Symptoms of Age-Related Macular Degeneration (AMD) An early symptom of wet AMD is that straight lines appear wavy. An Amsler Grid chart can help spot this early distortion of vision. You may also notice a small blind spot, resulting in a loss of central vision.
Traveling at approximately 29,000 km/h (18,000 mph) the shuttle orbits Earth every 90 minutes. By using current technology and a spacecraft powered by chemical rocket engines, a trip to Mars could take between six to nine months.
The space station looks like an airplane or a very bright star moving across the sky, except it doesnât have flashing lights or change direction. It will also be moving considerably faster than a typical airplane (airplanes generally fly at about 600 miles per hour; the space station flies at 17,500 miles per hour).