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The VSE Booster Switch

PRESS RELEASE
Date Released: Thursday, May 4, 2006
Source: Space Telescope Science Institute
NASA's Hubble Space Telescope is giving astronomers their most detailed view yet of a second red spot emerging on Jupiter. For the first time in history, astronomers have witnessed the birth of a new red spot on the giant planet, which is located half a billion miles away. The storm is roughly one-half the diameter of its bigger and legendary cousin, the Great Red Spot. Researchers suggest that the new spot may be related to a possible major climate change in Jupiter's atmosphere.

Dubbed by some astronomers as "Red Spot Jr.," the new spot has been followed by amateur and professional astronomers for the past few months. But Hubble's new images provide a level of detail comparable to that achieved by NASA's Voyager 1 and 2 spacecraft as they flew by Jupiter a quarter-century ago.

Before it mysteriously changed to the same color as the Great Red Spot, the smaller spot was known as the White Oval BA. It formed after three white oval-shaped storms merged during 1998 to 2000. At least one or two of the progenitor white ovals can be traced back to 90 years ago, but they may have been present earlier. A third spot appeared in 1939. (The Great Red Spot has been visible for the past 400 years, ever since earthbound observers had telescopes to see it).

When viewed at near-infrared wavelengths (specifically 892 nanometers -- a methane gas absorption band) Red Spot Jr. is about as prominent in Jupiter's cloudy atmosphere as the Great Red Spot. This may mean that the storm rises miles above the top of the main cloud deck on Jupiter just as its larger cousin is thought to do. Some astronomers think the red hue could be produced as the spots dredge up material from deeper in Jupiter's atmosphere, which is then chemically altered by the Sun’s ultraviolet light.

Researchers think the Hubble images may provide evidence that Jupiter is in the midst of a global climate change that will alter its average temperature at some latitudes by as much as 10 degrees Fahrenheit. The transfer of heat from the equator to the planet's south pole is predicted to nearly shut off at 34 degrees southern latitude, the latitude where the second red spot is forming. The effects of the shut-off were predicted by Philip Marcus of the University of California, Berkeley (UCB) to become apparent approximately seven years after the White Oval collisions in 1998 to 2000.

Two teams of astronomers were given discretionary time on Hubble to observe the new red spot.

[Left] -- This image, acquired April 8, 2006 with Hubble's Advanced Camera for Surveys (high-resolution channel), shows that the second red spot has a small amount of pale clouds in the center. A strong convective event, which is likely a thunderstorm, is visible as a bright white cloud north of the oval, in the turbulent clouds that precede the Great Red Spot. As the oval continues its eastward drift and the Great Red Spot moves westward, they should pass each other in early July. This contrast-enhanced image was taken in blue and red light. The group that performed this observation was led by Amy Simon-Miller (NASA Goddard Space Flight Center), Glenn Orton (Jet Propulsion Laboratory) and Nancy Chanover (New Mexico State University).

[Right] -- Hubble's Advanced Camera for Surveys (wide field channel) took this image of the entire disk of Jupiter on April 16. The second red spot appears at southern latitudes, below the center of Jupiter’s disk. The new spot is approximately the size of Earth's diameter. The image was taken in visible light and at near-infrared wavelengths, and does not represent Jupiter's true colors. The red color traces high-altitude haze blankets: the equatorial zone, the Great Red Spot, the second red spot, and the polar hoods. The Hubble group that conducted this observation is led jointly by Imke de Pater (UCB Astronomy) and Philip Marcus (UCB Mechanical Engineering). Other team members are Michael Wong (UCB Astronomy), Xylar Asay-Davis (UCB Mechanical Engineering), and Christopher Go, an amateur astronomer with the Astronomical League of the Philippines.

Images and additional information about the research are available on the Web at:

    * http://hubblesite.org/news/2006/19
    * http://www.berkeley.edu/news/

Hitting Europa Hard Could Have A Real Impact

by Leslie Mullen
for Astrobiology Magazine
Moffett Field CA (SPX) May 03, 2006
Jupiter's moon Europa is one of the most intriguing places in the solar system to Astrobiologists. An icy shell overlies a deep water ocean, and tidal flexing from Jupiter's gravity may provide energy for life.

But while scientists have been talking about developing a Europa mission for some time, so far NASA has not yet sent an orbiter to investigate the moon in detail.

Karl Hibbitts, a research scientist at the John Hopkins University's Applied Physics Laboratory, is working on developing a hyper-velocity impactor that could be carried on a future Europa orbiter.

In this interview with Astrobiology Magazine editor Leslie Mullen, he explains why smashing down into the surface of Europa could provide details about the moon that an orbiter or even a lander could not.

Astrobiology Magazine (AM): You have a proposal for something called the Europa Hyper-Velocity Impactor. Can you give me an overview of how it would work?

