Astronaut Scott Kelly, whose exceptional vision was part of the reason he was selected to be America’s first astronaut to spend a full year in space, says he's been forced to wear reading glasses since coming home.
John Phillips, who spent time on the International Space Station (ISS) in 2005, brought his sudden bouts of blurry vision home with him, and during his post-flight physical, NASA confirmed that his vision had gone from 20/20 to 20/100 in just six months.
NASA suspected that the condition - called visual impairment inter cranial pressure syndrome, or VIIP - was caused by the lack of gravity in space.
The hypothesis was that the microgravity of the ISS was building up pressure in astronauts’ heads, causing roughly 2 litres of vascular fluid to shift towards their brains.The one big difference between the two was that the long-duration astronauts had significantly more cerebrospinal fluid (CSF) in their brains than the short-trip astronauts, and the researchers say this - not vascular fluid - is the cause of the vision loss.
"What we've invented is an artificial leaf. You just drop it in water, sunlight hits it, off one side comes hydrogen, off the other side comes oxygen."
This system based on a cobalt-phosphorous alloy catalyst converts solar energy to biomass with 10% efficiencey, compared to 1% for the fastest growing plants.
“The beauty of biology is it’s the world’s greatest chemist — biology can do chemistry we can’t do easily. In principle, we have a platform that can make any downstream carbon-based molecule. So this has the potential to be incredibly versatile. ...
If you think about it, photosynthesis is amazing,” he said. “It takes sunlight, water, and air — and then look at a tree. That’s exactly what we did, but we do it significantly better, because we turn all that energy into a fuel.”
They are widely used in the food industry for producing syrups from starches.
This is based on zero data about extraterrestrial biology - so doesn't that mean we can ignore the risk?
Martin Rees - absence of evidence is not evidence of absence
- about intelligent extraterrestrial life.
" Life forms based on silicon, ammonia, and sulfur are among those who may have evolved on other worlds, and these possibilities are discussed...."
" At the moment, life on Earth is the only known life in the Universe, but there are compelling arguments to suggest we are not alone. As Carl Sagan said, the absence of evidence is not evidence of absence. This thought is well known in other fields of research. Astrophysicists, for example, spent decades studying and searching for black holes before accumulating today’s compelling evidence that they exist (Melia and Falcke 2001). The same can be said for the search for room-temperature superconductors, proton decay, violations of special relativity, or for that matter the Higgs boson. Indeed, much of the most important and exciting research in astronomy and physics is concerned exactly with the study of objects or phenomena whose existence has not been demonstrated...."
Example of Eukaryote that got ability to survive acidity pH 0 (like battrey acid) and tolerance to mercury and arsenic to genees from bacteria
Green Galdieria on a rock alongside yellow sulfur deposites, near Reykjavik, Iceland (Credit: Christine Oesterhelt). It's a "red algae" eukaryote (cell with a nucleus).
Heat causes the chemical bonds within proteins to break, which makes them collapse. This has a catastrophic effect on enzymes, which catalyse the body's chemical reactions. The membranes that encase cells also become leaky, allowing molecules in that would normally be kept out. Once a certain temperature has been reached, the membrane breaks and the cell falls apart.
can cope with life at 56C.
However, even more impressive is the algae's ability to tolerate acidity. Some of the hot springs have pH values between 0 and 1.
"Most other lifeforms can't withstand extreme heat or acidity," says Gerald Schoenknecht, a plant biologist at Oklahoma State University in Stillwater. "Galdieria survives pH 0, which is equivalent to surviving in dilute battery acid. Most other organisms, even bacteria, cannot handle pH values that low."
However, it is not just heat and acidity that Galdieria can tolerate. The alga is resistant to arsenic, mercury and can live in extremely salty environments. The poisonous elements are usually deadly to life, as they inhibit important enzymes involved in respiration. Too much salt, on the other hand, prevents plant cells from taking up water, drying them out and turning them into shrivelled husks.
In total Schoenknecht identified 75 genes in the algae that were taken from bacteria or archaea. Not all the genes give the algae an obvious evolutionary advantage, and the exact function of many of the genes is unknown.
However, many of the genes do help Galdieria survive in its extreme environment.
