Archive for the 'Sun' Category

In the previous article, the topic was Gliese 581c a Earth-like planet recently discovered. Gliese 581c is very noteworthy because this planet is located in the habitable zone of it’s “sun” (red dwarf star Gliese 581c). This means that the orbit meets the “Goldilocks principle” and it’s neither too close or too far from the heat of red dwarf sun. A lot of further research is needed to determine if 581c has other characteristics necessary for life (the presence of water has been theorized but is far from confirmed), but it has become of the most promising candidates for extraterrestrial life.

Let’s say that further tests do show an Earth-like atmosphere and large of amounts of water. We would obviously send a space probe, but could we ever send a manned mission there? Not impossible, but extremely difficult at this point because while 581c is “relatively close” it’s still 20.5 light years away (194 trillion km or 120 trillion miles) away!

This distance is extremely daunting because even at the top launch speed achieved by a space probe (the New Horizons mission to Pluto was clocked at 58,356 km/hr or 36,261 mph), it would take 379,132.96 years to get to Gliese 581c! We could launch a probe and maybe our great-(great times ~15,000)-grandchildren could analyze the data, but there is also a huge problem in that NASA is only comfortable with a lifetime of 63 years before today’s spacecraft technology will break down.

While researchers have explored in a serious matter some very exotic ways of getting there like wormholes and theoretical light-speed propulsion systems, I think it’s safe to say that we won’t be getting to Gliese 581c via Star Trek warp drive. However, more powerful propulsion systems are definitely down the road, so the commute to Gliese will probably be shortened. Regardless, it will take a long time to travel there and even microscopic cosmic dusk has a sandblasting effect that might cause serious damage and eventual long-term breakdown of the probe. A solution to that problem is that if humans were abroad, we could do the repairs necessary to keep things moving along. Repair robots could also do the job for a probe, but over thousands of years they would be just as vulnerable (even if these robots built new robots to replace themselves) and artificial intelligence does have it’s limits. This leads to probably the most feasible solution to exploring and settling Gliese 581c: a generation ship that would involve setting up a small society to live and reproduce inside a spacecraft along the long road to Gliese 581c.

Of course, this solution has its own set of unique problems. First, maintaining morale and order in this mini-society could prove to be difficult. There are stories from the Biosphere 2 project and the overall field of psychology that raise some ominous doubts about a generation ship. Biosphere 2 (Planet Earth is Biosphere 1) was an experiment were humans entered into air-tight greenhouse structure and tried to survive completely isolated from the outside. One of the biggest problems with Biosphere 2 was the psychology of humans living together in really close quarters, but the stress of not being to grow enough food is probably more to blame for the high level of tension inside. More and more studies of this nature would be needed to create a healthy mini-society for the generation ship.

The second problem would be maintaining a healthy gene pool through the years. A population of 150 would the bare minimum, but that would be cutting it close. This problem could be solved by building up a huge bank of frozen sperm and eggs, but a small population is still vulnerable to the any possible disease outbreaks and if societal breakdown does occur. The best solution would be send something like a 100,000 people that could be governed like a city. Plus, this set-up would be easily transferred to actually settling Gliese 581c as a new home. (Don’t forget the eventual goal of this ambitious mission) The serious drawback is that we would have to build an immense spacecraft, so there would probably have to be a compromise between population size and ship size.

Much more to come on intersteller travel and concepts like the generation ship. Obviously we have serious problems that we have to deal with on Biosphere 1 first, but it’s definitely something to keep on the backburner. While it’s a fun and fascinating concept to think about settling on another planet, it’s also a serious issue in case of some kind of extinction level event (ELE) that humanity can’t handle. No matter what, we can’t put it off “forever” because the Sun will become a red giant star one day. Notice that forever is in quotation remarks because that day is 4-5 billion years away. Interesting fact: the Earth won’t actually engulfed by the Sun as previously thought. Recent research has concluded that the Earth will be pushed away as the Sun enters the red giant phase, but all the water and atmosphere will be boiled away so our great-(great times ~160 million)-grandchildren will be pretty much screwed at that point.

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Posted by Tim Roth, author of the political blog Think Anew and Act Anew

Sources:
1. “Stunning new planet discovery”, previous article on this blog.

2. “Interstellar travel”, Wikipedia entry

3. “Biosphere 2″, Wikipedia entry

4. “Sun”, Wikipedia entry

One of many items on my “things to do before I die” list, is see a major aurora borealis (Northern Lights) event. I’ve seen a few here in Wisconsin, but they are nothing compared to the beautiful nighttime shows that take place in polar locations like Alaska. Or visit the Southern Hemisphere for a Southern Lights or aurora australis show. (australis is Latin for “of the south”)

What causes the auroras?
Like any nuclear reaction, the thermonuclear reactor that is our Sun emits a steady flow of hot plasma from it’s million-degree outer surface known as solar wind. (Plasma is a gas of free electrons and positions ions – as matter becomes more energetic it goes from solid to liquid to gas to plasma – this is a energy state so hot that the atoms break apart into separate particles). This stream of charged particles flows towards the Earth at about 400km/s (about 15,000 mph) and for the most part, the flows smoothly around the Earth’s protective magnetosphere and continues onward towards space. However, there are occasional disruptions which cause the particles to barrel down towards the Earth. These highly energized particles collide with gas molecules in the upper atmosphere and induces them into an excited energy state. As the gas molecule cools down to it’s original energy state it releases the stunning greens, blues, reds, and whites of the aurora.

While everyone agrees how breathtaking auroras are, there is debate among scientists about the mechanism of these disruptions that cause geomagnetic storms. On Saturday, NASA launched a Delta II rocket carrying five identical probes of the THEMIS mission that will work together to analyze the geomagnetic storms. Not only will the five probes be working on the case, there will a great collaboration between satellites of the European Space Agency’s Cluster mission, the Double Star mission of the Chinese space agency, and 20 ground stations in Alaska and Canada.

Stay tuned for updates on the THEMIS mission, auroras, and how the activity of sun affects our daily lives in the obvious and not so obvious ways.

Interesting factoid: THEMIS stands for Time History of Events and Macroscale Interactions during Substorms. That’s a mouthful, but a simpler factoid behind the mission name is that Themis is the mythological Greek goddess of justice, wisdom, good counsel, and the guardian of oaths.

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Posted by Tim Roth, author of the political blog Think Anew and Act Anew

Sources:
1. Official webpage of NASA’s THEMIS mission”
2. “NASA’s Aurora mission blasts off”, BBC article
3. “Aurora (astronomy)”, Wikipedia entry