Methanol Exhaust Emissions
John D Bernard
Jupiter Space Station Radio Observatory
As an organic gas molecule, methanol is characterized as a building block for life, star formation, and fuel cells. Methanol energy transition states at 6.7 and 12.2 GHz can be found in relative abundance along the Milky Way galactic plane and are seen spectroscopically as whirling maser pockets with cores and halo structures of 2 - 300 AU in diameter.
The Jupiter Space Station uses a methanol receiving chain comprised of a 12' dish, a custom tuned 12 GHz Seavey feed, a 60 dB gain LNA with a PLL controlled commercial downconverter, and the combination of a gas spectrometer, the SpectraCyber, and a sweeping spectrum analyzer. The spectrum analyzer has custom radio astronomy specific data acquisition software, DigiSpectrum, for analyzing Doppler shifted gas sources.
This paper is a report of prospective methanol indicators for life
in space, initial data collection, technical problem resolutions, and observing
considerations for mapping methanol in space.
Eagle Nebula, NASA - STScI-PRC1995-44a
The Jupiter Space Station (JSS) is located on 20 acres in Pendleton, South Carolina at 82° 40' 08" W and 34° 40' 34" N. The twenty or so professional men and women who build, maintenance, and run the station are volunteers from all walks of life and all disciplines: engineers, scientists, technicians, teachers, and ham radio operators. We define ourselves as professionals because we have specific research hypothesis and objectives, we execute research data collection plans, we use research grade instruments, and we both publish and present our data in scientific forums such as the South Carolina Academy of Science, the International Astronomical Union (IAU), and other radio astronomy venues.
The Jupiter Space Station has two radio dishes to do radio astronomy experimentation, including the exploration of life and intelligent communications in outer space. For the last four years our primary project has been the implementation of our SASER project. The SASER project is based on the weak signal transmission into a flare cavity on the sun for re-transmission at gigawatt power into outer space. Our initial attempts at testing a reasonably powerful transmitter for the project via EME proved doable but lacking in power. At the suggestion of the former Director of the National Astronomy and Ionosphere Center (NAIC), the JSS associates have decided to submit our 50 page proposal to the Arecibo proposal committee to use their 1 million watt planetary mapping gun to test the thesis. Details can be viewed at:
In the meantime the JSS has been putting our 12’ to work and completing the construction of our 24’ dish. We have begun work to explore another alternative for identifying life sources in space: the methanol gateway. Methanol (CH3OH) as an organic gas product is characterized as a building block for life, star formation, and fuel cells. Methanol energy transition states at 6.7 and 12.2 GHz can be found in relative abundance along the Milky Way galactic plane and are seen spectroscopically as whirling maser pockets with halo structures of 2 - 300 AU in diameter. "Methanol masers give us a probe into what is happening in the areas where massive new stars are forming (as do hydroxyl and water masers). Studying them also improves our knowledge of basic physics (why are they masing) and chemistry (why is there methanol present)." (Michael Gaylard, Hartebeesthoek Radio Astronomy Observatory, 2003) To appreciate the importance of this compound to both life and cosmic evolution one would be interested in three views of methanol:
· Methanol as an organic transformation catalyst,
· Methanol as a cosmic building block,
· Methanol as a fuel source.
Methanol as an organic transformation catalyst is found in treatment technologies in the waste management domain where methanotrophs biodegrade chlorinated hydrocarbons. Methanotrophs are bacteria that derive energy from the oxidation of methane to methanol. The organisms that are responsible for the degradation of compounds do not derive energy from the transformation of the chemical, but rather by cometabolism with enzyme or cofactors produced by the microorganisms.
Methanotrophs use the enzyme methane monoxygenase to catalyze the oxidation of methane to methanol. This enzyme will oxidize Trichlorethene which is the most common halogenated aliphatic hydrocarbon contaminant in groundwater. Trichlorethene becomes an unstable epoxide that will undergo decomposition to yield a variety of products including carbon monoxide, glyoxylic acid and a range of chlorinated acids. (Hickey and Smith, 1996) Where there are organic transformation opportunities, there may be life.
