mdatspace

"Honestly, I'm of the opinion that global warming is more about politics than science. For example, the accepted "scientific" mathematical models were not only completely wrong the last 15 years, during which time the Earth has actually cooled or stayed the same, and during which time Antarctic ice has actually grown and reached record levels, but they fail to model past weather which is known!" The 15 year gap is a commonly repeated myth with no basis in reality. Temperatures have still gone up. http://climate.nasa.gov/key_indicators#globalTemp "I believe they place far too much emphasis on CO2 in their models." CO2 is a greenhouse gas, and it is perhaps the one we emit most. It is not hard to see why so much focus is on it. "The reason why this smells political is because the bureaucracies involved are reluctant to publish any material which suggests that global warming is wrong." This suggests a conspiracy, a cover-up. But what is the motive? What if there is no cover-up. What if the evidence against GW is negligible? 97 percent of scientists supposedly agree on this, so this could be reality. "Now, do I believe in climate change? Of course. The Earth used to have an atmosphere of hydrogen cyanide, and endless tropical oceans. As for right now, I believe we are still coming out of the last mini ice age (did you know that 1000 years ago, Greenland used to be green?). And when the Earth comes out of an ice age, it tends to gradually warm up." Greenland got warmer while the rest of the world got colder. While it tends to warm up after an ice age, the speed of today's warming is not associated with said warming. "The question is not whether or not the climate is changing, but whether or not humans are playing a large role in this change, and in a direction which would not naturally occur. Honestly, the idea that humans could affect something of this magnitude comes off as pretty striking arrogance." Multiple factors point to humans. We are enormous quantities of CO2 into the atmosphere. We dump 80 to 270 times the CO2 than volcanoes into the atmosphere. It is scarcely arrogance to say we are associated.

False alarm. See Tiberion. That was one horrible late April fools joke.

I cannot choose. This situation makes me want to throw up.

Greenhouse gas emissions have gone down in the US. http://nation.time.com/2013/10/22/efficiency-natural-gas-keep-pushing-u-s-carbon-emissions-down/ Our emissions have gone down. http://www.resilience.org/stories/2013-09-23/if-we-burn-all-the-fossil-fuels From this article:"So here’s the lesson we need to learn from the Palaeocene-Eocene thermal maximum. For global warming we can assume that 75% of it is from CO2, and the remaining 25% is from other greenhouse gasses like methane and nitrous oxide. If we burn all the fossil fuels we have left in the ground, that’s about 10-15,000Gt of carbon that we could put in the atmosphere. That gives us 5x the CO2 from 1950, or 1,400ppm. This will give us 16oC of global warming. It will be a world where there’s an average temperature of 20oC on land and 30oC at the poles (the current average is 14oC). Keep in mind also, that 6oC of warming is generally enough for a mass extinction like the dinosaurs." I do not have a lot of time to respond, so the rest will come later.

Constellation was over-budget and behind schedule. The space shuttle was 1.5 B per launch and failed at its objective:to make space cheap.But this is bad. It would have greatly helped exploration of the outer solar system. It uses much less PU-238 than normal generators for the same power.

More powerful than the Saturn V? I am skeptical about this. Sounds like propaganda. But if it is real, this is something to take very seriously. But nationalism aside, go China!

Oh. So nukes are out. Figures. I was making a scenario. However, there are some completely differentiated asteroids(4 Vesta). A 250 km rock would have likely undergone internal heating early in its history. Most of the large rocky asteroids and planetesimals(Over 250 km) must have undergone some degree of internal heating and partial differentiation. Some asteroids have undergone more or less full differentiation(4 Vesta). Vesta is also unique as it has had magmatism early in its history. It is pretty close to a terrestrial planet in composition and internal structure. But back to the point. You can't destroy a 250 km rock by blasting off material. You can blow up a 5 km rock with enough force(That would cause it to fragment into equally deadly asteroid fragments). Debris blasted off of a 250 km partially differentiated rock will simply fall back to the ground.