One of these genes is for an "arsenic pump" which allows the algae to effectively remove arsenic from its cells. Other stolen genes found include those for metal transporters that allow Galdieria to excrete toxic metals, whilst simultaneously taking up essential metals from its environment. Yet other of the purloined genes control enzymes that allow Galdieria to detoxify metals such as mercury.
The algae had also nicked genes that allow it to tolerate high salt levels. Under normal circumstances, a very salty environment will suck the water out of a cell and kill it. But by synthesising compounds inside the cell that equalise the "osmotic pressure", Galdieria escapes that fate.
"It seems that adaptation to the low pH was mainly driven by removing any membrane transport protein from the plasma membrane that would allow protons to enter the cell," says Schoenknecht. "Most eukaryotes have numerous potassium channels in their plasma membrane, Galdieria has only a single gene encoding a potassium channel. So making the plasma membrane 'proton tight' seems to be the main approach to deal with low pH."
However those potassium channels perform important jobs, such as potassium uptake, or maintaining a voltage difference between the cell and outside. How Galdieria stays healthy without the potassium channels is currently entirely unclear.
It is also a mystery – for now – how Galdieria copes with extreme heat. The scientists were unable to identify genes that could explain that particular feature of its biology.
. G. sulphuraria has a unique position within the Cyanidiales because, in contrast to the other obligate photoautotrophic members of this group, it is able to grow photoautotrophically, mixotrophically, and heterotrophically. It is not only resistant to acid (pH 0) and heat (56ºC), but also to high salt (1.5 M NaCl), toxic metals, and many other abiotic stressors. This unusual combination of features such as thermophily, acidophily, resistance to a wide array of abiotic stressors, and an extraordinary metabolic plasticity make G. sulphuraria highly interesting model organism to study adaptation to extreme environments.
Even if it is completely alien, no DNA, not even RNA - how do we find it in a habitat that has been colonized by Earth microbes? This is the problem researchers find looking for a "Shadow biosphere" on Earth.
Even unrelated life is hard to discover.
"Finding a Second Sample of Life on Earth"
If alien life flourishes in similar environments as known life, then looking in novel environments is unnecessary. Rather, we need to devise a means by which to separate known from alien microbes. Any physical characteristic, e.g., size, membrane structure, might differentiate between them. An example, albeit controversial, is the socalled nanobacteria or nanobes discovered in nature, which seemingly are too small to contain ribosomes and, therefore, are potentially alien (Folk, 1993; Uwins et al., 1998). The problem of simply plucking an alien microbe from a general biological setting, however, is daunting. Very few known microbes, let alone alien microbes, can be cultured. An alien microbe might look superficially like a known bacterium; only a genetic analysis would disclose its exotic nature. Clearly a more systematic approach is necessary.
The primer sets that are currently being used in bio-prospecting could be generalized (Paster et al., 1998). An example of the necessity of this is the discovery via microscope of a novel Archeon that grows attached to Ignococcus but has such a divergent 16S rRNA sequence that no universal primer could detect it (Huber et al., 2002). A technique to identify non-DNA organisms is to apply DNA stains and then use flow cytometry to selectively remove DNA-based cells. Any remaining cells could then be scrutinized microscopically and biochemically. If alien microbes were DNA-based but non-ribosomal, they might be identified by fluorescent in situ hybridization probes and separated using flow cytometry (Michael Gillings, private communication).
Another possibility concerns chirality. The origin of biological chirality remains contentious (Eliel et al., 1994), but a plausible hypothesis is that it represents a frozen accident: Early life broke the symmetry at random, producing the observed chirality with 50% probability. It follows that there is a 50% chance that a second genesis (or similar life) would select the opposite chirality. This would assist the co-existence of alien and known life forms. It would also provide a means to detect alien life. If a nutrient broth with opposite chirality contents (“anti-soup”) were used as a culture medium, known life might be unable to grow, but oppositely chiral alien life may still flourish (Pauline Davies, private communication). Experiments with anti-soup have been performed on the sterile soils of the Atacama desert (Navarro-González et al., 2003), but as far as we are aware they have not been used to study more promising locales for alien life
Finally, if a means could be found to interrupt genetic machinery employing the universal genetic code, then any remaining signs of metabolism are likely to be indicative of either alien or novel organisms. Other mechanisms can be envisaged that target ribosome function or replicase enzymes. The alien life might then be identified by its metabolic products, or through labeled release experiments similar to the Viking procedures, or directly from microscopic searches and gene sequencing
"The problem of simply plucking an alien microbe from a general biological setting, however, is daunting. Very few known microbes, let alone alien microbes, can be cultured. An alien microbe might look superficially like a known bacterium; only a genetic analysis would disclose its exotic nature. Clearly a more systematic approach is necessary."
