Tag: science

The Taurus-Littrow valley

6:01 pm

Taurus-Littrow Valley
Click for full image.

It might not be Apollo 11, but during this 50th anniversary week of that mission, why not look at where the last Apollo 17 crew landed, in the middle of the Taurus-Littrow valley, as shown on the right in a Lunar Reconnaissance Orbiter (LR) image released by the LRO science team in 2018.

The image illustrates how ambitious NASA had become by this last Apollo mission. The Apollo 11 site was chosen because it was flat with as few risks as possible. By Apollo 17, the Apollo engineers and astronauts were quite willing to drop the LM down into this valley between gigantic mountains. Granted, the valley was more than 400 miles wide, but considering the risks of every Apollo flight, the choice was daring to say the least.

Taurus-Littrow also has a cluster of craters believed to have been formed by material flung out from the formation of 86-kilometer-wide Tycho crater about 100 million years ago. Tycho is 2250 kilometers from Taurus-Littrow, but the impact that formed it was violent enough that it cast material far across the Moon.

Nor is this location the most spectacular on the Moon. In fact, considering that all the manned and unmanned missions in total have probably covered less ground than a New York cab driver does in a single day, we have seen almost nothing there.

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A wave on the Moon

3:01 pm

A lunar ejector blanket

Continuing this week’s celebration of the 50th anniversary of the Apollo 11 mission means we get to look at another cool image from the Moon. The photograph on the right, reduced to post here, was released by the Lunar Reconnaissance Orbiter (LRO) science team in 2016.

What are we looking at? At first glance it looks like a black & white photograph of The Wave in northern Arizona. What it is instead is the pattern of ejecta laid down across the surrounding terrain immediately after the impact that created relatively fresh Chaplygin Crater. From the website:

The delicate patterns of flow across, over, and down local topography clearly show that ejecta traveled as a ground hugging flow for great distances, rather than simply being tossed out on a ballistic trajectory. Very near the rim lies a dark, lacy, discontinuous crust of now frozen impact melt. Clearly this dark material is on top of the bright material so it was the very last material ejected from the crater.

Below the fold is a wider shot of the entire crater and its surrounding terrain, with the rectangle indicating the region covered by the close-up above The dark crust near the rim mentioned in the quote can clearly be seen.
» Read more

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Weird lunar crater

2:58 pm

Concentric crater in Apollo Basin on the Moon

In celebration of the 50th anniversary of the Apollo 11 mission, it is time for another cool image from the Moon. The photograph on the right, reduced to post here, was taken by Lunar Reconnaissance Orbiter (LRO) in 2013. It shows a weird crater with concentric features that is found within Apollo Basin, a large 334-mile-wide double-ringed impact feature in the southern hemisphere of the Moon’s far side.

Concentric craters have an inner rim whose formation mechanism is not yet entirely understood, but the concentric mounds may indicate that there is a discontinuity, such as layers with different strengths, in the subsurface excavated by the impact.

Or to put it more bluntly, they really have no idea why this crater ended up looking as it does.

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Apollo 11 First Stage liftoff

6:01 pm

An evening pause: This was originally posted as an evening pause in 2016. I think that today, the fiftieth anniversary of the launch of Apollo 11, it is appropriate to repost it. As I wrote then,

Though the video is more than 8 minutes long, the actual events recorded lasted only about 30 seconds, beginning 5 seconds before T minus 0.

What struck me most as I watched this was the incredible amount of complex engineering that went into every single small detail of the rocket and the launch tower and launchpad. We tend to take for granted the difficulty of rocket engineering. This video will make you appreciate it again.

It is also mesmerizing. A lot happens in a very short period of time.

Tonight’s evening pause begins eight days of pauses dedicated to celebrating, and reliving, the Apollo 11 mission. To the Moon!

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A lunar crater wall two miles high

11:06 am

Giordano Bruno crater

Cool image time! Considering this week is the 50th anniversary of the Apollo 11 lunar landing, it seems appropriate to show some cool images from the Moon.

