A Lenten Reflection~ guest blogger Kaze Gadway plants some seeds

Kaze Gadway is a lay youth minister to an outreach project for Native American youth and young adults in Arizona.  Episcopal Diocese of Arizona

Julian of Norwich “Pray inwardly, even though you find no joy in it. For it does good, though you feel nothing, see nothing, yes, even though you think you cannot pray.”
Lent is not like Advent. Advent is a preparation of the celebration of God with us, God walking among us. Although Lent comes before Easter it is a season not like any other. It is forty days of intensifying holy practices.
All religions have holy practices. They are ways in which we discipline ourselves to be immersed in activities that expose us to the sacred. It may be putting money in a jar to give to the poor. Or depriving ourselves of food or pleasure to remind ourselves of what is really fundamental. Or writing down our faith responses in a journal. Or meditating on Holy Scriptures in a different way. Or spending time in contemplative silence. Maybe it is a walk in which you observe such awesome particulars such as a leaf. Or it could be intentional prayer.
I pray all the time. Usually it is in response to something. I am concerned for someone or someone asks me to pray. During Lent, I pray in a cycle to include all those who usually get left out of my conscious prayer life. I pray for those in danger, for those nations who are in social upheaval, for those crushed by the economy, for those disenfranchised in decision making, for those paralyzed by grief or loss, for those bruised in spirit in shame and guilt, and for those who have lost their way. How I feel doesn’t come into it. I go inward to hold up those that are disconnected and fragmented in their daily joy. I don’t usually have an outcome, like I hope everyone gets a job. I hold them up as significant to the God who dwells within us.
“What are you giving up for Lent?” asks a child who has heard this on TV. “Nothing,” I reply. “I don’t believe in giving up something like candy that I shouldn’t be doing for my health anyway. I do add things.” And I give her an abbreviated context of holy practices.
“I’m going to give up fighting with my mother,” says one youth proud of himself.
“That’s great,” I reply. “What are you going to do instead?”
There is a thoughtful silence in the small group. He says, “Maybe I should help around the house more. That’s what we fight about.”
Another youth who has been with us for a long time says, “Maybe you should clean a different part of the house every day. That would make it a spiritual practice, wouldn’t it?” He looks at me and I tell the story of Brother Lawrence again of finding the sacred in even the smallest of kitchen chores by doing it intentionally with reverence and dedicating it to God.
“We do that in Native ceremonies,” an older youth comments. “Every implement we use, everything we undertake is lifted up and prayed over.”
We talk about that in general terms in order not to reveal the particulars of confidential sacred ceremonies. They have all participated in some kind of intentional sacred practice, including helping at the altar in Church.
One of the youth confesses, “Sometimes I am only praying by rote. I don’t really feel anything.”
I assure him, “Feeling is not necessary but intentionally holding up some person or issue to God is. Like when we pray for Haiti. We’ve not been there but we can take the time to hold up that country to God. That puts it into our minds and it also declares that we believe that God holds this as important and worthy to be cherished.”
So we each make a list of things that we normally do not pray for and each holds up one thing. The responses are amazing—being bullied, car crashes on our interstate that goes through our town, stores that depend on the tourist trade, people dying without family present, forgotten birthdays, violence in homes, and neglected animals. Our prayer life is enriched just by listing these things. We decide to check in and see what happens when we do something every day that exposes us to the Holy.
It is an exciting season.
Blessed Lent everyone.
In faith,
Kaze

We Should Become Martians: Part II~ Regular guest blogger Claude Plymate concludes his thesis.

  Claude Plymate is the Telescope Engineer/Chief Observer at  Big Bear Solar Observatory in California, and is the  former chief  wrangler of the McMath-Pierce Solar Telescope at Kitt Peak National Observatory Arizona for many years. He is a regular contributor to Musical Milliner.

