Tag: science

Hayabusa-2 prepares to land

9:54 am

Ryugu's northen hemisphere

The JAXA science team has released a set of images taken in January by Hayabusa-2 of its landing site on Ryugu, describing how those images helped map the region where touchdown will occur on February 22. The image on the right is one such image.

[It] shows a diagonally imaged photograph of Ryugu, captured by moving the spacecraft towards the direction of the north pole. The upper side of the image shows the north pole and reveals a landscape dominated with many large boulders. The white band extending to the left and right slightly below the center of the image is the equatorial ridge (Ryujin Ridge). The arrow tip marks the planned touchdown site and you can see this site is on the main ridge.

This is the first time we have images the northern hemisphere of Ryugu. In this observation, we acquired data on the equatorial region of Ryugu, the southern and northern hemisphere. Imaging the entire area is very important for creating accurate global shape models for Ryugu.

They should begin beaming images down of the landing approach sometime tomorrow, and will do so about every 30 minutes throughout the sequence.

Leave a comment

New sky survey uncovers hundreds of thousands of previously unknown galaxies

11:02 am

Galaxies without end: A new radio telescope sky survey has discovered hundreds of thousands of previously unknown galaxies.

This discovery is part of a major release of papers outlining a number of discoveries made by this new sky survey.

I could of course also subheaded this post “The uncertainty of science.” Wanna bet that even with this discovery we have only seen the tip of the iceberg of the number of galaxies out there?

7 comments

A very old white dwarf star with rings?

10:19 am

The uncertainty of science: A citizen scientist has discovered a very old white dwarf star that apparently has one or more dust rings it should not have.

The star, LSPM J0207+3331 or J0207 for short, is forcing researchers to reconsider models of planetary systems and could help us learn about the distant future of our solar system. “This white dwarf is so old that whatever process is feeding material into its rings must operate on billion-year timescales,” said John Debes, an astronomer at the Space Telescope Science Institute in Baltimore. “Most of the models scientists have created to explain rings around white dwarfs only work well up to around 100 million years, so this star is really challenging our assumptions of how planetary systems evolve.”

In other words, we don’t really yet understand the processes that form solar systems or even stars. This isn’t because we can’t figure this out, but because we don’t yet have enough information on hand. What we do know tells us that stars and solar systems both form from accretion disks. The information also gives us a general idea of the pattern of formation, but not much more.

For example, one question I have asked a number of astronomers is: Why are some stars gigantic monsters and others dwarfs? Based on present theories of stellar evolution, it seems to me that all stars should be the same size, as accretion is thought to end when the star reaches a heavy enough mass to ignite its nuclear engine. Yet this is not what we find. Why? I’ve never gotten a good answer.

9 comments

A river valley floor on Mars

12:50 pm

Overview of Reull Valles region

Today’s cool image focuses in on a Mars Reconnaissance Orbiter (MRO) uncaptioned photograph taken of the valley floor of Reull Vallis, a meandering canyon that drains into Hellas Basin, the bottom of Mars.

The image on the right is not that photograph. Instead, it is an overview of the area surrounding it. The image location is indicated by the black cross, dead center within the floor of Reull Vallis itself. This valley, as well as Dao and Niger to the northwest but lower in elevation are all thought to have been formed from flowing water, all of which apparently drained from the east and to the west into Hellas Basin.

This last detail is very important and bears repeating before looking at today’s subject image. The river that formed Reull Vallis flowed from the east to the west. Now for that picture.
» Read more

Leave a comment

New LRO image of Chang’e-4 and Yutu-2

10:05 am

Chang'e-4 and Yutu-2

The Lunar Reconnaissance Orbiter (LRO) science team has released its third and best image of the Chinese Chang’e-4 lander and Yutu-2 rover. The image on the right is a full resolution cropped section, with the lander on the bottom and the rover above and to the left.

Just after midnight (UTC) on 1 February 2019 LRO passed nearly overhead the Chang’e 4 landing site. From an altitude of 82 kilometers the LROC Narrow Angle Camera pixel scale was 0.85 meters (33 inches), allowing a sharper view of the lander and Yutu-2 rover. At the time the rover was 29 meters northwest of the lander, but the rover has likely moved since the image was acquired. This view has close to the smallest pixel size possible in the current LRO orbit. In the future however, LROC will continue to image the site as the lighting changes and the rover roves!

These future LRO images will allow us to track Yutu-2 and get an idea of its research, even if the Chinese do not release any information.

