Tag: science

Astronomers confirm comet with largest nucleus ever found

9:29 am

Using the Hubble Space Telescope astronomers determined that the nucleus of Comet Bernardinelli-Bernstein (C/2014 UN271) is about 80 miles wide, making it the largest comet on record.

The estimated diameter is approximately 80 miles across, making it larger than the state of Rhode Island. The nucleus is about 50 times larger than found at the heart of most known comets. Its mass is estimated to be a staggering 500 trillion tons, a hundred thousand times greater than the mass of a typical comet found much closer to the Sun.

The behemoth comet, C/2014 UN271 (Bernardinelli-Bernstein) is barreling this way at 22,000 miles per hour from the edge of the solar system. But not to worry. It will never get closer than 1 billion miles away from the Sun, which is slightly farther than the distance of the planet Saturn. And that won’t be until the year 2031.

The previous record holder is comet C/2002 VQ94, with a nucleus estimated to be 60 miles across. It was discovered in 2002 by the Lincoln Near-Earth Asteroid Research (LINEAR) project.

This measurement does have a great deal of uncertainty, as Hubble cannot yet resolve the nucleus, and thus its diameter was determined by computer models based on the size of the comet’s coma, or surrounding atmosphere.

The comet itself has an orbit 3 million years long, which means it has zipped into the inner solar system many many times. The reason its nucleus remains so large is because its orbit never gets that close to the Sun, so its material does not get burned off so much with each perihelion. That it exists suggests there could be many such large comets which never dip close to the Sun.

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MAVEN and Al-Amal scientists sign agreement to collaborate

1:20 pm

Scientists running the Mars orbiters MAVEN (from NASA) and Al-Amal (from the United Arab Emirates [UAE]) have signed an agreement to share data and — more importantly — coordinate their observations of the Martian atmosphere.

A new partnership that encourages the sharing of data between NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) project and the Emirates Mars Mission’s (EMM) Hope Probe (Al-Amal in Arabic) will enhance scientific returns from both spacecraft, which are currently orbiting Mars and collecting data on the Red Planet’s atmosphere. The arrangement is expected to add value to both MAVEN and EMM, as well as the scientific communities involved in analyzing the data the missions collect.

MAVEN went into orbit around Mars in 2014. Its mission is to investigate the upper atmosphere and ionosphere of Mars, offering an insight into how the planet’s climate has changed over time. “MAVEN and EMM are each exploring different aspects of the Martian atmosphere and upper-atmosphere system,” said Shannon Curry, MAVEN principal investigator from the University of California, Berkeley. “Combined, we will have a much better understanding of the coupling between the two, and the influence of the lower atmosphere on the escape to space of gas from the upper atmosphere.”

The EMM Hope Probe, which went into Mars orbit in 2021, is studying the relationship between the upper layer and lower regions of the Martian atmosphere, giving insight into the planet’s atmosphere at different times of the day and seasons.

What this agreement means is that the two science teams can more quickly match up the data from both orbiters, and figure out the relationships between both.

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Interstellar meteor impacted Earth in 2014

10:28 am

According to classified military data just released, it appears that an asteroid from interstellar space impacted the Earth in 2014, with some of its pieces possibly hitting the ocean in the south Pacific.

The meteor ignited in a fireball in the skies near Papua New Guinea, the memo states, and scientists believe it possibly sprinkled interstellar debris into the South Pacific Ocean. The confirmation backs up the breakthrough discovery of the first interstellar meteor—and, retroactively, the first known interstellar object of any kind to reach our solar system—which was initially flagged by a pair of Harvard University researchers in a study posted on the preprint server arXiv in 2019.

Amir Siraj, a student pursuing astrophysics at Harvard who led the research, said the study has been awaiting peer review and publication for years, but has been hamstrung by the odd circumstances that arose from the sheer novelty of the find and roadblocks put up by the involvement of information classified by the U.S. government.

The speed and angle in which the object hit the atmosphere are why the scientists believe it comes from outside the solar system.

Siraj is actually hoping to mount a mission to recover parts of this asteroid, something that is extremely unlikely. First, the meteor itself was small, so it likely all burned up in re-entry. Second, even if pieces survived, finding them on the bottom of the Pacific is likely impossible.

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Curiosity retreating from Greenheugh Pediment

10:05 am

Overview map
Click for interactive map.

Because of the incredible roughness of the ground on the Greenheugh Pediment, the science team for the rover Curiosity has decided to make a major change in their route. Rather than continue their traverse across this terrain, as planned for years, they have decided to back off in order to protect Curiosity’s dinged wheels, and find a more friendly route up Mount Sharp.

“It was obvious from Curiosity’s photos that this would not be good for our wheels,” said Curiosity Project Manager Megan Lin of NASA’s Jet Propulsion Laboratory in Southern California, which leads the mission. “It would be slow going, and we wouldn’t have been able to implement rover-driving best practices.”

The gator-back rocks aren’t impassable – they just wouldn’t have been worth crossing, considering how difficult the path would be and how much they would age the rover’s wheels.

