Tag: science

Chandra captures black hole outburst over eight months

9:32 am

Four-frame movie of black hole outburst

Astronomers using the Chandra X-ray space telescope have documented the motion of two blobs moving away from a stellar-mass black hole over a period of eight months, producing a four-frame movie from their images and estimating the speed of those blobs to be 80% that of the speed of light.

The gif animation to the right shows that short movie.

The black hole and its companion star make up a system called MAXI J1820+070, located in our Galaxy about 10,000 light years from Earth. The black hole in MAXI J1820+070 has a mass about eight times that of the Sun, identifying it as a so-called stellar-mass black hole, formed by the destruction of a massive star. (This is in contrast to supermassive black holes that contain millions or billions of times the Sun’s mass.)

The companion star orbiting the black hole has about half the mass of the Sun. The black hole’s strong gravity pulls material away from the companion star into an X-ray emitting disk surrounding the black hole.

While some of the hot gas in the disk will cross the “event horizon” (the point of no return) and fall into the black hole, some of it is instead blasted away from the black hole in a pair of short beams of material, or jets. These jets are pointed in opposite directions, launched from outside the event horizon along magnetic field lines. The new footage of this black hole’s behavior is based on four observations obtained with Chandra in November 2018 and February, May, and June of 2019, and reported in a paper led by Mathilde Espinasse of the Université de Paris.

Hubble has produced similar movies of the activity around the Crab Nebula. Sadly, we don’t have enough space telescopes like these in orbit to monitor such objects more frequently and thus photograph their behavior more completely. If we did we’d be able to get a much better understanding of their ongoing activity. We would also be able to produce more movies such as this, with much higher resolution and more continuous coverage.

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That Jupiter Trojan comet-like asteroid was neither an asteroid nor a Trojan

9:14 am

Astronomers have now found that the asteroid that had suddenly become active, like a comet, and they had thought was part of the asteroids in Jupiter orbit called Trojans, was neither an asteroid nor a Trojan.

Instead, it is an actual comet captured in a strange unstable orbit around Jupiter.

[W]hen amateur astronomer Sam Deen used software on the Jet Propulsion Laboratory’s solar-system dynamics website to calculate the object’s orbit, he found P/2019 LD2 recently had a close encounter with Jupiter that left its orbit unstable. The model showed that the comet had likely been a Centaur, part of a family of outer solar system asteroids, with an orbit reaching out to Saturn. Then, on February 17, 2017, it passed about 14 million kilometers from Jupiter, an encounter that sent the comet on a wild ride and inserted it into an odd Jupiter-like orbit.

Yet although the swing past Jupiter put P/2019 LD2 into a Jupiter-like orbit, it didn’t move it near to one of the two Lagrange points where the combination of gravitational forces from Jupiter and the Sun hold Trojan asteroids. Instead of being 60° — one-sixth of the giant planet’s orbit — from Jupiter, P/2019 LD2 is only 21° ahead of Jupiter.

The orbit is unstable. It will bring the comet to within 3 million miles of Jupiter in 2063, but beyond that predictions are impossible. The exact closeness of that approach cannot be predicted with much precision, partly because of the chaotic nature of the orbit, and partly because of the random orbital changes that can occur because the comet is venting.

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A Martian crater with a straight edge

10:02 am

A mis-shapened crater on Mars
Click for full image.

Cool image time! The image to the right, cropped and reduced to post here, was released today by the science team of the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small Martian crater whose northern rim for some reason is flattened into a straight line. Such a crater is rare, since almost all craters rims are round, even in the case of a low angle impact. The cause is unknown, though there are theories. From the caption, written by Ingrid Daubar of the Lunar and Planetary Laboratory in Arizona:

One possibility is that there was a zone of joints or faults in the crust that existed before the impact. When the impact happened, the crater formed along the straight line of these faults. Something similar happened to Meteor Crater in Arizona. Our image doesn’t show any faults, but they could be beneath the surface.

Perhaps some sort of uneven collapse changed the shape of the crater. There are piles of material on the crater’s floor, especially in the northwest and northeast corners. If those piles fell down from the rim, why did it happen there and not in other places? This crater is near the size where larger craters start to show wall slumping and terraces, so this type of collapse could be occurring unevenly.

The crater is located in the southern cratered highlands of Mars, at about 32 degrees latitude. At that latitude, it is also possible that some past glacial activity could have misshapen this crater, though I have no idea how. The crater itself does not appear to have any glacial material in it.

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New observations confirm Earth-like planet orbiting nearest star

9:44 am

Worlds without end: New observations have confirmed the existence of an Earth-sized planet orbiting the nearest star to our Sun, Proxima Centauri, only 4.2 light years away..

The planet, Proxima b, is estimated to have a mass 1.17 of Earth’s, and orbit the star every 11.2 days. Based on that orbit, the planet is also in the star’s habitable zone. Whether there is life there however remains unknown.

Although Proxima b is about 20 times closer to its star than the Earth is to the Sun, it receives comparable energy, so that its surface temperature could mean that water (if there is any) is in liquid form in places and might, therefore, harbour life.

Having said that, although Proxima b is an ideal candidate for biomarker research, there is still a long way to go before we can suggest that life has been able to develop on its surface. In fact, the Proxima star is an active red dwarf that bombards its planet with X rays, receiving about 400 times more than the Earth. “Is there an atmosphere that protects the planet from these deadly rays?” asks Christophe Lovis, a researcher in UNIGE’s Astronomy Department and responsible for ESPRESSO’s scientific performance and data processing. “And if this atmosphere exists, does it contain the chemical elements that promote the development of life (oxygen, for example)? How long have these favourable conditions existed? We’re going to tackle all these questions.