It depends. If it is just some bacteria, I see no serious breach of ethics. If it is intelligent life we are talking about, I don't think terraforming would be very ethical.

The solutions may well depend on the asteroid's characteristics. I will make up a scenario. A 250 km rubble pile. A nuclear bomb of 50 MT power would throw off a large amount of fragments. Those fragments, however, would likely not leave orbit due to said objects gravitational influence. Now, a 250 km differentiated rock with a consolidated surface and interior. It has a Crust, mantle and core. It is of much higher density than said rubble pile. A 50 megaton bomb will create a nice crater, but nothing much will be thrown out of orbit, if at all.

The antipodes would be fractured. But, it depends where said antipodes are. If it is on oceanic crust, it will fracture. On continental crust, it will break a bit, but not so much.

The thinnest part of the lithosphere is oceanic crust. I could see something like a lunar mare forming, but if your are talking about continental crust, it would be more of a crater. The continental crust would be fractured, however, and those fractures are perfect conduits for rising magma. But a 250 km rock would completely destroy life, and I agree on that.Moho should be a hellish world. Make its orbit smaller and more eccentric, and tidal heating will do the work. @Skyler: Even if a Moho-sized body just passes by, it would stretch the earth. The area of stretching would simply melt due to tidal heating.

A 250 km rock will not melt the whole lithosphere.

Competition is one of the strongest motives there is.

I agree. I would like cooperation. More resources and better relations. But I am not sure that cooperation is going to happen with China. They have a space program fueled by nationalism, and I doubt that being friendly to their space rivals is part of that.@Skyler4856 I don't think that private corporations have much of a will to do space exploration anyways.

There are places which have been stable on this earth since the Archean. They are called cratons.

No. It would blow the thing up. The explosion would fragment it. The ice would turn into steam instantaneously and expand dramatically in volume. That creates a blast which can throw blocks of rock weighing multiple tons hundreds of meters from ground zero.

A steam explosion would occur, but the droplets of super-heated water would crystallize very quickly due to the frigid temperatures.

Nuclear isn't economical anymore even with its benefits. 4 plants have gone out this year, replaced by gas and renewables.

I can't even land a plane without a decent explosion in this game.

But is it better chemistry than a subsurface ocean? No. It is abundant and renewable, but that says nothing about its use to life. It is easy to see how much oceans do when it comes to life.

But there is something else in the favor of Europa: Tidal heating. Titan gets most of its internal heat by radioactive decay. Said heat depletes over time. Europa has radioactive decay and tidal heating. Looking at their surfaces, I think it is easy to judge which one has been more active. Titan is constantly resurfaced by erosion and deposition, covering up older features. Europa has only been resurfaced through endogenic processes, not to mention the differences within. While titan has a subsurface ocean, it likely does not get as much heat or nutrients as Europa, as there are likely subsurface vents spewing heat and nutrients every day and night.

Europa may have an ocean, and Rossby waves could help that. If so, hydrothermal vents could easily hold life. Methane is not as good of a solvent as water. Where the cryovolcanism is at, there is heat. That certainly helps life. What about Enceladus?

I am waiting on Juno. You are right. Europa may have a mantle of warm ice. If that is true, however, the chances of life there are little. If it has a large ocean, the chances are high.If life was on titan, there would be far more to see compared to Europa. Life living on a much different chemistry. I think titan has chances. It has cryovolcanism(Sotra Facula), and it likely erupts water and ammonia. That means that beneath said feature, there could be a reservoir filled with an water/ammonia mix. If that is true, which it likely is, titan may have more potential than Europa. Titan has the atmosphere. Landing there will be like earth. The geologist inside of me wants to know.

Indeed. NASA is trying to focus on mars the best it can, as it may be the only way to get back public interest. By doing so, they have kind of left the outer solar system to wait. You have to do both, but if they found life on Europa, it would be quite big.

I agree. It seems like NASA has something for mars.