Leave a comment

Recent Cuba meteorite estimated to have weighed about 360 tons

1:36 pm

Using its imaged track from several sources, scientists have now estimated the size and weight of the recent spectacular fireball over Cuba as being several meters across and weighing about 360 tons.

After reconstructing the trajectory in the atmosphere, the Colombian astronomers “played back” the impact and found that the culprit, a rock with an estimated size of several meters and a weight of about 360 tons, came from an eccentric orbit around the Sun with an average distance to our star of 1.3 astronomical units (1 astronomical-unit = 150 million km). Before impacting the Earth, the rock completed a turn around the Sun every 1.32 years. All that came to an end on February 1, 2019 when both, the rock and the Earth, found themselves at the same point in space, at the same time. The worse part was for the rock!

The article spends most of its time selling a computer model the scientists have developed that they claim can predict the approach trajectory of meteorites, something I find quite unconvincing. However, the result above is important for different reasons. Routinely astronomers today discover new small asteroids just days before they zoom harmlessly past the Earth. Each time one of these new near Earth asteroids is found, the press automatically goes into “Chicken Little mode,” suggesting that should this object have hit the Earth it would have caused massive damage.

Most of these newly discovered asteroids are about the same size as the Cuba meteorite, if not smaller. Thus, this meteorite gives us a clear idea of how completely harmless these other near Earth asteroids are. In fact, this impact suggests to me that in most cases an asteroid would have to be about ten times larger to pose a significant threat.

Keep this number — 360 tons — in mind the next time another near Earth asteroid is discovered.

4 comments

NASA about to pull plug on Opportunity

4:58 pm

Rumors today say that during a press conference tomorrow NASA will announce that it is closing the books on the incredibly successful rover Opportunity.

From the first link:

NASA said Tuesday it will issue a final series of recovery commands, on top of more than 1,000 already sent. If there’s no response by Wednesday — which NASA suspects will be the case — Opportunity will be declared dead, 15 years after arriving at the red planet.

Opportunity was supposed to last 90 days. Instead, it lasted just under fifteen years, drove 28 miles, and saw far more of the Martian surface than anyone ever expected.

It now sits inside the rim of fourteen-mile Endeavour Crater, waiting for those first explorers to come and get it. I wonder when that will be.

One comment

Strange crescent-shaped pit near Martian south pole

2:19 pm

crescent-shaped pit near Martian south pole

Cool image time! The south polar cap of Mars is a strange place. It is largely ice, with a seasonal cap of frozen carbon dioxide, or dry ice. Because the dry ice sublimates away during the summer months, the cap undergoes regular changes that reshape it, producing alien features that are not seen on Earth.

The image on the right is another example of these alien features. I found it in the February image release from the high resolution camera on Mars Reconnaissance Orbiter. I have merely cropped the full image to focus at full resolution on its primary feature, a region of stippled-like surface surrounding an area of black striping that in turn surrounds a crescent-shaped pit outlined by whiter material.

Why is there a pit here? Why is it crescent-shaped? Why is it surrounded by that whiter material? I could guess and say that the pit is a vent from which water vapor from the lower cap of water sprays out onto the upper cap of frozen carbon dioxide, staining it with white ice, but I am most likely wrong.

Moreover, what causes the black striping, as well as the stippled material surrounding it? The black stripes are probably related to a similar process that forms the spider formations found in the polar regions, except that these are not spiders. Why the parallel straight lines?

A lot of questions with no answers. While many features on Mars are strange, the features near the poles are probably stranger still, as they form in a place with chemistry, temperatures, gravity, and materials in a combination and scale that we on Earth have no experience with.

3 comments

Is a region in France the origin of Europe’s ancient standing stones?

9:48 am

The uncertainty of science: New research suggests that the European ancient standing stones, such as Stonehenge, might all trace their origin from a region in France.

The very earliest megaliths, she found, come from northwestern France, including the famous Carnac stones, a dense collection of rows of standing stones, mounds, and covered stone tombs called dolmens. These date to about 4700 B.C.E., when the region was inhabited by hunter-gatherers. Engravings on standing stones from the region depict sperm whales and other sea life, which suggests the precocious masons may also have been mariners, Schulz Paulsson says.

Northwestern France is also the only megalithic region that also features gravesites with complex earthen tombs that date to about 5000 B.C.E., which she says is evidence of an “evolution of megaliths” in the region. That means megalith building likely originated there and spread outward, she reports today in the Proceedings of the National Academy of Sciences.