The research data also suggests there might be another planet in orbit around Proxima Centauri, though this conclusion is very preliminary.

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Weird central peak in Martian crater

3:14 pm

Textured central peak in Martian crater
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter on March 18, 2020. It shows a very strange central peak in a crater on Mars. Not only does this peak stick out like a sore thumb in a relatively flat crater floor, its surface is strangely textured, patterned with what look like scallops.

The overview map below shows the area covered in the crater by the full image.

My guess is that the peak is the final impact melt from the original impact. Think of a pebble thrown into a pond. You get ripples (the crater rim) as well as an upward drop of water (the central peak). Unlike pond water, the material in a crater freezes quickly, leaving both the ripple and the upward drop frozen in place.

Close overview of crater

This peak however also reminds me of volcanic cones found in the American southwest, the remnant cone of a much larger volcano that has long ago eroded away.

The textures might be evidence of that erosion process, as they resemble scallops that wind and water erosion can cause on rock faces.

We also could be seeing dunes on the slopes themselves, though I think this is unlikely. This crater is on the edge of the vast Medusae Fossae Formation, the largest volcanic ash deposit field on Mars, as shown by the white cross on the overview map below. Thus, being on the edge of this ash field there is a lot of available dust and sand that can pile up on these slopes.

Wide Overview map

Still, the sunlight side of the ridge suggests the scallops are in bedrock, not sand dunes. And to assign their origin to either wind or water or ice erosion I think is a stretch.

So while the peak is probably the frozen melt remains of the original impact, the scallops are a geological mystery that needs unraveling.

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Amazing layers

11:07 am

Bedrock layering in Holden Crater
Click for full image.

Cool image time! The science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) today released a cool captioned image entitled “Exquisite Layering”, showing a place on the floor of Holden Crater where the dust and sand that normally covers most of the Martian surface has been wiped away, cleared off because these layers are on higher sloping terrain.

The image to the right, cropped to post here, focuses in on that exposed layering, believed to be sedimentary and must have therefore happened in the eons following the impact that caused the crater.

Overview map

The overview map to the right shows with the red box the location of this layering inside Holden Crater. The map also illustrates why this crater was considered a candidate landing site for Curiosity. Like Gale Crater, it has evidence — the large meandering canyon system flowing into the crater — that suggests it had once been filled with a water lake. These sedimentary layers support that hypothesis, suggesting that this lake was intermittent. Each time it refilled and then dried up, it laid down a new deposit of those sedimentary layers.

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More pits found on Mars

3:04 pm

Pit near Hephaestus Fossae
Click for full image.

Overview map

Since 2018 I have made it a point to document every new pit image taken on Mars by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The list of can be found at the bottom of this post.

In the most recent release from MRO, a number of new pits were photographed. All continue to suggest that Mars has a lot of underground voids, some caused by lava flow, some by tectonic activity, some by water ice erosion, and some almost certainly caused by processes we don’t yet know. The images also suggest that we have only identified a small fraction of those underground voids.

The first image to the right, cropped to post here, shows the one new pit in the northern lowlands of Utopia Planitia, near a series of meandering channels and canyons dubbed Hephaestus Fossae and Hebrus Valles.

This appears to be the fifth such pit found in this region. Previously I had documented the first four. The overview map to the right adds this fifth pit. Note how the pit is much closer to the head of Hephaestus. In the full image you can see fissures both to the north and south, as well as many nearby aligned depressions, suggesting the existence of more underground passages, some possibly linked to voids under this very pit.

The pit itself seems filled, with no apparent side passages, though to the southwest there might be something leading off in the shadows.

The overall terrain in this region, including these pits, the fissures, and the many aligned depressions, strongly suggests a lot of underground voids. As I noted in 2019:
» Read more

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Star to get within a trillion miles of Sun in 1.4 million years

10:04 am

Using the precise location and motion data obtained by the space telescope Gaia, astronomers have identified a star that 1.4 million years will come within a trillion miles of the Sun.

That distance puts it well within the outer parts of the theorized Oort cloud at the edge of the solar system. Since the star, Gliese 710, has a mass half that of the Sun, it will thus disturb many objects in that Oort Cloud, causing many to eventually fall sunward and produce a hail of comets several million years later. It will be, for a long time, the brightest object in the night sky, by far.

The data also identified a number of other stars that have in past or will in the future get close to the Sun. The most important result is not that these close approaches occur, but that they have found that they are relatively rare, and even the closest, Gliese 710, never really gets that close.

The universe is big, far bigger than we can really imagine.

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“Spots” orbiting Milky Ways central black hole

9:19 am

Using the ALMA ground-based telescope array in Chile, astronomers have detected two energetic “spots” that appear to be orbiting Sagittarius A* (pronounced A-star), the super-massive black hole at the center of the Milky Way.

The spots appear to be regions in the accretion disk surrounding the black hole that are emitting energy.

Their scenario is as follows. Hot spots are sporadically formed in the disk and circle around the black hole, emitting strong millimeter waves. According to Einstein’s special relativity theory, the emission is largely amplified when the source is moving toward the observer with a speed comparable to that of light. The rotation speed of the inner edge of the accretion disk is quite large, so this extraordinary effect arises. The astronomers believe that this is the origin of the short-term variation of the millimeter emission from Sgr A*.

