67

Right now, almost 100% of existing research on growth in gravity fields is basically at 0g (ISS/Mir/Skylab/whatever) or 1g. There are a lot of questions of what happens at 1/6g or 2/3g? No good experiments to demonstrate. Thus the Chinese lander is testing 1/6th g. SpaceX is likely to brute force test 38% g when they get to Mars. It is entirely possible ...


67

Once we introduce microorganisms into an environment, it makes it more difficult to study any microorganisms that might already be there, and it's basically impossible to undo. We won't be able to tell if any products of biological processes came from our contamination or from what was there before us. We won't be able to tell whether a particular ...


60

The answer to your formal question is: we cannot be certain we haven't already contaminated another world with our life, although we try not to. See NASA's notes on planetary protection protocols (1) for more information about that. However, I think it is more important to address the other question you propose. Paraphrasing, you ask: "Why wouldn't we ...


57

Tardigrades can survive vacuum, low temperatures, and moderate radiation for quite a while. They're multicelled organisms. How tough is the toughest hypothetically viable single-celled extremophile? How sure are you that we've found all of them on Earth already? It's a matter of caution. Contamination of another planet (or moon) is likely to be irreversible,...


43

To keep an animal alive, a spacecraft needs to create conditions (e.g. temperature, pressure, concentrations of gases or electrolytes) within the animal's normal physiological range. We can recreate nearly any environment; however, the resources necessary to do this may be prohibitive. Thus, the answer to the question is that it may be possible, yet ...


31

There are probably many answers, but for guesstimating hypothetical missions a look at delta-V/subway maps like this are highly informative in terms of problem scale. Working from that getting into LEO is 9.4 km/s, these are the rockets you see launching regularly, and can get about 5% of their launch mass into orbit. Earth escape needs another 3.41 km/s, ...


27

So back in the summer of 1935, some folks down in Australia were having problems with a beetle's larvae that were nomming on the sugar cane roots and harming crops. Since traditional methods of getting rid of the pest failed, they decided a good approach would be to introduce a few cane toads to go eat the beetles... a hundred or so of them in a couple of ...


27

tl;dr: There are "96 bags of poop, pee, and puke" on the Moon already! The bags of waste are ecosystems for sure, but like the ones you mentioned, they are not going to remain alive for very long. From Gizmodo's There's Poop on the Moon: There is, however, scientific value to the things left behind. Astrobiologists, for instance, hope to one day ...


26

Absolute 100% sterilization is impossible. There's always a tiny chance that some microbe lands on a component during manufacturing, gets entombed inside the packaging, and therefore is unreachable by sterilization. Getting such a microbe out to the environment would require breaking the spacecraft in a very peculiar way, without incinerating or damaging ...


23

@GremlinWrangler's answer sums up several important points; Getting a low mass rover from Earth all the way to landing on the surface of one of those Moons requires much much more rocketry (delta-v) than landing a much heavier and more capable/diverse probe on the surface of Mars. Solar won't work well there and RTG's are quite scarce Let's also consider ...


22

No. Look at the numbers: 10000 kg. => Your rocket 73420000000000000000000 kg. => The moon 5972200000000000000000000 kg. => The earth 1989000000000000000000000000000 kg. => The sun To put this to scale, the rocket has a similar mass towards the moon as that of one human cell towards a human. You can ...


21

Apparently on August 21, 2011, NASA put together a report titled "Would Contact with Extraterrestrials Benefit or Harm Humanity? A Scenario Analysis." that answers just that. Also found on Amazon for 1.99. This doesn't cover how a country would respond but how NASA would handle several scenarios to the idea. I'm guessing since NASA is heavily ...


21

The deciding factor is if the solar body has a chance of harboring life (or having done so in the past). Scientists don't want to run the risk of false positives: detecting life on another planet, only to find that we're the ones who brought it there. So probes sent to Mars are sterilized as best we can, while we don't sterilize probes to bodies that are ...


20

The two extremes are the most-likely sources of death for creatures in space - weightlessness and the g-force of takeoff. Weightlessness could be a critical issue for any creature which relies totally on gravity for swallowing - it's likely that some bird species would not be able to properly eat or drink in space. In the long-term, it's likely that a few ...


19

If the search for life on Mars is a particular concern, I think putting boots on the ground would be devastating (or bring smashing success, depending on your perspective). When we send robotic probes to Mars, we do our best to send them sterile so as to not contaminate our search. If we send human beings, which contain far more microbial cells than human ...


