# Tag Info

37

It can keep an atmosphere, and in fact does. The atmosphere is something akin to a high grade Earth-based vacuum. But that's probably not what you are looking for. Okay, so what would happen with, say, an Earth sized atmosphere on the Moon? A lot of really interesting things would happen actually. First of all, in longest days of the night, the atmosphere ...

24

There are some very good ideas. This requires a multiple answer approach. This can not be resolved by one method only. I don't believe mass is the issue (if) the iron core is large enough in comparison to the over all mass of the planet. If that is the case then re-starting the mantel is within our current technology to do. We may be able to reach and ...

22

This answers the question on how to block ions coming directly from the Sun from hitting Mars by a satellite stationed at L1. It does not cover the fact whether such a shield is effective in reducing the radiation level on Mars surface. See e.g. here for more details on radiation. First, let's have a look at the magnetic field needed. Inside a magnetic ...

22

This is being done with biosphere 2 and several similar projects and found to be very complicated. Specifically in a small sealed system there is little buffering or inertia available if one element is over or under producing or just having a seasonal change so die offs are hard to avoid. For this reason the plants on the ISS and proposed future projects ...

21

The underlying aerogel scheme seems to have some serious fundamental flaws: Aerogel is extremely expensive, and you need enough to cover a significant portion of a planet. Aerogel is extremely brittle and easy to pulverize. The poles are dark much of the year. Photosynthetic organisms won't function during the winter, and it'll get cold enough to form heavy ...

20

Planets are much, much bigger than you think. The total mass of all the bodies in the main asteroid belt is about half of 1% of Mars's present mass. There's no realistic way to round up enough loose matter to appreciably increase the mass of a planet. 38% of Earth's gravity is pretty substantial. Humans have managed to survive a year in microgravity ...

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 ...

15

A few of reasons for not mounting such a terraforming mission now are: Cost-effectiveness. It's expensive to go to Mars, and simply throwing some seeds and fertilizer at the place is too unlikely to yield a desirable result to be worth doing. All terrestrial life is adapted to terrestrial environments and ecosystems, especially complex life like plants. ...

15

The reason Mars gets more attention than Venus is because we could walk on Mars. Our current technology can handle Mars. Venus on the other hand everything dissolves in a few hours from the heat and acid which makes it a terrifying planet to visit. But on the subject of terraforming. Terraforming is still very much sci-fi and far off from any fact. We are ...

15

"Microbes that are genetically modified to produce perfluorocarbons" do not exist, for good reason. Carbon is a useful building block for life not only because each atom can form 4 bonds, but also because the building blocks can be taken apart and re-used to form a different compound. That's the whole idea behind the carbon cycle. Hydrogen and ...

13

Other factors being equal, planetary temperature (measured on an absolute scale e.g. degrees Kelvin) falls with the square root of distance from the sun, so a merely Earth-like atmosphere isn't enough to warm Mars. According to this planetary temperature calculator, an Earth-like planet (similar albedo and greenhouse-effect atmosphere) at Mars's orbital ...

13

Here Robert Zubrin and Christopher McKay talk about terraforming Mars. Have your browser find "Moving Ammonia Asteroids" and it will take you to the relevant section about 3/4 down the page. Zubrin and McKay talk about using a gravity assist. But using Saturn's gravity to toss down a 2.8 kilometer Centaur, not Neptune's gravity to toss down a 240 kilometer ...

12

PearsonArtPhoto covers the basic issue, which is that light molecules move so fast that they reach lunar escape velocity. The average speed of the molecules of a particular gas is proportional to the square root of (temperature in Kelvin divided by molecular mass) see https://en.wikipedia.org/wiki/Root-mean-square_speed I propose a couple of gases with a ...

12

There is nitrogen in the atmosphere of Venus, four times the amount of nitrogen on Earth. Because Venus' atmosphere is so dense, made up almost entirely of carbon dixode, the percentage of nitrogen is rather small in comparison to Earth's atmosphere, but the nitrogen is there. Space.com: Venus' Atmosphere: Composition, Climate and Weather Atmospheric ...

12

Mars' atmosphere scale height is, depending on who you ask, 10.8 to 11.1 km. Pressure at the bottom of Hellas Planitia: 1.16 kPa Earth sea level: 101.3 kPa Earth 6km altitude: ~50 kPa. So we need air pressure to increase by a factor of about 43; natural log of 43 = 3.76 scale heights -- so we need a trench about 41km deep. Start digging! This gets ...