Today the Lunar Reconnaissance Orbiter (LRO) science team released a spectacular oblique image of Giordano Bruno crater. The image on the right is cropped and very significantly reduced to post here. It looks across the crater, with the near rim across the bottom of the picture and the wall of the far rim filling the photograph’s top half.

That wall is what makes this image cool. It is a cliff about 10,000 feet high, equaling almost two miles. Moreover, at its base is a now-solidified melt pool left over from the impact that made the crater.

Faster than a speeding bullet – or rather ten times faster than a speeding bullet – is a good starting point in terms of grasping the energy released in a typical impact event. That is, for a bullet approaching 2 kilometers in diameter! The pressure and heat that were released during the collision not only excavated a hole much larger than the impactor but also melted a tremendous amount the target rock. Melt was sprayed and sloshed on the forming crater walls where much of it flowed back, seeking the lowest point in the impact crater. From the LROC vantage point you can follow the path taken by impact melt as it flowed across the irregular floor, ponding in closed depressions, and some of it ultimately reaching the lowest point.

Below the fold is a much higher resolution section of this photograph, focused on the crater wall and the melt pool. I have still been forced to reduce the resolution somewhat to post it here. Along that cliff wall can be seen partial avalanches (the dark splotch near the center) as well boulder tracks with the boulders (probably larger than most houses) still visible as white spots at the wall’s base.

The scale here is difficult to imagine. This cliff wall is three times as high as The Abyss, the steepest single drop viewpoint along the south rim of the Grand Canyon.
» Read more

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Chandrayaan-2 launch scrub caused by leak in helium bottle

8:50 am

Engineers today announced that the July 14 scrub of India’s Chandrayaan-2 lunar orbiter/lander/rover was caused by a leak in a helium bottle in the GSLV rocket.

“The good news is that we can fix the leak without dismantling the rocket, since there is an access door to the gas bottle which is atop the oxygen tank,” a senior scientist told TOI. “The bad news is that unless we ascertain the reason for the leak, there is a probability of the problem recurring.” Not having to dismantle means Chandrayaan-2 may be able to fly before the end of the July launch window, but a final failure analysis will be available only in a day or two.

Sources told TOI that the leak wasn’t serious enough to impair the flight, but Isro decided to apply “abundant caution,” given the importance of the Rs 978-crore project that would make India only the fourth country – after the US, Russia and China – to land a craft on the lunar surface.

I am willing to bet that if their investigation does not pinpoint the cause of the leak in the next few days, they will stand down from the July launch window. This mission, as well as proving the reliability of their GSLV rocket, are both too important to risk on an unknown and unsolved engineering issue.

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Hayabusa-2: Carbon-rich asteroids too delicate to reach Earth surface

1:57 pm

New data from Hayabusa-2 has confirmed the long-held suspicions of astronomers that the reason they find so few fragments of C-class asteroids, such as Ryugu, on Earth is because they are too delicate to reach the Earth’s surface.

Ryugu and other asteroids of the common ‘C-class’ [chondritic] consist of more porous material than was previously thought. Small fragments of their material are therefore too fragile to survive entry into the atmosphere in the event of a collision with Earth.

…Until now, only a few chondritic meteorites found on Earth have been identified as fragments of C-type asteroids, which are very common in the Solar System (‘C’ is the chemical symbol for the element carbon). …”We can now confirm that fragments of these asteroids are very likely to break up further when they enter Earth’s atmosphere, and then usually burn up completely. This means that only the largest fragments reach the Earth’s surface,” explains Grott. “That is why meteorites from this type of asteroid are so rarely found on Earth.”

The good news is that, because of this, Earth’s atmosphere offers increased protection from C-type asteroids, which account for 75 percent of all asteroids. …However, further research is necessary to determine the maximum asteroid size for which this atmospheric protection is effective.

It is likely that even the largest rubble-pile C-asteroids will not pose much risk. Even if some pieces reach the Earth’s surface they are probably going to be small and unable to do much harm.

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Two new science papers strongly question theory of man-made global warming

9:48 pm

The uncertainty of science: Two new science papers, from researchers in Finland and Japan respectively, both strongly question the theory that human activity and the increase of carbon dioxide are causing global warming.