Karl Hibbitts (KH): It's a projectile that would go really fast into the surface of Europa, creating a curtain of ejecta. So we could make measurements that reach beneath the solid surface of the moon, measurements that are not possible to make from orbit.

AM: How fast could you get it to fall to the surface of Europa?

KH: 13 kilometers per second. That's how fast Europa is going around Jupiter. You can come in faster than that if you want, but around 10 kilometers per second is reasonable, and that is actually how fast the Deep Impact mission went into comet Tempel 1.

The depth of penetration is largely dependant on the density difference between the impactor and the surface, so you want to make the impactor heavy so it goes down deep. We'd like it to weigh at least 100 kilograms, and much more if we can get it. The ejecta curtain can be a million times more massive than the impactor itself.

The shape of the impactor will also affect the ejecta. You can choose to make the impactor flat, and that will give you an immediate flash from the surface, and then a curtain of deeper material as it burrows down. Or we could make the impactor pointy, which makes it go deeper down but creates a more columnated plume of material.

We want to separate different plume ejecta from each other, so we need to find an equilibrium in how we eject the subsurface material. It's essential for us to do some supporting laboratory work on this to figure out how to provide the best science results. Europa's not a comet, so the results will be different from Deep Impact. We need to simulate its surface composition and properties better.

AM: Some models for Europa say the outer ice shell is between 20 to 100 kilometers thick, with the average thickness of about 40 kilometers. I would not imagine a small projectile could penetrate very far into that.

KH: That's true. It could only go in several meters at the deepest. The goal is to get below the radiation layer.

AM: What is the radiation layer?

KH: It's the layer of the surface that's been irradiated by all the particles and electrons in Jupiter's magnetic field. You can't assume that certain areas are not irradiated, because Europa's ice shell is decoupled from the subsurface. It floats slowly around on timescales of tens to hundreds of millions of years, so at some point in time an area could have been irradiated. So we'd want to target a place that looks like it's been in recent contact with the subsurface.

AM: So underneath that top irradiated layer is a subsurface layer that's not as altered, and maybe more indicative of what the whole moon is like?

KH: Yes. Of course, they are not discrete layers; it's a gradation from heavily irradiated to lesser irradiated. But at some depth, probably more than a meter down, basically it's unirradiated. Any organics would have to be below the radiation layer to survive.

AM: On the surface there're those veins of colored material, and scientists don't know what they are. Is that something an impactor could help figure out?

KH: That is one of the fundamental questions we're trying to answer. Is it a hydrated salt, or is it a hydrated sulfuric acid?

AM: You couldn't figure that out from spectroscopy?

KH: We could if there wasn't so much hydration there. The water ice absorbs the light at some very important wavelengths, so it overwhelms everything. And that gets back to why this technique is so powerful.

Ejecting material from the surface warms it up. Certainly some of it is super-heated, but the rest of it is warmed enough so that the ice would sublimate away and we could look at the non-ice component.

It's very similar to what happened with Deep Impact. Except because Deep Impact hit a comet, the ejecta hung around for hours, while for Europa, the ejecta will only be there for a few minutes. That's because of the difference in gravity -- the gravity of the comet is millimeters per second squared, so things don't move around very fast.

AM: So with the comet, once things sprayed out, there wasn't enough gravity to bring it back home, it was just going to keep spreading out. But with Europa, the ejecta will fall right back down.

KH: Right. And stay closer together, probably. We can study the initial flash, and we can study the material in the plume that shoots out, and those are two different things. The flash will tell us the composition of this non-ice material on the surface. The plume is made from material deeper down, and so the non-ice material there might be different.

AM: One thing we don't understand, given what we know of Europa's gravity and tectonics, is why the surface of Europa is relatively smooth. Why are there no ice mountains on Europa, for instance? Would an impactor tell us something about how the geology works there?

KH: It could potentially, because the way the crater will form in the ice will tell us about the strength of the material which it hits. So if we can image it in high enough resolution in an orbiter's subsequent flybys, then we could learn something about the upper few meters of the surface.

AM: One advantage an impactor seems to have is that it can go to places on the surface that a lander could not. A lander couldn't survive if it fell into a deep crack in the ice, whereas with an impactor you wouldn't have to worry so much about rugged or chaotic terrain.

KH: But even we are susceptible to that problem. So we would not aim for a chaos area; we'd probably want to aim for an area that was as smooth as possible. It would be bad to go into the middle of a crack.

AM: You wouldn't get your explosion?

KH: You would, but it would be very columnated. Or how about if we hit something at a glancing angle, how's that going to affect the partition of the energy into the surface? Our constraints aren't as tight as they are for a lander, but we still don't know exactly what our constraints are. So I have concerns about it that the impact specialists will need to address.

AM: You said that you wanted to go into a recently resurfaced area –- I would think that would be more chaotic than an older one.

