Tag: engineering

Giant impact covered almost half of Gandymede’s surface

9:31 am

Artist's illustration of Ganydmede
Click for full illustration.

The uncertainty of science: Computer modeling and a review of images taken by Voyager 1 and 2 and the Galileo orbiter of Jupiter’s moon Ganymede now suggest the existence of a giant impact so large that it covers almost half the moon’s surface.

The artist’s illustration of Ganymede on the right, based on our presently incomplete set of global images, shows this impact area as the circular dark region.

Many furrows, or trough formations, have been observed on the surface of Ganymede, one of the Jovian moons. This research group comprehensively reanalyzed image data of Ganymede obtained by NASA’s Voyager 1, Voyager 2, and Galileo spacecrafts. The results revealed that almost all of these furrows appear to be arranged in concentric rings centered around a single point, indicating that this global multiring structure may be the remains of a giant crater. The radial extent of the multiring structures measured along Ganymede’s surface is 7800 km. For comparison, the mean circumference of Ganymede is only 16,530 km. If correct, this is the largest crater yet identified in the Solar System. The previous record holder with a 1900 km radius is on Calisto, another Jovian moon.

The conclusion reached here is very uncertain, since we really do not have a high resolution global map of Ganymede. All three spacecraft were only able to send back a scattering of high resolution images. The global map is based on Earth observations and images from the Hubble Space Telescope.

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The four companies (one a Chinese government operation) aiming for first orbital launch in 2020

8:57 am

Link here. The three private companies are Astra, Firefly, and Virgin Orbit. The fake Chinese private company is Expace.

Of the four, only Firefly has not yet attempted to launch, and in many ways remains the dark horse in this competition, coming out of bankruptcy to become reborn with a new investor. All three of the American private companies however have made it clear they intend to launch before the end of the year. The Chinese company’s plans are unknown (not surprisingly). Astra will be first, with its next launch attempt set for later this month.

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OSIRIS-REx completes closest sample grab rehearsal

8:45 am

OSIRIS-REx yesterday successfully completed its closest sample grab rehearsal, bringing the spacecraft about 131 feet from the surface of the asteroid Bennu.

The approximately four-hour “Matchpoint” rehearsal took the spacecraft through the first three of the sampling sequence’s four maneuvers: the orbit departure burn, the “Checkpoint” burn and the Matchpoint burn. Checkpoint is the point where the spacecraft autonomously checks its position and velocity before adjusting its trajectory down toward the event’s third maneuver. Matchpoint is the moment when the spacecraft matches Bennu’s rotation in order to fly in tandem with the asteroid surface, directly above the sample site, before touching down on the targeted spot.

Four hours after departing its 0.6-mile (1-km) safe-home orbit, OSIRIS-REx performed the Checkpoint maneuver at an approximate altitude of 410 feet (125 meters) above Bennu’s surface. From there, the spacecraft continued to descend for another eight minutes to perform the Matchpoint burn. After descending on this new trajectory for another three minutes, the spacecraft reached an altitude of approximately 131 ft (40 m) – the closest the spacecraft has ever been to Bennu – and then performed a back-away burn to complete the rehearsal.

During the rehearsal, the spacecraft successfully deployed its sampling arm, the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), from its folded, parked position out to the sample collection configuration. Additionally, some of the spacecraft’s instruments collected science and navigation images and made spectrometry observations of the sample site, as will occur during the sample collection event. These images and science data were downlinked to Earth after the event’s conclusion.

The actual sample-grab-and-go attempt is scheduled for October 20th.

The short video below the fold shows spacecraft as it makes its closest approach. From the youtube page:
» Read more

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Endeavour at Cape, being prepped for next flight

8:46 pm

Capitalism in space: Endeavour, SpaceX’s Dragon capsule that was the first to fly two astronauts to ISS, has now arrived at the company’s facility at Cape Canaveral, where it will be inspected, refurbished, and prepped for its next manned flight in the the spring of 2021.

SpaceX teams at Cape Canaveral will remove the exterior panels from the Crew Dragon spacecraft, and begin inspections to assess how the spacecraft weathered its 64-day space mission, according to Benji Reed, SpaceX’s director of crew mission management. “We want to make sure that we kind of dig deep and understand everything that’s gone on with this vehicle, make sure we’re really ready to go, and then do some of the aspects of the refurbishment,” Reed said. “There are some things that we will replace, some things that are standardly replaced, some things that we want to upgrade based on lessons learned, or that were already planned in work.”