It is true that we currently do not have the technology to allow a human trip to Mars. Now that the shuttle has been retired (and rightfully so), the U.S. doesn’t even have a rocket that can get humans to low Earth orbit! Forty years ago, however, that was not the case. The Saturn-V rocket used for the Apollo lunar program could have been repurposed for a Mars mission. It would have taken more than a single launch of even the mighty Saturn-V for a Mars mission but it would have been feasible. Now that we finally retired the Space Shuttle, we are free to consider the next generation of boosters that will again be capable of taking us beyond Low
Earth Orbit (LEO).

NASA recently announced the Space Launch System (SLS). If funded, SLS will be a heavy lift vehicle derived from both Shuttle and Apollo-era technology. The SLS will initially have a payload capability to LEO of just over 1/2 that of the Saturn-V. The eventual plan is to continue to upgrade its lift capacity with larger strap-on boosters. This is expected to ultimately give it a payload to LEO of slightly greater than that of the Saturn-V. Unfortunately, the “evolved” boosters are scheduled to not be available before 2030.

SpaceX has proposed several very intriguing projects and has an amazing track record of following through on its claims by delivering working hardware. Its Falcon 9 rocket topped with their Dragon capsule has already flown and is scheduled to fly a resupply mission to the Space Station (ISS) soon. Falcon 9 (F-9) currently can only deliver about 1/2 of what the Space Shuttle could to orbit, good enough to get supplies and astronauts to and from the ISS but isn’t of a class necessary to do much more. SpaceX has, however, announced the Falcon Heavy. The Heavy is effectively three F-9 rockets strapped together! This simple evolution of the proven F-9 gives a projected launch payload of about 1 1/2 Shuttles! Now that’s beginning to get to the point that we can begin designing missions. But wait there’s more… SpaceX has proposed the eventual development of a Falcon X and derivative rockets dubbed the Falcon X Heavy & Falcon
XX (what SpaceX CEO, Elon Musk, has called the BFR for Big F@$#ing Rocket!). The Falcon XX would have a payload exceeding that of either the Saturn-V or SLS.

Below is a table comparing some current & proposed rocket payloads to LEO:

Rocket Chart

What I’m attempting to point out is that very capable Mars rockets are well within current technology and were even produced using 1960’s technology!

It’s an undeniable fact that a human mission to Mars would be expensive. I typically hear conservative estimates ranging somewhere in the ballpark of $150 Billion. Any way you look at it, that is a lot of money – roughly $500 for every US citizen. Keep in mind that any such program would be spread over at least 10 years which makes the cost per year around $15 Billion/yr. $15 billion is still a heap of money but less than the current annual NASA budget. (Don’t think, however, that I’m advocating dedicating the entire NASA budget to a Mars mission. NASA does a lot of other very important programs. I wouldn’t want to see the budgets for those other important programs get consumed.) It would seem that we either need to find ways of getting the costs down or increase the funding. Increasing budgets do not seem likelyin the current economic/political climate. If we want to go to Mars, we need to find a cheaper
approach.

Let’s examine why space flight tends to be so extremely expensive. One reason is that you much carry all of the fuel, hardware and resources for the return trip on the outward leg of the journey. Picture it this way; imagine if to fly from San Francisco to New York, the plane had to carry all it needed for the return flight – fuel, food, water, etc. The plane wouldn’t need to be just twice as large to carry it all; it would need to be MUCH larger. To carry the extra fuel and supplies, the plane would need to be built much stronger and heavier. This heavier plane would need larger engines to fly requiring yet more fuel which would require a bigger heavier plane… it becomes a vicious cycle. Costs quickly spiral out of control leading to the inevitable conclusion that transcontinental flight is simply not practical! We get around this by not carrying everything needed for the entire trip. Planes are refueled and restocked before their return flights. Estimates that I’ve seen indicate that somewhere around 90% of the cost of space missions are due to the penalty paid for the return trip. Think back to the iconic images showing the colossal Saturn-V sitting on the launch pad before heading off to the Moon. All that immense hardware was used up just to return three guys and some rocks sardined in that little
sedan-sized capsule!

So in this era of ever tightening budgets, how might we design an affordable human mission to Mars? What if we simply cut out all those massive costs accrued by the return flight? Now don’t be aghast. I’m not suggesting some suicide mission. Keep in mind, that my original justification for going to Mars was the eventual goal of colonization. Why not just start the process from the outset?

