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Recent News... Just for Pope Gregory... |
2002-03-08 - 10:49 a.m. Living with a star "Great achievement has no roadmap. The x-ray's pretty good, and so's penicillin, but neither were discovered with a practical objective in mind. When the electron was discovered in 1897 it was useless, and now we have an entire world run by electronics." - a physicist lobbying for funds to build a supercollider. 3/6/02 episode of West Wing 3100 B.C. The ancient build a tomb like structure at Newgrange, Ireland.. Above the entrance passage is a 'roof-box', which precisely aligns with the rising sun at the winter solstice, so that the rays touch the ground at the very centre of the tomb for about twenty minutes. 1408. A wedding is held at Hvalsey Church. This is the last written record of Greenland's Norse population. As ice closed over the bay, the Norse population dwindled. By 1480, the Norse population of Greenland has disappeared. 1612. Galileo, the first man to observe the sky with a telescope, spends the summer making drawings of sunspots. Strangely enough, over the next hundred years, few other scientist can confirm his observations. 1995. The Solar & Heliospheric Observatory is launched, providing scientists with an entirely new view of the sun which revoluntionizes solar physics. Our Earth was hit by one of the most powerful solar flares ever detected. The resulting geomagnetic storm knocked out satellites, affected communication across the world, and disrupted power grids. Ottawa was left dark for nine hours. The price of electricity rose overnight. What do all these things have to do with each other? The sun affects every aspect of our life on Earth. The Inca's built their entire civilization around it. Their calendar, their religion, their entire way of life was based on the solar year. Without it, the corn crops would fail, bringing famine to their people. Our sun is a star specializing in converting nuclear energy into magnetic energy and light. It's a tumultous engine of reaction, which reverses it's magnetic field approximately every eleven years in an event of incredible violence. This culmination of this cycle is known as solar maximum. During the peak of the sun's cycle, massive amounts of high energy particles are ejected from the sun's corona. When these ejections hit the earth's magnetosphere, geomagnetic storms result. (Don't panic. The earth's magnetosphere generally protects life on the surface.) But we don't live just on the planet's surface anymore. Since the last solar max, over 2000 satellites have taken up position around our blue ball, providing telecom, weather, GPS and science services that have become an integral part of our everyday lives. The Bastille Day event of July 14th was a harbringer for how space weather has come to affect our everyday lives. So our sun has an eleven year cycle. But it's not that simple. The Norse settlements in Greenland were finished off by the beginning of a minor ice age. The land was lush and green when they settled there, but with the changing climate their agrarian society could no longer survive. Dig through the glacial ice cores of our planet, and you'll find cosmogenic isotopes, indicators of solar activity, that tell us about the solar cycle for the past milleniums. Look through the records of the astronomers that followed Galileo and you realized that between 1615 and 1715, our sun went through a period of inactivity known as the Maunder minimum. Practically no sunspots were recorded, causing people to question Galileo's observations, and it coincided with a period of colder-than-average temperatures in northern Europe called the Little Ice Age. Dig further back and solar physicts theorize that there was a opposite period of warmth (dubbed the 'medieval maximum') around 1200 AD. [Didn't you costuming nuts ever wonder why late 16th and early 17th century, they wore so many more layers comfortably?] Is the Maunder minimum repeatable? For those hundred years the sun 'turned down', emitted a lot less energy? Why? Are the eleven year cycles we understand only a portion of the sun's activity? It's hard to tell using only Earth based observatories. The atmosphere and magnetosphere deflect so much of the light, the particles, the information about the sun's activity. Thus, the SoHo observatory was launched, to study the Sun from outside the obscuring atmosphere. And it has revolutionized solar physics in the same way the discovery of the electron changed our world. 1500 scientific publications later, and they've only scratched the surface of it's data. Here's the part of the story that makes an engineer's heart beat faster. In 1998, an incorrect command to the SoHo observatory sent it tumbling. In a matter of hours, it went from the flagship of solar physics to a frozen mass of space junk. For three months, the SoHo team co-opted the entire Deep Space Network. Like shouting into the ocean, they tried to contact the lost ship, frozen and alone an eighth of the way between Earth and the Sun. It was like trying to raise the Titanic blind, using nothing but a fishing line. After two months of grim faces in my office, the SoHo team got a response. The spacecraft was spinning, it's solar arrays barely glimpsing the sun, practically no power left in the batteries. The only way to stop the spin was to use the propulsion system. Except the fuel and the lines were frozen solid. With an amazing amount of good engineering, they managed to thaw the fuel. (I remember days of white board work in one of my coworker's offices as he tried to brainstorm ways to get SoHo back.) Despite the large chance the fuel lines were permanently damanged, despite the odds the observatory would explode, they managed to get the propulsion system working again, stop the spin, and to return the spacecraft to full operation. In a miracle, only one of the twelve instruments was even slightly damaged despite after three months of cycling from +100 degrees to - 100 degrees, when they were designed to live in stable sunny warmth. [Think about it - how well your car would survive if you heat cycled it through 200 degrees hundreds of times a day for months?] That, ladies and gentlemen, is your tax dollars at work. The story of SoHo, the effects of the Bastille day event - it became clear that we need to know more about how the sun affects life on our Earth. So, about two years ago, NASA started a program called Living With a Star for just that purpose. One of my raft of new assignments is to build the SoHo follow-on, the Solar Dynamic Observatory (SDO). Yesterday the engineering and science teams spent the entire day at the Baltimore Science center, trying to understand more about the spacecraft design and the science requirements. There's always a merry little war between the scientist wanting to push the capabilities of a spacecraft and the engineers wanting to design something that won't fail. The science team spent yesterday trying to get us excited about solar physics, to show us (to quote our project scientist) This stuff is just so freakin' cool. Solar physics is their passion, their vocation, and they want the engineering team to be just as excited. We watched the Solar Max IMAX film [which is an *excellent* summary of the evolution of solar science - you should all see it sometime] and listened to the scientific presentations all day. I must admit, after watching our project scientist do a full body interpretative dance trying to demonstrate the motion of a solar dynamo when the projector failed, I'm both amused and excited. I can live through many boring meetings, many long review, many less interesting assignments (Project N - sigh), just to be part of something this effin cool.
For anyone who cares, I used the Dr. Who quote. � � � 
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