“Is this all astronomers could do for Global Climate Change?”

 

"Studies of ancient climates suggest Earth is now on a fast track to global warming, World Scientists say Humans are Causing Global Warming, Impact of Global Warming on Weather Patterns Underestimated, NASA Study Shows Antarctic Ice Sheet Shrinking, Arctic Lakes Disappear; Researchers Blame Global Climate Change", these were the some of the headlines I have noticed off and on line since 2005. All these craters around one topic "Global Warming", more recently former USA Presidential candidate Al Gore's "An Inconvenient Truth" movie which is about Global warming was a big hit. Frankly I enjoyed watching it; it's very well done movie to make the public alert about "Global climate change." 

But in the first article of "FOCUS", I'm not going to talk about Global Warming; obviously my article has some link in astronomy. Last few weeks I was following the Climate Changing issue very much (we had a program at British Council also), but I was pretty amazed when CNN announced in there program, "that the worldwide astronomers suggest the "Sunshade" as a solution to the current Global Warming." 

So what is this space “Sunshade”? I first learned about this theory about 2 or 3 years ago through an article. This theory was first purposed by James Early of the Lawrence Livermore National Laboratory in 1989. The earlier ideas were for bigger, heavier structures that would have needed manufacture and launch from the moon, which is pretty futuristic. But recently Roger Angel, a University of Arizona Regents' Professor suggests launching a constellation of trillions of small free-flying spacecraft a million miles above Earth into an orbit aligned with the sun, called the L-1 orbit. The spacecraft would form a long, cylindrical cloud with a diameter about half that of Earth, and about 10 times longer. About 10 percent of the sunlight passing through the 60,000-mile length of the cloud, pointing lengthwise between the Earth and the sun would be diverted away from our planet. The effect would be to uniformly reduce sunlight by about 2 percent over the entire planet, enough to balance the heating of a doubling of atmospheric carbon dioxide in Earth's atmosphere. 

The lightweight flyers designed by Angel would be made of a transparent film pierced with small holes. Each flyer would be two feet in diameter, 1/5000 of an inch thick and weigh about a gram, the same as a large butterfly. It would use "MEMS" technology mirrors as tiny sails that tilt to hold the flyers position in the orbiting constellation. The flyer's transparency and steering mechanism prevent it from being blown away by radiation pressure. Radiation pressure is the pressure from the sun's light itself. 

The total mass of all the fliers making up the space sunshade structure would be 20 million tons. At $10,000 a pound, conventional chemical rocket launch is prohibitively expensive. Angel proposes using a cheaper way developed by Sandia National Laboratories for electromagnetic space launchers, which could bring cost down to as little as $20 a pound. 

The sunshade could be deployed by a total 20 electromagnetic launchers launching a stack of flyers “every 5 minutes for 10 years”. The electromagnetic launchers would ideally run on hydroelectric power, but even in the worst-case environmental scenario with coal-generated electricity, each ton of carbon used to make electricity would mitigate the effect of 1000 tons of atmospheric carbon.

But it still perpetuates our unfortunate habit of trying to solve problems created by technology with more technology. If unforeseen consequences of technologies like automobiles and electricity created the problem of global warming, what makes us think another large-scale technology like trillions of orbiting spacecraft won't lead to even worse unforeseen consequences?

And here’s the summary,
• Each flyer would be two feet in diameter, 1/5000 of an inch thick and weigh about a gram, the same as a large butterfly. Not really a big number? Consider how many would be needed. 
• To build such a cloud, 20,000 billions 'butterflies' would need to be sent into space. 
• This would represent about 20 million tons. 
• And even with the electromagnetic space launchers developed at Sandia National Laboratories which promise to send objects in space for about $20 per pound, the total cost would be about $1,000 billion. 
• Of course, you will need to launch these trillion spacecraft. With each such launch sending out 800,000 flyers, the project would require 20 million launches over a decade.
• And Angel summarizes the costs: "It could be developed and deployed in about 25 years at a cost of a few trillion dollars. With care, the solar shade should last about 50 years. So the average cost is about $100 billion a year, or about two-tenths of one percent of the global domestic product." 
• Even if these numbers look — rightly — astronomic — please remember that the monthly U.S. trade deficit is in the $60 to $70 billion range — per month!
While I keep an open mind about the theory, I would like if you could make your comments about the theory, so we could start an online discussion.

-Thilina Heenatigala.