By about 4300 B.C.E., megaliths had spread to coastal sites in southern France, the Mediterranean, and on the Atlantic coast of the Iberian Peninsula. Over the next few thousand years, the structures continued to pop up around Europe’s coasts in three distinct phases. Stonehenge is thought to have been erected around 2400 B.C.E., but other megaliths in the British Isles go back to about 4000 B.C.E. The abrupt emergence of specific megalithic styles like narrow stone-lined tombs at coastal sites, but rarely inland, suggests these ideas were being spread by prehistoric sailors. If so, it would push back the emergence of advanced seafaring in Europe by about 2000 years, Schulz Paulsson says.

What this research also suggests is that the belief system that prompted the construction of these megaliths also spread in this manner, and for a while at least dominated the early tribal cultures of Europe.

2 comments

A second Greenland crater discovered?

11:04 am

Scientists are now claiming they have found a second crater buried under Greenland’s icecap.

To confirm his suspicion about the possible presence of a second impact crater, MacGregor studied the raw radar images that are used to map the topography of the bedrock beneath the ice, including those collected by NASA’s Operation IceBridge. What he saw under the ice were several distinctive features of a complex impact crater: a flat, bowl-shaped depression in the bedrock that was surrounded by an elevated rim and centrally located peaks, which form when the crater floor equilibrates post-impact. Though the structure isn’t as clearly circular as the Hiawatha crater, MacGregor estimated the second crater’s diameter at 22.7 miles. Measurements from Operation IceBridge also revealed a negative gravity anomaly over the area, which is characteristic of impact craters.

“The only other circular structure that might approach this size would be a collapsed volcanic caldera,” MacGregor said. “But the areas of known volcanic activity in Greenland are several hundred miles away. Also, a volcano should have a clear positive magnetic anomaly, and we don’t see that at all.”

It must be emphasized that this conclusion remains very uncertain. What they have found is a depression that has features indicative of an impact crater, data that is far from sufficient to definitively prove the crater is real.

Leave a comment

LRO spots Chinese lunar rover

10:31 am

Yutu-2 and Chang'e-4 on far side of Moon

The Lunar Reconnaissance Orbiter (LRO) science team has now released a second and closer image of Chang’e-4’s location on the far side of the Moon, which now also shows the nearby rover Yutu-2.

The two arrows in the image to the right, cropped to post here, show both. The rover is the dot on the right, with the lander to the left, both just beyond the arrow tips. Both are very small, with Yutu-2 for example only two pixels across. Still, with both you can see their shadows, equally small, to the left of both bright dots. With sunlight coming from the right, all the craters, which are recessed, have their shadows on the right. The spacecraft, sticking up from the surface, have shadows going to the the left.

As Yutu-2 continues its travels, LRO will likely take more images, allowing us to track it even if the Chinese provide limited information.

One comment

New Horizons’ farewell image of Ultima Thule

4:34 pm

Ultima Thule's shape

The New Horizons science team has released the last sequence of images taken by the spacecraft as flew away after its flyby.

The link has a nice video of that sequence. However, it is the information gleaned from this sequence that is most interesting.

The newly released images also contain important scientific information about the shape of Ultima Thule, which is turning out to be one of the major discoveries from the flyby.

The first close-up images of Ultima Thule – with its two distinct and, apparently, spherical segments – had observers calling it a “snowman.” However, more analysis of approach images and these new departure images have changed that view, in part by revealing an outline of the portion of the KBO that was not illuminated by the Sun, but could be “traced out” as it blocked the view to background stars.

Stringing 14 of these images into a short departure movie, New Horizons scientists can confirm that the two sections (or “lobes”) of Ultima Thule are not spherical. The larger lobe, nicknamed “Ultima,” more closely resembles a giant pancake and the smaller lobe, nicknamed “Thule,” is shaped like a dented walnut.

The image on the right shows their preliminary guess at Ultima Thule’s overall shape, as suggested by these new images.

The spacecraft has still not sent back the images it took during its closest approach, so there are likely more surprises coming.

15 comments

Mysterious dark-toned Martian terrain

12:37 pm

Dark toned ridge in Martian southern highlands
Click for full resolution image

Cool image time! The picture on the right, cropped and reduced to post here, was part of the January image release from the high resolution camera of Mars Reconnaissance Orbiter (MRO). It shows an area in the Martian southern highlands where the surface suddenly gets darker, for no obvious reason.

The uncaptioned release image is titled “Dark-Toned Ridge at Junction with Dark-Toned Plain.” From the image itself it is hard to understand this title. In the full image the darkest terrain is a strip in the center, with slightly lighter dark terrain on either side, and the lightest terrain to the north or south. The photograph however does not show us how far this dark terrain extends to the west or east.