From the Finnish paper’s [pdf] conclusion:

We have proven that the [climate]-models used in IPCC report AR5 cannot compute correctly the natural component included in the observed global temperature. The reason is that the models fail to derive the influences of low cloud cover fraction on the global temperature. A too small natural component results in a too large portion for the contribution of the greenhouse gases like carbon dioxide. That is why 6 J. KAUPPINEN AND P. MALMI IPCC represents the climate sensitivity more than one order of magnitude larger than our sensitivity 0.24°C. Because the anthropogenic portion in the increased CO2 is less than 10 %, we have practically no anthropogenic climate change. The low clouds control mainly the global temperature. [emphasis mine]

From the Japanese paper:

“The Intergovernmental Panel on Climate Change (IPCC) has discussed the impact of cloud cover on climate in their evaluations, but this phenomenon has never been considered in climate predictions due to the insufficient physical understanding of it,” comments Professor Hyodo. “This study provides an opportunity to rethink the impact of clouds on climate. When galactic cosmic rays increase, so do low clouds, and when cosmic rays decrease clouds do as well, so climate warming may be caused by an opposite-umbrella effect. The umbrella effect caused by galactic cosmic rays is important when thinking about current global warming as well as the warm period of the medieval era.”

Essentially, both criticize the climate models for not considering changes in cloud cover and how those effect the global climate. The first paper looks back at the known climate data and compares it with known changes in cloud cover, and finds that cloud cover is a major factor in temperature changes.

The second paper looks at the causes for some of the changes in cloud cover, noting how the increase in galactic cosmic rays during the solar minimum can be tied to an increase in cloud cover, and thus colder temperatures.

Do these papers disprove man-made global warming caused by the increase in carbon dioxide in the atmosphere? Of course not. They just demonstrate again that the science here is very unsettled, that there are many large gaps in our knowledge, and that it would be foolish now to abandon western civilization and replace it with socialist totalitarian rule in order to prevent a disaster that either might not be happening, or if it is we may have no power to control.

I want to also point out that this post talks about scientists challenging the theory of man-made global warming. Attention must be paid to their conclusions. As for the ignorant opinions of politicians on this subject, who cares?

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Russia successfully launches Spektr-RG carrying two X-ray space telescopes

9:20 pm

Russia today successfully used its Proton rocket to launch Spektr-RG, carrying two X-ray space telescopes.

Spektr-RG was first conceived in the 1990s, but got shelved then because Russia did not have the money to launch it. The project got revived in 2005 when the Germans came on to build one of the two telescopes.

“We had an ambitious plan for the project which didn’t correspond to the power of the country of that moment,” [lead scientist Mikhail] Pavlinsky told Spaceflight Now. “We decided to restart it with a smaller version.”

The Russian and German space agencies signed an agreement in 2009 to jointly develop the Spektr-RG mission, but the project faced additional schedule delays due to technical problems and a decision to switch the observatory from a Zenit launcher to a Proton rocket.

Designers also changed Spektr-RG’s observing location from an orbit around Earth to a looping trajectory around the L2 Lagrange point.

Spektr-RG is the largest Russian astronomy satellite to launch since the Spektr-R radio observatory in 2011. Spektr-R stopped responding to commands from the ground in January after exceeding its planned five-year mission lifetime, and Russian officials declared the mission over in April.

Spektr-RG’s planned mission is set for seven years.

The leaders in the 2019 launch race:

9 China
8 SpaceX
8 Russia
5 Europe (Arianespace)

The U.S. continues to lead China in the national rankings 14 to 9.

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Mars Reconnaissance Orbiter image of Curiosity

1:01 pm

Curiosity as seen from orbit

The Mars Reconnaissance Orbiter (MRO) science team today released an image taken on May 31, 2019 by the orbiter’s HiRISE high resolution camera of Curiosity when it was nestled against the cliff at the bottom of Vera Rubin Ridge.

The image above is that enhanced color image, reduced and annotated to post here. I have added the track of Curiosity’s route down from Vera Rubin Ridge leading up to the point where this picture was snapped.

In the image, Curiosity appears as a bluish speck. Vera Rubin Ridge cuts across the scene north of the rover, while a dark patch of sand lies to the northeast.