Methanol as a cosmic building block:
There is the 12.2 GHz E energy transition, which was first discovered by Batrla et al (1987), and the 6.7 GHz A+ energy transition which was first detected by Menten (1991).
Maser emission from methanol has been detected near sources primarily identified with star formation. These masers have been divided into Class I and II classifications and are dependent on the maser electron energy transition. Class II masers include maser emission from the 20→3-1 E transition of methanol at 12.178 GHz. These masers are typically found to coincide with compact H II regions and sites of OH and H2O maser emission. Class II masers are thought to be associated with high mass star formation and appear to have a photon pumping mechanism. Class I sources are not found near compact continuum sources, while Class II masers are usually found close to very compact H II regions. The Eagle Nebula (M16), seen in the Abstract at the top of this paper, was one of our first methanol “star formation” targets.
Class I masers (6.7 GHz), defined by the 51→60 A+ transition, are not typically associated with centers of star formation. The pumping mechanism appears to be collisional and they are sometimes found in regions where there is some outflow activity. They also have been detected offset from the star formation activity.
Finally, methanol energy transition states at 6.7 and 12.2 GHz can be found in relative abundance along the Milky Way galactic plane and are seen spectroscopically as whirling maser pockets with cores and halo structures of 2 - 300 AU in diameter.
Methanol as a fuel source has a rich history and future here on earth. In the forties and fifties we heard the football fight songs with the words "we never stagger, we never fall, we sober up on wood alcohol." Back then methanol was a popular distillate from wood. Today there are direct methanol fuel cells which have hydrogen reacting with oxygen and producing an electrical current. We know the problems of storing hydrogen, the Hindenburg Effect. Normally it has to be contained in a high pressure vessel or in a cryogenic state as a super-cooled liquid.
An often overlooked but intriguing fact about methanol is: that there is more hydrogen in a gallon of liquid methanol than in a gallon of pure cryogenic hydrogen. So methanol turns out to be a very good carrier fuel for the hydrogen that fuel cells need. All that is required is a way to get the methanol to give up its hydrogen, and it turns out that methanol does this with ease.
In the past methanol cells have used a separate reformer to release the hydrogen from liquid methanol, then the pure hydrogen is fed into the fuel cell stack. The Materials Science & Technology Division at Los Alamos National Laboratory has developed a fourth-generation 30-cell 80-W Direct Methanol Fuel Cell (DMFC) stack that was delivered and integrated by Ball Aerospace into a complete demonstration system for the military. A 500 watt unit is now under development. (Zelenay, 2002) This tremendously simplifies the fuel cell, and it becomes a highly efficient replacement for not only the combustion engine but future space propulsion as well.
Hydrogen interstellar ramjet propulsion systems were once proposed and discarded because interstellar hydrogen does not have a concentration to support “scooping” as you fly. (Bussard, 1960) Instead of a hydrogen scooping propulsion system, now imagine an interstellar vehicle moving in a high methanol-rich space with its fuel scooper replenishing the fuel supply. Methanol maser condensations have been estimated at greater than 1029 grams or 10-4 of a solar mass: planetary size. Temperature estimates range greater than 100° K. (Slysh et al, 2001)
Finally, if one can visualize a network of interstellar service stations then space traffic could move from planetary system to planetary system with desert-like methanol maser filling stations in between.
This introduction is concluded with these observations:
· Methanol is a contributor to organic transformations,
· Methanol is a hallmark cosmological building block,
· Methanol can be an important fuel source in space travel.
The study of methanol in space can be a looking glass into the evolution of intelligent origins, interstellar space travel, and gateways pointing toward interstellar communications.
Methanol Project Background
The JSS has an established equipment chain and observing plan to see methanol sources, and to verify their signals by repeating the observing sequence. Our 12’ dish is not only the learning system, but is the test bed observing system. Everything will then transfer to the 24’.