So the mission is mapping out a new course for the rover as it continues to explore Mount Sharp, a 3.4-mile-tall (5.5-kilometer-tall) mountain that Curiosity has been ascending since 2014. As it climbs, Curiosity is able to study different sedimentary layers that were shaped by water billions of years ago. These layers help scientists understand whether microscopic life could have survived in the ancient Martian environment.

The plan is to retrace the rover’s path back through Gordon Notch and then head uphill though another gap that will take it directly onto the next sedimentary layer, dubbed the sulfate unit. On the overview map above, the red dotted line shows the long-planned route. The yellow lines indicate the area seen in the panorama I posted on April 6th, when Curiosity was at its farthest into the pediment. The blue dot marks Curiosity’s position two days ago. You can see that it has retreated backwards.

This change means the scientists will likely not get a close look at Gediz Vallis Ridge. However, it also means the rover will likely reach Gediz Vallis much sooner that previously planned.

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Neptune’s cooling when it should be warming

9:45 am

Neptune since 2006

The uncertainty of science: Observations of Neptune during the past seventeen years using the Very Large Telescope have shown the planet mostly cooling during this time period, even though Neptune was moving into its summer season.

Astronomers looked at nearly 100 thermal-infrared images of Neptune, captured over a 17-year period, to piece together overall trends in the planet’s temperature in greater detail than ever before. These data showed that, despite the onset of southern summer, most of the planet had gradually cooled over the last two decades. The globally averaged temperature of Neptune dropped by 8 °C between 2003 and 2018.

The astronomers were then surprised to discover a dramatic warming of Neptune’s south pole during the last two years of their observations, when temperatures rapidly rose 11 °C between 2018 and 2020. Although Neptune’s warm polar vortex has been known for many years, such rapid polar warming has never been previously observed on the planet. “Our data cover less than half of a Neptune season, so no one was expecting to see large and rapid changes,” says co-author Glenn Orton, senior research scientist at Caltech’s Jet Propulsion Laboratory (JPL) in the US.

The sequence of photos above show that change over time. Lower latitudes generally get darker, or cooler, while the south pole suddenly brightens, getting hotter, in 2020.

The scientists have no idea why this has happened, though they have theories, ranging from simple random weather patterns to the influence of the Sun’s sunspot cycle.

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Perseverance arrives at Three Forks at the base of Jezero Crater’s delta

12:01 pm

Panorama of delta in Jezero Crater
Original images found here, here, here, and here. Click for full resolution.

Overview map
Click for interactive map.

Cool image time! The panorama above was created from four navigation camera images taken by the Mars rover Perseverance on April 10th. Because the lens on Perseverance’s navigation cameras produce slightly curved images which are taken in pairs, the panorama is made of two parts, each a pair perfectly matched images looking from a different angle. I have overlapped the pairs but as you can see, the match at the center is imperfect. While this does not produce a single smooth image, the two paired panoramas show the foot of the entire delta that had flowed into Jezero crater in the past and is the prime geological target of the rover. What is it made of? What caused it to flow into the crater? When did it do it? How was Mars different when it did so? Was the crater wet? Was the delta mud when it flowed, or was it sediment under water, pushed out by that flowing water?

The location map to the right is taken from the “Where is Perseverance?” webpage but annotated to show the planned routes of both Perseverance and Ingenuity, as shown by the tan dashed lines. The red dot marks Perseverance present location, the green dot Ingenuty’s. The yellow lines the approximate area covered by the panorama.

What next? Expect Perseverance to move as close to the base of the delta’s cliff as possible and spend at least several months studying it. Ingenuity meanwhile will be flown to the west to scout the various hollows that are potential routes for Perseverance to climb up onto the delta.

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Splonk went the crater!

12:59 pm

Splonk went the crater!
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on February 18, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as a “degraded crater in Utopia Planitia.”

There is a lot of intriguing geology in this one image. First of course is the crater itself. We have to ask, is it from an impact or from some volcanic process? The location, at 44 degrees north latitude, argues that some form of ice or mud process was involved. Maybe we are looking at a frozen eruption from an underground ice layer. If this was instead caused by an impact, the crater’s ringlike structure could have been created by the ripples of melted ice and mud emanating away but then quickly refreezing.

Surrounding the crater are many small fissures, the largest ones all oriented in a north-south direction. If there is an ice layer near the surface, these cracks might be caused by that ice sublimating away. Why the largest cracks orient in the same direction however is a mystery.

The color variations suggest [pdf] dust (red-orange) as well as a variety of minerals (green). Since no blue appears visible in this version of the photo, if this crater was shaped by melting or erupting ice, that ice is well covered by that layer of dust and debris.

The location map below as always provides context.
» Read more

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New data contradicts accepted standard model of particle physics

9:35 am

The uncertainty of science: After years of analysis, physicists have refined their measurement of the mass of one important subatomic particle, and discovered that its weight violates the accepted standard model of particle physics, threatening to overthrow it entirely.