Look carefully at the inset image, and you can make out what it is likely Curiosity’s “head,” technically known as the remote sensing mast. A bright spot appears in the upper-left corner of the rover. At the time this image was acquired, the rover was facing 65 degrees counterclockwise from north, which would put the mast in about the right location to produce this bright spot.

Mirror-like reflections off smooth surfaces show up as especially bright spots in HiRISE images. For the camera to see these reflections on the rover, the Sun and MRO need to be in just the right locations. This enhanced-color image of Curiosity shows three or four distinct bright spots that are likely such reflections.

From this location Curiosity first continued along the cliff’s base to study that dark patch of sand to the northeast, then it turned almost due south in order to get back to its nominal route into Gediz Valles canyon, as shown in my May 30, 2019 rover update.

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Hayabusa-2’s second touchdown an apparent success

9:16 am

Japan’s Hayabusa-2 probe has successfully completed its second touch-and-go sample grab on the asteroid Ryugu.

Japan’s Hayabusa2 successfully completed its second touchdown on the asteroid Ryugu and probably captured material from its interior that was exposed by firing a projectile into the asteroid earlier this year. It is the first collection of subsurface materials from a solar system body other than the moon.

Engineers and technicians in the spacecraft’s control room near Tokyo could be seen erupting into cheers and applause on a YouTube live stream when Project Manager Yuichi Tsuda proclaimed the operation a success just before 11 a.m. local time. At an afternoon press briefing, Tsuda said, “Everything went perfectly.” He joked that if a score of 100 indicated perfection, “I would give this a score of 1000.”

They will now begin the journey home, with the samples arriving on Earth in December 2020.

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TMT construction begins July 15

8:43 pm

According to a press announcement today from the governor’s office in Hawaii, construction of the Thirty Meter Telescope will finally begin during the week of July 15 following several years of delays due to protests.

The State Department of Transportation announced that Mauna Kea Access Road will be closed and there could be lane and other road closures associated with large equipment movement beginning July 15. In addition, hunting units A, K, and G in the Mauna Kea Forest Reserve area will be temporarily closed to hunting effective July 15. Both measures are being taken to ensure the safety and security of the public and personnel involved in moving equipment for the TMT project up the Mauna Kea Access Road.

Expect more protests. The real question is whether the Democratic governor David Ige can stand up to them, especially because these protesters have been using the kind of identity politics that the Democratic Party relies on. Ige would have to defy that, and I haven’t seen a Democrat do that in decades.

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Trump drops plan to establish independent climate review panel

2:37 pm

The Trump administration has abandoned a plan to create a more balanced climate science review panel to review the climate change claims within government research.

It appears that while the idea to put government-paid research under a wider range of scientific review was laudable, the White House could not figure out how to do it, even as factions within the administration fought the proposal.

The idea to create the panel has caused strife within the White House. Among its critics are deputy chief of staff Chris Liddell; Kevin Hassett, the outgoing chairman of the Council of Economic Advisers; Larry Kudlow, director of the National Economic Council; and Kelvin Droegemeier, the president’s science adviser. Those supporting the plan include Trump’s son-in-law and senior adviser Jared Kushner and Brooke Rollins, assistant to Trump in the Office of American Innovation.

An official at NSC disputed the characterization that the panel was dead, even while confirming that it had been indefinitely delayed. The plan has suffered several downgrades over the months. It was initially proposed as a rapid response team of climate science critics who would challenge government publications on human-caused warming. Recent discussions have centered on the idea of forcing government climate scientists to participate in a debate with critics of their work who deny that humans are causing widespread changes on Earth (Climatewire, June 6). Most recently, the plan was diminished to creating dueling white papers that would elevate climate denialism to the level of consensus science.

The bottom line remains that a lot of climate research being done on the government dime today is, at a minimum, very suspect, and at the worst, demonstrably corrupt. A house-cleaning is necessary, even though it will likely be accompanied by a lot of squealing from those who get cleaned out.

