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Astronauts will face a host of obstacles when they visit the Moon again. There’s powerful radiation, wild temperature swings, and challenging gravity to deal with. There’s also dust and lots of it. Moondust was a hazard for the Apollo astronauts, and future lunar astronauts will have to contend with it, too.

What if they turn some of that dust into solid surfaces to drive on?

When Apollo 11 was preparing for the first Moon landing, they faced a lot of unknowns. They knew from orbital images that there was a lot of dust, but mission planners didn’t know how much or how deep. There was a risk of sinking into it. So serious was the risk that the lander had three dust-sensing probes extending downward from three of the lander’s feet. If they sank too deeply into dust, the landing could be aborted.

Apollo 11's Columbia Module photographed the Lunar Module Eagle in a landing configuration. The long rod-like protrusions under the landing pods are lunar surface sensing probes. Upon contact with the lunar surface, the probes sent a signal to the crew to shut down the descent engine. Image Credit: NASA
Apollo 11’s Columbia Module photographed the Lunar Module Eagle in a landing configuration. The long rod-like protrusions under the landing pods are lunar surface sensing probes. Upon contact with the lunar surface, the probes sent a signal to the crew to shut down the descent engine. Image Credit: NASA

They didn’t sink in, as we all know, but the dist did cause problems, and the Apollo astronauts weren’t on the lunar surface for very long.

Since then, we’ve learned a lot about lunar dust and the obstacles it imposes on exploration. The ESA will eventually establish a sustained human presence on the Moon so that our natural satellite can be more fully explored. Eventually, in-situ resource development will form part of the mission.

All that activity means the astronauts will need transportation, reliable transportation that lasts a long time. And that means somehow dealing with the fine, clinging dust that coats the Moon. Rather than engineer surface vehicles that are somehow impervious to dust, the ESA thinks they can melt the dust where it sits, forming a hardened driving surface. Will that solve the problem?

NASA modelling shows that when a spacecraft touches down on the lunar surface, it can send tons of fine dust above the surface before eventually settling. Due to the Moon’s low gravity, it can take a long time to settle. That wasn’t a huge problem for Apollo’s small landers, but future landers will be much larger. All that dust could foul the surfaces of landers and cause all kinds of problems. But what if the dust on landing areas and travelling surfaces could be melted with high-energy lasers?

The ESA decided this is a tactic worth pursuing. Their PAVER (paving the road for large area sintering of regolith) program investigated the idea. PAVER is a consortium of European companies and organizations. In controlled tests on simulated lunar regolith, they used a 12-kilowatt CO2 laser to melt simulated moondust. It created a smooth, glassy surface that has potential as roadways, landing areas, and other operational areas from the Moon’s plentiful dust.

The PAVER consortium made use of a 12-kilowatt carbon dioxide laser to melt simulated moondust into a glassy solid surface as a way of constructing paved surfaces on the face of the Moon. They melted 20 cm. triangular sections that can be interlocked to form a solid surface. Image Credit: PAVER Consortium. Did you miss our previous article…
https://mansbrand.com/protostars-can-siphon-material-from-far-away/

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Are Titan’s Dunes Made of Comet Dust?

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A new theory suggests that Titan’s majestic dune fields may be have come from outer space. Researchers had always assumed that the sand making up Titan’s dunes was locally made, through erosion or condensed from atmospheric hydrocarbons. But researchers from the University of Colorado want to know: Could it have come from comets?

The dunes of Titan

When the Cassini spacecraft arrived in orbit around Saturn, nobody had ever seen beneath the thick soupy atmosphere of Titan. So when it dropped the Huygens lander, and began probing Titan with cloud-penetrating radar, scientists were surprised to learn that Titan has a very earth-like appearance. It has a thick nitrogen atmosphere, rain, rivers, oceans and massive dune fields. But unlike the dunes of Earth’s sandy deserts in Namibia and southern Arabia, Titan’s dunes are enormous, and fill massive fields covering more than an eighth of the giant moon’s surface. These dunes are about 100 meters tall, 1 to 2 km wide at the base, and can stretch for hundreds of kilometers in length.

Dunes on Earth are made from sand, which is blown by the wind and heaped into drifts. Individual sand particles are nudge and blown by the wind with enough force to make them bounce and scatter, in a process called saltation. If the particles don’t bounce, then they cannot pile up on top of each other, but if the wind is able to lift them off the ground completely then they simply blow away. Saltation depends on the size and mass of the sand particles and the strength of the wind, but also needs the particles to be dry so that they can move freely without sticking together.