Two Mars Odyssey image strips of less resolution, here and here, show that this region is filled with several large patches of dark-tone surface. With this particular patch the center dark ridge is surrounded by that slightly lighter dark area.

MRO itself has not taken many images of this region, as shown in the overview image below. The red rectangles indicate MRO’s high resolution photographs, with this image indicated by the cross. At this low resolution this region seems somewhat nondescript. The Mars Odyssey image strips show that there many features here, but with little significant relief.

Location of dark toned ridge

At high resolution there does not appear to be much difference between the darker and lighter areas. The lighter areas in general seem less rough and at a slightly lower elevation, but both areas are dominated by ridges and dunes trending southwest-to-northeast.

Why is this slightly higher region darker? Let’s assume that this darker material was a lava flow overlaying the surface. Over eons wind erosion, trending southwest-to-northwest, roughly eroded both it and the lower layers around it, leaving behind this rough corroded terrain. The different make-up of the darker material allows it to erode in a rougher manner.

While possibly correct, I would not bet much money on this guess. It is not clear it is lava. It is not clear that it is a flow. It does not explain why there are two areas of different darkness. And it certainly not clear what the make-up of any of this stuff is.

This is simply another cool mystery on the Martian surface.

One comment

Rare asteroid orbiting near Venus discovered

11:51 am

The Zwicky Transient Facility (ZTF), a new sky survey telescope whose main goal is to find Near Earth asteroids, has discovered a rare asteroid orbiting near Venus.

A state-of-the-art sky-surveying camera, the Zwicky Transient Facility, or ZTF, detected the asteroid on January 4, 2019. Designated 2019 AQ3, the object has the shortest “year” of any recorded asteroid, with an orbital period of just 165 days. It also appears to be an unusually big asteroidal specimen. “We have found an extraordinary object whose orbit barely strays beyond Venus’ orbit—that’s a big deal,” said Quanzhi Ye, a postdoctoral scholar at IPAC, a data and science center for astronomy at Caltech. Ye called 2019 AQ3 a “very rare species,” further noting that “there might be many more undiscovered asteroids out there like it.”

…The orbit, as it turns out, is angled vertically, taking 2019 AQ3 above and below the plane where the planets run their laps around the sun. Over its short year, 2019 AQ3 plunges inside of Mercury, then swings back up just outside of Venus’ orbit.

The telescope, in operation since March 2018, and so far found

nearly 60 new near-Earth asteroids. Two of these were spotted in July 2018 mere hours before they gave Earth quite a close shave. Designated 2018 NW and 2018 NX, the duo of bus-sized asteroids whipped past at a distance of about 70,000 miles, or only a third of the way to the moon. Fortunately, the newfound 2019 AQ3 poses no threat; the closest it ever comes to Earth is about 22 million miles.

One comment

New Hubble images of Uranus and Neptune

9:28 am

Uranus (top) and Neptune

The Hubble Space Telescope’s new annual images of Uranus (top) and Neptune (bottom) has revealed new atmospheric features for both, a giant north pole cloud cap on Uranus and a new dark storm developing on Neptune.

For Neptune:

The new Hubble view of Neptune shows the dark storm, seen at top center. Appearing during the planet’s southern summer, the feature is the fourth and latest mysterious dark vortex captured by Hubble since 1993. Two other dark storms were discovered by the Voyager 2 spacecraft in 1989 as it flew by the remote planet. Since then, only Hubble has had the sensitivity in blue light to track these elusive features, which have appeared and faded quickly. A study led by University of California, Berkeley, undergraduate student Andrew Hsu estimated that the dark spots appear every four to six years at different latitudes and disappear after about two years.

Hubble uncovered the latest storm in September 2018 in Neptune’s northern hemisphere. The feature is roughly 6,800 miles across.

For Uranus:

The snapshot of Uranus, like the image of Neptune, reveals a dominant feature: a vast bright cloud cap across the north pole.

Scientists believe this feature is a result of Uranus’ unique rotation. Unlike every other planet in the solar system, Uranus is tipped over almost onto its side. Because of this extreme tilt, during the planet’s summer the Sun shines almost directly onto the north pole and never sets. Uranus is now approaching the middle of its summer season, and the polar-cap region is becoming more prominent. This polar hood may have formed by seasonal changes in atmospheric flow.

The images are part of an annual program that monitors both planets with images every year when the Earth is best placed to view them. This allows scientists to track atmospheric changes over time.