A one-way trip should be able to be carried out for around 10% the cost of a round trip mission – somewhere in the $15 billion ballpark range. In an era of $100 billion bailouts and Trillion dollar wars, this sounds like a bargain. Especially when put in the context of safeguarding against the potential extinction of humanity on this planet. I often hear economists say that the way out of our economic slump is to create jobs. What could be a more noble jobs creation plan than mobilizing our high tech industries and stimulating universities to develop technologies for our expansion into the solar system and the long-term safeguarding of our species? Add to this that historically every dollar invested in space has returned about $7 to the economy and you have a true win-win scenario. Perhaps what our economy really needs is an “Occupy Mars” movement.

The cost estimate above is admittedly rather simplistic and overly optimistic. Sustaining a Martian colony would require significantly more resources than a simple Apollo style “flats-and-footprints” out-and-back mission. They would need continued supplies, oxygen enriched atmosphere to breathe, water, pressurized habitats in which to live and work, greenhouses to grow food, spare parts and backup equipment and, of course, power. (A growing colony would need ever-growing sources of power.) Spreading these costs over the lifetime of the project still makes it comfortably affordable within existing budgets even if we assume it will end up costing
several times the overly simplistic estimate above.

Early settlers would have to be dependent on periodic resupply missions. I would envision that every couple of years when a launch window opens up, another ship would be scheduled to deliver more supplies, equipment and another batch of pilgrims. In this way, the initial base would naturally grow over time as infrastructure and population is added, evolving from base
to colony to settlement and eventually to society.

A high priority from the start would have to be placed on achieving self-sufficiency. Not only is it of economic interest for a Mars society to become self-reliant, it would be too risky to depend indefinitely on the Earth. It is inevitable that a supply mission will someday fail or changes to Earth bound economics, politics or public support might leave the new Martians on their own. For their own security, they would have to be able to take care of themselves as soon as possible.

Admittedly, this is an edgy high risk concept. Who could we find to sign up for such a dangerous mission, one that at very best would leave them with very little likelihood of ever returning t friends and family? Honestly, I think there would be no shortage of volunteers! Those that go would become legends. Their names would go down in history as the founders of a new world. I expect that humanity would be mesmerized by the daily drama. Each settler would become heroes on TWO worlds! Who wouldn’t dream of being part of such an historic project?

In light of the huge economic problems we’re currently in, when should such an epic project begin? My opinion is if not now then when? A one-way approach to Mars is affordable and starts down the path of making humanity a multi-planet society from its inception. I, therefore, suggest that our mantra be “Mars – one way to stay!”

(c)GosgGusMusic(ascap) 2012

We Should Become Martians: Part I. ~ Guest Blogger Claude Plymate Returns!

  Claude Plymate is the Telescope Engineer/Chief Observer at  Big Bear Solar Observatory in California, and is the  former chief  wrangler of the McMath-Pierce Solar Telescope at Kitt Peak National Observatory Arizona for many years. He is a regular contributor to Musical Milliner.

It likely won’t come as any surprise to those of you who know me or have read some of my earlier essays that I am a strong advocate of sending humans to Mars. What might surprise you are my reasons which are more about societal needs than about scientific exploration. Our population has now passed the 7 billion mark.

There are indicators all around us that this planet cannot maintain the pressure we’re applying to its resources and resiliency. There is little reason for me to go into the details here; you are all well aware of the risks we are subjecting ourselves to. Global climate change, fresh water depletion, famine, nuclear proliferation, pandemics and war are just a sampling of the dangers we pose to ourselves. On top of our self-imposed hazards, the solar system is in general a menacing place to live.  Asteroid impacts have already wiped out the dominant species on Earth at least once before.  A nearby supernova could disrupt our ozone layer with catastrophic consequences. We are fortunate to have a strong magnetic field and atmosphere that protects us from the harsh radiation coming from solar flares but civilization has left our technology quite vulnerable to such eruptions. It doesn’t appear that a “super flare” will kill us outright but just imagine the disruption to society if the Internet, electric grid, GPS system, radio communications and even telephones suddenly and unexpectedly went ‘dark’– and not just for a few hours but possibly days, weeks or even months!