The team supposes that the variation might affect the effort to make an image of the supermassive black hole with the Event Horizon Telescope. “In general, the faster the movement is, the more difficult it is to take a photo of the object,” says Oka. “Instead, the variation of the emission itself provides compelling insight for the gas motion. We may witness the very moment of gas absorption by the black hole with a long-term monitoring campaign with ALMA.” The researchers aim to draw out independent information to understand the mystifying environment around the supermassive black hole.

Everyone please repeat after me: Though this scenario makes sense, based on the facts and our knowledge, there is a lot of uncertainty about these conclusions.

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A Jupiter Trojan asteroid spouts a tail

9:54 am

The ATLAS telescope has discovered the first Jupiter Trojan asteroid to spout a tail like a comet.

Early in June 2019, ATLAS reported what seemed to be a faint asteroid near the orbit of Jupiter. The Minor Planet Center designated the new discovery as 2019 LD2. Inspection of ATLAS images taken on June 10 by collaborators Alan Fitzsimmons and David Young at Queen’s University Belfast revealed its probable cometary nature. Follow-up observations by the University of Hawaiʻi’s J.D. Armstrong and his student Sidney Moss on June 11 and 13 using the Las Cumbres Observatory (LCO) global telescope network confirmed the cometary nature of this body.

Later, in July 2019, new ATLAS images caught 2019 LD2 again – now truly looking like a comet, with a faint tail made of dust or gas. The asteroid passed behind the Sun and was not observable from the Earth in late 2019 and early 2020, but upon its reappearance in the night sky in April of 2020, routine ATLAS observations confirmed that it still looks like a comet. These observations showed that 2019 LD2 has probably been continuously active for almost a year.

While ATLAS has discovered more than 40 comets, what makes this object extraordinary is its orbit. The early indication that it was an asteroid near Jupiter’s orbit have now been confirmed through precise measurements from many different observatories. In fact, 2019 LD2 is a special kind of asteroid called a Jupiter Trojan – and no object of this type has ever before been seen to spew out dust and gas like a comet.

There are a number of mysteries here. First, why should it have suddenly become active, since its orbit is relatively circular (similar to Jupiter’s)? Second, it had been assumed that the Jupiter Trojans had been in their orbits for a long time and had long ago vented any ice on their surfaces. This discovery proves that assumption false. It suggests that either this asteroid is a comet that was recently captured, or that things can happen on these asteroids to bring some buried volatiles up to the surface, where they can then vent.

Above all, this asteroid shows that it is dangerous to assume all Jupiter Trojan asteroids are the same. I guarantee when we finally get a close look at a bunch, when the Lucy mission arrives beginning in 2027, the variety will be quite spectacular.

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OSIRIS-REx rehearsal and landing rescheduled

1:25 pm

The OSIRIS-REx science team today announced that, in order to give them more preparation time needed because of the coronavirus protocols, they have rescheduled their second rehearsal of the spacecraft’s touch-and-go sample grab from the asteroid Bennu from June to August, and delayed the actual touch-and-go sample grab from August to October.

The mission had originally planned to perform the first Touch-and-Go (TAG) sample collection event on Aug. 25 after completing a second rehearsal in June. This rehearsal, now scheduled for Aug. 11, will bring the spacecraft through the first three maneuvers of the sample collection sequence to an approximate altitude of 131 ft (40 m) over the surface of Bennu. The first sample collection attempt is now scheduled for Oct. 20, during which the spacecraft will descend to Bennu’s surface and collect material from sample site Nightingale.

Previously they had said that the rehearsal would get as close as 82 feet. Nothing has changed. That distance was the closest they expected the spacecraft to get. The new number, 131 feet, is in the middle of possible ranges. As explained to me by Erin Morton, head of communications for OSIRIS-REx in the Principal Investigator’s Office, “I originally chose the lowest altitude in that range to include in our public outreach materials, but later realized that it made more sense to use the mid-point altitude number, since that’s the average of the high and low possibilities.”

Though they have the ability to do two more sample grabs if the first in October is unsuccessful, they won’t bother if it succeeds. They must leave Bennu regardless in mid-2021 to return the sample to Earth on September 24, 2023.

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NASA names WFIRST after its first head of astronomy, Nancy Roman

9:09 am

NASA today announced that it has renamed the proposed Wide Field Infrared Survey Telescope (WFIRST) the Nancy Grace Roman Telescope in honor of the agency’s first head of astronomy.

Considered the “mother” of NASA’s Hubble Space Telescope, which launched 30 years ago, Roman tirelessly advocated for new tools that would allow scientists to study the broader universe from space. She left behind a tremendous legacy in the scientific community when she died in 2018.

…When she arrived at NASA, astronomers could obtain data from balloons, sounding rockets and airplanes, but they could not measure all the wavelengths of light. Earth’s atmosphere blocks out much of the radiation that comes from the distant universe. What’s more, only a telescope in space has the luxury of perpetual nighttime and doesn’t have to shut down during the day. Roman knew that to see the universe through more powerful, unblinking eyes, NASA would have to send telescopes to space.

Through Roman’s leadership, NASA launched four Orbiting Astronomical Observatories between 1966 and 1972. While only two of the four were successful, they demonstrated the value of space-based astrophysics and represented the precursors to Hubble. She also championed the International Ultraviolet Explorer, which was built in the 1970s as a joint project between NASA, ESA (European Space Agency) and the United Kingdom, as well as the Cosmic Background Explorer, which measured the leftover radiation from the big bang and led to two of its leading scientists receiving the 2006 Nobel Prize in Physics.

