A Letter Home from Mir
The following is Andy Thomas's last letter to those on Earth. The subject -- a view from space...
News story originally written on May 27, 1998
As I have orbited around the Earth, I have spoken to many amateur radio operators as well as television journalists conducting interviews. The questions perhaps most frequently asked are "What is the view like from space?" and "What can you see?" Over the course of the four months that I have been on Mir, I have taken many opportunities to look out the window and take photographs, and the view is captivating, both day and night.
When you first look down on the Earth you see its obvious curvature, and the thin layer of atmosphere on the horizon, with the dark blackness of space above it. It is striking to see the abundance of clouds carpeting the planet. Very seldom do we see extended areas that are free from cloud cover, particularly in the tropics. We can see these clouds building to thunderstorms during the day, and then collapsing at night back down to Earth and spreading out in huge circles as if they had been poured down onto the planet.
As you continue to watch the Earth, you begin to recognize land forms and can see that some countries have broad features allowing them to be recognized at a glance; northern Africa has its desert regions, south America has its forested regions, and Australia its redness. Then there are the characteristic coastlines that we are so accustomed to seeing on a map that stand out very clearly from space; the boot shape of Italy, the Red Sea, the Mediterranean, the Florida peninsular, the gulf of California, and so on. Finally, there are readily identifiable geographic features that only occur in certain places: the huge expanse of Lake Baikal, the Namib desert, the Himalayas bounding the plains of Tibet and the fertile areas of India, and the Andes separating the rain forests from the western deserts of South America. After even a short time in orbit, we learn to recognize these and can quickly know our approximate position above the Earth from a glance out the window.
Evidence of human habitation is visible from low Earth orbit. Cities can be seen, although, surprisingly, they do not stand out readily. But we can make out their grid-like patterns of streets. In remote areas, certain roads and railway lines can be seen as faint lines across the Earth, such as the road through the rain forests of Brazil, and the long straight railway line crossing south western Australia, but generally these are too small to make out clearly. The fencing off of farm land into individual fields can also be made out, particularly in the Midwest of the U.S. and Canada. There is even one area in South America where they alternate their growing cycles on adjacent fields, giving rise to a very obvious checkerboard pattern. Of course, national boundaries do not stand out by themselves as on a map, but some national boundaries can be seen where there are different land usage policies in effect on each side of a border, giving rise to different surface texture or color. In this way the southern border of Israel can be made out, as can part of the division between the U.S. and Canada. The stories about the Great Wall of China being visible form space may be true, but I have yet to see it.
One of the most readily visible signs of human presence, is the occurrence of contrails from aircraft in the upper atmosphere. These are crystals of ice formed from water, a byproduct of the combustion process in the aircraft engines, and which is collected into the wake vortices of the aircraft. They are very long lasting, and can be seen over virtually all parts of the world as white streaks across the sky. They can be striking around cities that are major air traffic hubs, and can often times be seen radiating out from these cities, like spokes in a wheel.
The view of the Earth at night is equally spectacular, and cities can be made out very clearly with all their street lights. Some areas stand out very noticeably such as Japan, where the high population density is given away by the abundance of night lights. In fact there are so many lights you can delineate the shape of the Japanese island chain with ease. The presence of myriad small points of light off shore, probably fishing boats, shows Japan's heavy reliance on seafood.
There are a host of natural phenomena that are spectacular at night. In the temperate zones, we can see vast thunderstorm fronts stretching for miles and being lit up by huge flashes of lightning. Occasionally I have seen lightning start at one point on a storm front and trigger a cascade of lightning flashes propagating along the storm front, like a falling row of dominoes.
Of course stars are visible at night, but without any atmospheric attenuation, so they can be seen clearly. They look much as they do when viewed from an isolated desert region away from city lights, but of course they do not twinkle. Perhaps one of the most sublime of all the cosmic sights I have seen to date is the Aurora Australis over the southern polar regions. Only visible at night, it is an eerie curtain of pale green phosphorescence that waves and twists above the Earth, stretching for hundreds of miles. Meteors are visible from space too. However, we have the unique vantage of being able to look down on the Earth and see meteors streaking into the atmosphere way below us. Having that perspective is a compelling reminder that we are indeed flying in space.
Unfortunately, this orbital vantage also gives us a unique view of the deleterious effects of human habitation. As I write this, there are huge areas in Central America that are burning. A giant pall of smoke is blanketing the entire south western peninsular of the North American continent and is being carried in the winds over much of the United States and as far north as Canada. Indeed, at the northern extreme of one of our orbits, while crossing the Great Lakes, I could see the smoke haze coming up from the distant south and blanketing the land below us. This kind of perspective from space allows us to appreciate that all lands are connected into a common biosphere and that the environmental policies in one country have far reaching effects in other countries.