It seems that the Trump administration is not prepared to deal with that squealing, especially because it appears that Trump himself is not passionate about this subject. He went after EPA aggressively, cutting the size of the agency and changing how it did business, but these actions were because he saw EPA as an out-of-control government agency imposing inappropriate regulations on American citizens. Corruption and data tampering and the politicization of the climate research field does not concern him so much. It appears he does not see this as directly affecting the American citizen.

For now.

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Study says space radiation less of a risk

9:05 am

A newly released study now claims that, based on a long term review of astronauts who have spent a considerable time in space, it appears that space radiation does not cause an increase in cancer later in life.

The new study analyzed information from 418 space travelers, including 301 NASA astronauts who had traveled to space at least once since 1959, and 117 Russian or Soviet cosmonauts who had traveled to space at least once since 1961. These participants were followed for about 25 years, on average.

During this time, 89 of the participants died. Among the 53 NASA astronauts who died, 30% died from cancer and 15% from heart disease; while among the 36 Russian or Soviet cosmonauts who died, 50% died from heart disease and 28% from cancer.

The researchers used a special statistical technique to determine whether deaths from cancer and heart disease likely had a common cause — in this case, the common cause would be space radiation. But their results did not point to a common cause of death. “If ionizing radiation is impacting the risk of death due to cancer and cardiovascular disease, the effect is not dramatic,” the authors wrote in their study, published July 4 in the journal Scientific Reports.

This story first appeared about two weeks ago, but I didn’t think it significant, and still don’t. The sample is just not large enough to draw any solid conclusions. Moreover, this is exposure in low Earth orbit, not on interplanetary missions where the radiation risk is higher. It would be a big mistake for future space engineering to accept these findings blindly.

Still, news reports keep popping up about it, and I decided I should at least note it here on Behind the Black.

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Hayabusa-2 begins second touch&go sample grab on Ryugu

8:26 am

The Hayabusa-2 science team has begun the approach to Ryugu for the spacecraft’s second tough-and-go sample grab.

The link outlines the plan and timing of the operation. You can view real-time images taken by the probe’s navigation camera here. The actual touchdown will take place on July 11 (Japan time).

You can also view a set of stereoscopic images of Ryugu produced by Brian May, lead guitarist of Queen who clearly wants to return to his roots as a trained astrophysicist.

As they note at the first link:

The 2nd touchdown is the last big operation at Ryugu for the Hayabusa2 project. We will proceed with caution and the upmost care. Please wish us success…!

If successful, their next big operation will be getting those samples back to Earth.

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Faking gravity in space with a spinning table

2:38 pm

Researchers at the University of Colorado in Boulder are experimenting with the use of a rotating table to give space-farers short doses of artificial gravity in order to mitigate the negative consequences of weightlessness.

In a series of recent studies, the pair and their colleagues set out to investigate whether queasiness is really the price of admission for artificial gravity. In other words, could astronauts train their bodies to tolerate the strain that comes from being spun around in circles like hamsters in a wheel?

The team began by recruiting a group of volunteers and tested them on the centrifuge across 10 sessions.

But unlike most earlier studies, the CU Boulder researchers took things slow. They first spun their subjects at just one rotation per minute, and only increased the speed once each recruit was no longer experiencing the cross-coupled illusion. “I present at a conference and everyone says, ‘she’s the one who spins people and makes them sick,'” Bretl said. “But we try to avoid instances of motion sickness because the whole point of our research is to make it tolerable.”

The personalized approach worked. By the end of 10th session, the study subjects were all spinning comfortably, without feeling any illusion, at an average speed of about 17 rotations per minute. That’s much faster than any previous research had been able to achieve.

The idea is that you could install this rotating table on a interplanetary ship, and have its occupants periodically spend time on it to get their daily dose of gravity. This way you would not have to build a giant spinning spaceship.

The research has potential. The one question that remains unanswered and is probably central to this concept is how little gravity is needed to avoid the problems of weightlessness. Right now, we do not know. It could be for example that 30 minutes at 1/10 g could do the job. Or maybe 1 g for 2 hours. If the former the engineering challenges become minor. If the latter the problems are more difficult.

I am aware of only one centrifuge experiment ever done in weightlessness, on a Russian space station. They rotated a plant at a very tiny percentage of g’s and found it might help plants prosper in space. The data point however is too small, with no followup. This is the kind of research that should be going on on ISS, and is not.