The sharpness of both images matches that of previous Hubble images, so these photographs do not show any decline in the telescope’s image capability. However, when they lose that next gyroscope and shift to one gyroscope mode, I believe it will be very difficult to get images even this sharp of the outer planets. In fact, I suspect this monitoring program will likely have to end, or will be badly crippled.

One comment

UK names rover for 2020 ExMars mission

9:01 am

The United Kingdom has named its rover for 2020 ExMars mission in honor of Rosalind Franklin, one of the scientists who contributed to the discovery of the helix structure of DNA.

Franklin is best known for her work on the X-ray diffraction images of DNA. Her data was a part of the data used to formulate Crick and Watson’s 1953 hypothesis regarding the structure of DNA. Unpublished drafts of her papers show that she had determined the overall B-form of the DNA helix. Her work supported the hypothesis of Watson and Crick and was published third in the series of three DNA Nature articles. After finishing her portion of the DNA work, Franklin led pioneering work on the tobacco mosaic and polio viruses. Franklin died from ovarian cancer at the age of 37, four years before Crick, Watson and Wilkins were awarded the Nobel Prize in 1962 for their work on DNA.

Though this isn’t entire clear from the press release, it appears that they will refer to the rover as either “Rosalind Franklin” or “Rosalind.”

One comment

Sunspot update January 2019: The early solar minimum

3:50 pm

As I have done every month since 2011, I am now posting NOAA’s the monthly update of the solar cycle, covering sunspot activity for January 2019. They posted this update on Monday, and I am posting it below, annotated to give it some context.

January 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

January saw a slight uptick in sunspot activity, but the overall activity remains comparable to mid-2008, when the last prolonged solar minimum began. If you go to my October 2018 update, you can see the graph when it included data going back to 2000 and see the entire last minimum.

That last minimum started in the last half of 2007, and lasted until mid-2009, a full two years. If you look at the red line prediction of the solar science community, it appears that they are expecting this coming minimum to last far longer, almost forever. I expect this is not really true, but that they have simply not agreed on a prediction for the next cycle. Some in that solar science community have hypothesized that we are about to enter a grand minimum, with no sunspots for decades and thus no solar maximum. Others do not agree.

Since neither faction really understands the mechanism that causes these sunspot cycles, there is no way now to determine what will happen, until it does so. What we do know from climate data is that the Earth cools when the Sun is inactive. Why remains unclear, though there is at least one theory, with some evidence, that attempts to explain it.

And despite the untrustworthy claims of NOAA and NASA scientists that the last few years have been hot, experience on the ground disputes this. Their data has been adjusted (tampered if one wants to be more blunt) to make it fit their global warming theory. The raw unadjusted data suggests things have instead cooled, which better fits with the brutal winters Americans experienced for the past decade or so.

If the Sun does enter a grand minimum in the coming decades, I suspect it will become increasingly difficult for NOAA and NASA to continue their temperature adjustments and continue claiming things are getting warmer. At a minimum, we will learn something about the Sun and its behavior and its influence on the climate that we never knew before.

6 comments

Hayabusa-2 to attempt asteroid landing on February 22

9:50 am

JAXA, Japan’s space agency, today announced that Hayabusa-2 will attempt a landing on the asteroid Ryugu on February 22.

The landing was delayed from October because of the unexpected roughness of Ryugu’s surface, which literally has no spot smooth enough and large enough for Hayabusa-2, as planned. This landing will therefore be attempted in one of two places that are almost large enough, but not quite. It thus carries some additional risks.

Leave a comment

Chinese cubesat snaps picture of Earth and Moon from deep space

9:21 am

The Moon and Earth

A interplanetary cubesat, Longjiang-2, launched with China’s communications relay satellite that they are using to communicate with Chang’e-4 and Yutu-2 on the far side of the Moon, has successfully taken a picture of both the Moon and Earth, as shown in the picture on the right.

Longjiang-2 is confirming what the MarCo cubesats proved from Mars, that cubesats can do interplanetary work.

And the picture is cool also. This was taken on February 3, when the entire face of the Moon’s far side is facing the Sun, illuminating it all. This timing also meant that the globe of the Earth would be entirely lit.

2 comments

MarCO interplanetary cubesats likely dead

2:29 pm

More than two months after they provided relay communications for the landing of InSight on Mars, and more than a month since any contact has been heard from them, engineers now consider the two MarCO cubesats to likely be dead.

Now well past Mars, the daring twins seem to have reached their limit. It’s been over a month since engineers have heard from MarCO, which followed NASA’s InSight to the Red Planet. At this time, the mission team considers it unlikely they’ll be heard from again.

