Tuesday, November 14, 2023

4221 - ASTEROIDS - what can we learn from samples?

 

-    4221   -   ASTEROIDS  -   what can we learn from samples?  -   After a years-long mission to collect and retrieve rock samples from the potentially hazardous asteroid Bennu.   The sample, between 3.5 to 8.8 ounces of rocky space rubble collected from the asteroid Bennu's surface contains water and carbon.  The sample was hurtled back to Earth at speeds of up to 27,000 mph, September 24, 2023.


------------------  4221  -    ASTEROIDS  -   what can we learn from samples?

-    After a seven-year, 4 billion-mile roundtrip, the capsule deployed its parachute and safely landed in the Utah desert before being transported to Johnson Space Center, where scientists have begun analyzing its contents for signs of life beyond our planet.

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-   Bennu is a potentially hazardous asteroid that has a 1-in-2,700 chance of striking Earth in the year 2182 which is the highest odds of any known space object.

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-    This is the biggest carbon-rich asteroid sample ever returned to Earth.  Carbon and water molecules are exactly the elements we wanted to find. They're crucial elements in the formation of our own planet, and they're going to help us determine the origins of elements that could have led to life.

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-    Earth's water is older than the planet itself and was probably brought here by asteroid and comet impacts. But water wasn't the only material asteroids brought to Earth. The building blocks of life likely hitched a ride on a space rock, too.

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-    Bennu is a B-type asteroid, which means it contains high amounts of carbon and, potentially, many of the primordial molecules present when life emerged on Earth.

Some of these building blocks, including uracil, one of the nucleobases for RNA, were recently found on the asteroid Ryugu by the Japan Aerospace Exploration Agency's Hayabusa2 spacecraft, which returned to Earth with its rock sample in 2020. OSIRIS-REx mission scientists are hoping to find other potential precursors for Earth's biology inside the Bennu sample.

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-    The bounty of carbon-rich material and the abundant presence of water-bearing clay minerals are just the tip of the iceberg.   These discoveries propel us on a journey to understand not only our celestial neighborhood but also the potential for life's beginnings.

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-    The sample was collected after nearly two years of fraught searching for a landing site on Bennu's craggy surface. Upon contact with the asteroid, OSIRIS-REx fired a burst of nitrogen from its Touch-and-Go Sample-Acquisition Mechanism  not only to stick the landing but to prevent the craft from sinking through the asteroid.

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-   The blast sent rocks and dust careening around the craft, and some of that rocky debris landed in a canister aboard OSIRIS-REx. A follow-up blast of OSIRIS-REx's thrusters later lifted it from Bennu, and the spacecraft completed a number of flyovers before leaving the asteroid for Earth in May 2021.

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-   Tiny particles of rock gathered from the asteroid Ryugu are some of the most primordial bits of material ever examined on Earth and could give us a glimpse into the origins of the solar system.

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-    Asteroid “162173 Ryugu” measures about 2,953 feet in diameter and orbits the sun between Earth and Mars, occasionally crossing Earth's orbit. The carbonaceous, or C-type, asteroid spins like a top as it hurtles through space, and like other C-type asteroids, Ryugu likely contains material from the nebula (giant cloud of dust and gas) that gave birth to the sun and its planets billions of years ago.

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-   In 2019, the Japanese spacecraft Hayabusa2 collected samples from the surface of Ryugu, and on December 6, 2020, those samples were successfully transported to Earth in an airtight container tucked inside the reentry capsule.

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-     In total, the asteroid samples include about 0.2 ounces of material. The largest particles of rock measure about 0.31 inches across; the smallest have diameters less than 0.04 inch, so they resemble fine dust. To the naked eye, the samples look like incredibly dark bits of black pepper.

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-   They kept the material in a vacuum chamber or in a sealed environment filled with purified nitrogen.  The samples have been handled without exposing them to the Earth's atmosphere.  The team assessed the samples using an optical microscope and various instruments that measure how the rocks absorb, emit and reflect different wavelengths of light in the visible and infrared spectra.

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-    The pitch-dark asteroid bits reflect only about 2% to 3% of the light that hits them. The samples' bulk density, the mass of the particles divided by the total volume was lower than that of known carbonaceous meteorites. This finding hints that the rocks are highly porous, meaning that between the individual grains of materials in the rocks exist many pockets of empty space that would allow water and gas to seep through.

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-   This finding aligns with preliminary data collected by the Hayabusa2 spacecraft, which also hinted that the rocks on Ryugu's surface are highly porous.

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-   They used a technique known as “hyperspectral microscopy” to take a closer look at the composition of the asteroid samples. The hyperspectral microscope works by illuminating the samples with different wavelengths of light in the visible and infrared spectra and snapping high-resolution pictures as it does so. Each snapshot measures about 0.2 by 0.2 inches, and each individual pixel provides data on the microscopic scale. In this way, the team revealed fine details of the rocks' color, structure and chemical composition.

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-   Snapshots of the Ryugu samples revealed that the rock particles are composed of a "hydrated matrix," which includes materials such as clay, with carbon-based compounds embedded throughout.  Some of the material properties were close to those of the “carbonaceous chondrites".