The initial observing plan was based on fundamental WYSIWYG (what you see is what you get) radio astronomy. Over a period of six months we would park in specific regions to see what might be present. Because our current frequency (12.178 GHz) is in the Ku satellite band we spent several months observing both on and near the Clarke Belt so that we can get a feel for both the signals and interference generated by satellite transponders.
We use a methanol receiving chain comprised of a 12' dish (see on the left), a custom tuned 12 GHz Seavey feed, a 60 dB gain LNA with a PLL controlled commercial downconverter, and the combination of a gas spectrometer, the SpectraCyber, and a sweeping spectrum analyzer. The spectrum analyzer has custom radio astronomy specific data acquisition software, DigiSpectrum, for analyzing Doppler shifted gas sources.
System minimum sensitivity dictates what we can actually see by using the Kraus equation 3-121 (Kraus, 1986):
dSmin = 2 * k / Ae * Ks * Tsys / (dNu * t * N)^1/2
The 12’ Tsys is from 100 – 145 depending upon feed, and has been benchmarked with hydrogen observing.
For continuum observing with integrations to 10 seconds the dSmin is approximately 20 jansky, and spectral mode with 0.1 sec integrations yields about 270 jansky. Since we have seen 275 signals we believe our sensitivity is far better because our system temperature under ideal conditions is closer to 100°K as determined by solar transit G/T calculations run in the past.
Seeing a 12.2 GHz source like G188.95+0.89 at 175 jansky may be difficult, but worth a try; our 12.2 preamp has a NF of 0.6 - 0.8 rather than 0.4 as our hydrogen feed has (which adds to the difficulty). The feed must be "tuned" perfectly to decrease our system temperature. This is achieved by a xyz gantry at the focus which we adjust to achieve a maximum signal from a 280°K ground source as measured by a spectrum analyzer or even a satellite signal meter.
The Seavey feed (on the left) can be seen with the xyz gantry setup which we simply mount to the prime focus plate with the four bolts on the top two horizontal rails.
Discussed later is the black probe rotator motor which gives us 4 modes of polarization. The pulse train to rotate the probe is provided by a Channel Master satellite receiver which is not in the rf chain.
Working with commercial satellite equipment like the Norsat LNB and the Standard Communications receivers creates several impedance mismatchs which we smooth out by inserting 50 ohm attentuators (1 – 3 db) in the receiving chain at transition junctions. For doing spectral work using an LNB like the Norsat, the PLL helps dramatically in keeping the signal reasonably locked once the LNB temperature stabilizes (around 20 minutes).
Other essential test equipment for us includes a Polarad signal generator, a 1420 MHz reference, and a frequency counter. Our HP 141T spectrum analyzer with the 110 MHz plus-in has custom software, DigiSpectrum, to capture traces and is extremely helpful in identifying rogue signals.
The observation of methanol with the 12’ is done very fundamentally with drift scan, sometimes twice in a 12 hour period: once on each wing of the galaxy. The primary target is set by a solar transit to establish azimuth and a digital level to set altitude. These references can be easily converted to a right ascension and declination or galactic coordinates. Both 6.7 and 12.2 GHz narrow the HPBW to 1° and 0.5° respectively so in a mapping mode we drop the altitude of each observing cycle by a HPBW. If we see anything on that transit, we park and work around the coordinates to further resolve the signal on subsequent days.
Methanol Data Collection
Methanol signals are collected with either the spectrum analyzer or the SpectraCyber gas spectrometer. Both these instruments have Windows based control and analysis software to assist in the collection of the data. Specifics about the hardware and software can be found at:
Methanol at 6.7 GHz has more known sources and larger flux densities than methanol at 12.2 GHz. We ran our custom built 6.7 GHz downconverter for two months and captured this signal using the SpectraCyber I spectrometer:
LAST is an acronym for Local Apparent Sidereal Time and the observed doppler is red shifted at -1200 KHz. The fully animated data plot sequence (movie player) can be seen at:
As in the above depicted spectral signal, different gas sources have unique spectral signatures which include positive or negative or multiple shaped doppler shifts over a wide bandwidth (2 – 5 MHz). There may be multiple irregular peaks in a single sweep. Continuum signatures typically exhibit a single gaussian shaped peak at one frequency and bandwidth. More animated data sets for both 6.7 and 12.2 GHz can been seen at the JSS web site.