MarCO, short for Mars Cube One, was the first interplanetary mission to use a class of mini-spacecraft called CubeSats. The MarCOs – nicknamed EVE and WALL-E, after characters from a Pixar film – served as communications relays during InSight’s landing, beaming back data at each stage of its descent to the Martian surface in near-real time, along with InSight’s first image. WALL-E sent back stunning images of Mars as well, while EVE performed some simple radio science.

All of this was achieved with experimental technology that cost a fraction of what most space missions do: $18.5 million provided by NASA’s Jet Propulsion Laboratory in Pasadena, California, which built the CubeSats.

WALL-E was last heard from on Dec. 29; EVE, on Jan. 4. Based on trajectory calculations, WALL-E is currently more than 1 million miles (1.6 million kilometers) past Mars; EVE is farther, almost 2 million miles (3.2 million kilometers) past Mars.

Their loss of contact more than a month after the November landing of InSight actually shows their incredible success. Both MarCO cubesats functions well past Mars, demonstrating that these tiny satellites can do much of the same things bigger satellites costing billions do.

One comment

The location for a future Martian colony?

2:03 pm

Pit draining into Kasei Valles

Regular readers of this webpage will know that I am a caver, and am fascinated with the pits and caves that have so far been identified on Mars, as illustrated by an essay I wrote only last week.

Some of the cave research I have cited has being led by planetary scientist Glen Cushing of the U.S. Geological Survey. Two weeks ago Dr. Cushing sent me a slew of pictures of caves/pits that he has accumulated over the years, many of which he has not yet been able to highlight in a paper. At least two were images that I had already featured on Behind the Black, here and here.

One pit image however I had never seen. A cropped and reduced close-up is shown on the right, with the full photograph viewable by clicking on the image. In many ways this pit is reminiscent of many pits on Mars. Its northern rim appears to be an overhang several hundred feet deep that might have an underground passage continuing to the north. The southern lip is inviting in that its slope appears to be very accessible for vehicles, meaning this pit/cave might be a good location to build a first colony.

Because of that accessible southern lip, I decided to do more digging about this particular pit. I was quickly able to find the uncaptioned release of the complete image by doing a quick search through the image catalog of Mars Reconnaissance Orbiter’s (MRO) high resolution camera. That image, reduced and cropped to post here, is shown below, on the right.
» Read more

4 comments

The Milky Way is warped?

8:39 am

The uncertainty of science: Distance data of more than 1,300 Cepheid variable stars gathered by the Wide-field Infrared Explorer (WISE) space telescope now suggests to astronomers that the disk of the Milky Way galaxy is warped.

Trying to determine the real shape of our galaxy is like standing in a Sydney garden and trying to determine the shape of Australia. But, for the past 50 years there have been indications that the hydrogen clouds in the Milky Way are warped. The new map shows that the warped Milky Way disc also contains young stars. It confirms that the warped spiral pattern is caused by torque from the spinning of the Milky Way’s massive inner disc of stars.

This research is good and helpful in getting us closer to a real picture of our Milky Way galaxy. However, need I say that this result carries with it a great deal of uncertainty? Or should I let my kind readers outline for me the many aspects of this research that leave me with doubts?

I think I want to do the latter. Where do you think the uncertainties are in this research? What assumptions are they making? Where is their data sparse or weak? Feel free to list them in the comments.

5 comments

Strange fernlike ridges on Mars

1:44 pm

Fernlike ridges on Mars

Cool image time! The two images on the right, cropped, rotated, and reduced in resolution to post here, were both taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO). To see the full resolution version of each, go to the 2009 and 2018 releases.

The 2009 release was a captioned release, whereby scientist Alfred McEwen of the science team provided his explanation of these strange features.

The dark branched features in the floor of Antoniadi Crater look like giant ferns, or fern casts. However, these ferns would be several miles in size and are composed of rough rocky materials.

A more likely hypothesis is that this represents a channel network that now stands in inverted relief. The channels may have been lined or filled by indurated materials, making the channel fill more resistant to erosion by the wind than surrounding materials. After probably billions of years of wind erosion the resistant channels are now relatively high-standing. The material between the branched ridges has a fracture pattern and color similar to deposits elsewhere on Mars that are known to be rich in hydrated minerals such as clays.

These strange fernlike features do not appear to be very common on Mars. In fact, I suspect that while Mars does have many inverted channels like this, the fernlike nature of these particular channels is unique on Mars. They are located on the floor of Antoniadi Crater, a large 240-mile-wide very ancient and eroded crater located in the Martian southern highlands but near the edge down to the northern lowlands.

