70
votes
Why are we trying to prevent life from spreading via landers rather than actively encouraging it?
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 ...
- 172k
67
votes
Why did the Chinese send flies and plants to the far side of the moon?
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 ...
- 80.5k
62
votes
Accepted
Why are we trying to prevent life from spreading via landers rather than actively encouraging it?
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) ...
- 2,621
43
votes
Are there types of animals that can't make the trip to space? (physiologically)
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 ...
- 48.3k
32
votes
Why aren't there any robotic missions on Europa or Enceladus?
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 ...
- 25k
28
votes
Is it ethical for Chang'e-4 to bring an entire ecosystem to the moon?
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 ...
- 151k
27
votes
Is there any demonstrated or even proposed technology that can sterilize a spacecraft with 100% certainty and yet leave it electronically functional?
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 ...
- 48.3k
23
votes
Accepted
Why aren't there any robotic missions on Europa or Enceladus?
@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) ...
- 151k
22
votes
Can a launch of a rocket or ship from Earth go so badly that it damages the Solar System?
No.
Look at the numbers:
...
- 13k
20
votes
Why do we worry about contaminating some solar bodies but not others?
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, ...
- 130k
20
votes
Are there types of animals that can't make the trip to space? (physiologically)
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 ...
- 301
18
votes
Why not bring life to Venus along with the next exploring mission?
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 ...
- 3,282
17
votes
Is there any demonstrated or even proposed technology that can sterilize a spacecraft with 100% certainty and yet leave it electronically functional?
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 ...
- 320
16
votes
Accepted
Can a launch of a rocket or ship from Earth go so badly that it damages the Solar System?
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 ...
- 2,350
14
votes
Accepted
How certain are we that we have not accidentally sent life to other planets/moons?
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 ...
- 122k
13
votes
Accepted
What would be the practical benefits of finding life in the Solar System?
One of the challenges of trying to live on another planet is finding or producing the essentials for human life there rather than having to ship everything. If we can free water, oxygen and building ...
- 20.4k
13
votes
Agriculture on an exoplanet
Ignoring the infrared radiation aspect of your question, what you are describing is a situation not too dissimilar to what exists in many parts of Australia.
The extreme degree of weathering that has ...
- 13.3k
12
votes
Is it ethical for Chang'e-4 to bring an entire ecosystem to the moon?
According to Jainism and some forms of Buddhism, the concept of Ahisma tell us that it not ethical to bring an ecosystem of living creatures to an environment that will almost assuredly kill them as a ...
- 237
12
votes
Does SpaceX plan to enhance/change the genome of space colonists to speed up the adaptation process to the living conditions on Mars?
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, ...
- 56k
12
votes
Are there types of animals that can't make the trip to space? (physiologically)
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, ...
- 49.5k
12
votes
Why are we trying to prevent life from spreading via landers rather than actively encouraging it?
Go ask an Aussie about rabbits. They've been trying to get quit of them for, I think, well over 100 years - but they breed, well, like rabbits, and getting them OFF the damned continent is thoroughly ...
- 311
11
votes
Accepted
Melanized fungi on the ISS - are they 'enjoying' the elevated radiation levels there?
The experiment Growth and Survival of Colored Fungi in Space (CFS-A) - 12.07.16 showed that:
fungi can grow inside the space station and could decompose food and other organic materials in humid ...
- 23.8k
11
votes
Accepted
Why is the northeastern region of Syrtis Major Planum a selected landing site for the Mars 2020 mission?
Edit - added more detail on the specific geological interests per the question revision
Selection Process
This letter to Dr Michael Meyer, lead scientist for the Mars Exploration Program, gives a ...
- 10k
11
votes
Why did the Chinese send flies and plants to the far side of the moon?
They did it for propaganda or pride mostly. What sprouted quickly died because it froze. They did not have a method to protect the biosphere from the temperature swings. This is what they expected ...
- 111
11
votes
Why are we trying to prevent life from spreading via landers rather than actively encouraging it?
Update: There is a thorough and well-sourced summary too long and detailed to reproduce here published in Nature Feb. 13, 2020: Lessons in space regulations from the lunar tardigrades of the Beresheet ...
- 151k
10
votes
Can a launch of a rocket or ship from Earth go so badly that it damages the Solar System?
Not in terms of physical damage, no. Rockets and spaceships and all the energy they contain is just so very, very, very, very small compared to everything.
There is one possibility for large scale ...
- 4,655
10
votes
Accepted
Why do we worry about contaminating some solar bodies but not others?
Early Mars probes were heavily sterilized. Further studies have shown that Mars's surface isn't habitable, at least not in most areas, and thus a low risk approach has been developed, where certain ...
- 122k
10
votes
Would a circular saw on one arm and a trowel on another on the Mars 2020 rover add scientific value?
The rover already has a core drill for this purpose: it drills through the top layers and exposes the rock underneath. The big advantage of a drill over a shovel is that a drill can go through (most) ...
- 130k
10
votes
Is it ethical for Chang'e-4 to bring an entire ecosystem to the moon?
Humans have already been to the Moon, and pretty much verified it is completely sterile. It isn't really an issue bringing plants to the Moon, it couldn't contaminate anything, as there is nothing ...
- 122k
10
votes
Accepted
Life on Mars: How do we know it is not from Earth?
One tool in the astrobiology toolbox is chirality, the property that many chemical compounds exist as "left-handed" and "right-handed" mirror images.
These have the exact same ...
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