Oh, sorry to be a damp blanket here, but I find that idea deeply improbable. Even if they stop all the current leakage of the atmosphere, where is the extra CO2 going to come from? Mars is still volcanically active, yes, but in a surface area as large as Earth’s land area, they are yet to find any sign of any volcanic activity at all, or even hot spots such as might be the sign of fumaroles.
And Earth doesn’t produce that much by way of CO2 from volcanoes.
You can also look at it another way. If it’s true that Mars lost all its atmosphere through solar wind erosion - how quickly did it happen? Suppose it lost 1 bar in a million years? That would be astonishingly rapid. Then that means that if we stop the erosion, well it’s going to take at least that long to regain 1 bar. But probably longer if it was in a steady state before. So - to double the atmosphere to 0.012 bars for instance would take 12,000 years, and reach a point where it is possible to have some liquid water but you still need a fully pressurized spacesuit.
It’s hard to see how it could double its atmosphere in less than many thousands of years and to reach 1 bar, hundreds of thousands to millions - but most likely hundreds of millions to billions of years. All that time you need to have this magnetosphere shield in place.
And - I don’t think there is any evidence that SpaceX are working on terraforming. There are papers by Chris McKay and others. Nothing by them. Elon Musk was just making an off hand remark here, as a kind of a joke. He had no figures to back it up and there would be not the slightest reason to keep that secret, if he had figures and details that showed that Mars could be terraformed quickly.
Paper itself is here:
396,329 / 475
995.2 Pages times new roman 12 point
MULTI-MICE: A Network of Interactive Nuclear
Cryo Probes to Explore Ice Sheets on Mars and Europa
The expanding venue and persistence of planetary mobile robotic
exploration—new technology concepts for Mars and beyond
Autonomous space flight system and planetary lander for executing a discrete landing sequence to remove unknown navigation error, perform hazard avoidance and relocate the lander and method
about MELOS japanese Mars rover
Should We Invest in Martian Brine Research to Reduce Mars Exploration Costs?
- doesn't say much
The situation for the rover was simplified
by the approach of an ultra-clean part of the rover interior.
All the sample processing and science observations
are happening in this ultra-clean zone. Although
now the number of instrument groups affected by the
stringent CC requirements was small the test procedures
and the effective implementation of the CC requirement
into the assembly and integration of the instruments
and rover was challenging. The amount of
contamination at the beginning of the science mission
on Mars was fixed, but the distribution to the individual
teams and the approach of every team to meet the
requirements had to be implemented.
The allowed amounts of organic contamination
were in the ng range and for every instrument parts
cleaning procedures and verification methods had to be
tested and approved. But the final prove of concept that
every part of the ultra clean zone was clean enough
would first be tested with the qualification model of the
PROGRESS REPORT ON DEVELOPMENT OF THE EXOMARS 2018 SAMPLE
PROCESSING AND DISTRIBUTION SUBSYSTEM (SPDS) AND RELATED OHB
SAMPLE HANDLING STUDIES
- doesn't have contamination levels though
The maximum Earth entry velocity will be < 12 km/s
In addition to recognizing the need for dedicated curation facilities, iMARS has also discussed the advantages
in setting up more than one facility, located in different countries. If there were multiple facilities, it
might be advantageous to set them up in a complementary rather than identical way. In addition, dividing
the sample set might improve overall sample security (e.g. vulnerability to a single catastrophic event) and
take advantage of the specifi c expertise of international partners. The
Tonga trench. The LEM carried a plutonium-238 heat source in a special transport cask designed to withstand reentry. It apparently did so. Periodic submarine checkups have detected no signs of leakage.
SAFE HAVENS: SELECTING LANDING SITES FOR VIKING
Interesting history. Also at one point they were wondering whether or not to include cameras on the Viking orbiter.
The story of Wei Lee, the most unlikely Messiah since L. Ron Hubbard. It is set on Mars 600 years after the Yankees tried to terraform it, and failed, and 500 years after the Red Chinese took over and finished the job. The author won the Philip K. Dick Award for "Eternal Light".