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-   The Ryugu samples are among the darkest ever examined.  We have to understand why and what it implies regarding the formation and evolution of this material. They discovered traces of ammonia-rich compounds in the rock, which could have some implications regarding the origin of Ryugu and our understanding of primordial material.

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-     Further assessments of the organic compounds and minerals in the samples will provide key information about how the asteroid and its original body first formed. They can examine the volatile compounds, or those that can be easily vaporized, within the samples; these sorts of tests can reveal how solar winds shaped the asteroid's surface over time.

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-   The sample between 3.5 to 8.8 ounces (100 to 250 grams) of rocky space rubble collected from the asteroid Bennu's surface.  It hurtled back to Earth at speeds of up to 27,000 mph on September 24, 2023, fter a seven-year, 4 billion-mile roundtrip, the capsule deployed its parachute and safely landed in the Utah desert before being transported to Johnson Space Center, where scientists have begun analyzing its contents for signs of life beyond our planet.

-

-    This is the biggest carbon-rich asteroid sample ever returned to Earth.   Carbon and water molecules are exactly the elements we wanted to find. They're crucial elements in the formation of our own planet, and they're going to help us determine the origins of elements that could have led to life.

-

-    Earth's water is older than the planet itself and was probably brought here by asteroid and comet impacts. But water wasn't the only material asteroids brought to Earth: The building blocks of life likely hitched a ride on a space rock, too. Bennu is a B-type asteroid, which means it contains high amounts of carbon and, potentially, many of the primordial molecules present when life emerged on Earth.

-

-    Some of these building blocks, including “uracil”, one of the nucleobases for RNA, were recently found on the asteroid Ryugu by the Hayabusa2 spacecraft, which returned to Earth with its rock sample in 2020. OSIRIS-REx mission scientists are hoping to find other potential precursors for Earth's biology inside the Bennu sample.

-

-    The bounty of carbon-rich material and the abundant presence of water-bearing clay minerals are just the tip of the cosmic iceberg.  These discoveries propel us on a journey to understand not only our celestial neighborhood but also the potential for life's beginnings. With each revelation from Bennu, we draw closer to unraveling the mysteries of our cosmic heritage.

-

-    The sample was collected after nearly two years of fraught searching for a landing site on Bennu's craggy surface. Upon contact with the asteroid, OSIRIS-REx fired a burst of nitrogen  not only to stick the landing but to prevent the craft from sinking through the asteroid.

-

-   The blast sent rocks and dust careening around the craft, and some of that rocky debris landed in a canister aboard OSIRIS-REx. A follow-up blast of OSIRIS-REx's thrusters later lifted it from Bennu, and the spacecraft completed a number of flyovers before leaving the asteroid for Earth in May 2021.

-

-    Tiny particles of rock gathered from the asteroid Ryugu are some of the most primordial bits of material ever examined on Earth and could give us a glimpse into the origins of the solar system.

-

-   Asteroid “162173 Ryugu” measures about 2,953 feet in diameter and orbits the sun between Earth and Mars, occasionally crossing Earth's orbit.   The carbonaceous, or C-type, asteroid spins like a top as it hurtles through space, and like other C-type asteroids, Ryugu likely contains material from the nebula (giant cloud of dust and gas) that gave birth to the sun and its planets billions of years ago.

-

-   The pitch-dark asteroid bits reflect only about 2% to 3% of the light that hits them. The samples' bulk density, the mass of the particles divided by the total volume they occupy, was lower than that of known carbonaceous meteorites. This finding hints that the rocks are highly porous, meaning that between the individual grains of materials in the rocks exist many pockets of empty space that would allow water and gas to seep through.

-

-    Hyperspectral microscopy was used to take a closer look at the composition of the asteroid samples. The microscope works by illuminating the samples with different wavelengths of light in the visible and infrared spectra and snapping high-resolution pictures as it does so. Each snapshot measures about 0.2 by 0.2 inches, and each individual pixel provides data on the microscopic scale. In this way, the team revealed fine details of the rocks' color, structure and chemical composition.

-

-   Snapshots of the Ryugu samples revealed that the rock particles are composed of a "hydrated matrix," which includes materials such as clay, with carbon-based compounds embedded throughout.  Some of the material properties were close to those of the carbonaceous chondrites," a class of carbonous meteorites.

-

-   The Ryugu samples are among the darkest ever examined.  They discovered traces of ammonia-rich compounds in the rock, which could have some implications regarding the origin of Ryugu and our understanding of primordial material.

-

-   These initial analyses represent the first step in figuring out what Ryugu can tell us about the early solar system, but exposing all of the space rocks' secrets will take some time.

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-    These additional techniques will include various chemical analyses, which can reveal the chronological history of when the asteroid first formed and at what ages it came into contact with water.

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-    Further assessments of the organic compounds and minerals in the samples will also provide key information about how the asteroid and its original body first formed. Researchers can also examine the volatile compounds, or those that can be easily vaporized, within the samples; these sorts of tests can reveal how solar winds shaped the asteroid's surface over time.   We have more work to do.  Universe secrets come slowly.

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November 14, 2023        ASTEROIDS  -   what can we learn?             4221

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--------------------- ---  Tuesday, November 14, 2023  ---------------------------------

 

 

 

 

 

           

 

 

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