18

Question: Why not bring cyanobacteria and fertilizer to the atmosphere of Venus to improve conditions for life there by producing oxygen ? ... Only a few scientists have speculated that thermoacidophilic extremophile microorganims might exist in the lower-temperature, acidic upper layers of the Venusian atmosphere. It has been speculated that the clouds ...


17

No, it is not possible to make it 100% sterile. Especially if you consider self-replication as only requirement to classify something as life (It's complicated. See obligatory xkcd reference) Few issues to consider: In addition to other answer, one would likely use chips and PCBs in your spacecraft. Those are usually manufactured outside Space agencies, and ...


16

First, some perspective. The impact of a single fragment of the Shoemaker-Levy comet on Jupiter released an estimated energy equivalent of six million megatons of TNT (approximately 600 times the size of the world's nuclear arsenal), leaving an impact scar that was visible for several months afterward. That was obviously a bad day for Jupiter, but that ...


15

Initially it looked like there was life, then that was dashed, but newer research might be indicative of life after all. From http://csep10.phys.utk.edu/astr161/lect/mars/viking.html, back in 1976 we had: The 4 basic experiments that the Vikings carried out to search for evidence of life were: Gas Metabolism: look for changes in the atmosphere ...


14

Plants don't just need carbon dioxide; like most organisms, they need oxygen to survive as well. They can produce oxygen from carbon dioxide, but that doesn't help cells that aren't exposed to sunlight; if you put a plant in a very low-oxygen environment, it will die. There are organisms that can survive on little to no oxygen (e.g. cyanobacteria, which can ...


14

There is a chamber at the German Aerospace Center designed to imitate the Martian environment. So far there are two published experiments showing that some organisms could survive in the chamber. An imitation of Martian regolith was used, and the organisms were exposed to an imitation of Martian atmosphere with the pressure, temperature range, moisture ...


14

First of all, rocks from Earth are probably just about everywhere in the Solar System. One simple example is this rock found on the Moon. A number of pieces of Mars have been found on Earth, and if that has happened, no doubt there are Earth rocks on Mars. If Earth life can survive a vacuum it has probably gotten to everywhere in the Solar System anyways. ...


12

For my money, I'd go with Jupiter's moon Europa. First, it has a thin oxygen atmosphere, and oxygen, as we've found, is not something normally found hanging around by itself. Given any chance, it bonds with natural "oxygen sinks" like iron and silicon. Europa has quite a bit of silica as well, and yet there's free oxygen in the atmosphere. We have deduced ...


12

Within 100 light-years, there are approximately 14,600 stars. Many of these are not even known. It is difficult to determine exactly the number of star systems as opposed to stars. 113 star systems within 100 light-years are confirmed to have exoplanets in them (listed from nearest to furthest): Alpha Centauri B → cont'd ↓ → cont'd ↓ ...


12

NASA made the record from stable, inert materials, and placed it in the vacuum of space where erosion is not an issue. The record sits underneath an aluminium cover. The only sources of decay are cosmic radiation and the interplanetary/interstellar medium. Cosmic radiation takes a long, long time to create visible distortion (basically it affects an area one ...


12

In fact, this is a subject of much debate. The bottom line is, bacteria wouldn't survive, but their spores might. A few of these spores will make it to Mars, and even a few could potentially spawn life on Mars from Earth. This has been proven from samples sent to the International Space Station. However, there are a lot of arguments against such protection. ...


12

No. SpaceX is a space launch company, not a genetic engineering company. That branch of science lies completely outside their research. Never mind the ethical aspect: the astronauts are volunteers, you don't breed people to produce 'optimal astronauts'! That's not to say if someone (some other company) comes up with this sort of adaptations, and people pick ...


12

Lugworms living in the sand below tidal sea waters. They need gravity to burrow in and feed from the tiny animals living between sand particles. They would survive some weeks without food. Starfish, sea urchin, sea cucumbers could not live in microgravity for longer time. They need the ocean floor to move and search for food. Starfish and sea urchins do not ...


11

On good authority (Steve Squyres, principal investigator for the Mars Exploration Rovers): You know, I'm a robot guy, that's what I have spent most of my career doing, but I'm actually a very strong supporter of human spaceflight. I believe that the most successful exploration is going to be carried out by humans, not by robots. What Spirit and ...


11

Dr. Tore Straume of NASA's BioSciences Division actually published a paper on this very topic. Titled: "Radiation Hazards and the Colonization of Mars: Brain, Body, Pregnancy, In-Utero Development, Cardio, Cancer, Degeneration" The study conducted by them concluded that the Space radiation negatively affects Male fertility. The Cosmic Radiation during ...


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