11

The Martian atmospheric pressure is around 600 Pascals. At that pressure the boiling point of water is around 0°C. The average temperature on the surface of Mars is -55°C. The melting point of water is also lower, but this usually changes by a much smaller fraction so we'll assume you want to get it to just below boiling. So you only need to increase ...

11

Rearranging the lifeless rocky planets might make terraforming and transportation easier. No, it mightn't, because the amounts of energy it would involve are so ridiculously gigantic that terraforming a planet is a very easy job in comparison. The kinetic energy of an orbiting body is $\epsilon_k = G\cdot \frac{m\cdot M}{2\cdot r}$ where $G$ is the ...

11

There's several advantages and disadvantages to Venus compared to Mars terraforming and colonization: Advantages: Venus's gravity is ~0.9 G which is very similar to Earth's Venus is closer to the earth with less communication lag and more frequent launch windows (around every 600 days instead of 800 days to mars) At high altitudes, temperatures are in ...

10

According to Wikipedia on formal definition of the dynamo theory, which itself paraphrases The Earth as a Distant Planet, Vázquez et al.: There are three requisites for a dynamo to operate: An electrically conductive fluid medium Kinetic energy provided by planetary rotation An internal energy source to drive convective motions within the ...

10

A short answer is no, Venus wouldn't lose its ionosphere if the target state of terraforming is matching Earth's atmospheric composition, temperature and pressure. The long answer is a bit more interesting though, particularly why that is a problem, and not a solution to Venusian lack of magnetic field. Let's first address the first point, and I'll slowly ...

10

Perchlorate contamination is a problem on Earth. Essentially, there is a series of water treatments and bioremediation, the process of using biological systems to fix the problem. Here is a detailed summary of one effective approach. The short answer is this: Engineers know how to do this on Earth, and the Martian solution is likely to be an adaptation of ...

10

There are easier ways to enhance Mars's atmospheric pressure, so no, don't use Venus materials. I calculated the energy required to lift a kg of nitrogen — or a kg of anything, for that matter — out of Venus's gravity well, and uphill through the sun's gravity well to Mars. Getting it away from Venus was a small part of the total, but that total was nearly ...

9

Setting aside the fact that this would be a very bad idea and that there are far less energy intensive ways to terraform the surface of a planet, the most energy efficient way to do this I can think of is by using Oort Cloud objects. It takes very little $\Delta V$ to make an Oort cloud object dive towards the Sun. In fact, it is the source of most comets. ...

9

The Venus ionosphere would definitely not be destroyed. Ionospheres are formed by interaction between the atmosphere and the ultraviolet radiation from the Sun. The UV radiation is more intense closer to the Sun, so Earth-like atmosphere on Venus would probably have even denser ionosphere than actual Earth has. Venus receives 1.9-times the irradiance in ...

9

This question assumes Mars doesn't have a magnetic field because Mars' core is frozen solid. It's not. Mars has a partially liquid core, just as does the Earth. (The Earth has a liquid outer core and a solid inner core.) Whether Mars has a solid inner core is unknown, but it certainly does have a liquid outer core (and possibly a fully liquid core). (See C.F....

9

First of all, while Xenon would be the most stable due to it's molecular weight being the largest non-radioactive gas, there are other gases that would work as well. Sulfur Hexafloride would be a particularly interesting choice, and that should be easier than Xenon to find. Okay, that notwithstanding, how well would it work to fly in an atmosphere of Xenon ...

9

If you are able to terraform Mars in some reasonable amount of time, let's say in 100 years, then you don't need a magnetic field. Just do whatever you did to terraform the planet, but at one billionth of that rate, in order to counter the loss of atmosphere to the solar wind. Or don't even bother at all, leaving the problem to your great1000000-...

9

Mars has no magnetic field to protect any atmosphere we might add to the planet, but fortunately it would be lost very slowly, over geological time. Fortunately, both protecting and creating a Martian atmosphere can be achieved by parking one giant powerful space station at the Lagrange 1 point which would broadcast a magnetic field which would protect the ...

8

Earth's atmosphere is also slowly "leaking" into space, but very slowly. This is because there are multiple processes involved in escaping atmospheres. One of those processes is Jeans escape, where due to Maxwell speed distribution and long enough mean free path molecules are able reach escape velocity and escape the atmosphere before "bumping" into another ...

8

The way to solve this problem has recently been proposed by NASA. Put a magnet on the L1 Legrange point (between Mars and the Sun) of about 2 Tesla. This is what it looks like: At present, atmospheric loss on Mars is balanced to some degree by volcanic outgassing from Mars interior and crust. This contributes to a surface atmosphere that is about 6 mbar in ...

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