New research from the University of Maryland, the University of St. Andrews, NASA's Jet Propulsion Laboratory, the University of Leeds and the Blue Marble Space Institute of Science suggests that long ago, Earth's atmosphere spent about a million years filled with a methane-rich haze. This haze drove a large amount of hydrogen out of the atmosphere, clearing the way for massive amounts of oxygen to fill the air. This transformation resulted in an atmosphere much like the one that sustains life on Earth today.
Has estimate of how big an impact would need to be for oceans to boil - ends up size of Vesta or Ceres as conservative lower bound.
good online simplify calculator
192900153618 to 23 decimal places. It's actually
high precision online calculator, up to 50 decimal places
How bio-friendly is the universe?
Possible Source for Martian Meteorite ALH 84001
Dr. Nadine Barlow of the University of Central Florida has searched a catalog of 42,283 martian impact craters and has found only two fresh craters of the right shape and size — circular and less than 100 kilometers across, or elliptical and less than 10 kilometers across. Only two craters appeared suitable
ice calving video for Europa section - another version
Searching for the Source Crater of Nakhlite Meteorites
We surveyed the Martian surface in order to identify possible source craters of the
nakhlite Martian meteorites. We investigated rayed craters that are assumed to be younger than
11 Ma, on lava surfaces with a solidification age around 1.2 Ga. An area of 17.3 million km2
Amazonian lava plains was surveyed and 53 rayed craters were identified. Although most of
them are smaller than the threshold limit that is estimated as minimum of launching fragments
to possible Earth crossing trajectories, their observed size frequency distribution agrees with
the expected areal density from cratering models characteristic for craters that are less than few
tens of Ma old. We identified 6 craters larger than 3 km diameter constituting the potentially
best source craters for nakhlites.
Third, the flux of terrestrial impactors must have been low (. 10-6 M? Myr-1
) to avoid
wholesale melting of Earth’s crust after 4.4 Ga, and to simultaneously match the number of observed lunar basins. This conclusion
leads to an Hadean eon which is more clement than assumed previously
Mars, panspermia, and the origin of life:
where did it all begin?
Was Mars the cradle of life?
Mars is the most Earth-like of our
neighbouring planets and enjoyed a
number of advantages during the early
history of the solar system. Though a
freeze-dried desert today, Mars was warm
and wet before about 3.6 billion years
ago. Being a smaller planet, it cooled
more quickly, making it suitable for life
sooner than Earth. Gene sequencing
indicates that the oldest and deepest
branches of the tree of life are occupied
by hyperthermophilic archaea and
bacteria, hinting that the earliest life
forms dwelt deep beneath the oceans
near volcanic vents, or even kilometres
underground in the crust itself.
The deep subsurface zone remains
populated on Earth today, and probably
offers the most promising location on
Mars for finding any extant life. It would
have become cool enough for
hyperthermophilic microbial life on Mars
perhaps as long ago as 4.5 billion years,
when the Earth’s crust was still sizzling.
Ensconced in this Hadean niche, shielded
by a kilometre of two or rock, Martian life
could have withstood the ferocious early
bombardment that afflicted Mars just as it
- needs updated, this cite below is wrong:
. It turns out that you need an oblique impact powerful enough to form a crater about 10 km in diameter, or a direct hit causing an impact crater about 100 km across (https://en.wikipedia.org/wiki/Martian_meteorite#Age_estimates_based_on_cosmic_ray_exposure). The impactor would be about 1 km across, and you would get impacts like that roughly every one or two million years.
A colossal impact enriched Mars’ mantle with noble metals
June 1017 http://onlinelibrary.wiley.com/doi/10.1002/2017GL074002/full
Theory that northern sea was result of a large Ceres sized impact into Mars and this may also have formed its moons.
Present-day seasonal gully activity in a south polar
pit (Sisyphi Cavi) on Mars
(unlikely to be water)
Alan Bean Surrounded by Blue Aura Thought to be Water-Vapor Ice Crystals; Photographed by Charles Conrad, Apollo 12, November 14-24, 1969 55, 1999
Alan Bean Surrounded by Blue Aura Thought to be Water-Vapor Ice Crystals; Photographed by Charles Conrad, Apollo 12, November 14-24, 1969
What we could learn - some examples
Other space treaties
OST text good link.