W bosons are elementary particles that carry the weak force, mediating nuclear processes like those at work in the Sun. According to the Standard Model, their mass is linked to the masses of the Higgs boson and a subatomic particle called the top quark. In a new study, almost 400 scientists on the Collider Detector at Fermilab (CDF) collaboration spent a decade examining 4.2 million W boson candidates collected from 26 years of data at the Tevatron collider. From this treasure trove, the team was able to calculate the mass of the W boson to within 0.01 percent, making it twice as precise as the previous best measurement.

By their calculations, the W boson has a mass of 80,433.5 Mega-electronvolts (MeV), with an uncertainty of just 9.4 MeV either side. That’s within the range of some previous measurements, but well outside that predicted by the Standard Model, which puts it at 80,357 MeV, give or take 6 MeV. That means the new value is off by a whopping seven standard deviations.

Further cementing the anomaly, the W boson mass was also recently measured using data from the Large Hadron Collider, in a paper published in January. That team came to a value of 80,354 MeV (+/- 32 MeV), which is comfortably close to that given by the Standard Model.

Personally, I always take this level of physics with a great deal of skepticism. The data involves a lot of assumptions and uncertainties. That other researchers came up with a different number illustrates this.

Nonetheless, these results could suggest that the standard model, the consensus theory for decades, is either incomplete, or wrong. The former would be more likely, but no possibility should be dismissed. And even if wrong, much of that model still works so well any new model must include large parts of it.

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Connecting the dots of the COVID lie

1:40 pm

What our leaders want us to be
What our leaders want us to be

There were many reasons the world panicked in 2020 when COVID appeared and spread from China. Some of that panic was motivated by natural fear of an unknown disease. Some of it was motivated by a desire for power, harnessing that fear to nullify the Bill of Rights and the legal restraints on dictatorship. Some of it was inspired by a simple blind hatred of Donald Trump, and saw an opportunity to use the virus as a tool for getting him out of power. And some of the actions of our leaders was motivated by pure and simple greed, willing to let millions die so that they could personally get rich, or richer.

To connect the dots to understand the worst players in this terrible story, we need to look at more than one story or report, each telling us something that the fear-mongers have tried to hide from us so that their dishonest and sometimes quite evil motives might not be recognized.

To begin, there are these two stories, showing that we now have solid evidence that the military committed fraud in order to hide data that showed the COVID shots were causing a terrible number of health injuries and deaths to soldiers being ordered to take them.

From the first story, describing a lawsuit that claims the Defense Department committed fraud:
» Read more

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Curiosity’s upcoming rough terrain

12:25 pm

Curiosity's view looking west on April 5, 2022 (Sol 3435)Click for high resolution. For original images go here, here, here, and here.

Overview map
Click for interactive map.

Cool image time! The panorama above, created by me from four photos taken by Curiosity’s right navigation camera on April 5, 2022, reveal much about the alien world of Mars that the rover is exploring. The red dotted line indicates approximately the rover’s upcoming route.

First there is the rough surface of the Greenheugh Pediment, the sloping plateau that Curiosity is presently traversing. Called “gater-back terrain” by the science team, this broken surface apparently is sandstone that was originally a dune field that in the past was periodically washed by water runoff and later hardened into this structurally weak rock.

Second, I have orientated the images so that the rim of Gale Crater, approximately 25 miles away, is horizontal. By doing so, we can see the upward slope of the Greenheugh Pediment. Curiosity is on a tilted surface, and while it will be traversing along a contour line as it heads west towards Gediz Vallis Ridge about 1,000 feet away, when it turns left and heads uphill, the climb will be steady and steep, as it has now been for the past year since the rover entered the mountains at the foot of Mount Sharp.

Taken together, these details indicate why Curiosity has moved very slowly in recent weeks, as shown by the white dots in the overview map to the right. The blue dot marks Curiosity’s present location, with the yellow lines indicate the approximate view in the panorama above.

Traversing the pediment carries real risk to the rover. Though its somewhat dinged wheels have held up well during this last year of traveling in these rough mountains, at any point the severe roughness here could damage one or more wheels significantly, even putting one or more out of commission. The rover team is traveling carefully to avoid this, but these factors illustrate a possible end for the rover, though hopefully still years away.

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Inspector General: NASA’s lunar rover VIPER mission on schedule, with some cost increases

11:19 am

VIPER's planned route on the Moon

According to a report [pdf] issued today by NASA’s inspector general, the agency’s VIPER lunar rover mission is generally on schedule for its ’23 launch, though it has experienced some cost increases and still carries some scheduling risks, mostly related to the development of Astrobotic’s commercial Griffin lunar lander, and its precursor Peregrine mission that ULA hopes to launch on its first Vulcan rocket test.

Although Astrobotic personnel explained that Griffin’s development schedule is largely independent of its Peregrine mission, the Peregrine Lander—planned to launch in 2022—has multiple systems and subsystems that will also be used on Griffin. Therefore, any technical problems with these systems may adversely affect development of the Griffin Lander because Astrobotic would only have about a year, depending on the Peregrine launch date and start of lunar operations, to resolve the issues prior to NASA delivering VIPER for integration and launch. Furthermore, any failures during the Peregrine mission may lead to Griffin delays as NASA and Astrobotic investigate the failures and develop corrective actions.

