Astronomy

[Dreamwoven]

The first pictures of the north pole of Jupiter from Juno at a height of 2,500 miles: http://www.universetoday.com/130608/...es-2500-miles/

This is the first of Juno's 30 or more orbits.

[YesNo]

It was interesting that the auroras were considered "noisy". I had not thought that was a feature that distinguished them even though they would not be audible to us without being shifted into our audible range.

[Dreamwoven]

Universe Today is a website I have come to use a lot. Just discovered a whole series of posts on colonising the nearby planets. I have to admit I react negatively to the idea of humankind spreading pollution and industry to our neighbouring planets and even the moon: http://www.universetoday.com/130482/...olonize-venus/. But perhaps it will happen as we exhaust more and more resources on Earth.

[YesNo]

I don't see why we would want to send human beings into outer space. Computers will soon be driving our cars. Let them go and collect the data or resources we need.

However, the idea of terraforming Venus gave me an idea. What if we could find a way to move Venus into the habitable zone? Then the environment could be cleaned up (by robots). That technology would be something we could use to keep Earth in the habitable zone as well. I know moving the orbit of Venus into the habitable zone sounds ridiculous, but it would make Venus closer to Earth than it is now and easier to get to.

And then we have the Moon. It is located in the habitable zone already, but it needs a magnetosphere to protect it from radiation.

[desiresjab]

I don't see why we would want to send human beings into outer space. Computers will soon be driving our cars. Let them go and collect the data or resources we need.

However, the idea of terraforming Venus gave me an idea. What if we could find a way to move Venus into the habitable zone? Then the environment could be cleaned up (by robots). That technology would be something we could use to keep Earth in the habitable zone as well. I know moving the orbit of Venus into the habitable zone sounds ridiculous, but it would make Venus closer to Earth than it is now and easier to get to.

And then we have the Moon. It is located in the habitable zone already, but it needs a magnetosphere to protect it from radiation.

If we whistle loud enough, perhaps it will come.

[desiresjab]

Universe Today is a website I have come to use a lot. Just discovered a whole series of posts on colonising the nearby planets. I have to admit I react negatively to the idea of humankind spreading pollution and industry to our neighbouring planets and even the moon: http://www.universetoday.com/130482/...olonize-venus/. But perhaps it will happen as we exhaust more and more resources on Earth.

I don't know why the thought bothers you at all. Pollution generated on the moon would do nothing but dissipate into space. On the other planets, it is not as if any livable environment is being messed up. Everyone on those planets will be living under a bubble anyway.

If you are worried about polluting planets after we terraform them, that seems even less appropriate. By the time we have conquered terraforming we should easily have conquered pollution. I think your objection is more aesthetic than rational. It has more to do with our poor record in the past than a real liklihood that we will still be polluting our environments in a future distant enough that terraforming is possible.

[Dreamwoven]

It won't happen in my lifetime anyway *shrugs*.

[Dreamwoven]

I don't see why we would want to send human beings into outer space. Computers will soon be driving our cars. Let them go and collect the data or resources we need.

However, the idea of terraforming Venus gave me an idea. What if we could find a way to move Venus into the habitable zone? Then the environment could be cleaned up (by robots). That technology would be something we could use to keep Earth in the habitable zone as well. I know moving the orbit of Venus into the habitable zone sounds ridiculous, but it would make Venus closer to Earth than it is now and easier to get to.

And then we have the Moon. It is located in the habitable zone already, but it needs a magnetosphere to protect it from radiation.

I think Venus is also in the habitable zone, the Goldilocks zone. Anyway, the kind of changes you suggest are way beyond the technology we have, or even likely to have, moving planets around like that.

[YesNo]

I checked this site: http://hzgallery.org/venus.html

It looks like Venus is in the habitable zone where surface water is in liquid form. However, it is also in a "Venus zone" where a runaway greenhouse effect occurs. It looks like we are not currently able to distinguish exoplanets in the habitable zone from those that are also in the Venus zone.

I agree that we can't move planets further or nearer the Sun, but I don't think we can terraform them either with current technology. I remember an old Flash Gordon show where Emperor Ming was moving his planet closer to Earth for some devilish reason. That may be as close as we get to moving planets around.

[Dreamwoven]

http://www.universetoday.com/130560/...ighbor-quaoar/

[YesNo]

So Quaoar is pronounced “Kwa-war”.

I was thinking more about terraforming Venus. Perhaps we could leave the planet where it is, but put an umbrella of satellites between it and the Sun. The satellites would block out some of the Sun's radiation and perhaps use that radiation for energy to terraform Venus. This way we would also be ready when the Earth entered the Venus zone. We could practice on the Moon.

[Dreamwoven]

http://www.universetoday.com/130710/...ennu-and-back/

Samples of an asteroid will be collected and brought back for analysis. Should learn something of the origins of Earth.

[prendrelemick]

At least they are able to increasingly narrow down the possible location of planet 9. It also makes me wonder about dark matter. That is based on gravitational effects. If enough objects are found in the Oort Cloud would that disprove the existence of dark matter in our solar system?

The problem is that to create enough baryonic matter to hold things together, would need a great deal more stars than there are, or have been. Remember heavier elements that make rocky debris are created in extremely large, hot stars in the first place. The amount of stars needed would shine across the universe (from our past) and light up the night sky.

Also, the models that are built on a non constant gravitational effect do not predict the universe we have. A mass that interacts only with gravity does (what ever it is.)

The Link below is a lecture by Carolin Crawford that looks at the ever evolving evidence for dark matter, a story of different scientific fields arriving at similar conclusions.

http://www.gresham.ac.uk/lectures-an...or-dark-matter

[YesNo]

I admit I don't understand dark matter, prendrelemick. Crawford's summary is interesting. I am also looking at one by Freeman and McNamara ("In Search of Dark Matter") just to make more sense of the topic.

Crawford mentions around page 9 something called "modified gravity", but she says the various modifications to the laws of gravity have not so far accounted for all the observations.

There seems to be two sources where error can enter:

1) Do the current laws of gravity correctly model reality?

2) Are we able to measure the universe accurately enough to answer questions about dark matter?

If both 1 and 2 are true, then we need something called "dark matter", but no one has found any so far.

In all of this there is also "dark energy" which seems to me to be a sort of "anti-gravity" mechanism allowing the universe to accelerate faster than it should based on assumptions about the big bang.

Another thing that keeps coming to mind when I think of gravity (and anti-gravity) are Qigong masters who have been reported to walk on water or people who levitate when they meditate. Given the laws of gravity that should not be possible. Now I know most people would dismiss these as stories, but then we have not found any dark matter yet either.

[Dreamwoven]

These two posts hint at the likelihood of running water on Mars and more exotic combinations on the ice giants - Neptune and Uranus.