"We know that gypsum is naturally found on Mars, so applying our current finding will also help us understand and predict the hydrological conditions at the time of gypsum formation on other planets,"
James Lovelock's argument for a lifeless Mars
Issues and Future
- 1991 version.
The Agency also showed that comet 67P/Churyumov–Gerasimenko – the target of Rosetta's mission and where Rosetta will reside after the mission ends in September 2016 – will have no encounters with Mars closer than 94 million kilometres within fifty years after the launch of the spacecraft, despite crossing the orbit of Mars. The lander, Philae, also satisfies these constraints by virtue of the comet's low probability of impacting Mars.
Sutherland’s team reports that it created nucleic acid precursors starting with just hydrogen cyanide (HCN), hydrogen sulfide (H2S), and ultraviolet (UV) light. What is more, Sutherland says, the conditions that produce nucleic acid precursors also create the starting materials needed to make natural amino acids and lipids. That suggests a single set of reactions could have given rise to most of life’s building blocks simultaneously.
Could update with quote from Elon Musk here:
purple pigments maybe early - caretenoids then retinal pigments then chlorophyll
Could "Planetary Protection" Scuttle Otherworldly Exploration?
The Astrobiology Science Conference (AbSciCon) took place at the Mesa Convention Center in Mesa, Arizona on April 24–28, 2017.
Physicist, running risk innovation lab at ASU.
"I think that we learn a lot about climate change on Earth by exploring other planets. It is not one or the other. Science is integrated in such a way that you can address a lot of questions at the same time.
But I wanted to say about forward contamination being this big issue for astrobiologists, is that a lot of the public desire for space exploration is to send humans and if we send humans anywhere we will contaminate the planet, because we are dead if we are sterile, so there is a huge conflict between trying to understand microbial life anywhere and human exploration in particular."
That is a really big value disconnect. Talk about risk. You have got the people that are really dedicated to getting humans on other bodies see people who don't like that idea because of contamination as a risk to their mission. On the other hand if you're interest is in alien life, or the evolution of life or life like systems in other systems, the idea of putting humans on another body is a risk to what you think is incredibly important. So how do we begin to find the common ground between those.
Linda Billings, a researcher at George Washington University
"If NASA were to spend $5 billion on a life detection mission, and over the course of the mission it is discovered that the life we discovered was Earth life, the loss of public trust would really shoot up."
Andrew Maynard: "I can't think of any one good example where colonization has been uniformly good. As a species it's been a history of bad ideas, bad mistakes, that somehow we've been able to bumble through and actually make some sort of progress for some people afterwards. So we don't have a great track record here."
Margaret Race, Seti Institute. "
Keith Cowing editor of adastra and astrobiology.com
If parents can tell kids "wash your hands before dinner
"Basic aspects of microbiology is not hard to grasp. If whatever audience you have today is not getting your message, you need new messengers. We had a whole group about just explaining this to people. And I frankly don't see enough of that these days. You guys may know the topic but you didn't take that class in college of talking to the public.
Andrew Suegar work in field of planetary protection.
"The surface of Mars has a very wide range of biocidal factors, 15 to 20.
So really the concern is if we have communities or assemblages from Earth transported to Mars, able to survive those biocidal factors, be dispersed into niches and then become estabalished, 48 minutes into this video.
Contamination that is able to establish itself and
15 to 20 biocidal factors.
Communities able to survive those factors,
Alcohol and hypochlorite more sterilizing than either separately
We observe that CO2 ice is weakly probable where and/or when some lower amplitude activity
occurred. In particular, all new bright deposits are poorly compatible with CO2 ice while they are
linked with water ice. These bright deposits are preferentially observed on warmer nonpole-facing
orientations and, at Gasa crater, in late winter around sublimation time. A specific formation
mechanism linked with water ice sublimation could thus be acting at these locations.
Overall, our observations are consistent with the existence of several mechanisms currently
participating to gully activity.
The effect of hypochlorite on spores of Bacillus subtilis lacking small acid-soluble proteins
The common burden of “spacemankind”
by Kamil Muzyka
Perchlorate on Mars: A chemical hazard and a resource for humans (PDF Download Available). Available from: https://www.researchgate.net/publication/242525435_Perchlorate_on_Mars_A_chemical_hazard_and_a_resource_for_humans [accessed Jul 11, 2017].