In addition, VIPER long-lead acquisitions—such as the rover solar power array and avionics unit—have been affected by aerospace industry supply chain delays caused by COVID-19 as have delivery of computer boards and motor parts. Both of these issues have impacted design verification testing needed for the mission’s Critical Design Review, while COVID-19 also delayed some component development schedules.

Peregrine’s launch has been delayed by a year because Vulcan has been delayed because of Blue Origin’s problems with the BE-4 rocket engine. Though ULA hopes the Vulcan/Peregrine launch can occur late this year, that date remains very much in doubt. Further launch delays would thus threaten the launch of Griffin and VIPER.

As for the cost increases, the IG found that NASA had been forced to increase the budget for VIPER by 18.1%, a relatively minor increase compared to many of NASA’s other big projects. The IG noted however that further cost overruns are very possible, especially if the Peregrine mission experiences problems.

The photo above shows the rover’s presently planned route in the relatively flat area about 85 miles from the Moon’s south pole and near the western edge of Nobile Crater (pronounced No-BEEL-e).

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Scientists decide propaganda and commercials are better than good research results

10:47 am

The on-going dark age: In a new study scientists have discovered that — instead of depending on hard research that is repeatedly confirmed by others — if they simply use a trusted spokesman in commercials promoting their work they can get people to accept their conclusions, at face value.

This momentous discovery occurred when some researchers decided to find out if putting Trump in a 30-second commercial asking people to get the COVID jab would encourage them to do so. This is what the test learned:

A creative effort to use former President Donald Trump to persuade people to get a COVID-19 vaccine shot appears to have paid off. An online advertisement created by a team of political scientists and economists that featured Trump recommending COVID-19 shots led to increased uptake of the vaccines in U.S. counties that had low vaccination rates, concludes a new analysis.

“We were so thrilled,” says Marc Hetherington, a political scientist at the University of North Carolina, Chapel Hill, who helped create the ad and co-authored the study. “How often do political scientists and economists do anything that helps the world? The answer is, like, 0% of the time.”

…The results highlight that “health communication needs to come from trusted messengers and to meet people where they are,” says behavioral scientist Katherine Milkman of the University of Pennsylvania, who was not involved in the study. [emphasis mine]

Hetherington’s highlighted quote was intended to imply that this research proved that political scientists and economists sometimes do do something that helps the world. I think it only proves that they never do.

Using advertising to sell a scientific conclusion is without doubt the most corrupt and idiotic method for selling a scientist’s work. It only proves the work itself, in this case the COVID shots, have questionable aspects that need propaganda to convince people of their value.

Other quotes from different scientists at the link also illustrate how divorced from actual research and data these scientists are. To their minds, the doubt that many people have of the COVID shots can only be attributed to an “antivaccine ecosystem” touting its own political agenda. The extensive research and data that suggests the shots carry risks while appearing possibly useless is either ignored by these scientists, or they are willfully ignorant of it.

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Europe to put instrument on Japanese rover being launched and landed on the Moon by India

9:49 am

The new colonial movement: The European Space Agency (ESA) has signed an agreement with Japan’s space agency JAXA to put a science instrument on a Japanese rover that will be launched by India to the Moon and landed there on an Indian lander.

Under the deal, ESA would provide instruments for the Japanese rover, which would be used in the exploration of the Moon’s south pole under the mission targeted for 2024. … The lunar endeavour between the Indian Space Research Organisation (ISRO) and JAXA is called the Lunar Polar Exploration Mission (LUPEX) which aims to launch an Indian lander and a Japanese rover to the Moon.

In the next three years a lot of landers and rovers are planning to land on the Moon, most built by private American companies flying NASA and private payloads, but also joined by probes being sent by Russia, China, and now this Japanese-Indian-European mission. Even if only half succeed, the exploration of the lunar surface will still be quite busy.

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Astronomers discover a solar twin whose sunspot cycle changed into a grand minimum

9:19 am

Astronomers studying the sunspot cycle of several dozen stars that are twins of our Sun have identified for the first time a star whose 17-year cycle suddenly ceased, going into an extended grand minimum.

Comparing these stars to the Sun enables astronomers to better determine how typical – or not – the Sun is as a star. The Sun’s magnetic activity is defined by its 11-year sunspot cycle. Of the 59 stars that Baum’s team surveyed, 29 appeared to also have starspot cycles, and the period of those cycles could be measured for 14 of them.

“Of these 14 stars, the average length of their cycle is just under 10 years, which is similar to the Sun’s 11-year cycle,” Baum tells Physics World. However, not all the stars adhered to this time frame. One star that was surveyed has a cycle lasting less than four years, while another star, HD 166620, had a cycle 17 years long.

Note the past tense. Sometime between 1995 and 2004, HD 166620’s starspot cycle simply stopped.

When or if the star’s sunspot activity resume is unknown. The Sun’s last grand minimum, dubbed the Maunder Minimum, lasted 70 years during the 1600s.

No one yet understands why stars do this. This discovery however now shows that the Sun is not unique in this behavior.

