Hell frozen over

I've mentioned the Cassini probe, which has been orbiting the planet Saturn for about three years now, in a previous post. Among many other data, it has been sending a lot of information back about Titan, Saturn's giant moon (bigger than the planet Mercury), with its dense, other-wordly atmosphere.


I'm reproducing here the description found on NASA's Jet Propulsion Laboratory's site:


Saturn's mysterious moon Titan is one of the strangest and most Earthlike places in our solar system.
Larger than Earth's moon and the planet Mercury ... it's the only moon in our solar system that has clouds and a dense atmosphere, mostly nitrogen and methane.
Titan's surface remained shrouded in secrecy below the clouds until July 2004. That's when NASA's Cassini spacecraft arrived at Saturn. With its RADAR and infrared imaging instruments, Cassini was able to lift the veil on Titan.
What scientists saw on Titan's surface astonished them.
Here was a world that looked a lot like home. Its surface is complex and varied, with Earthlike features like riverbeds; vast deserts, covered in dunes; and hydrocarbon lakes. These are the first open bodies of liquid found anywhere in our Solar System, besides Earth.
On Jan. 14, 2005, scientists got an even closer look. The Huygens probe, built by the European Space Agency, parachuted through Titan's atmosphere, taking detailed measurements. The probe survived for several hours on the surface of Titan and returned stunning images.
In spite of their apparent similarities, the differences between Earth and Titan are even more extreme. If you stood on the surface of Titan, the pressure would be like standing at the bottom of a swimming pool. The temperature is minus 289 degrees Fahrenheit (minus 178 degrees Celcius), far colder than Antarctica.
While rocks on Earth are made of silicates, the rocks on Titan are made of water ice.
While Earth's lakes and rivers are filled with liquid water, Titan's flow with liquid methane. In fact, if free oxygen were also present, a single spark would send the entire moon up in flames.
Most scientists agree that life as we know it would be unlikely on this bizarre world. But the study of Titan, the most Earth-like body in the solar system will help us understand our own Earth and even help guide the design of future missions, like Terrestrial Planet Finder, that are designed to search for Earth-like planets beyond our solar system.
The exploration of Titan has only just begun. Over the coming years, Cassini will fly close to the moon several dozen more times, gathering additional data and images, and unlocking more secrets of this strange new world ... an alien Earth in our own solar system.

Here are a couple of pictures of Titan's topology, returned by the Huygens probe, which was carried along with Cassini, and was released into Titan's atmosphere to descend by parachute to the surface:








Building Our New View of TitanJune 1, 2007

This composite was produced from images returned on 14 January 2005, by ESA's Huygens probe during its successful descent to land on Titan. It shows the boundary between the lighter-coloured uplifted terrain, marked with what appear to be drainage channels, and darker lower areas. These images were taken from an altitude of about 8 kilometres with a resolution of about 20 metres per pixel.
Credits: ESA/NASA/JPL/University of Arizona







Huygens at Titan 1January 14, 2005

This raw image was returned by the ESA Huygens DISR camera after the probe descended through the atmosphere of Titan. It shows the surface of Titan with ice blocks strewn around.

It was taken with the Descent Imager/Spectral Radiometer, one of two NASA instruments on the probe.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The Descent Imager/Spectral team is based at the University of Arizona, Tucson, Ariz.
Credit: ESA/NASA/University of Arizona

You may also be interested in the following movie:

http://saturn.jpl.nasa.gov/news/features/feature20070129.cfm


Imagine, rocks made of ice, liquid methane rivers and lakes, "colder than hades".

If there is a hell frozen over, this is it.

An update

I see that Derek's not been posting for a couple of days. I'd like to assure everyone that he's doing ok. Last night he went to the Barcamp Vancouver and has gone again today. That's good news. It means to us that he has sufficient stamina to go through several hours of meeting and talking to people. Our niece is looking after the girls, and they've gone to a garage sale near our niece's home. We appreciate days like this.

Maybe there is life here, too?

Here's an image from the Galileo orbiter which circled Jupiter at the time. Europa is an ice-covered moon of Jupiter (in order of increasing distance from Jupiter: Io, EUROPA, Ganymede, Callisto). This picture shows a small area on Europa, bringing out the details of ridges, furrows, spots, all of which is much speculated about. The general consensus appears to be that there is an ocean of liquid water underneath all this, and that the observed phenomena relate to upwelling and gravitational warming of this ice ("squeezing" by Jupiter and those other moons). If there is water, is there a chance for some kind of "life"?