Playing ‘space billiards’ to save earth - interview with Dr. Sima Adhya

As a part of a programme conducted by British Council, Colombo to improve the science knowledge among Sri Lankan students as well as the general public, four UK scientists delivered their lectures last week in leading schools in Colombo and Kandy. 

Thilina Heenatigala, General Secretary of Astronomical Association of Sri Lanka had a brief interview with the team’s space scientist Dr. Sima Adhya. Indian born Adhya studied natural sciences at Cambridge, and read her PhD at UCL on how spacecrafts wobble in their orbits due to sunlight. Her PhD was in collaboration with a team at NASA’s Jet Propulsion Laboratory, where some of the techniques she developed have now been included in NASA’s routine orbit determination software.

As a space mission scientist she works at the Space Department of QinetiQ, where her duties are to look at every aspects of a space mission; analysing data, writing programmes and putting in place all the systems that are needed. She was also the runner up of FameLab Competition, which is a British national competition to find the new voices in science and engineering.

Q: What kind of research are you involved in as a space scientist? 
A: Well, I work as a Space Mission Scientist in the Space Department of QinetiQ, based in the UK and am currently working for the European Space Agency on a mission study designed to deflect an asteroid. Actually, it is a practice run to test our technology, in case an asteroid is on a collision course with Earth in the future. 

Q: Could you explain the mission plan?
A: The plan is to deflect an asteroid. You can think of it as space billiards, but on a vast table with tiny, tiny balls! What we’re going to do is hit a very small asteroid which is very far away – about 30 million miles – with a spacecraft. There are actually two spacecrafts. The first one would basically orbit around the asteroid and map it, while taking measurements such as mass and density etc. And the second one will lock onto it and then smash into the asteroid at about 10km per second, which is pretty fast, while the first spacecraft will be monitoring the whole collision. As a space scientist, this is a kind of mission you dream of being involved in.

Q: We have seen the nightmare scenario of asteroid collision in movies like, Armageddon and Deep Impact, but what are the chances of such an asteroid hitting the Earth?
A: Well, you have to say that the chance of an asteroid hitting us is very slim. Though we have predicted an asteroid will come very close to the earth in 2029, that asteroid named Apophis is expected to pass within 30,000 km from the Earth.

Q: Should we earthlings be afraid or not?
A: If it’s something very big, or if it’s a comet, I would say that we don’t have any hope for the moment, so might need to be a little afraid. But I’m sure if something like that happens all of the states around the world would cooperate.” 

Q: How did you get interested in science?
A: I was always interested in science. I found pure science and mathematics the most interesting and rewarding. The theory of evolution inspired me too. It makes you to see the world in a different manner. Since my childhood I wanted to be an astronaut. But unfortunately, UK doesn’t fund manned-missions at the moment. Maybe in the future I might ravel at least as a space tourist if the price ever becomes as normal as regular travelling costs.

Q: What is the purpose of your visit to Sri Lanka?
A: Actually I’m here to do a science workshop sponsored by your local British Council. I have been visiting quite a few schools this week in Colombo and Kandy, and trying to inspire the young students to pursue a career in science.

Q: How is the feedback on your programmes in Sri Lanka?
A: The response has been fairly good though some students were shy to ask questions. But in some places they didn’t let me go. After my 45 minute talk in Kandy, I had to answer their questions for another 45 minutes. So, it has been a very interesting visit. 
It’s been hard work, but it’s been rewarding, quite stretchy but challenging. I’m very grateful; people here have been really welcoming.

Q: What do you think of the science knowledge of Sri Lankan students?
A: Sometimes it is a bit hard to tell, but I have had some really interesting questions from students. But I don’t see any difference between the students back home and here.

Q: Do you have any suggestions for us?

A: Since I’m staying only a few days here I really can’t suggest anything specific. But I think organising something like FameLab would be an interesting step forward. Oh!! And FameLab is a National Competition held in UK, it’s more like an American Idol of the scientific world. I’m one of the finalists of last year’s competition. Actually, it makes science more fun.

Thilina Heenatigala.

MARS MANIA

Recently I came across with quite a few articles & some e-mail forwards regarding MARS. It’s a usual thing that I get these kind of information as I’m involved in Astronomy, but this time it was not the regulars I was getting. 

It concentrated on one topic, one massage to spread throughout the world. It was about the “close approach of Mars 2005”. O.K. we know that it’s having a close approach with us. But was it close as these bunch of people pointed out!


Mars Hoax

Here are some snippets I found,

"The Red Planet is about to be spectacular."

"Earth is catching up with Mars [for] the closest approach between the two planets in recorded history."