Above all, Roman is credited with making the Hubble Space Telescope a reality. In the mid-1960s, she set up a committee of astronomers and engineers to envision a telescope that could accomplish important scientific goals. She convinced NASA and Congress that it was a priority to launch the most powerful space telescope the world had ever seen.

This is a nice and very fitting gesture to honor one of the many unsung heroes who were important in the history of space astronomy. I just hope that Roman’s telescope doesn’t end up like James Webb’s, so over budget and behind schedule that it destroys all other NASA space telescope projects. Sadly, its track record so far suggests this is what will happen, which is why the Trump administration has been trying to get it canceled.

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A shadowed ice patch on Mars

1:26 pm

A shadowed ice patch on Mars
Click for full image.

Cool image time! The evidence coming back from Mars in the past two decades has increasingly suggested that there is a lot of water in that planet’s mid- and high latitudes. In the mid-latitudes the evidence suggests that ice is locked in a lot of buried and inactive glaciers that were laid down during periods when the planet’s rotational tilt, its obliquity, was greater so that the annual seasons were more extreme. During those times the mid-latitudes were colder than the poles, and water was being transferred from the poles to those mid-latitudes.

The image to the right appears to be more such evidence. Taken on March 21, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and cropped and brightened by me to bring out the important details, it shows what looks to be a distinct patch of ice on the south-facing slope of the rim of a large crater. Since this crater is in the southern mid-latitudes (34 degrees south), that south-facing slope generally gets much less sunlight, even in the summer, so any remaining buried glacial ice on that slope will linger for a longer period.

Think of the lingering ice and snow patches on shadowed locations on Earth. Because the Sun does not directly shine on them, they will be the last patches to melt away.

What I think is likely important about this patch are the exposed layers along its edge. These are the spots that are melting first, as they are where the ice is exposed, unprotected by a layer of dust and debris. It is also here that we have a window into that geological history. Even at this resolution you can see that the ice was laid down in layers, meaning that it contains evidence of those repeated climate cycles produced by Mars’ shifts in obliquity.

Those layers even seem to show the same sharp and sudden change from brighter and dirtier layers, as seen in the layers of the north pole ice cap, that occurred about 4.5 million years ago.

How tantalizing. The entire climate history of Mars is sitting there for us to decipher. We need only drill a few core samples and voila! the pieces of that history will start to fall into place.

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The edge of an eroded buried Martian glacier

12:55 pm

The edge of an eroded buried Maritian glacier
Click for full resolution image.

Overview

Cool image time! The image to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) on April 6, 2020.

The image shows the dying edge of a debris flow coming down from a mesa, the edge of which can be seen as the dark slopes in the upper left. The white arrows point up slope. It is located in the chaos terrain of a mid-latitude region called Deuteronilus Mensae, in the transition zone between the southern highlands and northern lowlands, where many such glacial-like features are found. I featured a similar nearby glacial edge only two months ago, where the image showed the glacier’s break up and collapse at its edge.

Here, the debris flow isn’t breaking up so much as crumbling away, its edge a line of meandering depressions, with the uphill slope covered with many knobs and tiny depressions, reminiscent to me of the many features I see in caves, where the downward flow of water shapes and erodes everything to form cups and holes and knobs, all the same size. If you click on the full resolution image and zoom into that debris slope and then compare it with the linked cave formation photo, you will see the resemblance.

We are almost certainly looking at a buried inactive glacial flow coming off that mesa, though it appears to be eroding at its foot. The overview image to the right shows the context, with the red dots indicating this image as well as similar features in adjacent mensae regions (featured in the linked images above). While the chaotic and rough terrain found along this transition zone does not make them good first settlement sites, the ample evidence of vast reservoirs of buried ice, combined with a variety of topography, will likely someday make this good real estate for those living on Mars.

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China’s space station

9:05 am

The new colonial movement: China’s propaganda news services today released an article outlining in a somewhat superficial manner the overall design and program of its first full-sized space station, Tiangong-3.

The article does not really provide any new information that was not already reported back in 2016, except for this intriguing detail:

The Long March-2F carrier rocket and Shenzhou manned spacecraft will be used to transport crew and some materials between Earth and the space station. The Shenzhou can carry three astronauts and be used as a rescue spacecraft in emergency.

Earlier reports had suggested they would be using their as-yet unnamed second generation manned capsule and the Long March 5B for these functions. It now appears that they are planning to use both manned ships, probably beginning with the Shenzhou and transitioning to the new manned capsule over time.

The article also describes again their plan to launch and fly in formation with the station a two-meter optical telescope, maintaining it in orbit during the 10-year life of the station using crew from the station. This concept was one that NASA actually considered when it was first conceiving Hubble, but put aside when it was realized that the U.S. station would not launch in time.

Note also that this Chinese space telescope is only slightly smaller than Hubble, its mirror 2 meters across compared to Hubble’s 2.4 meter diameter. It will thus be the second largest optical telescope ever launched, and if it works will allow for astronomical research that will dwarf all the giant ground-based telescopes western astronomers have spent all their time and millions building in the past two decades, rather than launch several Hubble twins.

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Large majority of COVID-19 infections are asymptomatic

9:17 pm

The evidence continues to build that the majority of people who get infected with the Wuhan flu end up showing no symptoms and do not even know they caught the virus.

