining far more heat than previously believed have admitted that their paper has many errors that make its conclusions far more uncertain.

Scientists behind a major study that claimed the Earth’s oceans are warming faster than previously thought now say their work contained inadvertent errors that made their conclusions seem more certain than they actually are.

Two weeks after the high-profile study was published in the journal Nature, its authors have submitted corrections to the publication. The Scripps Institution of Oceanography, home to several of the researchers involved, also noted the problems in the scientists’ work and corrected a news release on its website, which previously had asserted that the study detailed how the Earth’s oceans “have absorbed 60 percent more heat than previously thought.”

“Unfortunately, we made mistakes here,” said Ralph Keeling, a climate scientist at Scripps, who was a co-author of the study. “I think the main lesson is that you work as fast as you can to fix mistakes when you find them.”

The central problem, according to Keeling, came in how the researchers dealt with the uncertainty in their measurements. As a result, the findings suffer from too much doubt to definitively support the paper’s conclusion about how much heat the oceans have absorbed over time. [emphasis mine]

To put it more bluntly, their conclusions are worthless, the data being too uncertain.

When this paper came out two weeks ago I looked at it, and found myself questioning its results. They seemed too certain. Moreover, their work was too perfect for confirming the theory that the oceans are retaining more heat and thus causing the pause in global warming that no global warming model predicted. It fit the model of most climate research these days, unreliable and unconvincing, which is why I did not post it on Behind the Black.

Now, only two weeks later, we find the researchers backing off from their certain conclusions. If anything is a perfect demonstration of confirmation bias, this story is it. These global warming scientists want desperately to prove their theories, and since their models haven’t been working they are desperately searching everywhere they can for explanations. In this case that search led them astray.

The truth is that maybe the climate field should take a step back and reconsider its entire assumptions about carbon dioxide and global warming. They might actually end up doing better science, and thus do a better job at getting us closer to the truth.

A side note: That this paper passed peer review, and was strongly touted by the media and the science community, illustrates once again how much that media and science community has allowed its biases to cloud its vision. This paper should never have been published with these errors. Period.


Scientists discover giant impact crater buried under Greenland ice

Scientists have discovered the existence of a giant impact crater buried under the Greenland ice.

An international team of researchers, including a NASA glaciologist, has discovered a large meteorite impact crater hiding beneath more than a half-mile of ice in northwest Greenland. The crater — the first of any size found under the Greenland ice sheet — is one of the 25 largest impact craters on Earth, measuring roughly 1,000 feet deep and more than 19 miles in diameter, an area slightly larger than that inside Washington’s Capital Beltway.

They think, based on the data, that this crater is very young, one of the youngest known on Earth. At the most is is no more than 3 million years old.


Null result from Spitzer suggests Oumuamua was small

The uncertainty of science: The inability of the infrared Spitzer Space Telescope to detect the interstellar object Oumuamua as it exited the solar system suggests the object is small.

The fact that ‘Oumuamua was too faint for Spitzer to detect sets a limit on the object’s total surface area. However, since the non-detection can’t be used to infer shape, the size limits are presented as what ‘Oumuamua’s diameter would be if it were spherical. Using three separate models that make slightly different assumptions about the object’s composition, Spitzer’s non-detection limited ‘Oumuamua’s “spherical diameter” to 1,440 feet (440 meters), 460 feet (140 meters) or perhaps as little as 320 feet (100 meters). The wide range of results stems from the assumptions about ‘Oumuamua’s composition, which influences how visible (or faint) it would appear to Spitzer were it a particular size.

The new study also suggests that ‘Oumuamua may be up to 10 times more reflective than the comets that reside in our solar system – a surprising result, according to the paper’s authors.

These results fit the models that explain Oumuamua’s fluctuations in speed as caused by the out gassing of material, like a comet. They also do not contradict the recent hypothesis that the object might have been an alien-built light sail.

The simple fact is that we do not have enough data to confirm any of these theories.


Volcanic rivers on Mars

Granicus Valles

Cool image time! The photo on the right, cropped and reduced to post here, was part of the November image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO). If you click on the image you can see the full resolution picture.

The uncaptioned release webpage is dubbed “Faults in Granicus Valles.” The image itself only shows a small part of Granicus Valles, named after a river in Turkey, that flows down from the estern slopes of the giant volcano Elysium Mons. While far smaller than the four big Martian volcanoes in the Tharsis region to the east and near Marines Valles (which I highlight often), Elysium Mons still outshines anything on Earth at a height of almost 30,000 feet and a width of 150 miles. It sits at about the same northern latitude of Olympus Mons, but all by itself, rising up at the very northern edge of the transition zone between the southern highlands and the northern plains, with the vast Utopia Basin, the second deepest basin on Mars, to the west.

Overview of Elysium Mons and Granicus Valles

Granicus Valles itself is almost five hundred miles long. At its beginning it flows in a single straight fault, but once it enters the northern plains of Utopia Basin it begins to meander and break up into multiple tributaries. The MRO image above shows only a tiny portion in the northern plains, as illustrated by the white box in the overview map to the left.
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SuperEarth orbiting Barnard’s Star?

The uncertainty of science: Astronomers have discovered a candidate exoplanet orbiting Barnard’s Star, the closest single star to our solar system and the second closest stellar system after Alpha Centauri.

The planet candidate, named Barnard’s star b (or GJ 699 b), is a super-Earth with a minimum of 3.2 Earth masses. It orbits its cool red parent star every 233 days near the snow-line, a distance where water would be frozen. In the absence of an atmosphere, its temperature is likely to be about -150 ºC, which makes it unlikely that the planet can sustain liquid water on its surface. However, its characteristics make it an excellent target for direct imaging using the next generation of instruments such as NASA’s Wide Field InfraRed Survey Telescope (WFIRST, [3]), and maybe with observations from the ESA mission Gaia [4].

The reason I put a question mark in the headline is that this is not the first time a candidate exoplanet has been proposed to orbit Barnard’s Star. In the 1960s astronomer Peter van de Kemp claimed the star had at least one gas giant orbiting it every 24 years. It was later found that the periodic motion variations he measured were due to “to an artifact of maintenance and upgrade work” at the telescope he was using.

The result above has not been confirmed by other means, so they must list this superEarth as a candidate exoplanet. More observations are necessary to confirm it.

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