Hat tip Marcus A.

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Wheel update on Curiosity

11:38 am

Periodically, the Curiosity science team stops from its research to reassess the condition of the rover’s wheels. To do this they use the rover’s color camera, dubbed the Mast Camera (Mastcam), taking close-up pictures of the wheels to compare those with earlier photographs see if there has been any additional damage and deterioration over time.

Yesterday Mastcam took a new series of images of the rover’s wheels. Below are two pictures, the left taken on August 27, 2017, the right taken on July 7, 2019. I have annotated the images to help indicate where they match.
» Read more

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Engineers adjust Voyagers 1 & 2 because of steadily dropping power

6:35 pm

In recognition that the available power on both Voyager 1 and Voyager 2 continues to drop due to the age of the spacecraft, engineers have decided to make some major changes in how they operate both spacecraft.

For example, to save power on Voyager 2 they have turned off the heaters for the instrument that confirmed last year that the spacecraft had entered interstellar space. Even so, the instrument is still functioning and sending back data. It is expected it will continue to work for some time before finally succumbing to the cold of deep space.

They have also decided to reactivate the back-up thrusters on Voyager 2, just as they did with Voyager 1 in 2017.

Another challenge that engineers have faced is managing the degradation of some of the spacecraft thrusters, which fire in tiny pulses, or puffs, to subtly rotate the spacecraft. This became an issue in 2017, when mission controllers noticed that a set of thrusters on Voyager 1 needed to give off more puffs to keep the spacecraft’s antenna pointed at Earth. To make sure the spacecraft could continue to maintain proper orientation, the team fired up another set of thrusters on Voyager 1 that hadn’t been used in 37 years.

Voyager 2’s current thrusters have started to degrade, too. Mission managers have decided to make the same thruster switch on that probe this month. Voyager 2 last used these thrusters (known as trajectory correction maneuver thrusters) during its encounter with Neptune in 1989.

It is thirty years since those thusters on Voyager 2’s were used. If they work it will be an incredible testament to the engineers who designed both spacecraft.

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The Greatest Scientific Fraud Of All Time — Part XXIII

12:29 pm

Link here. The author continues a long running series outlining the data manipulation and tampering that has been going on at NOAA and NASA to distort the global temperature record so it will confirm the theories of global warming activists. As he notes,

Sure enough, there have been additional adjustments, as always in the same direction — older down, and newer up. But those adjustments between v.3 and v.4 have been relatively minor. More significantly, Kirye discovered a different maneuver which is even more incredible, and which he proves by direct links back to NASA’s own website: In the v.4 graphs that it provides, NASA has relabeled the hugely-adjusted v.3 data as “unadjusted.”

He pinpoints how NASA is now taking its adjusted data and labeling them unadjusted, so that it can justify even more adjustments, all always cooling the past and warming the present. As he adds,

Funny that once again, each one of the adjustments somehow enhances the warming trend. Is it really possible that never once does any new data, or adjustment to data, lead to a change in the other direction?

This is political hackwork disguised as science. Until the climate science community does something to stop this and clean up the mess in its global temperature data, they will find themselves unable to convince anyone of their scientific credibility. Which by the way is generally in the sewer.

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Sunspot update June 2019: Down to zero again, with next cycle making an appearance

11:54 am

Below is the June graph of sunspot activity released by NOAA yesterday. As I do every month, I am posting it here, annotated to give it some context.

After three months of slightly increased sunspot activity, the Sun in June was essentially blank, with sunspots visible on its facing hemisphere on only five days. In addition, the 36 day stretch of spotless days that began in May and stretched through most of June was the longest such stretch since the last minimum in 2009.
June 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. 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, extended in November 2018 four years into the future.

Even while the solar minimum continues and heads for its low point, the first indications of the next solar solar cycle have appeared:
» Read more

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Astronomers find kilometer-sized asteroid with shortest year

10:10 am

Astronomers have found a kilometer-sized asteroid with a year only 151 days long, the shortest year of any asteroid.

The asteroid has been dubbed 2019 LF6.