Titan’s geology

Titan is the second largest moon in the entire Solar System, beaten only by Ganymede, orbiting Jupiter. It is Saturn’s largest moon, and very old. Unlike most of Saturn’s moon, which were captured over time, Titan would have formed together with Saturn billions of years ago. Despite having so many features in common with Earth, it is a very different place. It is so intensely cold that, instead of water, its rain and rivers are made from liquid hydrocarbons like methane. Water, on the other hand, is frozen into hard ice; rocks on Titan are made from water ice, instead of granite and basalt, and Titan’s equivalent of lava and magma are made from liquid water and ammonia.

This means that sand on Titan is not made from silica eroded from larger rocks, since those materials are not found on the surface. One popular theory is that it could instead be made from ice. When liquid methane rains and flows, it could erode the water-ice bedrock, grinding chunks together to a sand of ice grains. An alternative idea is that the sand particles are instead made from tholins. These are found all over the colder regions of the Solar System, where cold hydrocarbons in comets or the outer atmospheres of planets and moons react with ultraviolet light from the Sun to create complex compounds. Tholins formed in the dry atmosphere of Titan could clump together with static electricity to form small grains of soot that then settle to the ground, creating both dust and sand.

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Comet 109P/Swift-Tuttle captured during its last pass by Earth on Nov. 1, 1992. Credit: Gerald Rhemann

What do comets have to do with this?

But a paper presented at this year’s Lunar and Planetary Science Conference (LPSC) suggests a new idea: What if the sand came from comets? Comets, as we know, are made from materials left over from the creation of the Solar System. Most of the primordial gas and dust that collapsed from an ancient nebula to form the Solar System would have ended up in the Sun, with the bulk of the remains forming the planets. But this still would still have left a lot of material floating free, and some of that would have gradually coalesced into lumps of dust and ices, which we see today as comets. When comets are nudged into elliptical orbits and pass through the inner Solar System, some of their ice heats up and sublimates into gas which blows out, carrying dust with it. This dust is scattered throughout the Solar System, concentrated along the various comet’s orbits. Individual grains often collide with the Earth, which we see as meteors, burning high in our atmosphere. Recent surveys in Antarctic ice

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The Milky Way’s Most Massive Stellar Black Hole is Only 2,000 Light Years Away

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Astronomers have found the largest stellar mass black hole in the Milky Way so far. At 33 solar masses, it dwarfs the previous record-holder, Cygnus X-1, which has only 21 solar masses. Most stellar mass black holes have about 10 solar masses, making the new one—Gaia BH3—a true giant.

Supermassive black holes (SMBH) like Sagittarius A Star at the heart of the Milky Way capture most of our black hole attention. Those behemoths can have billions of solar masses and have enormous influence on their host galaxies.

But stellar-mass holes are different. Unlike SMBHs that grow massive through mergers with other black holes, stellar black holes result from massive stars exploding as supernovae. SMBHs are always found in the center of a massive galaxy, but stellar black holes can be hidden anywhere.

“This is the kind of discovery you make once in your research life.”

Pasquale Panuzzo, National Centre for Scientific Research (CNRS) at the Observatoire de Paris

Astronomers found BH3 in data from the ESA’s Gaia spacecraft. It’s Gaia’s third stellar black hole. BH3 has a stellar companion, and the black hole’s 33 combined solar masses tugged on its aged, metal-poor companion. The star’s tell-tale wobbling betrayed BH3’s presence. At only 2,000 light-years away, BH3 is awfully close in cosmic terms.

Astronomers have found the most massive stellar black hole in our galaxy, thanks to the wobbling motion it induces on a companion star. This artist's impression shows the star's orbits and the black hole, dubbed Gaia BH3, around their common centre of mass. The European Space Agency's Gaia mission measured this wobbling over several years. Image Credit: ESO/L. Calçada
Astronomers have found the most massive stellar black hole in our galaxy, thanks to the wobbling motion it induces on a companion star. This artist’s impression shows the star’s orbits and the black hole, dubbed Gaia BH3, around their common centre of mass. The European Space Agency’s Gaia mission measured this wobbling over several years. Image Credit: ESO/L. Calçada

A new research letter in Astronomy and Astrophysics presented the discovery. Its title is “Discovery of a dormant 33 solar-mass black hole in pre-release Gaia astrometry.” The lead author is Pasquale Panuzzo, an astronomer from the National Centre for Scientific Research (CNRS) at the Observatoire de Paris.

