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Complex organic molecules are not proof of life, as Urey's experiment (an electrical discharge in a spherical glass containing methane, ammonia, water, and hydrogen) allowed the creation of complex organic molecules. Those are not themselves life, but they are precursors. Other such experiments include hydrogen sulfide.
It is paradoxical that of those chemicals, only water is a significant part of the Earth's atmosphere today. Except for water, the other chemicals would reach chemical equilibrium as water itself, nitrogen, carbon dioxide, and sulfates. All of those compounds were apparently present in the early atmosphere of the Earth -- when oxygen had not yet become a significant part of the atmosphere. But life itself suggests that these compounds were present.
Life cannot form anew on Earth because of the oxygen, and the combination of carbon dioxide and nitrogen indicates that life could not form on Mars today even with amenable temperatures.
Conditions in the distant past may have been amenable to the formation of the precursor chemicals of life on Mars.
The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated Communist but instead the people for whom the distinction between fact and fiction, true and false, no longer exists -- Hannah Arendt.
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Material older than the Solar System (Murchison meteorite) now shows biochemical and related substances.
The Murchison meteorite is one of the most studied meteorites due to its mass (>100 kg or 220 lb) and the fact that it was an observed fall. It fell in Australia in 1969 near Murchison, Victoria. It belongs to a group of meteorites rich in organic compounds.
In January 2020, astronomers reported that the oldest material found on Earth to date is the silicon carbide particles from the Murchison meteorite, which have been determined to be 7 billion years old, about 2.5 billion years older than the 4.54-billion-year age of the Earth and the Solar System.[a] The published study noted "dust lifetime estimates mainly rely on sophisticated theoretical models. These models, however, focus on the more common small dust grains and are based on assumptions with large uncertainties."
Murchison contains common amino acids such as glycine, alanine, and glutamic acid as well as unusual ones such as isovaline and pseudoleucine.[8] A complex mixture of alkanes was isolated as well, similar to that found in the Miller–Urey experiment. Serine and threonine, usually considered to be earthly contaminants, were conspicuously absent in the samples. A specific family of amino acids called diamino acids was identified in the Murchison meteorite as well.[9]
The initial report stated that the amino acids were racemic and therefore formed in an abiotic manner, because amino acids of terrestrial proteins are all of the L-configuration. Later the amino acid alanine, which is also a protein amino acid, was found to have an excess of the L-configuration,[10] which led several scientists to suspect terrestrial contamination according to the argument that it would be "unusual for an abiotic stereoselective decomposition or synthesis of amino acids to occur with protein amino acids but not with non-protein amino acids".[11] In 1997, L-excesses also were found in a non-protein amino acid, isovaline,[12] suggesting an extraterrestrial source for molecular asymmetry in the solar system. At the same time, L-excesses of alanine were found in Murchison, but with enrichment in the isotope 15N,[13] however, the isotopic pairing was contested later, on analytical grounds.[14] By 2001, the list of organic materials identified in the meteorite was extended to polyols.[15]
Compound class[16]
Concentration (ppm)
Amino acids 17–60
Aliphatic hydrocarbons >35
Aromatic hydrocarbons 3319
Fullerenes >100
Carboxylic acids >300
Hydrocarboxylic acids 15
Purines and pyrimidines 1.3
Alcohols 11
Sulfonic acids 68
Phosphonic acids 2
Total
>3911.3
The meteorite contained a mixture of left-handed and right-handed amino acids; most amino acids used by living organisms are left-handed in chirality, and most sugars used are right-handed. A team of chemists in Sweden demonstrated in 2005 that this homochirality could have been triggered or catalyzed, by the action of a left-handed amino acid such as proline.[17]
Several lines of evidence indicate that the interior portions of well-preserved fragments from Murchison are pristine. A 2010 study using high resolution analytical tools including spectroscopy, identified 14,000 molecular compounds, including 70 amino acids, in a sample of the meteorite.[18][19] The limited scope of the analysis by mass spectrometry provides for a potential 50,000 or more unique molecular compositions, with the team estimating the possibility of millions of distinct organic compounds in the meteorite.[20]
https://en.wikipedia.org/wiki/Murchison_meteorite
The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated Communist but instead the people for whom the distinction between fact and fiction, true and false, no longer exists -- Hannah Arendt.
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Signal reported by SETI (Search for Extra-Terrestrial Intelligence), allegedly from Proxima Centauri B:
A stable radio source at roughly 982 Megahertz has apparently emanated from the second star of the Proxima Centauri star system. The planet lies within the habitable zone of a red dwarf star, and natural causes are unlikely. Very little transmission comes from this frequency well outside of the broadcast bands of radio, wireless, or military communications. To be sure, false alarms have happened, as when someone opened a microwave oven too soon.
The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated Communist but instead the people for whom the distinction between fact and fiction, true and false, no longer exists -- Hannah Arendt.
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Happy super-conjunction day! Site for seeing it longer (the conjunction will be visible for at most a short time anywhere before it sets, and not in polar regions at all) -- or places with bad weather for seeing the night sky.
Saturn is slightly to the north of Jupiter, and the two planets are between the astronomical shapes of Sagittarius and Capricornus. Indeed, you will not have much of a window for seeint the event live.
The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated Communist but instead the people for whom the distinction between fact and fiction, true and false, no longer exists -- Hannah Arendt.
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It's a great time to go look in the early night sky. Mars is still much closer than usual, a sparkling reddish, energy-bestowing presence. And a rare great visible conjunction that represents a new start for society, with the Moon nearby.
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Using the NASA/ESA/CSA James Webb Space Telescope, astronomers have captured a direct image of HIP 65426b, an extrasolar gas giant about 6 to 12 times more massive than Jupiter.'
HIP 65426b is located approximately 363 light-years away in the constellation of Centaurus.
First discovered in 2017, the planet is 1.5 times larger than Jupiter and up to 12 times as massive.
It orbits the A2-type star HIP 65426 (also known as HD 116434), which is almost 3,000 K hotter and twice as massive as the Sun.
HIP 65426b orbits the parent star at a distance of 92 AU (astronomical units); it is sufficiently distant from the star that Webb can easily separate the planet from the star in the image.
“This is a transformative moment, not only for Webb but also for astronomy generally,” said Dr. Sasha Hinkley, an astronomer at the University of Exeter.
“I think what’s most exciting is that we’ve only just begun,” said Dr. Aarynn Carter, an astronomer at the University of California, Santa Cruz.
“There are many more images of exoplanets to come that will shape our overall understanding of their physics, chemistry, and formation.”
“We may even discover previously unknown planets, too.”
https://www.sci.news/astronomy/webb-super-jupiter-hip-65426b-11160.html
The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated Communist but instead the people for whom the distinction between fact and fiction, true and false, no longer exists -- Hannah Arendt.
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