The author gives eight solid examples where testing found a large population infected, with most asymptomatic. These included the crew and passengers on three different ships, prison systems in four different states (85% to 98% asymptomatic), a meat-packing plant, the homeless, pregnant women, and even in three nursing homes (!):

A survey published in the New England Journal of Medicine at an anonymous nursing home found that more than half with positive results were asymptomatic. In another nursing home in Washington state, 56% of those who tested positive were asymptomatic. One nursing home in Miami County, Ohio, tested every resident last week, and so far all of those who tested positive are still asymptomatic. [emphasis mine]

He also notes that in all but the last example, the number of fatalities were tiny, or none.

He then makes four common sense points. First,

The overwhelming majority of those infected are asymptomatic, which grows to an absolute super-majority when you factor in the mildly symptomatic. The fatality rate is therefore very small and very confined to a known population. Thus, it makes no sense to lock down younger and healthier people who overwhelmingly don’t get seriously ill, much less deathly ill, even if they contract the virus.

This confirms what was suggested from the beginning, that the death rate for the Wuhan flu is likely comparable to the flu.

Second, this shows it is absurd to release criminals. They almost certainly already have the disease, and weren’t bothered by it. They should serve out their punishments.

Third, “Contact tracing of the entire country is utterly insane. Most people have been spreading this virus while asymptomatic for months. What is left to trace?”

And finally,

By going back to normal with basic precautions for most of the population, we will be able to achieve herd immunity much less painfully than previously thought while shielding the more vulnerable population. … The fact that so many of the more exposed and vulnerable already got it and so many were asymptomatic means we could achieve herd immunity much quicker with fewer lives lost, certainly compared to lockdown.

The lock downs must end. We need to stop panicking and go back to normal. This disease is not the plague the press and politicians have been pushing. It does not require extreme measures to fight.

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OSIRIS-REx’s landing spot on the asteroid Bennu

10:24 am

Bennu, annotated
Click for full resolution unlabeled image.

The OSIRIS-REx science team today released another image of the asteroid Bennu, this time showing the planned Nightingale touch-and-go sample grab landing site.

The image to the right, reduced, cropped, and annotated by me, is that image. From the caption:

The crater where sample site Nightingale is located can be seen near the top, center of the image – it is a small region containing dark, fine-grained material. Bennu’s prime meridian boulder, Simurgh Saxum , is also visible in the lower left of the image, near the asteroid’s limb. Directly east of Simurgh is Roc Saxum . The field of view is 0.3 miles (0.5 km). For reference, Simurgh is 125 ft (38 m) across, which is about the size of a commercial airliner.

Nightingale is only about 50 feet across, which is about a third the size of the kind of smooth areas they had designed their grab-and-go equipment around. This global image illustrates the difficulties they face with that sample grab. Though there appear to be larger areas in this photo that seem smooth, they really are not. The asteroid has no dust, and the sample grab equipment is designed to suck up particles smaller than 0.8 inches in diameter. Most of the surface is covered with pebbles and gravel larger than this.

Thus they needed to find a spot where the bulk of the material is “fine-grained.” Nightingale fits that bill, though it has a small footprint and also has larger particles that pose a risk to the sample grab because they could damage the spacecraft, or clog the sample grab equipment.

Either way, for the spacecraft to autonomously guide itself accurately down to this small spot, surrounded as it is by much larger boulders, will be challenging, and is why they have done one dress rehearsal already, getting as close as 213 feet, and will do a second in June, getting down to 82 feet.

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Supermassive black hole binary flares as predicted

9:17 am

The distant binary of two super massive black holes, dubbed QJ287, flared within four hours of its predicted time in July 2019, proving the existence of this system.

The central black hole has a mass 18 billion times that of the Sun. The smaller black hole has a mass of 150 million Suns. Its orbit is twelve years long, and when it makes its close approach the interaction between these two monsters causes high energy flares.

We know all this because astronomers have been watching OJ 287 since the 1890s, before they knew what it was. In the intervening century, the system has shot off two outbursts roughly every 12 years, almost like clockwork.

Yet this pattern took time to decipher, as the bigger black hole in OJ 287 is also a blazar. Its black hole, or the disk that feeds it, powers twin plasma jets shooting out along opposite directions, and one of these jets is pointed almost right at Earth. The volatility of this plasma-and-photon stream makes OJ 287 a highly variable visible-light source. It wasn’t until a century after its discovery that astronomers realized that there was a periodic signal hidden within the noise — and that dual dancing black holes could cause it.

Observations in 2005 confirmed those ideas, and astronomers made increasingly precise predictions for subsequent flares in 2007 and 2015. Now, Seppo Laine (Spitzer Science Center, Caltech), Lankeswar Dey (Tata Institute of Fundamental Research, India), and colleagues are publishing observations of the latest flare in the Astrophysical Journal. The authors predicted, and then watched for, a flare expected to arrive in the early hours of July 31, 2019.

QJ287 is 3.5 billion light years away, which makes this prediction and the observations even more remarkable.

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The blobby wettish flows of Mars

12:21 pm

flow-like feature in Utopia Planitia
Click for full image.

Cool image time! Rather than talk about shut downs, lying politicians, and our tragically fear-filled society, let’s go exploring on Mars. The image to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on February 8, 2020. Dubbed a “Flow-Like Feature within the Adamas Labyrinthus”, it shows what appears to be a very distorted and eroded pedestal crater surrounded by strange triangular-shaped flow features.