What I’m trying to point out is that there are many real threats to our civilization and even our existence as a species. Some are self-imposed, some are natural.

This leads us to the question of how to mitigate such threats to humanity.  Consider how you deal daily with risk management of other items you regard as valuable. For example, you wish to protect your documents and photos stored on your computer’s hard drive. What do you do? Of course, you backup your files onto a separate drive stored  in a separate location. (You do back up your files, don’t you?)  Applying this same rationale to society naturally leads to the conclusion that to survive long-term, humanity must expand beyond this one little planet.  Then, even if the unthinkable occurs, all that humanity has achieved won’t completely disappear from history.

The obvious first destination for a human outpost beyond Earth is Mars. Mars is the most Earthlike of the other planets within the solar system. It is close in astronomical terms and has an atmosphere. Mars is a place we can live. Plus, the lower surface gravity of Mars (about 1/4  that of Earth) makes getting on and off its surface much easier than here on the Earth.

Unfortunately, the atmosphere on Mars is very tenuous with a mean surface pressure ~ 600 Pa (0.087 psi), equivalent to an Earth atmospheric altitude of around 90,590 ft (27,612 m). On top of that, it’s a toxic mixture of mostly carbon dioxide. Anyone on the surface would have to wear a pressure suit (space suit). Even this exceedingly thin atmosphere could be used to pressurize suits & shelters. All that would be needed would be a compressor to pressurize the interiors. Simple inflatable structures could even be used for such things as storage, workshops and greenhouses. You still couldn’t breathe in the high CO2 environments but an oxygen mask would be all that’s required for people to work in otherwise shirtsleeve comfort. There are likely many plants that could thrive in these pressurized greenhouses. Obliviously, living quarters would need more oxygen to make a breathable atmosphere which is easily attainable
by liberating O2 from either CO2, water or even iron oxides (rust!) in the soil that gives the planet its red color.

Water means life. We need water to drink, water for crops and water to make oxygen. Recent Mars probes are making it clear that water (at least in the form of ice) is much more common on Mars than previously believed. What is required to harvest the water is energy; energy to drill wells or mine ice, energy to extract the O2. Possible sources for power include solar panels and/or nuclear generators and perhaps even geothermal. I suspect that the atmosphere is simply too thin to support wind power.

There are two primary arguments against going to Mars that people normally state; interplanetary spaceflight is beyond our technical ability and the cost would be far too great. I’d like to address these arguments one at a time.

Stay tuned for We Should Become Martians: Part II next week.

(c)GosGusMusic(ascap)2012

Ricordare

Two years ago today we lost our good friend. None of us saw it coming. I have a story to share, and a list of Mark’s wisdoms.

Soon after his mother died, I received a large package in the mail. It was the corduroy patchwork quilt she had made some thirty years before as a going away gift for Mark as he went off to college.Over the years, Marilyn had collected scraps of the fabric from her son’s trousers and shirts, and created this beautiful thing. When I followed Mark up to Northern California, it became my quilt, too.

For Mark to pass this on to me, a quilt over which his mother had lovingly labored, which had been so skillfully sewn as to have no tears or snags after so many years of use was a great comfort to me. Mark’s mother had for some years mothered me as well, and I miss her, too.

In my home, the quilt holds an honored place. We call it “The Mothers Quilt.” Any time someone is ill, or needs some warmth and comfort, out comes the quilt, and a cup of tea. The person is wrapped like a big corduroy burrito, and being a quilt of near magical powers and full of mother love, never fails to raise the spirits of whomever is wrapped within it.

For me, the quilt remains one of the strongest reminders of Mark’s legacy.

Here is a list of words I recall Mark saying, or sentiments I can attribute to him.
1. Always be kind.
2. Consider that the other guy may have had a worse day than you.
3. Wave pedestrians and other cars through a four-way stop.
4. Hug your mother while you still can.
5. Learn three corny jokes. Use them to disarm people and demonstrate that you are not their better.
6. If a friend needs some money, know it was hard for them to ask and give them small chores in exchange so they save face.
7. Remember that most folks really want to do their best.
8. Forgive and forget as often as possible.
9. It’s okay to keep your opinions to yourself.
10.When all is said and done, true love remains forever.