Hi there, I don't know if I'm somehow missing something obvious, but it seems to me that article 9 does mention nationals of the State in the second sentence, "If a State Party to the Treaty has reason to believe that an activity or experiment planned by it OR ITS NATIONALS in outer space, including the moon and other celestial bodies, would cause potentially harmful interference with activities of other States Parties in the peaceful exploration and use of outer space, including the moon and other celestial bodies, it shall undertake appropriate international consultations before proceeding with any such activity or experiment."
(Emphasis mine). Wouldn't "nationals" there include private citizens, so long as they are US citizens (in the case of the US)? Or if not, what am I missing there. It seems to me to suggest that the authors of the treaty intended it to be interpreted as meaning that the State is responsible for the activities and experiments of its nationals. So for instance, wouldn't it mean that if Elon Musk planned to land humans on Mars, that would count as an activity or experiment that could potentially interfere in a harmful way with, e.g, the activities of ESA's ExoMars looking for life on Mars and future experiments by Russia, India, China, Japan etc? So then the US would need to undertake appropriate international consultations before proceeding. Where by "proceeding" that must surely mean letting its nationals do the activity or experiment? What else could it mean?
Also this matter of the way the activity would interfere with the activities of ESA, and Russia, China, Japan, or anyone else who wants to send life detection experiments to Mars - I think is a potential basis for interpreting "harmful contamination" as including interference with the scientific work of other States. Not exclusively that, but it is surely included as part of the interpretation?
To me, this seems the natural way to interpret what they say, and it's not introducing anything new that they didn't say in the treaty text. Or is it? If so why?
My background is that I think the science value of Mars is paramount, and could lead to new discoveries in biology, medicine, agriculture etc, it could potentially be the most important discovery in biology of this century, perhaps since the discovery of evolution, if they found microbes that were not based on DNA, as one example.
Also, the spacecraft that we send to Mars are not impoverished in this respect. In clean room assays of DNA, again, a fair bit of the DNA is from species that are not sequenced or cultivated. Here is a paper about the archaea recovered from clean room samples - though they couldn't be cultivated, the authors write, "It was unclear whether the detected Archaea were alive at the time of sampling, would be capable of growth in extraterrestrial environments, or able to withstand space travel, but given the ubiquitous nature of Archaea it would be naive to completely dismiss any of these possibilities."
Planet Formation and the Origin of Life
Nice overview article by PI of Osirix Rex
If early Mars was generally arid and cold, impact-induced heating punctuated this surface state by intermittently destabilizing the near-subsurface cryosphere to generate regional-scale hydrothermal systems. Rather than being deleterious to the proclivity of Noachian Mars to host an emergent biosphere, this intense early impact environment instead enhanced the volume and duration of its surface/subsurface geophysical habitable zone.
Mass flux in the ancient Earth-Moon system and benign implications for the origin of life on Earth
Scaling for flux, size, and energy to the Earth suggests that impacts capable of evaporating the oceans, even indirectly, are unlikely to have occurred after ~4.35 Ga, even during the cataclysm.
According to Zahnle and Sleep , hundreds of objects like the Imbrium and Orientale impactors must have struck the Earth during the basin-forming era. Nonetheless, an Imbrium-sized impactor scaled to terrestrial collision energy had only 1% of the energy needed to evaporate Earth's oceans, assuming an ocean mass similar to today's and that 25% of the energy of such an impact was partitioned into the ocean [Zahnle and Sleep, 1997] (a model assumption of unknown validity). Such an impact would have vaporized only the upper few tens of meters of ocean by heating from above by an atmosphere of hot silicate. Even impacts orders of magnitude larger would have been far from sufficient, boiling off a few hundred meters. Ocean-vaporizing impacts were considered rare after 4.4 Ga in the estimation of Zahnle and Sleep ; the lunar record suggests that they may have been absent.
Our results show that LHB does not excavate/melt all of Hadean continental crust
directly, but over 70% of the Earth’s surface area can be covered by subsequent
melts in a broad range of a. If there have been no overturns of the continental
crust until today, LHB could be responsible for the absence of Hadean rocks because
most of Hadean continental crust is not be exposed on the Earth’s surface
in this case.
It suggests the absence of Hadean rocks could be explained by
LHB if the stratigraphic succession has been preserved until today because most of Hadean
continental crust is not be exposed on the Earth’s surface in this case.