It also shows, as does much other research, that the northern mid-latitudes of Mars have a lot of frozen water, much of it buried very close to the surface.

Assuming this is a pedestal crater (which it might not be), this feature has to be very old. Pedestal craters require age, as to stand out above the surrounding terrain a lot of time is needed to erode that terrain away. This age is confirmed by the bunch of newer craters on top.

At the same time, the partially filled small crater near its bottom, as well as the soft eroded depressions on top, suggest that much of this surface has been reshaped by more recent flows, changing its shape over time.

The surrounding triangular flows probably occurred at the original impact, and suggest that there is ice near the surface, making the material here act almost like wet mud when heated. Since this location is right in the middle of the mid-latitude bands where scientists have found lots of evidence of buried glaciers and ice near the surface, this supposition seems reasonable.

The overall location provides some further context.
» Read more

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Parker extends length of science operations during upcoming fifth solar fly-by

9:22 am

The science team for the Parker Solar Probe have decided to extend the period the spacecraft’s instruments are operating during its fifth close fly-by of the Sun, based on the data they have obtained from the first four fly-bys.

On May 9, 2020, NASA’s Parker Solar Probe began its longest observation campaign to date. The spacecraft, which has already completed four progressively closer orbits around the Sun, activated its instruments at a distance of 62.5 million miles from the Sun’s surface, some 39 million miles farther from the Sun than a typical solar encounter. The four instrument suites will continue to collect data through June 28, markedly longer than the mission’s standard 11-day encounters.

The nearly two-month campaign is spurred by Parker Solar Probe’s earlier observations, which revealed significant rotation of the solar wind and solar wind phenomena occurring much farther from the Sun than previously thought. The earlier activation of the science instruments allows the team to cover a larger range in order to trace the evolution of the solar wind as it moves away from the Sun.

Perihelion will occur on June 7 at a distance of 11.6 million miles from the Sun. That will match the previous record set during Parker’s previous orbit for the closest solar fly-by ever. They will then follow this with another fly-by of Venus, which will tighten the orbit even more.

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Bennu’s equatorial craters

10:05 am

Bennu's craters
Click for full image.

The OSIRIS-REx science team today released a neat image of Bennu, highlighting the string of impact craters along the rubble-pile asteroid’s equatorial ridge. The image to the right, cropped and reduced to post here, shows that image. From the release:

Bennu’s darkest boulder, Gargoyle Saxum , is visible on the equator, near the left limb. On the asteroid’s southern hemisphere, Bennu’s largest boulder, Benben Saxum , casts a long shadow over the surface. The field of view is 0.4 miles (0.7 km). For reference, the largest crater in the center of the image is 257 ft (78 m) wide, which is almost the size of a football field.

The photo was taken from a distance of six miles on April 28. The craters illustrate well the rubble pile/sandbox nature of this asteroid. They all look like what you’d expect if the impact was able to easily drive itself deep into the a pile of sand and loose rocks. The resulting crater thus has a very indistinct rim and a sloping floor down to a central point.

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The salty liquid water on Mars

9:49 am

Map of seasonal salty liquid water on Mars
Click for full unannotated image.

The map above, reduced and annotated by me, comes from a new science paper that has attempted to model where on Mars we might find liquid very salty water, based on the planet’s known temperature and make-up. From the press release:

The team of researchers used laboratory measurements of Mars-relevant salts along with Martian climate information from both planetary models and spacecraft measurements. They developed a model to predict where, when, and for how long brines are stable on the surface and shallow subsurface of Mars. They found that brine formation from some salts can lead to liquid water over 40% of the Martian surface but only seasonally, during 2% of the Martian year.

“In our work, we show that the highest temperature a stable brine will experience on Mars is -48°C (-55° F). This is well below the lowest temperature we know life can tolerate,” says Dr. Rivera-Valentín. “For many years we have worried about contaminating Mars with terrestrial life as we have sent spacecraft to explore its surface. These new results reduce some of the risk of exploring Mars,” noted Dr. Alejandro Soto at the Southwest Research Institute and co-author of the study. [emphasis mine]

I have added a red rectangle to the map, showing the candidate landing zone for SpaceX’s Starship. This paper illustrates again that this choice is a good one. We know from other research that there is a lot of ice very close to the surface here. This research indicates that for a little less than one percent of each year, some of that ice will turn to liquid brine.

Whether it will be easier to process the ice or the brine into drinkable water remains unknown. This location however will give future colonists that option.

That this model also suggests that there is little risk of contaminating Mars accidently with terrestrial life is really not a surprise. All the research of Mars for decades has found that it is inhospitable to terrestrial life. This data however is further confirmation, and tells us once again that worrying about contaminating the planet is a irrelevancy. For scientific reasons some precautions should be taken, but to spend a lot of time and money sterilizing the spacecraft we send there will be a fool’s errand. For humans to settle Mars will require a very very high level of engineering and adaptation, something we humans are very naturally good at, but something that shouldn’t be burdened with unnecessary tasks or restrictions.

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Sunspot update: The deep minimum continues

1:00 pm

Last week NOAA updated its graph for tracking the monthly activity of sunspots on the Sun’s visible hemisphere. Below is that updated graph, annotated by me to show the past and new solar cycle predictions.