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Ingenuity completes its 24th flight on Mars

9:14 pm

Overview map
Click for interactive map.

Ingenuity today completed its 24th flight on Mars, traveling a short 33 feet for 69.5 seconds in order to place it in a good position for an upcoming record-setting 25th flight.

With Flight 24 in our log book, it is now time to look forward to our upcoming effort that charts a course out of Séítah. Flight 25 – which was uplinked yesterday – will send Ingenuity 704 meters to the northwest (almost 80 meters longer than the current record – Flight 9). The helicopter’s ground speed will be about 5.5 meters per second (another record) and we expect to be in the rarefied Martian air for about 161.5 seconds.

The red dot on the map to the right indicates Perseverance’s present position. The green dot shows where Ingenuity landed today. The tan dashed lines indicate the planned routes for both. Ingenuity’s next flight will take it out of the rough terrain of Seitah and much closer to Three Forks.

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Looking down into a Jupiter hurricane

11:25 am

Looking down into a Jupiter hurricane
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was created by citizen scientists Kevin Gill and Navaneeth Krishnan from a raw image taken by Juno during its 40th close fly-by of Jupiter in February 2022.

I don’t have a scale, but I would guess that this storm is at least a thousand miles across. The depth is harder to measure, but we looking down into a deep whirlpool for sure.

To bring out the details Gill and Krishnan enhanced the colors significantly. The original is quite bland in comparison, with this storm being the faint dark spot just below the center near the photo’s left edge.

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UAE wants to prioritize private enterprise for its space effort

10:17 am

Capitalism in space: According to officials of the United Arab Emirates (UAE) space agency, that nation is working to encourage the growth of a private space industry, funded initially using government money, in its effort to become a major world player in space.

“We’ve spent well over Dh1.5 billion ($408 million) on building capacity within the space industry over the last eight years and we’re more than doubling that over the next decade.”

Laws and regulations, including permits, which would allow interested companies to set up base in the UAE, are already available through a space law passed in 2019.

Companies would also have access to funding from a new initiative launched by the space agency, called Space Analytics and Solutions, which has a budget of Dh20 million. The programme aims to help start-ups build space-based applications that focus on food security, climate change, infrastructure and the oil and gas industry.

The space agency hopes that as these companies progress, they would become less reliant on government funding.

While the UAE’s Al-Amal Mars orbiter was mostly built and launched by foreign companies, it hopes its next major mission, to send an unmanned probe to seven asteroids, will be built almost entirely by companies run by UAE citizens, something they claim they have achieved with an upcoming smallsat Earth observation satellite.

The article also mentioned as an aside that the UAE has ended its 2019 agreement with Virgin Galactic to allow it to launch from the UAE. Instead, it is negotiating with Blue Origin “to set up spaceports.”

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Astronomers directly image the orbital motion of Jupiter protoplanet 531 light years away

1:41 pm

AB Aurigae B's motion over thirteen years
Click for original image.

Astronomers, using a number of ground- and space-based telescopes, have now directly photographed the orbital motion of a Jupiter protoplanet orbiting a star 531 light years away over a thirteen year time span.

The image to the right, cropped to post here, shows images produced by two Hubble instruments. The caption:

Researchers were able to directly image newly forming exoplanet AB Aurigae b over a 13-year span using Hubble’s Space Telescope Imaging Spectrograph (STIS) and its Near Infrared Camera and Multi-Object Spectrograph (NICMOS). In the top right, Hubble’s NICMOS image captured in 2007 shows AB Aurigae b in a due south position compared to its host star, which is covered by the instrument’s coronagraph. The image captured in 2021 by STIS shows the protoplanet has moved in a counterclockwise motion over time.

From the paper’s abstract:

Using the Subaru Telescope and the Hubble Space Telescope, we find evidence for a Jovian protoplanet around AB Aurigae orbiting at a wide projected separation (~93 au), probably responsible for multiple planet-induced features in the disk. Its emission is reproducible as reprocessed radiation from an embedded protoplanet.

The accretion disk around AB Aurigae happens to lie face on to our line of sight, which facilitates these observations. The data also shows two additional potential proto-planets farther from the star.

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The most valuable real estate on the Moon

10:09 am

The most valuable real estate on the Moon
Click for full image.

Cool image time! The photo to the right, reduced and annotated to post here, is an oblique view of the terrain near Shackelton Crater and the Moon’s south pole, taken by Lunar Reconnaissance Orbiter (LRO) and released today.

Shackleton-de Gerlache ridge, about 9 miles long, is considered one of the prime landing sites for both a manned Artemis mission as well as the unmanned Nova-C lander from the commercial company Intuitive Machines. To facilitate planning, scientists have created a very detailed geomorphic map [pdf] of this region. As explained at the first link above,

Going back to time-proven traditions of the Apollo missions, geomorphic maps at a very large scale are needed to effectively guide and inform landing site selection, traverse planning, and in-situ landscape interpretation by rovers and astronauts. We assembled a geomorphic map covering a candidate landing site on the Shackleton-de Gerlache-ridge and the adjacent rim of Shackleton crater. The map was derived from one meter per pixel NAC image mosaics and five meters per pixel digital elevation models (DEM) from Lunar Orbiter Laser Altimeter (LOLA) ranging measurements.

