"Go back to Mars. Earth is so dangerous!"

Our Earth is fragile, and if we have to look for a new shelter in the Universe, many people will think of Mars, our neighbour in the Solar System. However, the red planet was actually named after the god of war and had been ominous in the night sky in ancient times. Similarly, people called it "Yinghuo" in ancient China, which literally means dazzling and confusing. Mars's irregular and ever changing movements with respect to other stars made people confused and fearful. Have you ever wondered why Mars is red in colour, symbolising danger?

The rocks on Mars are iron-rich and they erode to form sands in the absence of moisture. While the sands are exposed to air, the irons oxidise and turn reddish. Therefore, Mars is red with all these iron-rich dust and the red colour doesn't mean Mars is dangerous. But if we want to live safely on Mars, we must bring sufficient water, a respirator, and wear a protective suit. All living things we know require liquid water to survive. Although scientists have already found water ice hiding beneath Martian poles, liquid water is still absent on its dust-covered surface. On the other hand, Mars's atmosphere is so thin that it can't protect us from harmful cosmic radiation and retain heat. Its temperature varies greatly between day and night. 96% of Mars' atmosphere is carbon dioxide, so we can't breathe freely like we do on Earth too.

Without sustainable water resources and breathable air on Mars, it seems our planet Earth is a safer and more habitable shelter for us and the living things here. Moreover, terraforming Mars (making the planet hospitable) will require extreme efforts. So if we can't settle on the red planet easily, how about we move to the other neighbour of Earth – the sparkly-shiny Venus?