In seeing the new 2018 image, I was immediately compelled to place it side by side with 2009 image to see if anything had changed in the ensuring near-decade. There are color differences, but I suspect these are mostly caused by different lighting conditions or post-processing differences. Still, the dark center to the crater in the upper left of both images suggests a change in the dust dunes there, with the possibility that some of the dust has been blown from the crater over time. Also, you can see two horizontal tracks cutting across the center of the 2018 image, which I would guess are dust devil tracks, with one more pronounced.

I can imagine some planetary geologists have spent the last few months, since the second image was taken, pouring over both photographs, and have might even located other interesting changes. And if they find no significant changes, that in itself is revealing, as it gives us a sense of the pace at which the Martian surfaces evolves.

3 comments

InSight’s seismometer now fully operational

1:06 pm

The InSight science team has completed the deployment of the spacecraft’s seismometer by the placement of its protective domed shield over it.

The Wind and Thermal Shield helps protect the supersensitive instrument from being shaken by passing winds, which can add “noise” to its data. The dome’s aerodynamic shape causes the wind to press it toward the planet’s surface, ensuring it won’t flip over. A skirt made of chain mail and thermal blankets rings the bottom, allowing it to settle easily over any rocks, though there are few at InSight’s location.

The shield also helps protect the instrument from temperature changes.

With this deployment completed they will next deploy the heat flow package to the surface, where it will begin to drill its probe sixteen feet into the ground.

Leave a comment

ULA gets launch contract for Lucy asteroid mission

10:21 am

Capitalism in space: NASA has awarded ULA a $145 million contract to launch the Lucy asteroid mission on its Atlas 5 rocket.

The price is high for such a launch in today’s market, and is even higher than the cost of some recent military launches, which routinely tack on extra requirements that cause the price to rise. I wonder why. Is it because NASA doesn’t care how much it spends? Or is there a political component here, providing a contract to a company that is having trouble winning contracts in the private sector because their price is too high?

It could be that the mission requires things from the launch that add to the cost. The press release mentions that it “includes the launch service and other mission related costs” but does not specify what they are.

One comment

The base of Mt Sharp is less compacted than expected

2:06 pm

The uncertainty of science: Using data from Curiosity in Gale Crater on Mars, scientists have found that the material making up the lower layers of Mount Sharp is less compacted that they would have expected.

Scientists still aren’t sure how this mountain grew inside of the crater, which has been a longstanding mystery.

One idea is that sediment once filled Gale Crater and was then worn away by millions of years of wind and erosion, excavating the mountain. However, if the crater had been filled to the brim, the material on the bottom, which now makes up the crater’s surface, would have been pressed down. But the new Science paper suggests Mount Sharp’s lower layers have much less compacted than this theory predicts, reigniting the debate about how full the crater once was.

“The lower levels of Mount Sharp are surprisingly porous,” said lead author Kevin Lewis of Johns Hopkins University. “We know the bottom layers of the mountain were buried over time. That compacts them, making them denser. But this finding suggests they weren’t buried by as much material as we thought.”

I can’t help wonder whether we don’t yet really understand the influence of Mars’ lower gravity on geology, and that might explain the porosity.

One comment

China’s unsupervised radio antenna in Argentina

12:01 pm

A Chinese invasion? A Chinese radio antenna in Argentina, initially proposed as a communications facility for use with China’s space program, operates without any supervision by the Argentinian government and appears to have military links.

Though U.S. government officials are pushing the idea that this facility is being used by China to eavesdrop on foreign satellites, and though China’s space program is without doubt a major arm of its military, I doubt the radio antenna is being put to military use. As the story notes

Tony Beasley, director of the U.S. National Radio Astronomy Observatory, said the station could, in theory, “listen” to other governments’ satellites, potentially picking up sensitive data. But that kind of listening could be done with far less sophisticated equipment. “Anyone can do that. I can do that with a dish in my back yard, basically,” Beasley said. “I don’t know that there’s anything particularly sinister or troubling about any part of China’s space radio network in Argentina.”

It was installed to support China’s effort to send spacecraft to the Moon and Mars, and that is likely its main purpose. China does not wish to be dependent on the U.S.’s Deep Space Network for such interplanetary communications. This facility helps make that independence possible.

At the same time, the fact that China has been allowed to establish a remote facility in another country and operate it with no oversight is definitely an issue of concern. Essentially, China has obtained control over a piece of Argentinian territory, and unless the Argentine government takes action, China can do whatever it wants there. While the antenna itself might not be an issue, the facility itself is.

