Slashdot Mirror

We just launched STEREO not too long ago and both satellites are imaging the Sun in a number of wavelengths. One of the points of the mission is to image coronal mass ejections (CMEs), which are the source of the charged particles which cause aurora.

CMEs can cause serious trouble:
-fry power grids on Earth
-interfere with instruments/avionics on airplanes
-lethal radiation dosage for astronauts
-damage satellites
-...

Pretty fisheye image of an aurora from a CME in 2004.
http://antwrp.gsfc.nasa.gov/apod/ap041109.html

STEREO homepage:
http://stereo.gsfc.nasa.gov/

http://www.spacescience.com/headlines/y2000/ast07a pr_2m.htm

You (and others) are misusing the term "solar wind". The solar wind is composed of particles (mostly protons), and is mostly absorbed and not reflected. The proposals I've seen for using it for propulsion involve large magnetic bubbles. They are quite interesting but a long way from being ready to test in space, I believe. See http://spacescience.com/headlines/y2000/ast04oct_1 .htm for example.

The Cosmos craft is a solar sail, which uses the light from the sun, not the solar wind, to maneuver as you describe.

http://spacescience.com/headlines/y2000/ast04oct_1 .htm/ I think this is a very interesting technology, and it's been around for 4 years. Basically it's a couple of really powerful magnets creating a small magnetic field around a craft, and pumping it full of low energy plasma (Argon and Helium)to increase the size of the field. In the article they mention a 15km target size for the field, which should capture about 600kw of energy from the solar winds at a cost of 1kw of power, and less than 1kg of fuel per day. I'm not sure whether they'd be able to capture helium and argon in space, but I'd say it's definitely worth looking into. IANARS (I Am Not A Rocket Scientist)but it looks like this may solve the problem of slowing the craft down, by either changing the alignment of the magnetic field, or reducing power to the field. It should also provide an additional layer of radiation shielding to any sensitive cargo on-board the craft, whether it be manned or not. Maybe one of the other /. readers knows a bit more about this?

Despite this being /. I decided to perform a bit of research, so here are a few links to pages that I think support my point, that terraforming as far as a more hospitable atmosphere on Mars is possible:

• http://quest.arc.nasa.gov/mars/background/terra2.h tml
• http://ganymede.nmsu.edu/tharriso/ast301/class23.h tml
• http://spacescience.com/headlines/y2000/ast22jun_2 .htm?list
• http://www.users.globalnet.co.uk/~mfogg/zubrin.htm

They may be wrong, I may be wrong, but simply claiming the fact that the current Martian atmosphere is very thin as proof that no sustainable atmosphere is possible on Mars, that does not cut it. I will grant you that a 99% earth-like biosphere is unlikely, but a lot less is needed for it to be of use to a colony. Even a slight increase in temperature and pressure would make it easier to live on Mars, some plants might be able to grow (genetically modified mountain plants), the domes (or whatever it might be) needed for habitation might have to handle a smaller difference in pressure, or the time an astronaut might survive in an accident might increase.

And besides, even if it only lasts a few thousand years, an atmosphere might still prove useful. Not that I think we should do something like this without considering the consequenses, but once we have the technology, the trade-offs and risks might prove to be small enough for us to attempt terraforming Mars.

From the article: .Noticing it was "quite hot", she showed it to her father Niel.

The problem with this is that meteors are not hot. See this link and this one. From the first link:

Objects from space that enter Earth's atmosphere are -- like space itself -- very cold and they remain so even as they blaze a hot-looking trail toward the ground. "The outer layers are warmed by atmospheric friction, and little bits flake away as they descend," explains Yeomans. This is called ablation and it's a wonderful way to remove heat. (Some commercial heat shields use ablation to keep spacecraft cool when they re-enter Earth's atmosphere.) "Rocky asteroids are poor conductors of heat," Yeomans continued. "Their central regions remain cool even as the hot outer layers are ablated away."

And from the second:

Are asteroids hot or cold as they descend through Earth's atmosphere? (Level II, They are cold as they enter and remain so even as they blaze a hot-looking trail toward the ground. The outer layers are warmed by friction and little bits flake away as they descend.)

So I suppose it is part of abilated material if it is real, that would explain why it was hot. That would probably still make it a meteor. It might also explain why she still owns her foot.

NASA's been talking about this for over a year now, here and later here. The second article includes a reference to the NASA report about the space elevator. Additionally, it, also, includes details on other propulsion technologies that can come out of this study.

NASA has been working on an alternative to the Solar Sail. The Solar Sail has one major draw back in its design (other than being technically difficult to implement), and that is the farther out in space it goes, the less force is transmitted to it by the solar wind. (Inverse square law.) A geophysicist is currently working on the idea of using a magnetic bubble as a solar sail. The advantage of this approach is that the mag bubble grows as the solar wind decreases. This creates a force that would be relatively constant until the heliopause (the end of the solar winds effective range) is reached.