"Mars will look as large as the full moon to the naked eye"

And finally, "NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN."

Only the first sentence is true. The Red Planet is about to be spectacular. The rest is a hoax.

These articles & e-mails I got was so misleading and I’m sure it could easily arouse the curiosity of the public and make them really believe it. In fact I met few students who were very keen on the topic & really believed that it’s having a close approach as they show off. They were asking why the NASA or anyone sending astronauts to the Mars if it was getting so close. I know, for anyone in touch with Astronomy, this is hilarious, but as an astronomy student it was my duty to get them into the reality, with a great effort, I convinced them the truth. I can still remember how disappointed they were when they realized that they have misled. 

Mars Reality
Let’s check what’s really happening. Earth and Mars are converging for a close encounter this year on October 30th at 0319 Universal Time. Distance: 69 million kilometers. To the unaided eye, Mars looks like a bright red star, a pinprick of light, certainly not as wide as the full Moon.
Disappointed? Don't be. If Mars did come close enough to rival the Moon, its gravity would alter Earth's orbit and raise terrible tides.  
Sixty-nine million km is good. At that distance, Mars shines brighter than anything else in the sky except the Sun, the Moon and Venus. The visual magnitude of Mars on Oct. 30, 2005, was -2.3. Even inattentive sky watchers noticed it, raised at sundown and soaring overhead at midnight.

Mars 2003 Vs 2005

You might remember another encounter with Mars, about two years ago, on August 27, 2003. That was the closest in recorded history, by a whisker, and millions of people watched as the distance between Mars and Earth shrunk to 56 million km. This October's encounter, at 69 million km, is similar. To casual observers, Mars will seem about as bright and beautiful in 2005 as it was in 2003.

Let’s see some comparison of 2003 & 2005,

Mars in 2005 Compared to 2003*

Mars                                       2003                                        2005 

Won't Be As Close                0.34 AU                                    0.46 AU (24% farther) 
Appear as Bright mag.        -2.9 mag.                                  -2.3 (58% dimmer) 
Appear as Large                  25.1"                                          20.2" (20% smaller) 
   
   
  

                                 Mars will not appear larger than 20 arc sec until 2018! 

*Notes on Units
1. Astronomical Unit (AU) Essentially the mean distance between Sun and Earth
  (about 93 million mi or 150 million km). 
2. magnitude (mag) An astronomical unit of brightness (brighter has lower assigned number).
3. arc second (arc sec or " ) Angular unit of measure = 1/3600 of a degree (°).
 (Moon's angular diameter is about 1800 arc sec.) 

                                               Mars’ position in its orbit in 2003 & 2005

Catch the Red Planet

I can hear someone saying, O.K. October 30th is over, so can we still see the Mars? Of course you can still observe it. Oct 30th was the peak. 

What can amateurs easily see?

If you have a good four-inch (or more) telescope (refractors are favored)will easily show the waxing and waning polar caps and many dark markings. With larger telescopes, Mars subtle dark areas should be easily seen. With a Mars ’chart in hand, Olympus Mons, the solar system ’s largest volcano, shows as a white spot and Vallis, Marinaris should be easy to spot. Blue filters bring out Martian clouds, so you can even watch its weather. I hate to say this, but those who are with a telescope is very lucky that they could see the features. 
 

Well what about those who don’t have telescopes, the “naked eye observers”? Don’t worry you can still do some observations. Get hold of a star chart (available from Astronomy & Space Study Center). Try to figure out the constellations Pisces & Aries. Mars is lying between these two constellations. Everyday at a same time (if possible), plot the Mars’ position in the sky in the star chart. It’s one of the visual observations you could do.
Then again if you are familiar with the visual magnitudes of the stars, you can also include the magnitude of Mars and observe it’s fading magnitude when the days passing by.

As it approaches Earth, it will swell from a small apparent disk of 6" in April 2005 to a maximum diameter on October 30, 2005, and then shrink as it moves away. Opposition occurs on November 7, 2005. April 2005 throughout February 2006 are the prime observing months.

Although this time Mars is not close enough as 2003, it’s close enough to have some GOOD Observing! So go out at night and admire this Red Planet lies high in the sky. If you are armed with a telescope, I urged you to do some observation and sketch the Mars as possible. If you do so, don’t forget to send a copy of your observation to me.
As I get busy with observing Mars, I wish all with a clear sky & good observing. Now go ahead and catch the Mars.

Clear Skies & Keep Looking UP!!!

Thilina Heenatigala.

Observing Coordinator

Astronomy & Space Study Center Piliyandala.