Such geology maps guide planning and exploration, but actual images tell us what the first explorers will see. Below is a close-up overhead view of small area at the intersection of the ridge and the rim of Shackleton.
» Read more

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Sunspot update: Sunspot activity continues to outpace predictions

3:23 pm

It is the first of the month, and NOAA has once again updated its monthly graph showing the long term trends in the Sun’s sunspot activity. As I do every month, I post it below, annotated with additional data to provide some context.

In March the Sun continued its unexpected high activity since the end of the solar minimum in 2020. The number of sunspots once again rose steeply, while also exceeding the predicted count for the month. The actual sunspot count for March was 78.5, not 34.1 as predicted. The last time the count was that high for any month was September 2015, when the Sun was just beginning its ramp down from solar maximum.
» Read more

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Strange terrain at the Martian equator

12:41 pm

Strange terrain at the Martian equator
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on January 29, 2022 by the high resolution camera of Mars Reconnaissance Orbiter (MRO). It shows a small portion of the floor of 41-mile-wide Tuskegee Crater, sitting at the Martian equator on the rim of the outlet to the giant canyon Valles Marineris.

I have purposely focused on a section of the color strip, because of its strange green color. Most MRO images are reddish (indicating dust) or blue (indicating coarse rocks or ice). Green seems to me to be rare, and in fact is not even mentioned in the MRO science’s team explanation [pdf] of the colors the instrument produces. Since green is neither dust nor ice, this suggests some form of hard bedrock, with a mineralogy that produces that color.

The overview map below gives some context.
» Read more

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A large Martian river basin with delta

11:44 am

Map of Hypanis Valles river basin on Mars
Click for full image.

Cool map time! The map to the right, reduced to post here, is figure 1 in a new paper outlining the known geology of what appears to be a large ancient and now dry river basin with delta on Mars, found north of Valles Marineris and draining into the northern lowland plain dubbed Chryse Planitia where both Viking-1 and Mars Pathfinder landed, in 1976 and 1997 respectively.

The river basin itself is called Hypanis Valles. The white splotch at the river basin’s outlet is dubbed the Hypanis Deposit, and is thought by some scientists to be a delta of material that was placed there when the river was active 3.6 billion years ago and poured into what some scientists believe was an intermittent ocean in Chryse Planitia. From the paper’s conclusion:

As proposed in prior works, Hypanis may have formed subaqueously as a delta, and may record a water level drop of about 500 m[eters, or about 1,600 feet] as a shoreline retreated to the northeast. We identified kilometer-sized cones and mounds which appear to have erupted onto the surface. Characteristics of these features more closely resemble those of outgassing, sedimentary diapirism, and mud volcanism rather than of igneous volcanism.

The intermittent ocean theory has problems however. For this delta to have formed underwater that ocean would have to have been much much larger than estimated based on the present known data, extending out to cover almost all of Chryse Planitia, in some places to a very great depth.

Some scientists have hypothesized that the ocean need not have been that large because a land dam would have confined it to a smaller region at the river’s outlet. This research however found no evidence of such a dam. However, the paper also noted that “Further work could examine the role of ice or glaciers in the formation of Hypanis and determine if an ice dam would be plausible.”

And of course there remains the more fundamental mystery of liquid water on the Martian surface, which makes the river basin itself a puzzle. No generally accepted model allowing for surface liquid water on Mars presently exists. The possibility that ice and glaciers could have done the job comes to mind again. Though the geology in this region reveals what looks like to our Earth eyes to be a very large river system, now dry, this is not Earth but an alien planet. Tributary systems like this might form from different and as yet not understood processes on Mars, some of which might involve glaciers.

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Scientists: On Mars surface elevation doesn’t matter that much in terms of radiation protection

9:41 am

In a paper published in February, scientists determined from models and data that the thickness of Martian cave ceilings required to protect you from radiation is not that much different whether you are on top of Olympus Mons (the Mount Everest of Mars), or at the bottom of Hellas Basin (Mars’ Death Valley).

From the paper’s conclusion:

Overall, the atmospheric thickness is not a dominant parameter for the required shielding. However, at a low-altitude crater where the surface pressure is above 1,000 Pa, the required subsurface shielding is about 10–20 cm [4 to 8 inches] less than at the top of high mountains where the pressure is below 100 Pa. Moreover, solar activities which determine the GCR flux arriving at Mars play an role. To reduce the annual effective dose to be below 100 mSv, the required shielding is 1.5–1.6 m [about 5 feet] during solar minimum and 0.9–1.1 m [a little more than 3 feet] during solar maximum. For a threshold of 50 mSv, the required shielding is 2.1–2.2 m [about 7 feet] during solar minimum and 1.7–1.9 m [about 6 feet] during solar maximum.