KH: It depends on how it's deformed. A young area that's deformed like a mountain-building area on the Earth is going to be chaotic. But how about an area that would have formed very similar to the Columbia flood basalts out West, where you had the ground just open up and the lava flooded everything? That's the kind of area we would like to go into -- young and smooth. Smooth on the scale of tens of meters, so something like pahoehoe flows would be fine for us, but it would really bad for a lander.

AM: What if the ice models are wrong, and the ice isn't thick, and the impactor goes right through the ice into the underlying ocean and disappears with a “bloop!”

KH: That would be brilliant, wouldn't it?

AM: But there'd be no ejecta, right?

KH: No, there'd be huge ejecta. The ocean water's like rock, at those velocities.

AM: So it would be similar to if a meteorite hit the ocean on Earth, creating a huge blast and maybe generating a tsunami.

KH: Those are bigger, but yes, it's the same thing. And, of course, you'd look at an image of the impact crater later and see that we punched through thin ice. So then we would know it would be a good place for a lander to go. That would be a wonderful success, but it's very unlikely.

AM: Are there any contamination issues for the impactor?

KH: No, I already talked to the Planetary Protection Office about that. It self-sterilizes. The impactor would be destroyed because it would disintegrate upon impact. And it would be made of a material like copper, or something that would not be in great abundance on Europa.

AM: Would there be any instruments on impactor itself, or would it just be a big metal ball?

KH: We'd have a camera just like the Deep Impact mission had. A camera would provide some useful information for a lander, because you get surface roughness at a very fine scale at one point. As you approach, your spatial resolution from the camera gets higher and higher.

AM: What are your thoughts about the possibility for a NASA Europa mission, given the current budget issues?

KH: It will happen in the future. Political priorities do waffle, but the science priorities have remained constant for the last 10 years. And Europa has always been a top priority. There are competing destinations, of course –- Titan and now Enceladus, for instance.

But Titan would be a prebiotic Earth –- there's no chance of life there, with the temperature being only 94 Kelvin on the surface. I personally would love to see a mission to Titan for reasons other than astrobiology.

It's easy to get to, you can have a lander, and you can look for some unique things there. But for an astrobiological perspective, Europa is still at the top of the list.

it's worth noting that we have just realized that New Horizons itself will be traversing through one of the Trojan regions of Neptune in 2014.

I don't think that Bush would use tac nukes on Iran. But having that option out in the media helps bush with the dipmo sid. If iran really thinks that bush would nuke them, then they would be more willing to give up their nuke power plans.

One good thing about the USA it has alot of power, lots of nukes to back up its demands. One of the must powerful statements a country can say "Are words are back by nukes, and we have used them before on people like you. "
Iran has to understand we have nuked before, and have no problem of doing it again.

Also I dont care what the islamic world think of the USA, they should fear us. Islamic invaders have controled the christen and jewish lands of the mid east. We are just liberating these lands from the Islamic invaders. Christs Kindom will get back its lands. Th lion will eat the camel.

You sea Christens also sea the Arabs as invaders in there homeland, and the jews too. So you arguement that jews invaded a Imlamic state are false, the jews were just moving back to their homeland Israel.

There are opposition groups to the current theocracy but the majority of them are even more anti western than the current regime.

Since when? 70% of the population is under 30 and has nothing against the west, and while proud Iranians, they are not going to fight a foe who lacks the ability to occupy the country, goes to great pains to avoid civilian destruction, and has ill will only towards the very same theocracy they do.

The same 70% who are raised on the stories of the 1st gulf war and are exposed to the Islamic jihadist talk in the mosques they go to pray in. The ones who are told the stories of when Iran was the greatest empire in the world and see that for there country to progress they need to advance and that means electricity. In this case with the conditions that are present in Iran the only means they see that might work is nuclear power. They have oil but it will run out and they want something for there future. There is a lot of support for nuclear power in Iran they want all the advantages that a regular source of electricity can give them. They have a lot of problems and they know that there reliance on oil for everything cannot last. The high unemployment rate in Iran is something that they want to change and with regular power they can start manufacturing goods with the low costs of labour and parts they could be the China of the middle east. So there goverment tells them and they listen.

The tricky part is devoting enough resources to weaken the mullahs enough that when the people see their chance, its not a complete bloodbath. The last thing we want is a repeat of the 91 uprising against Saddam, were we stood by and watched while Saddam burtally put it down. On the other hand, we also want to avoid looking like were occupying the place.

The people see there chance. What does that mean why should they rise up against there religion. You must remember that 95% of the population are islamic and as a population are very highly supportive of that. How do you intend to weaken the mullahs. You must also remember is that the current goverment was democratically elected.

What should be done with Iran, some people want to use tac nukes on them. That would slove the problem and give President Bush a lasting note in history.

Like what ? like the guy who would have risen the wrath of millions human bombs voluteering to kill as many US citizens as they can ?
Can't you think another way than as a technobarbarian ?