Leave a comment

Measles makes a comeback in the liberal and anti-vaccine northwest

10:51 am

The coming dark age: An outbreak of measles has infected forty people in the Portland region, known for its strong anti-vaccine movement.

In Clark County, 27 of the confirmed cases have been among children 10 or younger, while just one patient was over 18. At least 34 patients were unvaccinated, while local health officials had not verified the immunization status of four patients.

Measles can linger in the air for up to two hours after an infected person has left the area, and the virus is so contagious that nearly everyone who isn’t immunized and is exposed to it will get sick.

The Portland area is known as an anti-vaccination hot spot, and state data show only about 77 percent of Clark County kindergarteners had completed their vaccinations for the 2017-2018 school year, far below the roughly 95 percent of people that health experts say should be vaccinated to create “herd immunity” against a contagious disease like measles.

“It’s pretty simple: You prevent measles outbreak by getting the measles vaccine,” Washington Secretary of Health John Wiesman said in a call with reporters Wednesday. The outbreak could last “weeks to months,” Wiesman said, and health officials expect to see more cases as measles continues to spread to other counties.

I must point out that, in general, the anti-vaccine movement is mainly linked to the liberal and leftist side of the political spectrum, and to my mind is only another indication of the left’s willingness to ignore facts in its loyalty to utopian fantasies. Because of the measles vaccine, measles vanished as a threat to children in the 1960s. It has now returned, and only because of a desire of some to ignore the facts. While there is always a very very tiny risk in taking the vaccine, the benefits so completely outweigh that risk that it makes no sense to refuse vaccination. Yet many in the liberal community do, and the result is that their children are now getting sick, and are posing a risk to others.

10 comments

The unfinished search for the Hubble constant

10:40 am

The uncertainty of science: Scientists continue to struggle in their still unfinished search for determining the precise expansion rate for the universe, dubbed the Hubble constant in honor of Edwin Hubble, who discovered that expansion.

The problem is, the values obtained from [two different] methods do not agree—a discrepancy cosmologists call “tension.” Calculations from redshift place the figure at about 73 (in units of kilometers per second per megaparsec); the CMB estimates are closer to 68. Most researchers first thought this divergence could be due to errors in measurements (known among astrophysicists as “systematics”). But despite years of investigation, scientists can find no source of error large enough to explain the gap.

I am especially amused by these numbers. Back in 1995 NASA had a big touted press conference to announce that new data from the Hubble Space Telescope had finally determined the exact number for the Hubble constant, 80 (using the standard above). The press went hog wild over this now “certain” conclusion, even though other astronomers disputed it, and offered lower numbers ranging from 30 to 65. Astronomer Allan Sandage of the Carnegie Observatories was especially critical of NASA’s certainty, and was dully ignored by most of the press.

In writing my own article about this result, I was especially struck during my phone interview with Wendy Friedman, the lead scientist for Hubble’s results, by her own certainty. When I noted that her data was very slim, the measurements of only a few stars from one galaxy, she poo-pooed this point. Her result had settled the question!

I didn’t buy her certainty then, and in my article, for The Sciences and entitled most appropriately “The Hubble Inconstant”, made it a point to note Sandage’s doubts. In the end it turns out that Sandage’s proposed number then of between 53 and 65 was a better prediction.

Still, the science for the final number remains unsettled, with two methods coming up with numbers that are a little less than a ten percent different, and no clear explanation for that difference. Isn’t science wonderful?

One comment

Parker begins second orbit around Sun

8:43 am

The Parker Solar Probe has completed its first full orbit of the Sun and has begun full science operations.

On Jan. 19, 2019, just 161 days after its launch from Cape Canaveral Air Force Station in Florida, NASA’s Parker Solar Probe completed its first orbit of the Sun, reaching the point in its orbit farthest from our star, called aphelion. The spacecraft has now begun the second of 24 planned orbits, on track for its second perihelion, or closest approach to the Sun, on April 4, 2019.

Parker Solar Probe entered full operational status (known as Phase E) on Jan. 1, with all systems online and operating as designed. The spacecraft has been delivering data from its instruments to Earth via the Deep Space Network, and to date more than 17 gigabits of science data has been downloaded. The full dataset from the first orbit will be downloaded by April.

They have been somewhat tight-lipped about any results from the data already obtained. I suspect it has not yet been analyzed fully, and the scientists are reserving comment until they complete their first science papers and get them published.

Leave a comment
1 … 110 111 112 113 114 … 271