SpaceX will still need to build a new trunk for each Crew Dragon mission. The trunk is an unpressurized module mounted to the rear of the Crew Dragon capsule, providing electrical power with solar arrays, and radiators to maintain steady temperatures inside the spaceship.

I guarantee the company will use what it learns in this inspection to improve later Dragon manned capsules. Right now they plan on from 5 to 10 flights per capsule. Since their contract right now only calls for six flights, that likely means the company only needs to build at most three to cover this NASA contract. However, NASA is certain to extend that contract, since six flights will only cover about two to three years, and ISS will be manned longer than that. Moreover, SpaceX has at least two tourist flights booked, so that calls for additional capsules as well.

Either way, we must shift our thinking. These might only be Dragon capsules, but they each get a name because each will fly more than once. It is thus appropriate to use that name instead of just calling them Dragon.

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Martian sand traps and elongated dunes

9:14 am

Elongated dunes on Mars
Click for full image.

Cool image time! The photo to the left, rotated, cropped, and reduced to post here, was taken on June 23, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I was attracted by the uncaptioned image’s title, “Elongating Linear Dunes at Meroe Patera.” What are elongating linear dunes?

The photo shows two such dunes, stretching out to the southwest away from the pile of sand that abuts the cliff to the northwest. Unlike most dunes, which usually form and travel in groups, these for some reason form single straight lines extending for some distance.

I contacted the scientist who requested this image, Joel Davis of the Natural History Museum in London, hoping he could answer some questions about these strangely shaped dunes, and discovered that he was studying this exact subject for a paper since published. As noted in the paper’s introduction,
» Read more

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SpaceX prepares sixth Starship prototype for hop

7:56 am

Capitalism in space: Having moved its fifth Starship prototype back to its facility at Boca Chica for repairs to its legs following its first light, SpaceX is simultaneously preparing its sixth Starship prototype for its own hops.

They plan more short hops to smooth out the launch process, aiming for the ability to do several per day, followed later by a much higher altitude hop. Expect the next hop within about two weeks.

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Snapped cable damages Arecibo radio telescope

12:25 pm

One of the cables that supports the central platform above the Arecibo Observatory’s giant dish snapped yesterday, damaging the dish and shutting down operations.

The break occurred about 2:45 a.m. When the three-inch cable fell it also damaged about 6-8 panels in the Gregorian Dome and twisted the platform used to access the dome. It is not yet clear what caused the cable to break. “We have a team of experts assessing the situation,” says Francisco Cordova, the director of the observatory. “Our focus is assuring the safety of our staff, protecting the facilities and equipment, and restoring the facility to full operations as soon as possible, so it can continue to assist scientists around the world.”

The radio telescope has not much luck the past few years. It was badly damaged and shut down for a long time after Hurricane Maria in 2017, with repairs from that still on-going.

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The edge of Mars’ south polar layered cap

12:10 pm

The edge of the Martian south pole layered deposits
Click for full image.

Cool image time! The photo to the right, rotated and cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on April 10, 2020, and shows the edge of what scientists have dubbed Mars’s south polar layered deposits. The high point, towards the south, is at the bottom, and the terraced layers descend downward to the plains as you move up the image, to the north.

In essence, this spot is the edge of the southern ice cap, though unlike the north polar ice cap, this edge is not the edge of the visible ice cap, but the edge of a much larger field of layered deposits of mixed dust and ice. In the north the ice cap almost entirely covers these layered deposits. In the south the residual ice cap does not. Instead, the layered deposits extend out far beyond the smaller residual ice cap.

The map below provides the geography of the south pole, with the location of this image indicated by the blue cross.
» Read more

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TESS completes primary mission

9:33 am

Having now imaged 75% of the entire night sky and completing its primary mission, scientists have now begun the extended mission for the Transiting Exoplanet Survey Satellite (TESS), designed to look for transiting exoplanets.

TESS monitors 24-by-96-degree strips of the sky called sectors for about a month using its four cameras. The mission spent its first year observing 13 sectors comprising the southern sky and then spent another year imaging the northern sky.

