If there is a dark line on the “three o’clock” side of the planet, it is the arrival of night. If it’s all dark, it is night. Or maybe you’ve got your eyes closed. If there is a dark line on the “nine o’clock” side of the planet, it is the arrival of dawn.
One planet. Our home. It’s damn long way to any thing else even slightly habitable. We stand, live and die here. If we try to leave – like to get to Mars, the next nearest ‘option’ we have to make a decision about sending older people (so their loss because of the cancer caused by the radiation exposure while travelling is underwritten by the fact that they’ve lived a long life already), or young people who can quickly breed and establish a colony (before they die of the cancer caused by the radiation exposure while travelling).
Please make an effort to look after your corner of the planet. This is it. There’s no one coming to rescue us – this is our one shot at it. Take care.