Original Caption Released with Image:
Reddish spots and shallow pits pepper the enigmatic ridged surface of Europa in this view combining information from images taken by NASA's Galileo spacecraft during two different orbits around Jupiter.
The spots and pits visible in this region of Europa's northern hemisphere are each about 10 kilometers (6 miles) across. The dark spots are called "lenticulae," the Latin term for freckles. Their similar sizes and spacing suggest that Europa's icy shell may be churning away like a lava lamp, with warmer ice moving upward from the bottom of the ice shell while colder ice near the surface sinks downward. Other evidence has shown that Europa likely has a deep melted ocean under its icy shell. Ruddy ice erupting onto the surface to form the lenticulae may hold clues to the composition of the ocean and to whether it could support life.
The image combines higher-resolution information obtained when Galileo flew near Europa on May 31, 1998, during the spacecraft's 15th orbit of Jupiter, with lower-resolution color information obtained on June 28, 1996, during Galileo's first orbit.
The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov .
Image Credit:
NASA/JPL/University of Arizona/University of Colorado

Check things

At my age, it is prudent to check blood pressure. I've been doing this for some time, with an electronic BPM (Blood Pressure Monitor), which we've had for years. The Velcro, which holds the pressure cuff to your arm, is worn, so I decided to check the latest models on Consumer Reports website. This organization is not sponsored by any other organization; it tests consumer products by buying them as you and I would. Any major purchases we intend to make are first vetted by us here. So, when I looked for test results for BPMs, I found the top model. I went to our mall and looked for it, found the shelf on which it was supposed to sit at a pharmacy there. The shelf had the label of the correct model, but the BPM sitting there was a different model, by the same manufacturer. Since the people at the pharmacy did not have the model I wanted in stock, I decided to take the model I found.

Starting with this new BPM, I found that my blood pressure readings seemed to be about 20mmHg (20 mm of mercury) higher than on my old unit. This certainly caused me some concern. At that point I didn't know whether the old BPM had given me incorrect readings all along, or whether the new one was incorrect. This discrepancy persisted, so I made an appointment with our doctor. The intent was to compare the new machine with the doctor's BPM. Well, the result was that the new BPM read about 20 mmHg higher than the doctor's, too.

So, my advice, if you are doing something similar, go to your doctor and make sure the readings on your BPM matches the ones on his/hers to within a couple of points, or so. Take your BPM along with you, so you can compare them. Both you and your doctor may be making medication decisions based on the readings you are taking at home (to avoid the "white coat" syndrome). If these decisions are based on incorrect readings, the medical consequenses might be more serious than a blood pressure problem itself.

Nice day

Because it's such a nice day today, we sat on the back porch this morning, had breakfast, and had a nice talk with Derek, Airdrie, and the girls. Derek is having a good day. He has gained some more weight, but is still fairly limited in the kind of food he can take. None-the-less, things are looking up. His blood sugars are in very good shape. He had another CT scan yesterday, but doesn't know the results yet.

We have friends who phoned from Europe this morning; they have relatives who are dealing with cancer as well - it's also three steps forward and two steps back for them in their recovery. So, yes, it's frustrating for everyone concerned, but fighting cancer is a real, biological war and the battle lines move constantly. It involves family and friends, too; I think that's what makes us human. We are thankful to all of you for your support.

The Perseids

Yesterday, I looked for the "falling stars" I talked about in the previous post. I saw a couple of bright ones around 10:30pm, one of them through binoculars. That one did not seem to be part of the Perseids; it came from a different direction. However, it was quite bright, and I could see it break up into several smaller pieces just as it finished. That happens when the heat buildup inside gets high enough to explode the original meteor.

Unfortunately, a broken cloud cover drifted in around 10:45pm, so I probably missed more of the Perseids. I went into the house at that time. Though I woke up a couple of times during the night and the sky had cleared again, I didn't see any more Perseids during the few minutes I looked out the Window at those times.

Perhaps other people had more luck. According to predictions, there should have been a fair number visible this year.

Falling stars

For those of you interested in seeing a phenomenon in the sky without the need for a telescope or binoculars:

This weekend we have the annual re-appearance of the Perseid Meteor Shower. What we should see (barring cloudy skies and too much light pollution from surrounding lights) is the "burning up" in the Earth's atmosphere of tiny particles which Earth encounters every year in its orbit around the Sun. The "debris" which the Earth encounters at this time each year is shed by a comet which also orbits the Sun, named Swift-Tuttle (the discoverers). If you are located away from the big cities, and have a clear sky, you might see a "falling star" once a minute, or so. In the cities, you'll only see the brighter ones, but there is always a possibility of a really bright "fireball". The maximum "rate" is expected on Sunday night, into Monday morning.

Look towards the north-east when the sky gets dark. Here are two images of the same area generated by the "Starry Night" computer program simulating the view at about 11:15pm. The Perseus constellation is pictured just below centre in each image. The lines connecting the stars are imaginary, they don't exist in reality. Click on the pictures for a larger view:









As you would see the sky away from the city.









Shown with annotation.




The frequency of falling stars will increase after midnight, when the Earth's rotation carries you you around to a more "head-on" direction. This is the direction into which the Earth is heading on its way around the Sun.

The Perseids get their name from the constellation from which they appear to come, called the "radiant". This purely a perspective effect; the stars which comprise this constellation are infinitely farther away than this comet-debris, which originates in the solar system. As the night progresses, this radiant moves higher and higher into the sky, due to the Earth's rotation.

Good luck, and clear skies!