Now in its extended mission, TESS has turned around to resume surveying the south. In addition, the TESS team has introduced improvements to the way the satellite collects and processes data. Its cameras now capture a full image every 10 minutes, three times faster than during the primary mission. A new fast mode allows the brightness of thousands of stars to be measured every 20 seconds, along with the previous method of collecting these observations from tens of thousands of stars every two minutes. The faster measurements will allow TESS to better resolve brightness changes caused by stellar oscillations and to capture explosive flares from active stars in greater detail.

These changes will remain in place for the duration of the extended mission, which will be completed in September 2022. After spending a year imaging the southern sky, TESS will take another 15 months to collect additional observations in the north and to survey areas along the ecliptic – the plane of Earth’s orbit around the Sun – that the satellite has not yet imaged.

So far the telescope has spotted more than 2,100 exoplanet candidates, with 66 confirmed.

All told, TESS has divided the sky into 26 sectors, 13 in the north and 13 in the south. It can only look at one at a time for a month, and scientists use that one month data, collected more than once, to see if there are any changes. Because of the gaps in TESS’s view of each sector, however, it is guaranteed to miss some exoplanets (the majority) whose transits occur when it is not looking.

Imagine if we had 25 more of these space telescopes in orbit, so that each sector could be watched continually. This is totally doable now, and would make it possible to soon create a census of transiting exoplanets across the entire sky.

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SpaceX to build resort near Boca Chica

8:51 am

Capitalism in space: SpaceX is seeking to hire a manager to lead the design and construction of a resort near Boca Chica for future spaceport customers.

The job posting seeks a manger to “oversee the development of SpaceX’s first resort from inception to completion,” with the ultimate aim of turning Boca Chica into a “21st century Spaceport.” That would include overseeing the entire design and construction process, as well as getting all necessary work permits and regulatory approvals, and completing the ultimate build of the facility.

Makes perfect financial sense, assuming Starship does eventually fly. Customers will need and expect a nice place to stay before and after their flights, and SpaceX has the land and is best positioned for providing it. And even if Starship doesn’t fly, during the rocket’s development there is money to be made providing tourists the best viewpoint for watching test flights, while also creating a source of profit independent of actual flight.

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Cryovolcanism on Ceres still ongoing?

10:02 am

3D simulation of Occator Crater on Ceres
Click for full 3D simulation image.
Click here for animated movie.

According to a new detailed analysis of data from the Dawn mission, scientists are now postulating that cryovolcanism in Occator Crater on Ceres began immediately after impact about 22 million years ago and has continued in fits and starts since.

Occator Crater was formed about 22 million years ago by a large impact. As in many other impact craters on Earth and on other planets, a central peak was formed, which collapsed again after some time. About 7.5 million years ago, brine rose to the surface within the remnants of the central peak. The water evaporated and certain salts, so-called carbonates, remained. They are responsible for the prominent bright deposits we see today, called Cerealia Facula, in the center of Occator Crater. Due to the loss of material in the interior, the inner part of the crater subsided. A round depression with a diameter of about 15 kilometers formed.

In the following millions of years, activity concentrated mainly on the eastern part of the crater floor. Through cracks and furrows, brine also rose to the surface there and produced further bright deposits, the Vinalia Faculae. About 2 million years ago the center of the crater woke up again: brine rose to the surface and within the central depression a dome of bright material was formed. “This process continued up to a million years ago and maybe even until today,” Dr. Nico Schmedemann from the University of Münster summarizes.

This hypothesis is further supported by second paper that proposes there remains a reservoir of salty underground liquid water in the tiny planet’s interior. Both add weight to the idea that any object in space that is large enough for gravity to force it into a spherical shape is going to behave like a planet, with a complex and active geology.

The first paper has a lot of uncertainty, however, centering entirely on its dependence on crater counts to determine age. While providing a rough age estimate, the method depends on many assumptions, is indirect, and could easily be entirely wrong.

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Air Force terminates development contracts to ULA, Blue Origin, Northrop Grumman

9:44 am

In awarding ULA and SpaceX exclusive launch rights for all launches through 2026, the Air Force also decided to end prematurely the development contracts to ULA, Blue Origin, and Northrop Grumman aimed at helping these companies develop new rockets.

