Linus and Moons
CHAPTER 63 Vitamin C and Space Stuff
This column may be a relatively short one, due to me experiencing the worst cold or flu I've had in decades. I must thank our daughter-in-law Cindy and her husband Harry, our Lamb cartoonist, for taking complete charge of handling the Thanksgiving dinner in our home last week. Although I had a flu shot, it sure feels like the flu to me.
In last month's column I tried to convince myself that I understand how one gene in my DNA could code for the manufacture of more than one different protein. I did not plan to write about DNA or genes again for some time. However, the first line in an article by Jocelyn Kaiser in the November 6 issue of Science made me change my mind. That line: "Maybe Linus Pauling was onto something after all." The mention of Pauling brought back memories. When I was in graduate school at the University of Pittsburgh from 1946 to 1950, I went to a lecture by Pauling at the Mellon Institute, which later merged with the Carnegie Institute of Technology to become today's Carnegie Mellon University. Pauling had not yet won his Nobel Prize in Chemistry or his Nobel Peace Prize. One of the books I most frequently referred to in my graduate work and later during my career at Bell Labs was Pauling's over-400-page book "The Nature of the Chemical Bond". I am surprised to find that I still have the book and must admit that most of the material in it is way over my head. However, leafing through the book this week I was pleased to see that I had underlined a lot of material, even material in the last two paragraphs of the book! Had I actually read the whole book?
Pauling was a controversial character. His espousal of vitamin C as having beneficial properties in a number of diseases, including cancer, influenced a lot of people. For some time many, myself included, were taking high doses of vitamin C based on Pauling's reputation. Later studies discredited his vitamin C postulates and I stopped taking any extra doses. However, the article in Science discusses recent work in mice and on certain cultured cells with mutations in genes related to colon cancer. The results of these studies suggest the possibility that high doses of vitamin C may indeed kill certain mutations of colon cancer tumors and even some pancreatic cancer cells. The results are promising enough that human trials in selected cancer patients may be started soon. To get the high doses will probably require the vitamin to be injected in human patients. The article describes the dosage in some of the mice experiments as being equivalent to a human eating 300 oranges. Let's hope that Pauling turns out to be right, at least for human patients having certain types of cancer.
OK, it's time for me to get back to my obsession with space-related items. One of the space missions that has provided a wealth of interesting discoveries is the Cassini mission, launched over a decade ago as the Cassini-Huygens mission to explore Saturn, its rings and its moons. When the mission was launched there were only 18 known moons. Since then, the number of known moons has increased to over 60, with Cassini itself discovering a number of moons. Cassini's first spectacular achievement came back in 2004, when it dispatched its European Space Agency's Huygens probe parachuting down to the surface of the moon Titan. Titan turned out to be a fascinating moon with seas and peaks resembling volcanoes. The seas aren't water but probably mixes of such compounds as liquid methane and ethane. The moon is loaded with organic chemicals. Recently, as winter closes in on Titan, a huge ice cloud has been observed forming over its south pole. Of course, the "ice" on Titan isn't water but some mix of organic compounds.
One of the instruments on board Cassini is RADAR, which has been mapping Titan's surface by shooting microwaves at it and measuring the time it takes for the signals to be reflected back - just as we use radar here on Earth. In a recent issue of Discover magazine, Liz Kruesi cites a reanalysis of early Cassini RADAR data by Marco Mastrogiuseppe using software he used to study subsurface water on Mars. Feeding old Cassini data into his Mars software revealed two peaks from a scan of a sea on Titan. One peak was the reflection of the microwaves from the surface of the sea, the other from the seafloor. Turns out the sea, Ligeia Mare, is 520 feet deep.
While Titan is a very interesting place, my favorite these days is Enceladus, where the ice is good old water ice. As promised, Cassini swooped down just a mere 30 miles above the surface of Enceladus on October 28. I am truly impressed that we can control a spacecraft many millions of miles away to come that close to a body and not crash into it. The main goal of the close flyby was to sniff the atmosphere over Enceladus with its geysers of icy water. Cassini discovered these plumes years ago. I was hoping that by now NASA would have released some results of the sniffing. However, NASA's Cassini Web site stresses that it will take months of careful analysis to determine what's in those icy plumes. The key thing that the Cassini team is looking for is molecular hydrogen, H2. If molecular hydrogen is present it would be an indication that hydrothermal action is going on in the ocean under the surface of Enceladus, as it is in our own oceans here on Earth. This would raise the possibility that life of some sort might exist on that moon. NASA also points out that Cassini does not have the capability to detect life.
What about Mars, which once had flowing water in sufficient quantities to support life? NASA recently reported on the results obtained by its MAVEN (Mars Atmosphere and Volatile Evolution) mission. MAVEN has been orbiting over Mars for more than a year and has come up with data that relate to how Mars lost the atmosphere that allowed the water to exist on Mars in a liquid state. Speculation is that there may have been carbon dioxide in that atmosphere, resulting in a greenhouse effect raising the temperature above water's freezing point. What happened to that CO2?
The MAVEN data indicate that currently the solar wind is stripping away from the Mars atmosphere about a quarter of a pound of material every second. Over long periods of time that's significant! MAVEN has also found that the rate of loss is greater during solar storms. The feeling is that billions of years ago our Sun was more active and solar storms more frequent. The solar wind of particles such as electrons and protons streams out of the Sun's atmosphere at about a million miles an hour. It doesn't seem surprising that such a wind would knock molecules out of an atmosphere. I assume that we on Earth are lucky that we have a strong magnetic field that deflects electrons and protons from the solar wind. Mars apparently had a strong magnetic field at one time but, being smaller than Earth, its molten core responsible for generating the magnetism cooled down and solidified. We really are lucky!
Well, sorry if this column seems somewhat disjointed but I'm still not in great shape and you women out there will know how men are when they have a cold. Next column, hopefully, on or about January 1 of 2016, a few days after my 88th birthday.
Allen F. Bortrum