See here for a 'interesting' lunar meteor impact report, caught on video.

I don't know about you, but when I think "car", I usually imagine something a bit more substantial than a 5hp electric motor strapped to a couple of aluminum bars and wiremesh wheels.

Even in full earth gravity, two or three average men can usually pick up and move a golf cart, and the moon buggy was substantially smaller and lighter than the average golf cart: it weighed all of 80 pounds.

Just what you need for, er, something or other.

The final three Apollo missions were largely devoted to geological surveys and sample-taking. The moon buggy was used to transport the astronauts to craters they would not have been able to reach on foot in order to fulfill those goals.

Ironically, it's those very rock samples that the lunar rover was used to help collect that provide the "hardest" (har har) evidence that the moon landings really happened and that you're a shit-spewing troll, as hundreds of independent geologists have examined the samples, and not one of them has claimed that they were from anywhere other than the moon.

The two articles have the same artist rendition at the top, and drops the same numbers, but the September article has more cool pictures.

--brian

Hemos posted on this same topic just a few months ago...guess he forgot ;)

They even used the same (rather silly) concept art.

Xentax

Well, perhaps we're looking in the right place, but we just don't know what we've found. Take the sugar that was found in a cloud of gas near the center of our Milky Way. If that isn't a calling card for carbon-based life, I don't know what is. Since we search for electro-magnetic signals we make assumptions that other life will be of a similar tech than us. We are really a fledgling race in our capacity to study the heavens constantly being startled by the phenomena we find in space. It is still too early for us to identify when something is not standard out there. That supernova might just be a distress beacon.

An excellent novel (if a wee bit cycical) dealing with some of the problems of our search for sentient life is His Master's Voice by Stanislaw Lem. He proposes the problem of how to interpret a purposeful signal once we find it. The scientists in the book are attempting to decipher a neutrino stream that they accidently detect coming to us in a repeating pattern for a fixed amount of time. The answers are not entirely satisfying. Do we really have the capacity to think outside our little box?

This page shows that Jupiter's moon Amalthea is tidally locked.

This page discusses the case of Mercury, which as I said isn't yet tidally locked but does have a day tidally related to its year. "Although Mercury is not tidally locked to the Sun, its rotational period is tidally coupled to its orbital period. Mercury rotates one and a half times during each orbit."

This page states that all four of Jupiter's Galilean moons are tidally locked.

That took about 5 minutes. Altavista found a total of 499 pages containing the phrase "tidally locked."

You do not know what you are talking about. Climate change due to human activities absolutely HAS been proven, for any reasonable standard of 'proof'.

Some random links. Yes I know these aren't authoratitive primary sources but you can't deep link into the `Nature' site :(
BBC News
BBC News
paper in `Science'
Crowley in `Science'
(UN) IPCC
more U.N.
NASA
NASA
NASA
Nature
BBC News
New Scientist's excellent overview, ideal for clueless know-nothing^W^W getting a basic grounding in the major issues

Next time, try to avoid talking nonsense on a subject you know nothing about.
--
If the good lord had meant me to live in Los Angeles

The man was a genius. End of story.

People have proposed "seeding" the ocean with algae to reduce carbon dioxide levels and lower the temperature. If they do that, northern North American will be under ice in fifty years.

Global warming is just a theory, people, and a poorly based one at that. I direct you to this article: Contrary thermometers (NASA) before you flame me.

--

Apologies for any accidental misinfo in this.
HTH
Camaron de la Isla 'When I sing with pleasure, my

Apologies for any accidental misinfo in this.
HTH
Camaron de la Isla 'When I sing with pleasure, my

Basically, the way the world was turned, the only debris that the midwest would see would be rocks that only skipped on the surface, due to the steep angle due to the early time. At 1 AM, we might see some short streaks due to meteors coming straight down, burning out quickly. but in this particular case, we got to see a very large one burn out slowly no the upper levels of the atomosphere, and it was quite impressive!
--
Gonzo Granzeau

I saw it as well in Illinois. It was part of the meteor shower. the direction alone can verify that (heading out of the leo sector). There's a news story about it as well, not in a local paper. When I saw it, it was one big mass, and I saw it break up into 3 pieces.
--
Gonzo Granzeau

I basically was getting out of work, looked up and saw this huge greenish fireball. it then seemed to split into 3 parts leaving a long trail behind it and was heading towards lake michigan. It took around 30 seconds to pass over me and out of sight. I was like 'whoa' and then heard people on a local radio station getting calls about it. It was really cool.

Good news is that I think I could live with that image as my memory of the meteor shower, so that means I can actually get some sleep tonight!
--
Gonzo Granzeau