An issue at hand is the termination of the Launch Service Agreement contracts that the Air Force awarded in October 2018 to Blue Origin and Northrop Grumman, as well as to ULA. The purpose of the agreements was to help Phase 2 competitors pay for launch vehicle development and infrastructure. Blue Origin received $500 million; Northrop Grumman $792 million and ULA $967 million. The funds were to be spread out through 2024, and the Air Force from the beginning said the LSAs would be terminated with those companies that did not win a Phase 2 procurement contract.

Despite political pressure to not end the LSAs, the agreements will be terminated, Assistant Secretary of the Air Force for Acquisition Will Roper said Aug. 7 during a video conference with reporters. “We will work with those two companies to determine the right point to tie off their work under the LSA agreements,” Roper said. The intent of the LSAs “was to create a more competitive environment leading into Phase 2,” he said. “The point is not to carry them indefinitely.”

LSA funds supported the development of Blue Origin’s New Glenn rocket and Northrop Grumman’s OmegA launch vehicle. ULA will continue to receive funds for its Vulcan Centaur vehicle.

Almost immediately after the award of these contracts was announced in 2018, ULA and Blue Origin announced one year delays in the development of Vulcan and New Glenn. Apparently, meeting the additional requirements of military’s bureaucracy in exchange for getting the cash slowed development.

Now they won’t be getting a large part of that cash, making the decision to take it a deal with the devil. The delay in development has definitely hurt both companies in their competition with SpaceX. First, it likely has raised the cost and complexity of their new rockets, making it harder to compete in price. Second, the delay has given SpaceX more time to grab more customers while improving its own rockets.

SpaceX initially protested not getting a share of this development money, but has subsequently chosen to no longer pursue such government money for Starship because it doesn’t want itself hampered by obtuse government officials and their mindless requirements.

Meanwhile, Northrop Grumman’s Omega rocket is almost certainly dead. That company took the old big space company approach, structuring development around government cash. Without it there is no R&D money at Northrop Grumman to continue work. Furthermore, Omega was designed to serve only once customer, the military. Without any launch contracts there are no customers for Omega, especially because it likely has too high a launch price.

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Ascraeus Mons, Mars’ second highest mountain

3:06 pm

Ascraeus Mons

Today’s cool Mars’ image started out when I came across an interesting image of a depression on the northern flank of the giant Martian volcano Ascraeus Mons, the northernmost of the line of three giant volcanoes just to the east of the biggest of all, Olympus Mons.

To provide context I created an overview showing the entire volcano (with the white rectangle showing the location of the depression image), and suddenly realized that this overview might actually be more interesting to my readers. To the right is that overview of Ascreaus, with a scale across the bottom to indicate the elevation of the mountain above what scientists have determined to be Mars’ pseudo sea level.

Notice that this volcano, the second highest on Mars, rises more than 43,000 feet above the surrounding plains. Its peak is estimated to be about 59,000 feet high, making it taller than Mt. Everest by about 30,000 feet (more than twice its height). Its diameter is approximately 300 miles across, giving it a much steeper profile than the higher but more spread out Olympus Mons. The map below shows this mountain in relation to Olympus as well as its nearby partner volcanoes.
» Read more

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Hayabusa-2’s future asteroid targets

10:02 am

Link here. There are two prime candidate asteroid targets, both near Earth astroids.

The possible secondary targets include the oblong asteroid 2001 AV43 or the asteroid 1998 KY 26. They’re each about the size of a large house and both orbit the Sun in roughly 500 days. The proposed plan would see Hayabusa 2 arriving at 2001 AV43 in the late 2029 time frame, or reaching 1998 KY 26 in July 2031. Both asteroids have a low enough relative speed relative to the spacecraft to put them within (eventual) reach after Hayabusa 2’s December flyby.

Interestingly, 2001 AV43 will fly 313,000 km from Earth (0.8 times the Earth-Moon distance) on November 11, 2029.

The two asteroids were selected from an initial field of 354 candidates, which was winnowed down based on accessibility and scientific interest. Both are fast rotators, as evidenced by their light curves, each spinning on its respective axis once every 10 minutes. This represents the shortest “day” of any known object in the solar system, suggesting that these asteroids are in fact solid objects and not simply loosely aggregated “rubble piles.” A visit to one of these asteroids would mark the first time a space mission has seen such an enigmatic fast rotator up close.