Essentially, what this research suggests is that to properly shield any underground facility, you need to cover it with at least seven feet of material, or be in a cave where the ceiling is that thick. It really doesn’t matter how much atmosphere is above you. Even at its thickest at the lowest elevation, Mars’ atmosphere doesn’t provide much protection.

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Astronomers think they have detected the most distant star ever

9:24 am

The most distant star ever detected?
Click for full image.

The uncertainty of science: Using the Hubble Space Telescope astronomers now think they have detected the most distant single star ever located, the light of which is estimated to have come from a time only less than a billion years after the Big Bang itself.

The star, nicknamed Earendel by astronomers, emitted its light within the universe’s first billion years. It’s a significant leap beyond Hubble’s previous distance record, in 2018, when it detected a star at around 4 billion years after the big bang. Hubble got a boost by looking through space warped by the mass of the huge galaxy cluster WHL0137-08, an effect called gravitational lensing. Earendel was aligned on or very near a ripple in the fabric of space created by the cluster’s mass, which magnified its light enough to be detected by Hubble.

The arrow in the image, cropped and reduced to post here, points to the theorized star. Note the arc that tiny dot lies along. This arc is the result of the gravitational lensing, and illustrates quite bluntly the large uncertainties of this discovery. We are not seeing the star itself, but the distorted light after it passed through the strong gravitational field of the cluster of galaxies. The scientists conclusion that this dot is thus a single star, must be view with great skepticism.

Nonetheless, the data is intriguing, and will certainly be one of the early targets of the James Webb Space Telescope, which could confirm or disprove this hypothesis.

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Active volcanoes on Pluto?

9:16 am

Elevation map of Wright Mons on Pluto
Elevation map of Wright Mons on Pluto

The uncertainty of science: According to new research published yesterday, scientists now posit that there might be recent volcanic activity on Pluto, based on data and images sent back by New Horizons during its fly-by of the planet in 2015.

You can read the paper here. From its abstract:

The New Horizons spacecraft returned images and compositional data showing that terrains on Pluto span a variety of ages, ranging from relatively ancient, heavily cratered areas to very young surfaces with few-to-no impact craters. One of the regions with very few impact craters is dominated by enormous rises with hummocky flanks. Similar features do not exist anywhere else in the imaged solar system. Here we analyze the geomorphology and composition of the features and conclude this region was resurfaced by cryovolcanic processes, of a type and scale so far unique to Pluto. Creation of this terrain requires multiple eruption sites and a large volume of material (>104 km3) to form what we propose are multiple, several-km-high domes, some of which merge to form more complex planforms. The existence of these massive features suggests Pluto’s interior structure and evolution allows for either enhanced retention of heat or more heat overall than was anticipated before New Horizons, which permitted mobilization of water-ice-rich materials late in Pluto’s history. [emphasis mine]

The image to above is Figure 10 in the paper’s supplementary material [pdf]. It shows the volcano-like appearance of Wright Mons on Pluto, a mound approximately 3,000 feet high with a central depression equally deep, with a volume “similar in magnitude to that of the Hawaiian volcano Mauna Loa.”

These conclusions are quite tantalizing, but the amount of data is sparse, and thus it is wise not to take them too seriously. For example, the scientists have no idea how Pluto could presently have any form of liquid or active volcanism. Another mission to Pluto — studying it over a long time from orbit — will be required to determine how active the planet really is, or if it is active at all.

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Scientists: Ice layers in Burroughs Crater confirm Martian orbital climate cycles

10:29 am

Layering in the west side of Burroughs Crater
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According to a new paper published today, scientists have used the ice layers inside Burroughs Crater on Mars to confirm the theory that the Red Planet has undergone numerous climate cycles during the past four million years, caused by the swings in the planet’s rotational tilt and eccentric orbit. From the press release:

Previously, Martian climate scientists have focused on polar ice caps, which span hundreds of kilometers. But these deposits are old and may have lost ice over time, losing fine details that are necessary to confidently establish connections between the planet’s orientation and motion and its climate.

Sori and his colleagues turned to ice mounds in craters, just tens of kilometers wide but much fresher and potentially less complicated. After scouring much of the southern hemisphere, they pinpointed Burroughs crater, 74 kilometers wide, that has “exceptionally well-preserved” layers visible from NASA HiRISE [Mars Reconnaissance Orbiter’s high resolution camera] imagery, Sori said.

The researchers analyzed the layers’ thicknesses and shapes and found they had strikingly similar patterns to two important Martian orbital dynamics, the tilt of Mars’ axis and orbital precession, over the last 4 to 5 million years.

The photo above of those layers was taken by Europe’s Trace Gas Orbiter on March 13, 2019, cropped and reduced to post here.

This research greatly strengthens the theory that the ice on Mars gets distributed to different latitudes in cycles, depending on the cyclical fluctuations in the planet’s orbit and tilt. However, it does not yet confirm these cycles apply to the glaciers found in craters in lower latitudes. Burroughs Crater is at 72 degrees south latitude, near the southern polar ice cap, well south of the band of glaciers scientists have discovered in the mid-latitudes down to 30 degrees latitude. Nonetheless, this research strongly suggest the same cycles apply in those lower latitudes.

