On the afternoon of October 20th, we are so lucky to have Professor Li as our project expert talking about the space weather topic Zoom video meeting. She is the professor of Astronomy department of the Boston University. Here is her personal website.
Professor Li talked about the importance of knowing space weather. For example, the solar wind is strong enough to bring city-wide area power outage for days. The unstable energetic charged particles might cause GPS doesn’t function well. There is space physics subject behind these problems. We could study hard on math and science to prepare ourselves for these advanced topics. At the same time, we can read the articles from “Nature” and “Science” periodical as non-fiction supplements. She gives us a really motivational and knowledgeable speech. I do appreciate her.
At this meeting, Professor Li was explaining the basics of “space weather” along with solar flares, magnetic belts, the magnetosphere, the Van Allen's Belt, and much, much more.
The most important thing in my opinion was the concept of solar flares and the plasma (ionized and superheated gas) blasting unpredictably out of the sun at some rare occasions. These flares can cause huge amounts of damage to satellites, destroying their electrical components, and causing them to rapidly shut down and become space debris. Also, these flares are so powerful that even with the Earth’s protective magnetosphere, the flares can still penetrate the shield and destroy many electrical wires, and radio transmissions. A small amount of energy in the flare is actually stored inside of the magnetosphere and as the return shockwave hits, the energy is pumped into the skies at the poles, causing what is known as aurora borealis. These spectacular dances of green and red light at the skies in the poles are made from the transported energy that is deployed from Earth’s magnetosphere. This solar flares can also disrupt GPS signals too. GPS satellites need huge amount of precision to track their objects. Even a small wind can knock the GPS out of orbit, and causing their objects to track to be “confused” sometimes, in massive flares, you may see your GPS display some sort of no signal interference.
The Van Allen Belts are a pair of radioactive belts around the Earth. To astronauts, the fatal dose of radiation from the belts are from if you stay in the belts for a few days. There is no way around this obstacle, so NASA has developed a shield to block this radiation. The dose is not too substantial, even almost ignorable. Each planet has its own belt, and Professor Li is studying Jupiter’s belt.
By Hendry.
If you didn’t know, the sun sometimes ejects hot gas, which is most commonly known as solar wind. It is made up of plasma, which is also why sometimes it is called a plasma wave. It is harmful, and if it reached the Earth, it would annihilate us. But it didn’t. We have a magnetic shield-the correct term is radiation belt-around our planet, made up of really dangerous stuff like radiation and other harmful things.. Too much could kill you. But that is the thing that keeps the plasma from reaching the surface of the planet. But that will be discussed later. You might have heard of the Aurora Borealis, or the Northern/Southern Lights. This is made from the plasma spreading towards those magnetic poles because of the shield. The solar wind/plasma wave is really what causes it. The Aurora Borealis is visible from the Arctic Circle and the Southern Circle. Professor Li and her group of students are researching this because it can damage spacecraft. Those kind of things can cost $250 billion dollars, which is money wasted. So, her job is to try to predict where and when the solar wind is going to come. It doesn’t just waste money-it can disturb GPS too! A GPS works because of satellites. The solar wind can change the signals’ wavelengths, which lead to no signal. Also, because it changes signal wavelengths, it interferes with airline and military communication. If it is powerful enough, it can disrupt power grids and pipelines. One time, people in Canada lost power for 9 hours because of it. Now, onto the radiation belt. Because the radiation belts are made of electrons that only move up and down, when they get hit, it forces them to go in different directions. An interesting thing about this is that when put into data charts, it looks like sound frequencies. If converted using audio converters to sound, it makes a high squeaking sound that can hurt the ears a bit. It’s like someone screaming. If you play an instrument, its like when a string instrument squeaks or when a woodwind instrument squeaks. When I mentioned that the radiation can kill you if you receive a certain amount, I mean it. This is why NASA wants spacecraft with people in them to get out of the radiation belts ASAP. If you know the first Apollo mission to the moon, NASA launched it because they were sure that the astronauts would receive an amount of radiation that wouldn’t kill them. 1 minute won’t hurt, and the astronauts from the Apollo mission to the moon were there for about an hour (52 minutes to be exact) and they received a teeny bit, less than 1. Another fun fact is that every time they sent an Apollo mission, the amount of radiation received went up. You would expect modern things to be better. There are some radiation resistant materials, but they have to be thick and strong. Professor Li didn’t have the name of the material, but it is thick and strong.
By Emily
From professor Li’s research, I learned that space weather may also be a big problem, along with space debris. For example, space weather is causing satellites and probes to malfunction, TURNING THEM INTO SPACE DEBRIS! Also, the Van-Allen belts also eat away at satellites and probes, causing even MORE space debris! This is an ongoing poisonous cycle, and it needs to be fixed.
I also learned that space weather (solar wind) creates the aurora we see in the night sky up north, or down south. It rarely happens, but if the solar wind is strong, the aurora can reach all the way down to Florida!
By Shining