Nov 11, 2021 11:36 PM
Earth is the Solar System’s densest planet. It shouldn’t be.
https://bigthink.com/starts-with-a-bang/...st-planet/
INTRO: When it comes to the Solar System, the elements that make up each planet are determined by how they all formed. Closest to the Sun, the high temperatures, large amounts of solar radiation, and intense solar winds can easily kick the lightest elements off of any protoplanets that are forming. But farther away from the Sun, these factors have more difficulty expelling light elements. As a result, we wind up with planets that are disproportionately made of heavier elements the closer you get to the Sun, and that have lower density compositions — and large amounts of lighter atoms — the farther out we venture.
In the innermost part of the Solar System is the planet Mercury, which has only a negligible atmosphere and is made largely of rocky and metallic material. As we travel farther away from the Sun, atmospheres become common, as do greater proportions of lighter elements. If we were to look at each planet’s composition in terms of the atoms that make it up, Mercury would have the highest percentage of heavier elements, trailed by Venus and Earth, with Mars even farther behind.
You might think that would make Mercury the densest planet, but that’s not true at all. If you measure each planet’s mass and divide it by its volume, it turns out that Earth, not Mercury, is the densest world in our Solar System. Here’s the surprising science behind why... (MORE)
The Moon’s top layer alone has enough oxygen to sustain 8 billion people for 100,000 years
https://theconversation.com/the-moons-to...ars-170013
EXCERPT: . . . ome people call the Moon’s surface layer lunar “soil”, but as a soil scientist I’m hesitant to use this term. Soil as we know it is pretty magical stuff that only occurs on Earth. It has been created by a vast array of organisms working on the soil’s parent material — regolith, derived from hard rock — over millions of years.
The result is a matrix of minerals which were not present in the original rocks. Earth’s soil is imbued with remarkable physical, chemical and biological characteristics. Meanwhile, the materials on the Moon’s surface is basically regolith in its original, untouched form.
One substance goes in, two come out
The Moon’s regolith is made up of approximately 45% oxygen. But that oxygen is tightly bound into the minerals mentioned above. In order to break apart those strong bonds, we need to put in energy.
You might be familiar with this if you know about electrolysis. On Earth this process is commonly used in manufacturing, such as to produce aluminium. An electrical current is passed through a liquid form of aluminium oxide (commonly called alumina) via electrodes, to separate the aluminium from the oxygen.
In this case, the oxygen is produced as a byproduct. On the Moon, the oxygen would be the main product and the aluminium (or other metal) extracted would be a potentially useful byproduct.
It’s a pretty straightforward process, but there is a catch: it’s very energy hungry. To be sustainable, it would need to be supported by solar energy or other energy sources available on the Moon.
There are multiple alumina (aluminium oxide) refineries in Australia, including this one pictured in Gladstone, Queensland. Aluminium is produced in two stages. Before pure aluminium can be released using electrolysis (in what is known as the Hall-Heroult process), alumina refineries must first refine naturally occurring bauxite ore to extract the alumina (from which pure aluminium is later retrieved). Dave Hunt/AAP
Extracting oxygen from regolith would also require substantial industrial equipment. We’d need to first convert solid metal oxide into liquid form, either by applying heat, or heat combined with solvents or electrolytes. We have the technology to do this on Earth, but moving this apparatus to the Moon – and generating enough energy to run it – will be a mighty challenge.
Earlier this year, Belgium-based startup Space Applications Services announced it was building three experimental reactors to improve the process of making oxygen via electrolysis. They expect to send the technology to the Moon by 2025 as part of the European Space Agency’s in-situ resource utilisation (ISRU) mission.
That said, when we do manage to pull it off, how much oxygen might the Moon actually deliver? Well, quite a lot as it turns out... (MORE - details)
https://bigthink.com/starts-with-a-bang/...st-planet/
INTRO: When it comes to the Solar System, the elements that make up each planet are determined by how they all formed. Closest to the Sun, the high temperatures, large amounts of solar radiation, and intense solar winds can easily kick the lightest elements off of any protoplanets that are forming. But farther away from the Sun, these factors have more difficulty expelling light elements. As a result, we wind up with planets that are disproportionately made of heavier elements the closer you get to the Sun, and that have lower density compositions — and large amounts of lighter atoms — the farther out we venture.
In the innermost part of the Solar System is the planet Mercury, which has only a negligible atmosphere and is made largely of rocky and metallic material. As we travel farther away from the Sun, atmospheres become common, as do greater proportions of lighter elements. If we were to look at each planet’s composition in terms of the atoms that make it up, Mercury would have the highest percentage of heavier elements, trailed by Venus and Earth, with Mars even farther behind.
You might think that would make Mercury the densest planet, but that’s not true at all. If you measure each planet’s mass and divide it by its volume, it turns out that Earth, not Mercury, is the densest world in our Solar System. Here’s the surprising science behind why... (MORE)
The Moon’s top layer alone has enough oxygen to sustain 8 billion people for 100,000 years
https://theconversation.com/the-moons-to...ars-170013
EXCERPT: . . . ome people call the Moon’s surface layer lunar “soil”, but as a soil scientist I’m hesitant to use this term. Soil as we know it is pretty magical stuff that only occurs on Earth. It has been created by a vast array of organisms working on the soil’s parent material — regolith, derived from hard rock — over millions of years.
The result is a matrix of minerals which were not present in the original rocks. Earth’s soil is imbued with remarkable physical, chemical and biological characteristics. Meanwhile, the materials on the Moon’s surface is basically regolith in its original, untouched form.
One substance goes in, two come out
The Moon’s regolith is made up of approximately 45% oxygen. But that oxygen is tightly bound into the minerals mentioned above. In order to break apart those strong bonds, we need to put in energy.
You might be familiar with this if you know about electrolysis. On Earth this process is commonly used in manufacturing, such as to produce aluminium. An electrical current is passed through a liquid form of aluminium oxide (commonly called alumina) via electrodes, to separate the aluminium from the oxygen.
In this case, the oxygen is produced as a byproduct. On the Moon, the oxygen would be the main product and the aluminium (or other metal) extracted would be a potentially useful byproduct.
It’s a pretty straightforward process, but there is a catch: it’s very energy hungry. To be sustainable, it would need to be supported by solar energy or other energy sources available on the Moon.
There are multiple alumina (aluminium oxide) refineries in Australia, including this one pictured in Gladstone, Queensland. Aluminium is produced in two stages. Before pure aluminium can be released using electrolysis (in what is known as the Hall-Heroult process), alumina refineries must first refine naturally occurring bauxite ore to extract the alumina (from which pure aluminium is later retrieved). Dave Hunt/AAP
Extracting oxygen from regolith would also require substantial industrial equipment. We’d need to first convert solid metal oxide into liquid form, either by applying heat, or heat combined with solvents or electrolytes. We have the technology to do this on Earth, but moving this apparatus to the Moon – and generating enough energy to run it – will be a mighty challenge.
Earlier this year, Belgium-based startup Space Applications Services announced it was building three experimental reactors to improve the process of making oxygen via electrolysis. They expect to send the technology to the Moon by 2025 as part of the European Space Agency’s in-situ resource utilisation (ISRU) mission.
That said, when we do manage to pull it off, how much oxygen might the Moon actually deliver? Well, quite a lot as it turns out... (MORE - details)