(c) GoshGusMusic(ascap)2012)

Memorie

Like most children, I looked forward to the Christmas season. Deep in my memory is a tray of Kodak (pre-carousel) slides flashing vignettes on a white wall.

The first tray contains slides when my mother was still walking.

I see my dad taking pleasure and effort to make from found items, a giant arrangement of red candles in graduated sizes, each wired with a different colored light atop, and attached to a platform which was displayed in front of the house on the lawn outside my mother’s kitchen window.  Something about a neighborhood decorating competition. Something about the wires occasionally shorting out. I found the whole thing fantastic.

I see him on a ladder, held by my eldest brother and being cautioned by my mother, taking care to hang lights under the eves.  I remember the glow of the soft colors filling my bedroom as I fell asleep, and how magical that felt.

I have a flash of my mother trying to make potica, a Slovenian holiday bread my father grew up with, and her quiet mumbling as she struggled to get it right.  I’m not sure if she ever did, but I wouldn’t have eaten it, being too picky to try unfamiliar foods like most little ones.

Then there was a year when my father had erected some tacky cardboard fireplace and mantle.  I attribute this to his solution of pestering questions about how could Santa come down the chimney when we didn’t have one.  None of the ranchers where I grew up had them because it rarely got cold enough.  Some companion slides appear on the wall, and I see my parents, who seemed to entertain a lot, sitting around with a living room full of happy people on Christmas Eve after church, and I in my jammies wanting to wait up for Santa.  I remember what I thought was a sonic boom, but, given the day and time of night was probably a quick, sharp earthquake jolt, and the adults telling me that the noise was Santa parking on the roof, and I’d better get to sleep or he wasn’t going to come inside.  Snap.  I woke up later and quietly padded into the living room (the squeaky parquet floor was a challenge) to find that Santa had left many presents, including a doll for me!

My next oldest brother convinced me to get back to bed before we got caught.

The milk and cookies we had left for Santa were gone!

There are slides of our family at Midnight Mass on Christmas Eve.  The creche scene behind the rail suddenly replaced by humans.  I was told many times that I made my stage debut as the baby Jesus when I was twelve days old, and slept peacefully per the script.  I  can’t forget the well dressed man next to us who dripped some astounding green-red glop from his nose onto a crisp white hankie. I couldn’t have been more than three or four years old, yet I remember this fellow. He is stuck on that slide.

The fragrant tree so beautifully decorated.  The ceramic creche underneath the spruce with which I  entertained myself, rearranging the cattle and sheep. Moving Joseph around.  Keeping the straw tidy and off the carpet for my mother.

Slides of the company- all the visitors.  The endless trays and dishes full of food.  The shock of seeing the rector in collar, sitting on a sofa with a cigarette and a glass of Scotch, and not having a clue as to how to deal with this contextual confusion.

It was a time of innocence which all children deserve.  By the time I was five, my mother was no longer able to walk.

The second tray of slides sits quietly in my mind.  The wall is blank. I don’t want to look at them.

(c)GoshGusMusic(ascap) 2011

Fiume Rocce

Ever boulder-hop when you were a kid? In a big river? You have to keep crossing back and forth. Every time you jump, you wonder if you will make it, or miss it and get carried downstream. Worse is to jump, think you’ve landed safely, yet almost immediately find yourself helplessly sliding down some hidden slime covered patch while trying to find another rock to grab to save yourself?

Must keep…jumping.
Must keep…hopping.
Must keep…hope.

I am a force of nature, full of light and life.
I am a she-devil, spreading hurt and confusion.
Will I find just a measure of rest in the night?
And might I prevail, fending off  illusion?

(c)GoshGusMusic(ascap) 2011

Rituale

It goes like this.