The asteroid 1998 KY26 is also a possible carbonaceous (C-type) asteroid, and Hayabusa 2’s exploration of such a space rock would be another first.

Going to 1998 KY26 would also require a distant pass of another asteroid. Going to 2001 AV43 would require a fly-by of Venus, which could provide more data on that planet. Based on this information, my guess is that they will opt for 1998 KY26.

The decision must likely be made before Hayabusa-2 drops off its Ryugu samples to Earth on December 6, 2020.

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Russia to ship Nauka to Baikonur launch site August 10

9:48 am

Russia now plans to ship its Nauka ISS module to Baikonur on August 10th, three days later than previously planned, where it will begin the final nine months of preparations for launch.

“The stage of electrical tests takes about six months together with preparations because there is a large number of systems. Scheduled operational measures take another three months from this moment to the launch. This involves direct preparations for the launch together with the provision of microbiological protection, fueling and other operations,” he explained.

Nauka will provide the Russians a second toilet on ISS, plus produce oxygen and water (from urine) for six astronauts. It will also become the cabin for a third Russian-flown astronaut, either tourist or professional.

Nauka is a quarter century in the making, its construction having started in 1995. As a government-run project, that pace matches well with SLS, Orion, the James Webb Space Telescope, and many other big government projects not related to space. The goal isn’t to accomplish anything really but to create the justification for fake jobs that can last a lifetime.

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OSIRIS-REx preps for final rehearsal of sample grab

9:40 am

The OSIRIS-REx science and engineering team is getting ready for its August 11th final rehearsal of the sample grab-and-go at the asteroid Bennu that it plans to do in October.

If the rehearsal goes right, the spacecraft will descend to within 131 feet of the surface of Bennu as it deploys its equipment as if it would continue down to the surface. It will also fly in formation above the Nightingale sample site when it does this, taking the highest resolution images yet of the surface of the asteroid.

It will then back off, returning to its home orbit farther from Bennu. Engineers will then review what happened, and use that data to prepare for the actual sample grab-and-go, set for October 20, 2020.

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SpaceX launches more Starlink satellites

12:17 am

Capitalism in space: SpaceX tonight successfully put two commercial satellites for another customer plus another 57 of its own Starlink satellites into orbit, using a Falcon 9 rocket that was reusing a first stage flying for the fifth time.

This brings the total number of Starlink satellites now in orbit to 595. They also successfully landed the first stage, making it now available for a sixth flight.

19 China
12 SpaceX
9 Russia
4 ULA

The U.S. has retaken the lead from China in the national rankings, 20 to 19.

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Slushy floor of southern Martian crater?

1:45 pm

Knobby floor of southern crater
Click for full image.

The cool image to the right, rotated, cropped, and reduced to post here, shows the northwest section of the floor of a crater in the southern cratered highlands of Mars, in a mountainous region dubbed Claritus Fossae, located south of Valles Marineris. The photo was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on May 14, 2020.

The entire crater floor appears to be covered by these strings of closely-packed knobs, reminiscent of the brain terrain found in the mid-latitude glacial regions of Mars and thought to be the result of underground ice sublimating upward.

Below is the area in the white box, in full resolution.
» Read more

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California & Space Force to encourage private launches at Vandenberg

9:46 am

Capitalism in space: The state government of California has signed an agreement with the U.S. Space Force to expand private launches facilities at Vandenberg Space Force Base

It appears that the Space Force is aggressively trying to encourage new private launch operations to take flight out of Vandenberg. The article however is very unclear about exactly what this new agreement accomplishes. I could not find its actual text, and from the story all we get is typical government blather:

[Chris Dombrowski, acting director of the Governor’s Office of Business and Economic Development] said the organizations under the [agreement] will develop a “master plan that identifies the required infrastructure, human capital development, governance and financing necessary to support the United States Space Force mission and position California as a leader in the future of the commercial space industry.”

“This MOU serves as a critical investment in California’s innovative economy as we work to safely recover from the COVID-19 induced recession,” he said.

If anything, it appears that California’s Democratic and very power-hungry government is using this agreement to take control of any new private operations, so that it can dictate how they operate, according to its whims. If so, don’t expect much private enterprise to prosper at Vandenberg.