April 2020 sunspot activity

The graph above has been modified to show the predictions of the solar science community for both the previous and upcoming solar maximums. The green curves show the community’s two original predictions from April 2007 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

Because of the design of this graph, revamped by NOAA in April, it is difficult at this scale — which for context shows both the past cycle and the predicted future cycle — to see the addition of the April sunspot total, when compared to last month’s graph. Trust me, it is there. In April sunspot activity went up, but trivially so, with only four sunspots during the month, three of which had a magnetic polarity assigning them to the next solar maximum.

The solar minimum remains very deep, deeper than the very deep previous minimum, and possibly the least active in two hundred years. The presence however of more sunspots for the new cycle strengthens the expectation that we will not be entering a grand minimum, with no sunspots for decades. It just appears that, as predicted, the next solar maximum will be a very weak one.

How this weak activity will effect the climate remains an unknown. In the past, such as the weak maximum that just ended as well as during past weak maximums at the beginning of the 1800s and the 1900s, the Earth’s climate cooled. It also cooled during the Little Ice Age in the 1600s, during the last grand minimum.

Whether the same will happen in the next decade remains unknown. Global warming activists will claim impossible, we are all going to die from overheating. The data for the past decade proves them wrong, though in the coming years they might be vindicated.

All we can do is wait, pay attention to the data, and make our conclusions from that.

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The epidemic model that panicked the world was junk

12:17 pm

A software engineer has done a careful fact-based analysis of the code that runs the computer model of now disgraced and fired Neil Ferguson of Imperial College in London — the computer model that had predicted millions would die in mere weeks from COVID-19 and thus triggered the worldwide panic over it — and found that it is buggy, unreliable, produces different results with the same data, and often does so for completely irrelevant factors (such as simply running it on different computers).

Hat tip Rand Simberg at Transterrestrial Musings.

The conclusion from this software engineer:

All papers based on this code should be retracted immediately. Imperial’s modelling efforts should be reset with a new team that isn’t under Professor Ferguson, and which has a commitment to replicable results with published code from day one.

On a personal level, I’d go further and suggest that all academic epidemiology be defunded. This sort of work is best done by the insurance sector. Insurers employ modellers and data scientists, but also employ managers whose job is to decide whether a model is accurate enough for real world usage and professional software engineers to ensure model software is properly tested, understandable and so on. Academic efforts don’t have these people, and the results speak for themselves.

The second paragraph applies equally to all computer modeling in the climate field, which has been repeatedly found to have similar problems.

Science should be based on data, from the field, not models predicting that data. Models have a minor use as a guide, but it is beyond dangerous to depend on them in any manner at all. Had our politicians relied on the available data when COVID-19 first started to spread, instead of these fake models, they would not have panicked, and would have instead done what they should have, focused on protecting the elderly and the sick, the only part of the population under serious threat.

Similarly, had the public and the press ignored these bad models and focused on that same data, they too would not have been frozen in fear, and would have demanded a more rational approach to the epidemic.

I know I have been repeating myself on this subject, but it must be driven home. The modelers are unreliable. The modelers are often driven by political agendas, not the facts. The modelers must not be relied upon for any long term policy.

Repeat this mantra to yourself, over and over again. It should sound a warning in your brain every time you read another article predicting doomsday from something, from global warming, from sea level rise, from the ozone hole, from some disease, from any crises these frauds want to latch onto.

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Evidence suggests Ryugu was once closer to Sun

11:38 am

The uncertainty of science: Spectral data collected of the surface of Ryugu by Japan’s Hayabusa-2 probe suggests that the asteroid once spent a period of time much closer to the Sun.

The combined data show an oddly striated world. Ryugu’s equator and poles are tinged blue and are brighter compared with its darker, reddish mid-latitudes. These color differences wouldn’t be obvious to the human eye, although the brightness changes might be.

…As Tomokatsu Morota (University of Tokyo) and colleagues write in the May 8th Science, Ryugu’s boulders likely start bluish. Then a combination of solar wind exposure, meteoroid impacts, and solar heating reddens them. This redder stuff migrates to the asteroid’s mid-latitudes over time, because topographically those are the lowest on Ryugu’s surface. That movement leaves the higher equator and polar regions relatively bluer and brighter.

Based on this data, the scientists posit that Ryugu was closer to the Sun from 800,000 to 8 million years ago, and that the evidence also suggests that the asteroid is only at most 17 million years old.

To put it mildly, there are great uncertainties to these conclusions.

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Chinese manned test capsule returns to Earth

9:03 am

The new colonial movement: China’s first unmanned test flight of its new manned capsule, still unnamed, ended today with that capsule’s safe return to Earth.

Before re-entry into the atmosphere, the capsule executed a skip maneuver employing aerodynamic lift in the high upper atmosphere. The technique is used to extend the re-entry time for vehicles returning to Earth from the Moon to avoid having to shed a large amount of velocity in a short time causing very high rates of peak heating. The skip reentry was used by Apollo Command Module returning from the Moon, as well as the Soviet Zond Probes and the Chinese Chang’e 5-T1.

Following atmospheric reentry, and at a determined altitude, two deceleration parachutes were opened, stabilizing the vehicle. Then, the three main parachutes were deployed, slowing the flight speed of descent. According to the China Aerospace Science and Technology Corporation (CASC), moments before touching down the heat shield was discarded and six airbags were deployed and inflated to help it land softly.

More here from China’s propaganda press, which included this detail:

Different from the three-capsule structure of Shenzhou spaceships currently in use, the new spacecraft comprises a return capsule, which is the command center and the living place for astronauts, and a service capsule, which provides power and energy, according to the CAST.