I park my car on the street across the driveway. I check my look in the rear view mirror because appearances matter. As I walk around to the passenger side to gather up the heavy satchel, the purse, the stainless steel water bottle, I pause to look down a few blocks to the ocean where I can see the water line of the shelf out some distance from the beach. Often it is grey from high fog.

The wrought iron gate on the house has an old label, “Please push both buttons.” I wait for the buzz which lets me press the bars open, and hear the echo in the turret as the second floor door is opened. Careful to quietly close the gate, I walk down the foyer and climb up the winding stairs where I can hear another singer’s lesson in progress.

I dump my burdens on the floor, close the door, and head into the kitchen to select a mug and a tea bag. I imagine most of us have a favorite. The cups are  souvenirs from productions or festivals. Of course, I favor one or two from places I’ve been. Peppermint.  Always.  A turn of the knob on the stove and  I wait for the kettle to rumble.

And I listen to the lesson or coaching in progress as I wait with my tea,  seated  out of view on the loveseat behind the kitchen wall. Those ten minutes are interesting and often instructive. I pay attention.

This particular ritual plays out weekly, but sometimes more or less frequently, depending on my needs. I am bound to all kinds of ritual. The predictability sets up routine which in turn summons my attention, and inspires me to focus on the task at hand.  Ritual may help us create meaning or intention. Rituals  strengthen connection between us.

In music, as with most big brain activities, repetition and ritual are daily bread.

(c)GoshGusMusic(ascap) 2011

Risposte

Over the summer I have read and skimmed through seventeen books on repertoire, musicology, pedagogy, and read through almost as many opera scores and song cycles. This has left me with more questions than answers, but has brought me to certain conclusions.

I am disturbed by the pedagogues, many of whom are not singers, but theoreticians related in ways similar to musicologists. I am reminded of the adage that “music should be seen and not heard” so often smirked toward the direction of our academic brethren. There is much voodoo and little common sense. Most alarming are those tomes dedicated to surveying “great singers on singing.”   In some cases, it is obvious by the way a singer speaks of her technique just why she has vocal issues.

As to answers to my questions, I have begun a sure process and feel I understand my own vocal direction. I am a beginner in my new fach. I am looking at repertoire which other folks, audience and singer alike already know, but I do not. Music I should have known but never familiarized myself with because I had so much to learn within the bandwidth in which I used to sing.  Had you told me that at this point in life I would be best suited to Strauss and Puccini I would have thought you absolutely mad. With confidence my teacher and two coaches have finally convinced me otherwise.

I still have books to read and dissect. The San Francisco Main Library has been a regular haunt as I work through the music stacks and the audio section. I’ve learned what I do not know and must now learn. This is a very good thing.

(c)GoshGusMusic (ascap) 2011

Tirannia

“…so he had power over me. That’s all tyranny is: it’s not in a personality; it’s in a set of circumstances. It’s being trapped with your enemy in a limited space- a country or a family- where the balance of power between you is unequal and the weaker one has no recourse
-Tessa Hadley, The New Yorker, 6/6/11.

Life in the Universe, Part III~How to Find a Planet

Guest writer astronomer Claude Plymate, chief wrangler of the McMath-Pierce Solar Telescope at Kitt Peak National Observatory, lets us in on some fascinating facts. Geek or non, you will enjoy Claude’s latest installment

                  How to Find a Planet

Imagine gazing at an extremely bright light bulb on a dark night with a 1 mm diameter ball bearing placed about 40 feet away from it. You can probably appreciate that the blinding light would make the ball bearing all but impossible to see. Now imagine looking at the light and metal BB from a distance of about 2000 miles away. Believe it or not, the tiny angle (0.77 arcseconds) between light bulb and BB can be easily resolved in modern telescopes but the dim little BB would be completely lost in the glare of the intense light source. This is what it is like to try and spot an Earth sized planet orbiting a one of our nearby stellar neighbors. Most stars, however, are much farther away making it that much more difficult to spot any potential orbiting planets. Hunting planets around other stars is hard work! It is quite a testimonial to human ingenuity that, despite the difficulty, as of this writing over 1700 planets have been discovered orbiting stars other than our Sun! To find these extrasolar planets, or “exoplanets”, astronomers have tried various techniques with varying levels of success. Only two techniques have so far proven to be very successful.

