Staffed missions into Space, satellites and telescopes are being used to explore our Solar System and galaxies beyond. We are continuing the exploration of Space that began when people first looked up to contemplate the Moon and stars, and furthering the science of astronomy that has been so important to maritime navigation.
The movement of the stars and planets relative to the Earth was an ancient way of marking the passing of the seasons for irrigation and harvest, the foundation of religious beliefs based on the night sky, and a reliable means of navigation. In 1609, Galileo introduced telescopes to the science of astronomy, using them to look at the surface of the Moon. Telescopes relied on glass lenses (refracting telescopes) and then adopted curved mirrors (reflecting telescopes) to magnify objects in the distance. The Royal Observatory in Greenwich was established in 1675 to improve navigation through astronomical discovery.
The desire to physically explore Space led to the Russian launch of an aluminum scientific satellite called Sputnik 01 in 1957. Since then, many missions have been launched, some involving people and some only computers and machinery.
Even telescopes themselves have moved beyond the Earth to explore the depths of the universe, and to escape the negative effects of the Earth’s atmosphere on viewing Space. Images sent by the Hubble Telescope, which orbits about 600 km above the Earth, are being used by astronomers to look at events in our universe such as the birth and death of stars. Increasingly powerful telescopes will allow us to see greater distances. Because of the way light travels, this will allow astronomers to discover celestial events that occurred during other eras in time.