Most scientists agree that if a planet had smacked into Earth and the moon came about as a result, than the moon ought to be made of some of that other planet as well. Some say the laws of physics suggest it would be somewhere in the neighborhood of forty percent. If that’s the case, why don’t studies of rocks brought back by the Apollo missions show evidence of this other planet?
A glancing blow would mean that the Moon would be mostly made of Theia, and would therefore have a different oxygen isotope fingerprint than Earth. But the fact that the Earth and Moon are indistinguishable from each other means that Theia had to have been destroyed, or rather, had to become part of both the Earth and the Moon.
- 2.6 km / sec Mars return to Earth
We report on laboratory experiments which simulate the breakdown of organic compounds under Martian surface conditions.
The quantum efficiency for the decomposition of glycine by light at wavelengths from 2000 to 2400 Å was measured to be 1.46±1.0×10-6 molecules/photon. Scaled to Mars, this represents an organic destruction rate of 2.24±1.2×10-4 g of C m-2 yr-1. We compare this degradation rate with the rate that organic compounds are brought to Mars as a result of meteoritic infall to show that organic compounds are destroyed on Mars at rates far exceeding the rate that they are deposited by meteorites
- answer draft
- could update
his paper with e.g. "Some Evidence Supporting the Hypothesis of Conscious Stars"
I think Moon first is definitely the way to go with humans, after that - a flyby but not in a tiny spaceship like Inspiration Mars - a crew of six or seven, specialists, once we have the technology - and the best flyby is probably the double Athena - same advantage of a “free return” trajectory that once you leave Earth, then you are guaranteed to return back to the vicinity of Earth even if your rockets fail completely. All the delta v is at the start of the journey apart from minor adjustments. But it has two flybys of Mars and you are close enough for telepresence for hours at a time each time and then reasonably close for days and much closer than Earth for months until the next flyby, so much more opportunity for telerobotic exploration. I think it’s a good first mission for safety reasons, also for planetary protection. Then an orbital mission but that needs an insertion burn into a sun prescessing Molniya orbit and another burn to get out of it, so more to go wrong, and you also need to be sure of your burns that they can’t end up with you hitting Mars. Then Phobos / Deimos base, but with robotic scouts first.
I think that could well take us not just years but a decade or two, after bases on the Moon. I think they are wildly optimistic to hope to get that far without being reckless, by the 2020s. Maybe 2040s? 2030s if there is a huge push, some major international effort?
- relevant to OK to Touch?
- can answer
Yes could be. There is just no way to know - the “alien” bacteria could out compete the Earth originated bacteria, the Earth originated bacteria could take over from the Mars bacteria, or they could co-exist. One thing the Earth bacteria would do for sure is confuse the situation if there are habitats they can survive in on Mars.
So - you need to distinguish between decisions we do now, when we have no idea whether there is Mars life on Mars, are not sure if there are habitats that Earth life can occupy there, and don’t know what Earth life would do to those habitats or Mars life if introduced, from decisions we might make, perhaps a decade or two from now, or whenever it is we have answers to those questions. I’m saying that we shouldn’t introduce Earth life now and should leave decisions until we know more.
Did 40-year-old Viking experiment discover life on Mars?
An Instrument Suite to Search for Brines in the Shallow Subsurface of Mars
A new family of extraterrestrial amino acids in the Murchison meteorite
Even though the Murchison meteorite has been studied for the occurrence of amino acids for almost 50 years, this study has revealed the presence of ten new amino acids, including a new family of nine hydroxy C3 and C4 amino acids.
Thirty amino acids between C2 and C6
Lots of interesting looking planetary protection articles.
A legal look at Elon Musk’s plans to colonize Mars
by Michael J. Listner
Thanks! Yes, I suppose they’d be smaller mass than the Tsar Bomba - didn’t research into that, but the Tsar remains the highest yield nuclear bomb. The Mars south pole is mainly carbon dioxide to depths of kilometers, the north pole is mainly ice. Still that’s only enough dry ice to roughly double the atmospheric pressure of Mars if it was all released.
Add to Science20 and quora post.
In 1960, Joseph Kettinger was doing a high altitude parachute drop from a balloon - wisely wearing a space suit.
One of his gloves lost pressure - and his hand rapidly swelled to twice it’s normal size - and he had all of those “gas boiling out of blood” problems. The pain was so phenomenal that he was completely unable to do anything to help himself.