The Radial Velocity or “Wobble” Method

It’s not quite correct to say that the Earth orbits the Sun. Technically, both the Earth and Sun orbit about the center of mass of the of the Earth-Sun system. Picture a hanging mobile sculpture, the Sun on one side and the Earth on the other with a stick between them that the whole system is suspended from. Since the Sun is much bigger and heavier than our little Earth, the mobile is suspended from a point close to but not centered on the Sun. When you spin the mobile, the planet sweeps out a large arc while the large Sun moves just a little.

The same is true for orbits. Planets swing around in their orbits, all the while gravitationally tugging on their host stars. A planet’s star reacts to this tug by circling around the balance point between them just like with the spinning mobile. Since stars are so much more massive than their planets, the radii of their orbits are correspondingly smaller. The point about which the star orbits is normally well inside the star itself!

Viewed from above – face on to the orbital plane of the stellar system – an orbiting planet will cause its star to wobble ever so slightly, like a boat rolling over waves, as it drifts through the galaxy. Astronomers spent decades carefully measuring the positions of the closest stars in our celestial neighborhood. Try as they might, no deviations in any star’s path due to a planetary system was ever detected. Either the perturbations were too small to measure or there simply weren’t any planets out there tugging on the stars.

Then, starting in the late 1980’s, astronomers tried a different approach. Instead of looking for the side-to-side wobble imposed by a face-on orbital system, they decided to use the in-and-out (radial) motion induced by an edge-on planetary system. If our vantage point happens to be more-or-less in the orbital plane of a star’s planets, the star will appear to move towards us half the time and away the other half of the time. A star’s radial (in-and-out) motion might seem like a more difficult measurement to make compared to simply plotting its zig-zag motion across the sky, but believe it or not, up until very recently (see the Photometric Method below), this is how the vast majority of extrasolar planets have been found. At the time I’m writing this, the total of number of planets found with the radial velocity method is 531!

How can astronomers measure such small radial motions in stars that are many light-years away? Spectroscopy. You are likely familiar with the fact that astronomers have long used “red shifts” of spectral features in distant galaxies to measure their “Doppler” velocity. A close look at any star’s spectrum (it’s rainbow of colors) reveals a plethora of gaps or dark lines breaking up the continuum. These “spectral lines” are due to the various gasses that make up its atmosphere. Every type of atom and molecule absorbs light at numerous precisely known wavelengths (colors). The star’s spectrum is then the combination of all the spectra of the gasses that make it up. Stars can then be categorized by their “spectral signature” – sometimes likened to a stellar barcode.

The radial velocity of a star or galaxy causes its entire spectrum to shift towards the red (longer wavelengths) if moving away from us or towards the blue (shorter wavelengths) when coming nearer. (This is how it was determined that the Universe is expanding. Hubble – the guy not the telescope – found that the farther away a galaxy is, the greater its red shift velocity tends to be. His conclusion that the Universe much be expanding was one of the major discoveries of the 20th century.) The same phenomenon is experienced with sound waves whenever a fast moving vehicle zips past making that characteristic Eeeeeeeeooooooooo sound.

We can easily distinguish that tonal shift in sound from relatively slow moving vehicles because the speed of sound itself is relatively slow (~349 m/s). The speed of light, however, is MUCH faster (~300,000,000 m/s), about 860,000 times faster! The Doppler shift seen in light is exceedingly small for slow moving objects. Still, by the 1980’s spectrographs had reached the exquisite resolution and stability required to measure the slow back-and-forth velocities of stars do-si-doing with their planets – at least their BIG planets! Small planets like the Earth are still beyond our detection limit.

