Page 450 - Canadian BC Science 9

Words to Know
ethics geosynchronous orbit optical telescope probe
radio telescope
rover
satellite
terraforming
12.3 Exploring Space: Past, Present, and Future
Telescopes allow humans to extend their ability to observe space. Different telescopes study different parts of the electromagnetic spectrum, including optical, radio, infrared, and X-ray waves. Satellites and probes visit regions in space too difficult for humans to explore. New technology is quickly making ideas such as colonization and terraforming possible.
Our success in learning about the sky and beyond has long depended on the tools available to extend our vision. Observation improved greatly after the invention of the first optical telescope in the 17th century. Suddenly, people were able to see details they could never have imagined were there before. This was how they came to realize that the Moon has craters, stars exist in the millions rather than thousands, and Earth is not the centre of the universe (Figure 12.19).
Constant improvement of a range of tools and technologies has helped astronomers continue to make new discoveries, both from Earth and by going into space.
Physically exploring outside Earth’s atmosphere is more than just an activity to answer scientific curiosity. Humans are now pushing the
limits of technology to travel into space for fun and profit. Since the first astronaut was sent into space in 1961, more than 400 people have successfully journeyed there and back again. In the next 50 years, even average citizens may be regularly paying for the opportunity to take the trip of a lifetime.
Earth-based Observation
Technology
The first telescope was invented by the Dutch eyeglass maker Hans Lippershey in 1608. Since then, many changes to its design have improved its light-collecting capabilities. There are two types of optical telescopes: refracting and reflecting.
Figure 12.19 The mysteries of the universe have long captured the curiosity and imagination of humans.
432 MHR • Unit 4 Space Exploration