Methanol Data Collection Problems
There are significant problems with working at 12.2 GHz: Ku band satellite interference from the SBS 6 bird (Hughes/PanAmSat) when transponders are turned on to open a commercial feed. We can be 20 degrees off the satellite and pick up interference. Much time has been spent classifying "man-made" signals versus natural galactic signals and it is critical that collected signals replicate the known spectral signatures from other research radio observatories.
Here are our criteria for evaluating potential signal sources to eliminate rogues:
· The signal lasts for less than 2-3 HPBW of the dish,
· The signal reoccurs the next drift scan 4 minutes earlier,
· The signal spectral bandwidth is less than a megahertz,
· The signal fades when the dish is moved,
· The signal is not a satellite ricochet off a slow flying aircraft overhead.
The JSS is considering a simple solution to the rogue satellite signal problem: the installation of a small DSS dish to serve as a "bird dog" on the Clarke Belt to supplement our captured signal data to confirm whether or not interference on our frequency was present.
Two other reception considerations are atmospherics during the observing window and the selection or interception of dSmin threshold targets. It is our opinion that rain, fog, and snow degrade our rf balanced 12' system dramatically, and that Earth Van Allen Belt magnetics can play a role in whether we see or not see a threshold signal. As a result we may see a signal one evening and nothing on the next evening. The observing plan is to drift scan a HPBW until a source is ruled in or ruled out.
Methanol Project Conclusions
The project is at the point where we can commence a methanol mapping of a galactic quadrant or test for polarization in methanol sources, or plan for further research projects such as comparisons of methanol regions along side Hydroxyl or H II gas regions.
The observing and research plan for 2003 includes locking onto stronger methanol signals and using the 4 polarization modes of the Seavey feed to see if there exist any polarization components in the gas sources. Soon the 24' will be hoisted, motorized, and brought on-line with the 12' rf chain installed on it. Once it comes online, the 24' will give us a better, more forgiving rf collection system.
One implication of this paper, based on the importance of methanol in the cosmic scheme of things as presented in the Introduction, is the opportunity for the SETI League to search in a region of the galaxy where methanol is prevalent. As outlined, these Class II methanol masers are typically found to coincide with very compact H II regions and sites of OH and H2O maser emission, and are thought to be associated with high mass star formation.
As a proposal for a joint project, the SETI League could coordinate their associate Project Argus instruments toward a predefined, rich methanol quadrant [mapped by the Jupiter Space Station Radio Observatory] for two weeks to search for an intelligent signal from a potentially life-rich portion of the galaxy.
The study of methanol in space can be a looking glass into the evolution of intelligent origins, interstellar space travel, and gateways pointing toward interstellar communications.
The JSS would like to acknowledge the 24' teamwork and hard work of Doug Starwalt, Doug Fagan, Cris Bailey, Stewart Lee, Tim Fortner, and Mel Tooker. We receive valuable counsel from Charles Osborne, Lew Fitch, and Gary Spangenberg. The best custom hardware designs on this planet came from Carl Lyster, Tommy Henderson, and Mike Krueger. Jeff Lichtman of Radio Astronomy Supplies is always there with the right filter or downconverter or hardware recommendation. The Departments of Industrial Mechanics, Machine Tool Technology, and Welding at Tri-County Technical College are always there with help.
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7. Zelenay, Piotr. Direct Methanol Fuel Cells. Annual OAAT Fuel Cells Program Review, National Renewable Energy Laboratory, Golden, CO, May 2002.