Early detections were of strange so called “Hot Jupiters”, that is big planets orbiting very close to their stars. These planetary systems didn’t much resemble our solar system with its small terrestrial planets in close and the big gas giants farther out. We’d always assumed our solar system is rather typical. Is this not the case or might this simply be a “selection effect?” The bigger the planet the larger its influence on its star. Likewise, the closer the planet is to its star, the larger the perturbations of its parent star will be. So, the radial velocity method is most sensitive to big, close in planets. It’s of little surprise then that that is what we see! The farther a planet is from its star, the longer its orbital period. Finding smaller planets that are farther from their star, therefore, takes more spectral resolution and more time. To succeed in this business, you have to be both obsessively precise and patient.

Once the period of a planet’s orbit and its star’s mass (found from its spectral class) are known, determining the lower limit of the planet’s mass becomes a trivially simple calculation. The calculated mass is only a lower limit because we don’t know if we are looking truly edge-on to the stars back-and-forth motion or at some skew angle. Any deviation from straight-on will diminish the motion along our line of sight. To absolutely measure the size of a planet relative to its star takes…

The Transit or Photometric Method

Occasionally, by happy coincidence, we happen to be precisely aligned along the axis of an exoplanet’s orbital plan such that we see the planet transit across the disk of its star. This creates a mini-eclipse which ever so slightly dims the light we receive from that star. By plotting how much the star is dimmed, the relative size of the planet compared to its star can be calculated. Such measurements are known as Photometry (“photo” meaning light plus “metry” meaning to measure, is the measurement of light).

The axes of planetary orbits around stars are randomly distributed. They can be tipped at any angle from face on (looking down from above or up from below) to edge on where the orbital axis cuts right across the star. A planet the size of Earth at its distance from our Sun makes a really small target. For the Earth to appear to cut across the Sun as viewed from far outside the solar system, the viewing angle would have to be within about +/- 0.3 degrees of our orbital axis. From a random position, the chances of this are only about 1 in 300. To have a good chance of catching some planets that transit across the disk of their stars, you need to observe a LOT of stars! Also, remember that the Earth takes a year to go around the Sun.

To catch a transit of Earth from our imaginary vantage point outside of the solar system, we’d have to watch for a year to see just one transit. To be sure that what we saw was a planetary transit and not some random even (Sun spot, a random star moving across the primary target star, equipment problem, etc.), we’d need to see at least a 3 transits. And in the case of the Earth, this would take a minimum of 3 years. If you see a star dim once, you can’t say what caused it. If you see it happen twice, it’s always possible that it was caused by two separate objects. Seen a third time, you can be confident you know that it’s something in a regular orbit and you know what that orbital period is. So, not only do you need to observe a lot of stars but you need to watch them for a long time – at least several years!

Enter Kepler. Kepler is a NASA spacecraft that was launched in March of 2009. Its mission is to continuously stare at one area of the sky between the constellations Cygnus and Lyra. The spacecraft continuously monitors around 100,000 objects in a roughly 10×10 degree field of view. Being in space, Kepler does not have to contend with the shimmering fluctuations and weather variability of our atmosphere. This gives it an undisturbed and exceedingly stable vantage point resulting in unsurpassed sensitivity to stellar brightness variations. The Kepler science team recently announced more than 1200 candidate planets have been seen transiting stars in its field of view! On top of that, 54 of these planets appear to be at the right distance from their stars to be in the “habital zone” where planetary temperatures can allow liquid water to exist! Assuming these all pan out, this represents a huge jump in the number of worlds we now know about. This first list of exoplants is only the tip of the Kepler’s iceberg based on its first year of observations. We can expect many more discoveries to trickle in as Kepler continues its mission over the next few years.

Although Kepler’s transit approach to exoplanet detection is proving to be remarkably prolific, the method can’t tell us all that we’d like to know about the planets its finding. For this, other methods will need to be employed. Eventually, we should have telescopes that will be able to capture the spectrum of the planets themselves. A spectrum can tell us what makes up the planetary atmospheres. I don’t know when it’ll happen but someday we’ll hit pay dirt when oxygen and other molecules formed by biology are found in the atmosphere of an exoplanet. That will be the day when we indisputably learn that the Earth is not alone and unique in this galaxy. We will finally know that we have kindred among the stars and that life thrives throughout the Universe.

(c) GoshGusPublishing (ascap) 2011