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Study: Lava tubes on Mars and the Moon will be gigantic

9:34 am

A new study comparing lava tubes on the Earth with those detected from orbit on Mars and the Moon now suggests that tubes on those other worlds will be many times larger than on Earth.

Researchers found that Martian and lunar tubes are respectively 100 and 1,000 times wider than those on Earth, which typically have a diameter of 10 to 30 meters. Lower gravity and its effect on volcanism explain these outstanding dimensions (with total volumes exceeding 1 billion of cubic meters on the Moon).

Riccardo Pozzobon adds: “Tubes as wide as these can be longer than 40 kilometres, making the Moon an extraordinary target for subsurface exploration and potential settlement in the wide protected and stable environments of lava tubes. The latter are so big they can contain Padua’s entire city centre”.

Moreover, the data suggests their roofs, even at this size, will be very stable because of the lower gravity, making them excellent locations for large human colonies.

The researchers also suggest that there are many intact such lava tubes under the mare regions on the Moon, their existence only hinted at by the rare skylights created due to asteroid impact.

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SpaceX and ULA get launch contracts from SES

9:28 am

Capitalism in space: The satellite communications company SES yesterday announced the award of new launch contracts to both SpaceX and ULA.

It appears that the contract was for one launch from each company, each putting up two satellites. Previously SES’s satellites were generally too large for either the Atlas 5 or the Falcon 9 to launch two at one time. This suggests that the satellite company is slimming down the design of its satellites.

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Jeff Bezos sells $3 billion more in Amazon stock

9:23 am

Jeff Bezos this week sold another $3 billion in his Amazon stock, bringing the sales this year along to more than $7 billion.

Amazon stock has soared since mid-March as millions of customers rely on the e-commerce giant amid the pandemic for online shopping, cloud computing, and more. Last week the company posted $88.9 billion in revenue, up 40% from the year-ago quarter, with profits far ahead of Wall Street expectations at $5.2 billion.

Bezos said in 2017 that he was selling $1 billion a year to fund his Blue Origin space venture, but he has been increasing the size and frequency of the stock sales. He sold $2.8 billion worth of Amazon stock a year ago, and around $4 billion earlier this year.

Since 2017 Bezos has now raised more than $11 billion from sales of his Amazon stock. Initially he had said such sales were to finance his space company Blue Origin, but more recently he has indicated he wants to use the bulk of this cash to fight climate change, with portions also devoted services for the homeless and early childhood education.

In fact, it appears that Blue Origin is likely getting only a very small portion of this money, though at several billion this isn’t chicken-feed. At a minimum it likely matches what SpaceX has raised through private investment capital for its Starship/Starlink projects, and more likely exceeds it.

Yet, SpaceX continues to outpace Blue Origin, several times over. If anything, as the cash from Bezos has rolled in Blue Origin’s pace of test flights with New Shepard as well as the development of its BE-4 rocket engine and New Glenn orbital rocket seemed have slowed. Initially New Glenn was going to make its first orbital launch this year. Now they say it will launch next year but we hear little about any development progress. And the company only delivered a test engine of the BE-4 (not flight worthy) to ULA only about a month ago, far later than first promised.

Though the lack of news could simply be Blue Origin’s more secretive way of doing things, compared to SpaceX, I have my doubts. Rockets are big things, and building and testing them is not something easily kept under wraps, especially by private companies. The lack of news from Blue Origin continues to suggest that simply having lots of money does not necessarily guarantee success.

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Astronomers use Hubble to detect ozone on Earth

8:57 am

Using the Hubble Space Telescope, scientists have shown that it will be possible to detect ozone in the atmospheres of exoplanets, using larger telescopes while observing transits of those exoplanets across the face of their star.

What the scientists did was aim Hubble at the Moon during a lunar eclipse. Moreover, they timed the observations so that the sunlight hitting the Moon and reflecting back to Earth (and Hubble) had also traveled through the Earth’s atmosphere on its way to the Moon.

They then looked at the spectrum of that light, and were able to glean from it the spectral signal of ozone in the Earth’s atmosphere. When giant ground-based telescopes under construction now come on line in the coming decades they will have the ability to do this with transiting exoplanets.

