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.
It could take as long as 120 days. Most space probes do not accelerate constantly, but use planetary gravity effects to speed up or slow down, which involves long, complex orbits taking a year or more. In this case, a spacecraft actually has to decelerate from the Earth's orbital speed (about 107,000 km/hr) to reach Venus or Mercury.