In its orbit, the asteroid swings out beyond Venus and, at times, comes closer in than Mercury, which circles the sun every 88 days. 2019 LF6 is one of only 20 known “Atira” asteroids, which are objects whose orbits fall entirely within Earth’s.

Atira asteroids are difficult to find because they are so close to the Sun, which makes observations difficult if not impossible. Expect more such discoveries as the technology to make these observations improves.

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Jupiter’s changing Great Red Spot

12:53 pm

The changing Great Red Spot
Click for full resolution image.

Using Juno images produced during four different orbits, beginning in July 2017 through February 2019, citizen scientist Björn Jónsson has created a montage, reduced in resolution to post on the right, that shows the changes that have occurred in Jupiter’s Great Red Spot during that time. As he writes,

This is a montage of four map-projected [Spot] mosaics processed from images obtained during these perijoves (at the time of this writing perijove 20 is the most recent perijove). The mosaics show how the [Spot] and nearby areas have changed over the course of the Juno mission. The mosaics cover planetographic latitudes 4.7 to 38 degrees south.

The resolution of the source data is highly variable and this can be seen in some of the mosaics. The viewing geometry also varies a lot. Some of the images were obtained almost directly above the [Spot] (in particular some of the perijove 7 images) whereas other images were obtained at an oblique viewing angle (in particular the perijove 17 images).

These are approximately true color/contrast mosaics but there may be some inaccuracies in areas where the original images were obtained at a highly oblique angle. The contrast is also lower in these areas.

What strikes me the most is how the Spot itself seems relatively unchanged, while the bands and surrounding cloud formations changed significantly during this time.

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A journey to Saturn’s moon Dione

1:08 pm

Global Map of Dione

Cool image time! Today, for a change, I decided to spend some time rummaging through the Cassini raw image archive, mainly because I wanted to see some variety. At this time sadly almost all the good images coming from space are limited to Mars images, and I wished to post a cool image from somewhere else in the solar system.

The global map above was compiled from photographs of the Saturn moon Dione taken by Cassini during its thirteen years in orbit around the ringed giant.

The orange box indicates the sector of interest. The white outline indicates the location of the next photograph below and to the right, taken by Cassini during its first close fly-by of the moon on October 11, 2005, when the spacecraft was approaching the moon.
» Read more

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Astronomers map exoplanet atmosphere of super-Earth

9:26 am

Worlds without end: Using both the Hubble and Spitzer space telescopes, astronomers have characterized the atmosphere of an exoplanet with a mass between that of the Earth and Neptune.

Astronomers enlisted the combined multi-wavelength capabilities NASA’s Hubble snd Spitzer space telescopes to do a first-of-a-kind study of GJ 3470 b’s atmosphere. This was accomplished by measuring the absorption of starlight as the planet passed in front of its star (transit) and the loss of reflected light from the planet as it passed behind the star (eclipse). All totaled, the space telescopes observed 12 transits and 20 eclipses. The science of analyzing chemical fingerprints based on light is called “spectroscopy.”

“For the first time we have a spectroscopic signature of such a world,” said Benneke. But he is at a loss for classification: Should it be called a “super-Earth” or “sub-Neptune?” Or perhaps something else?

Fortuitously, the atmosphere of GJ 3470 b turned out to be mostly clear, with only thin hazes, enabling the scientists to probe deep into the atmosphere. “We expected an atmosphere strongly enriched in heavier elements like oxygen and carbon which are forming abundant water vapor and methane gas, similar to what we see on Neptune”, said Benneke. “Instead, we found an atmosphere that is so poor in heavy elements that its composition resembles the hydrogen/helium rich composition of the Sun.”

To me, our knowledge of exoplanets today is beginning to resemble our knowledge of the planets in the solar system c. 1950. The little data we have gives us a vague idea of what’s there, but there are so many gaps and uncertainties that no one should be confident about drawing any firm conclusions.

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ExoMars 2020 parachutes damaged during test

9:02 am

Bad news: The parachutes for the European/Russian ExoMars 2020 mission were damaged during a parachute test.