“No one was expecting to find a high-mass black hole lurking nearby, undetected so far,” said Panuzzo. “This is the kind of discovery you make once in your research life.”

This black hole is remarkable for its considerable mass. Researchers have found stellar black holes with similar masses, but always in other galaxies. The size is confounding, but astrophysicists have pieced together how they may become so massive.

They could result from the collapse of metal-poor stars. These stars are composed almost entirely of hydrogen and helium, the primordial elements. Scientists think these stars lose less mass over their lifetimes of fusion than other stars. They retain more mass, so they collapse into more massive black holes. This idea is based on theory; there’s no direct evidence.

But BH3 could change that.

Binary stars tend to form together and have the same metallicity. Follow-up observations showed that BH3’s companion star is likely a remnant of a globular cluster that the Milky Way absorbed more than eight billion years ago. Since binary stars tend to have the same metallicity, this metal-poor companion bolsters the idea that low-metallicity stars can retain more mass and form larger stellar black holes. This is the first evidence supporting the idea that ancient and metal-poor massive stars collapse into massive black holes. It also supports the idea that these early stars may have evolved differently than modern stars of similar masses.

But there’s another interpretation.

Supernova ESO II edited 1Did you miss our previous article…
https://mansbrand.com/the-solar-eclipse-like-weve-never-seen-it-before/

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The Solar Eclipse Like We’ve Never Seen it Before

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You had to be in the right part of North America to get a great view of the recent solar eclipse. But a particular telescope may have had the most unique view of all. Even though that telescope is in Hawaii and only experienced a partial eclipse, its images are interesting.

You had to be in the right part of North America to get a great view of the recent eclipse. Image Credit: DKIST/NSO/NSF/AURA
You had to be in the right part of North America to get a great view of the recent eclipse. Image Credit: DKIST/NSO/NSF/AURA

The Daniel K. Inouye Solar Telescope (DKIST) is at the Haleakala Observatory in Hawaii. With its four-meter mirror, it’s the largest solar telescope in the world. It observes in visible to near-infrared light, and its sole target is the Sun. It can see features on the Sun’s surface as small as 20 km (12 miles.) It began science operations in February 2022, and its primary objective is to study the Sun’s magnetic fields.

This is a collage of solar images captured by the Inouye Solar Telescope. Images include sunspots and quiet regions of the Sun, known as convection cells. (Credit: NSF/AURA/NSO)
This is a collage of solar images captured by the Inouye Solar Telescope. Images include sunspots and quiet regions of the Sun, known as convection cells. (Credit: NSF/AURA/NSO)

Though seeing conditions weren’t perfect during the eclipse and the eclipse was only partial when viewed from Hawaii, the telescope still gathered enough data to create a movie of the Moon passing in front of the Sun. The bumps on the Moon’s dark edge are lunar mountains.

via GIPHY

“The team’s primary mission during Maui’s partial eclipse was to acquire data that allows the characterization of the Inouye’s optical system and instrumentation,” shares National Solar Observatory scientist Dr. Friedrich Woeger.

The Moon plays a critical role in measuring the telescope’s performance. Its edge is well-known and as a dark object in front of the Sun, it acts as a unique tool to measure the Inouye telescope’s performance and to understand the data it collects. Since the telescope has to correct for Earth’s turbulent atmosphere with adaptive optics, the Moon’s known qualities help researchers work with the telescope’s optical elements.

The Daniel Inouye Solar Telescope at the Haleakala Observatory on the Hawaiian island of Maui. Image Credit: DKIST/NSO
The Daniel Inouye Solar Telescope at the Haleakala Observatory on the Hawaiian island of Maui. Image Credit: DKIST/NSO

“With the Inouye’s high order adaptive optics system operating, the blurring due to the Earth’s atmosphere was greatly reduced, allowing for extremely high spatial resolution images of the moving lunar edge,” said Woeger.
Did you miss our previous article…
https://mansbrand.com/the-milky-ways-history-is-written-in-streams-of-stars/

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