The measurements detected the strong spectral fingerprint of ozone, a key prerequisite for the presence – and possible evolution – of life as we know it in an exo-Earth. Although some ozone signatures had been detected in previous ground-based observations during lunar eclipses, Hubble’s study represents the strongest detection of the molecule to date because it can look at the ultraviolet light, which is absorbed by our atmosphere and does not reach the ground. On Earth, photosynthesis over billions of years is responsible for our planet’s high oxygen levels and thick ozone layer. Only 600 million years ago Earth’s atmosphere had built up enough ozone to shield life from the Sun’s lethal ultraviolet radiation. That made it safe for the first land-based life to migrate out of our oceans.

“Finding ozone in the spectrum of an exo-Earth would be significant because it is a photochemical byproduct of molecular oxygen, which is a byproduct of life,” explained Allison Youngblood of the Laboratory for Atmospheric and Space Physics in Colorado, USA, lead researcher of Hubble’s observations.

Ozone does not guarantee the presence of life on an exoplanet, but combined with other detections, such as oxygen and methane, would raise the odds significantly.

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Filled and distorted craters on Mars

9:12 pm

A very distorted and filled crater on Mars
Click for full image.

Cool image time! The photo to the right, rotated and cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on May 25, 2020. The entire image was dubbed “Cluster of Filled Craters”, but I decided to highlight the crater of the cluster that was most strangely distorted of them all. The material that fills all the craters in the full image is almost certainly buried ice and is dubbed concentric crater fill by scientists.

This crater is located in the northern lowland plains the mid-latitudes between 30 and 60 degrees, where planetary scientists have found ample evidence of many such filled craters and glaciers.

Not only does the crater’s interior seemed filled with glacial material, its distorted rim suggests that it has been reshaped by glacial activity that might have covered it entirely over the eons as the mid-latitude glaciers of Mars waxed and waned with the extreme shifts that happen regularly to Mars’ rotational tilt. Moreover, there is strong evidence that in these lowland northern plains an underground ice table exists close to the surface, allowing for more distortion over time.

The overview map below provides some location context.
» Read more

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Lightning and mushballs on Jupiter

3:49 pm

Artist's illustration of Jupiter lightning
Click for full illustration.

Using data from Juno, scientists now theorize that Jupiter produces what they dub “shallow lightning” as well as ammonia-water hailstones dubbed “mushballs.”

The image to the right, cropped and reduced to post here, is only an artist’s illustration of the lightning. Sadly Juno’s camera doesn’t have the resolution to capture such flashes.

An unexpected form of electrical discharge, shallow lightning originates from clouds containing an ammonia-water solution, whereas lightning on Earth originates from water clouds.

Other new findings suggest the violent thunderstorms for which the gas giant is known may form slushy ammonia-rich hailstones Juno’s science team calls “mushballs”; they theorize that mushballs essentially kidnap ammonia and water in the upper atmosphere and carry them into the depths of Jupiter’s atmosphere.

As with the InSight results below, there is much uncertainty with these results, especially the hypothesis of mushballs. These features fit their present data from Juno, but we must remember that the data is still somewhat superficial.

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Scientists make first rough estimate of Mars’ internal structure

3:33 pm

Artist's cutaway showing theorized Martian interior
Artist’s cutaway of theorized Martian interior

Using data from InSight’s seismometer, scientists have made their first approximation of the internal structure of Mars.

The first boundary Deng and Levander measured is the divide between Mars’ crust and mantle almost 22 miles (35 kilometers) beneath the lander.

The second is a transition zone within the mantle where magnesium iron silicates undergo a geochemical change. Above the zone, the elements form a mineral called olivine, and beneath it, heat and pressure compress them into a new mineral called wadsleyite. Known as the olivine-wadsleyite transition, this zone was found 690-727 miles (1,110-1,170 kilometers) beneath InSight. “The temperature at the olivine-wadsleyite transition is an important key to building thermal models of Mars,” Deng said. “From the depth of the transition, we can easily calculate the pressure, and with that, we can derive the temperature.”

The third boundary he and Levander measured is the border between Mars’ mantle and its iron-rich core, which they found about 945-994 miles (1,520-1,600 kilometers) beneath the lander. Better understanding this boundary “can provide information about the planet’s development from both a chemical and thermal point of view,” Deng said.

Because they only have one seismometer on the planet, this approximation has a great deal of uncertainty. Only when we have multiple such seismic instruments, scattered across the entire Martian globe, will scientists be able to hone their models more accurate of the planet’s interior.

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