A May 28 test of the parachute system used a high-altitude balloon above the Swedish Space Corporation’s Esrange test site in northern Sweden. The test was intended to demonstrate the end-to-end performance of the entire system, including both the pilot and main chutes as well as the mortars used to extract the pilot chutes.

ESA said that the first main parachute suffered several radial tears in its fabric, all occurring before reaching its maximum load. The second main parachute also suffered a single tear, also before peak loading.

The other parts of the parachute system worked as expected, and ESA said “a good level of the expected aerodynamic drag was nevertheless achieved” despite the damage sustained by the parachutes. However, the agency acknowledged that the problem needs to be understood and corrected prior to the mission’s launch in one year.

They can easily get the parachutes repaired before the July 2020 launch. The problem is figuring out what caused the damage and fixing that in the time left. They already had planned two more parachute tests, but these cannot happen prior to all the fixes, and then they have to work.

Considering that they will only assemble the spacecraft at the end of this year, I am increasingly thinking that ExoMars 2020 will not launch in 2020. And if it does, I will not be surprised if it turns out to be a failure.

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The Martian seabed?

2:24 pm

Cones and strange blobs
Click for full image.

Cool image time! Above is an image taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) in November 2018 of an area in the vast relatively featureless northern lowlands of Mars. I have rotated, cropped, and reduced it to post here.

I have also indicated two sections, indicated by the white boxes, that I have cropped out of the full resolution image to highlight some interesting features. Both images can be seen in full resolution below.

While the northern lowlands seem featureless from a distance, with few craters, a closer look always reveals many things that are both baffling and fascinating. In this case the region is called Galaxias Colles, a region of mesas and knobby hills. This particular image was dubbed “Cones in Galaxias Colles,” and was clearly taken to get a better look at these strange blobby features.
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Astronomers declare: Oumuamua was not an alien spacecraft!

7:36 pm

The uncertainty of science: An international team of astronomers have announced that after much consultation and discussion it is their conclusion that the interstellar object Oumuamua that zipped through the solar system in 2017 was a natural object, not an alien spacecraft.

[A] review of all the available evidence by an international team of 14 experts strongly suggests that ʻOumuamua has a purely natural origin. The research team reported their findings in the July 1, 2019, issue of the journal Nature Astronomy.

“We have never seen anything like ʻOumuamua in our solar system,” said Dr. Matthew Knight, the team leader from the University of Maryland “but our preference is to stick with analogs we know, unless or until we find something unique. The alien spacecraft hypothesis is a fun idea, but our analysis suggests there is a whole host of natural phenomena that could explain it.”

It is perfectly reasonable for these scientists to choose the simplest and most likely explanation for Oumuamua, which would be a natural object. Moreover, their conclusion does fit the data we have reasonable well.

At the same time, for anyone to assume there is any certainty to this conclusion would be a grave mistake. It is merely the best guess, based on the available but somewhat limited data. The data however does not preclude more exotic explanations. Nothing is certain.

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New image of Eta Carina from Hubble

7:27 pm

Eta Carina
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Using the Hubble Space Telescope, astronomers have taken a new spectacular image of the Luminous Blue Giant star Eta Carina. The image on the right is that photograph, reduced to post here.

Using Hubble’s Wide Field Camera 3 to map the ultraviolet-light glow of magnesium embedded in warm gas (shown in blue), astronomers were surprised to discover the gas in places they had not seen it before.

Scientists have long known that the outer material thrown off in the 1840s eruption has been heated by shock waves after crashing into the doomed star’s previously ejected material. In the new images, the team had expected to find light from magnesium coming from the same complicated array of filaments as seen in the glowing nitrogen (shown in red). Instead, a completely new luminous magnesium structure was found in the space between the dusty bipolar bubbles and the outer shock-heated nitrogen-rich filaments.

Eta Carina had a major eruption in the 1840s, followed by other lesser outbursts, the evidence of which is obvious in this and other earlier Hubble images. In fact, over the past twenty-five years Hubble has actually tracked the expansion of those two lobes of material being flung from the star hidden deep in the material.

Someday in the far future astronomers believe it will die as a supernova, though that is only a hypothesis at this point, based on our presently limited understanding of stellar evolution.

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