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Ice sheets on Mars below 30 degrees latitude?

12:56 pm

Cracks in Ice on Mars?
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on November 29, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a collection of scattered thin surface fractures, grouped in clusters of parallel lines with the orientation of the clusters all somewhat random to other clusters.

The fractures, as well as the material inside the craters, appears to resemble glacial features, suggesting that these fractures are the result of either the past motion of the glacial sheet, or the sublimation of the buried ice, which causes it to crack and shrink as it slowly dissipates away.

The problem with that hypothesis is the location, as shown by the overview map below.
» Read more

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Curiosity presently traveling over broken sandstone from an ancient dune field

10:27 am

Gator-back terrain on Mars
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According to a new paper, scientists now think that the rough and broken cap layer of the Greenheugh pediment that Curiosity is presently traveling across was originally a dune field periodically washed by water runoff, which with time eventually hardened into sandstone.

That broken terrain, dubbed “gator-back terrain” by the Curiosity science team, is shown clearly in the image to the right, taken on March 20, 2022. From the paper’s abstract:

The Greenheugh pediment is capped by a unit of broadly uniform thickness which represents the remains of the Stimson dune field that existed <2.5 Ga (mid- to late-Hesperian). ChemCam geochemical data shows that the sands deposited at the Greenheugh capping unit were sourced from a nearby olivine-rich unit. Surface waters then cemented the windblown sand deposits, ponding at the unconformity with the underlying mudstone unit, creating concretions towards the base. Episodes of groundwater circulation did not affect the rocks at Greenheugh as much as they did at other Stimson localities with the exception of acid-sulfate alteration that occurred along the unconformity. These results suggest that the ancient Stimson dune field was a dynamic environment, incorporating grains from the surrounding geological units on Mt Sharp. Furthermore, liquid water was stable at the surface in the Hesperian and was available for multiple diagenetic events along bedrock weaknesses.

In other words, material from Mount Sharp formed the dune fields, all of which were reshaped by groundwater circulation, with the dunes higher on the mountain seeing less groundwater.

The biggest uncertainty of these findings is explaining how surface liquid water could exist on Mars. Scientists have yet to develop an accepted model that would allow it. Another possibility would be the recent data that suggests Gale Crater was filled with glaciers. If so, scientists would need to figure out how the interaction of a Martian glacier might have geologically changed those dunes in a manner similar to groundwater.

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Solar Orbiter takes closest image of Sun so far

10:18 am

Solar Orbiter's closest image of the Sun, so far
Click for full interactive image, where you can zoom in, a lot.

Cool image time! The European Space Agency (ESA) yesterday released several new images from its Solar Orbiter probe, taken when the spacecraft made its most recent closest approach of the Sun.

One of the images, taken by the Extreme Ultraviolet Imager (EUI) is the highest resolution image of the Sun’s full disc and outer atmosphere, the corona, ever taken.

Another image, taken by the Spectral Imaging of the Coronal Environment (SPICE) instrument represents the first full Sun image of its kind in 50 years, and by far the best one, taken at the Lyman-beta wavelength of ultraviolet light that is emitted by hydrogen gas.

The images were taken when Solar Orbiter was at a distance of roughly 75 million kilometres, half way between our world and its parent star. The high-resolution telescope of EUI takes pictures of such high spatial resolution that, at that close distance, a mosaic of 25 individual images is needed to cover the entire Sun. Taken one after the other, the full image was captured over a period of more than four hours because each tile takes about 10 minutes, including the time for the spacecraft to point from one segment to the next.

The photo to the right, reduced to post here, is the EUI photo.

Solar Orbiter has been in its science orbit since November, though that orbit over time will slowly be adjusted to swing the spacecraft into a higher inclination so that it can make the first close-up observations of the Sun’s polar regions. It is also working in tandem with the Parker Solar Probe, which observes the Sun from even closer distances using different instruments.

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Ingenuity completes 23rd flight on Mars

11:05 pm

Overview map
Click for interactive map.

JPL announced tonight in a tweet that Ingenuity today completed its 23rd successful flight on Mars.

23 flights and counting! #MarsHelicopter successfully completed its 23rd excursion. It flew for 129.1 seconds over 358 meters [1,175 feet].

The overview map to the right was taken from the “Where is Perseverance?” webpage and annotated by me to show the planned future routes of both Perseverance and Ingenuity. The white dotted line shows Perseverance’s path, now having almost circled the rough ground on its way to the delta and Three Forks. The tan dotted line indicates Perseverance’s future route. The dashed pink and green lines indicate two possible future flight paths for Ingenuity.

The green dot marks the position the science team marked on the map for where Ingenuity landed after today’s flight. They have not yet calculated the actual flight path, which is why it is shown by the tan dashed line. This also means there is as yet some uncertainty about this landing spot.

Originally, the plan had been to get to this spot in one flight. For reasons not yet explained, when the helicopter took off on its 22nd flight during the March 19-20th weekend, it stopped after only about 100 feet. Today’s flight apparently completed the plan, putting the helicopter where it was supposed to be.

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