In other words, the Shenzhou copied the Soyuz design, while this new spacecraft copied the American design used in all our manned capsules.

I have embedded below the fold a short video released by China’s state-run press, showing the reentry. That capsule sure looks a lot like an Apollo capsule. It also looks surprisingly scorched.
» Read more

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Arctic ozone hole closes

10:13 am

The uncertainty of science: The largest ozone hole ever detected over the north pole has now closed.

After looming above the Arctic for nearly a month, the single largest ozone hole ever detected over the North Pole has finally closed, researchers from the European Union’s Copernicus Atmosphere Monitoring Service (CAMS) reported. “The unprecedented 2020 Northern Hemisphere ozone hole has come to an end,” CAMS researchers tweeted on April 23.

The hole in the ozone layer — a portion of Earth’s atmosphere that shields the planet from ultraviolet radiation — first opened over the Arctic in late March when unusual wind conditions trapped frigid air over the North Pole for several weeks in a row. Those winds, known as a polar vortex, created a circular cage of cold air that led to the formation of high-altitude clouds in the region. The clouds mixed with man-made pollutants like chlorine and bromine, eating away at the surrounding ozone gas until a massive hole roughly three times the size of Greenland opened in the atmosphere, according to a statement from the European Space Agency (ESA). [emphasis mine]

Note that the north pole hole occurred because of unusually frigid and cold conditions, something I thought we were never going to see again because of global warming.

The last paragraph of the article at the link reveals a lot of ignorance by its writer, Brandon Specktor, where he discusses the south pole ozone hole. First, he says it “has existed for roughly four decades.” Wrong. The south pole ozone hole was first detected in the 1950s, and has likely existed every winter for eons.

Next, he wonders if it is “starting to close.” Wrong. That ozone hole opens every winter and closes every summer, like clockwork. When winter arrives and the south pole is in darkness, oxygen molecules are no longer being ionized by sunlight and thus there is a drop in the production of ozone, producing the hole. When sunlight begins hitting the upper atmosphere in the spring it starts ionizing oxygen molecules again to produce ozone, and the hole goes away.

Then he notes that scientists hope the hole will “heal” and forever disappear by 2050. Wrong. The data says instead that the south pole ozone hole is a natural phenomenon that occurs every winter. It is not a wound against the earth.

Finally, he claims that the south pole ozone hole exists almost entirely because of us evil humans, first because of global warming and second because until 1987 we put ozone-depleting pollutants into the atmosphere. Wrong. As I said, the ozone hole is almost entirely a natural phenomenon, caused each winter because sunlight is no longer hitting the upper atmosphere above Antarctica and thus oxygen molecules are no longer being ionized into ozone. Those pollutants might have made it slightly larger in the late 20th century, but then, that theory has a problem, as most of those pollutants were released in the northern hemisphere, where they would have little or no interaction with the atmosphere of the southern hemisphere. (The atmospheres of the two hemispheres are largely independent.) Yet it was only in the south that we have generally seen an ozone hole

I predict, very confidently, that come 2050 climate scientists will discover, “unexpectedly”, that the south pole ozone hole has not “closed” or “healed”, but continues to reappear, each winter. And they will have by then discovered that depending on circumstances, a north pole ozone hole also appears during some colder winters, which despite their repeatedly failed predictions of global warming will likely continue to happen.

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The closest black hole: 1,000 light years away?

8:48 am

The uncertainty of science: Astronomers now think they have detected evidence of a stellar-mass black hole only a thousand light years away and orbiting a star system that is visible to the naked eye.

Thomas Rivinius, an astronomer with the European Southern Observatory (ESO), and his colleagues studied the unusual star system HR 6819 in this way using a 2.2-meter telescope in Chile, operated by ESO and the Max Planck Society. They thought it was a binary system, but there was an extra wobble in the periodic light shifts of one of the stars that indicated something else was asserting its presence. It turned out to be a triple system, with one star in a fast 40-day orbit with an unseen companion and another star on a more distant, slow-moving trajectory, they write today in Astronomy & Astrophysics. The invisible companion’s mass was large enough—four times the mass of the Sun—that, if it was a star, “we would have seen it,” Rivinius says.

Though there are a lot of uncertainties, this discovery is reasonable, and expected. In the coming years astronomers will surely find more such stellar-mass black holes, with some even closer to Earth.

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The eroding edge of Mars’ largest volcanic ash field

1:45 pm

Eroding yardangs at the edge of Mars' largest volcanic ash field
Click for full image.

Cool image time! In the regions between the biggest volcanoes on Mars is the Medusae Fossae Formation, a immense deposit of volcanic ash that extends across as much surface area as the nation of India. As planetary scientist Kevin Lewis of Johns Hopkins University explained to me previously,

In general, much of the [formation] seems to be in net erosion now, retaining very few craters on the surface. …One hypothesis is that this long term erosion, since it’s so enormous, is the primary source of the dust we see covering the much of the planet’s surface.

The image above, cropped and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on January 25, 2020. It shows one very small area at the very edge of the Medusae ash deposit, in a region where that deposit is clearly being eroding away by the prevailing southeast-to-northwest winds. The mesas of this ash that remain are called yardangs, their ash more tightly pressed together so that it resists erosion a bit longer than the surrounding material.

In the context map below the location of these yardangs is indicated by the white cross, right on the edge of the Medusae ash field.
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