Imagine you are taking a bus home at night. Suddenly your cellphone loses its signal. The television on the bus has no programs. Everything around us black-except for some strange colorful lights dancing in the sky. What is going on?

These are just the kinds of problems a solar storm might cause. Solar storms happen when solar flares (耀斑)break from the sun and travel towards Earth quickly. Actually, since Sept.4, 2017, the sun has burst out two big solar flares, the most powerful ones since at least 2008 according to NASA. They hit Earth on Sept.7.

Normally, Earth is protected by its magnetic field (磁场). But when strong solar storm mix with it, things change. On the one hand, the colourful lights of the aurora (极光)can be seen from the US and Europe, rather than just from polar (极地的)areas. But on the other hand, the storms can stop the satellite systems that control our computers, cell phones and GPS. They can even cause blackouts (断电) for weeks or months.

, but they can put astronauts in danger. Spacewalking astronauts might have only minutes to hide. For this reason, NASA never plans spacewalks during solar storms.

Scientists now have a new tool called EEGGL, which can predict solar storms and hopefully give us warnings when they arrive. As for the recent storm, scientists say it is still too early to know its effect on our technology. They are closely watching for any long-term effects.

Some people believe that humans could live on the planet Mars by the year 2100. Our own planet, the Earth, is becoming more and more crowded and polluted. It is hoped that people could start all over again and build a better world on Mars. Here is what life there could be like.

At present, our spacecraft are too slow to carry large numbers of passengers to Mars—it would take months. With the development of technology, by the year 2100, the journey might only take about 20 minutes in spacecraft that travel at the speed of light! However, the spacecraft would travel really fast, so the journey to Mars might be quite uncomfortable. Many people would feel ill.

Humans can’t live without water, air or food. So far, nobody knows whether there would be enough water or air on Mars for people. Moreover, scientists are not sure whether plants could grow on Mars. Food would most probably be in the form of pills (药片) and would not be so tasty.

Compared with life on the earth, life on Mars would be better in some ways. People would have more space. They might live in houses with huge comfortable rooms. Also, robots would do most of their work so that they could have more time to relax. There would probably be no schools on Mars. Every student would study at online schools with “e-teachers”.

Life on Mars would be interesting and challenging (有挑战性的). However, it may take hundreds of years to make it true. So the most important thing we need to do now is to protect our beautiful blue planet—the Earth!

Shlander is a man from space. He thinks the people and things on the earth are very strange. He is now writing a letter to his friend at home. Here is part of his letter. Read it and answer the questions.

Now I am in a strange world. It is very nice. There are many new things here. There are many earth monsters here, too. The earth monsters look very funny. They have just one head, two arms and two legs. They have thin black strings on their heads. Some earth monsters have brown or yellow strings. The earth monsters have a hole in their face. Every day, they put nice things and balls from the trees into the hole. They put water into the hole, too. The earth monsters do not walk very fast. They move from place to place in tin boxes.

At night, the earth monsters like to look at a square window box. This box has very small earth monsters in it.