Unit E Lesson 6: Our Improved Understanding of Space
Completion requirements
Unit E Lesson 6: Our Improved Understanding of Space
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Learning Targets |
Big Question: How have technological advancements contributed to an improved understanding of space?
Our telescopes and space scanning technologies allow us to very far away, and very far into the past.
Our telescopes and space scanning technologies allow us to very far away, and very far into the past.
At the end of this inquiry, you should be able to answer the following questions:
- What type of telescope is the Hubble Space Telescope?
- What is the benefit of having a telescope such as the Hubble Space Telescope located in space?
- What is interferometry and how is it used?
- What are the challenges of having a telescope in space?
Pages 437 and 438 in your textbook will help you answer in this lesson.
Introduction
The Big Bang Theory
In 1929, Edwin Hubble discovered that galaxies outside the Milky Way were moving away from us. He theorized that, at some instant in time, the entire universe had been contained in a single point in space. The violent event, thought to have occurred about 14 billion years ago, during which the Universe was born has come to be known as the 'Big Bang'.
How were humans able to go beyond simply observing celestial bodies to gaining such powerful insights into the origins of the universe?
As technology advanced, researchers have been able to see further and further, which means that they have been able to see further back in time and to gather information about the nature of the universe from beginning to end.
In 1929, Edwin Hubble discovered that galaxies outside the Milky Way were moving away from us. He theorized that, at some instant in time, the entire universe had been contained in a single point in space. The violent event, thought to have occurred about 14 billion years ago, during which the Universe was born has come to be known as the 'Big Bang'.
How were humans able to go beyond simply observing celestial bodies to gaining such powerful insights into the origins of the universe?
As technology advanced, researchers have been able to see further and further, which means that they have been able to see further back in time and to gather information about the nature of the universe from beginning to end.
Reflectors
Huge Reflectors β Segmented mirrors
Reflectors use mirrors to magnify and focus an image, early reflectors used polished metal rather than glass mirrors. They were unable to shape the mirror precisely. In 1856 and 1857 a German team developed a technique that produced a lightweight, inexpensive, glass mirrors that improved the precision of the telescope and the capability of scientists to greatly increase its size. These huge reflectors allowed researchers to make significant strides in their understanding of other galaxies.
The Multiple Mirror Telescope (MMT) used six lightweight mirrors to construct a huge telescope with the light collecting power of one enormous mirror. A computer ensured that all the mirrors were always lined up properly.
Reflectors use mirrors to magnify and focus an image, early reflectors used polished metal rather than glass mirrors. They were unable to shape the mirror precisely. In 1856 and 1857 a German team developed a technique that produced a lightweight, inexpensive, glass mirrors that improved the precision of the telescope and the capability of scientists to greatly increase its size. These huge reflectors allowed researchers to make significant strides in their understanding of other galaxies.
The Multiple Mirror Telescope (MMT) used six lightweight mirrors to construct a huge telescope with the light collecting power of one enormous mirror. A computer ensured that all the mirrors were always lined up properly.
Combined Reflectors β Interferometry
Similar to combining multiple mirrors to produce a clearer image, scientists can use a number of telescopes connected together to improve the resolution of an image. Two or more telescopes used in combination can detect objects at greater distances and with greater clarity than one telescope alone. This is called interferometry. By using interferometry, each telescope can be smaller and cheaper to build and easier to maintain. A computer is used to combine the images.
Similar to combining multiple mirrors to produce a clearer image, scientists can use a number of telescopes connected together to improve the resolution of an image. Two or more telescopes used in combination can detect objects at greater distances and with greater clarity than one telescope alone. This is called interferometry. By using interferometry, each telescope can be smaller and cheaper to build and easier to maintain. A computer is used to combine the images.
Space Reflectors β Orbiting Telescopes
Throughout the twentieth-century, reflecting telescopes became larger, but they still encountered a major obstacle. The Earthβs atmosphere bent light in unpredictable ways, which affected the sharpness of the image. In the 1990s, scientists began launching telescopes, such as the Hubble Space Telescope, into space and placing them in orbit around the Earth. From space, the images captured are clearer because they are not affected by Earthβs atmosphere. These telescopes allow astronomers to view the universe in all wavelengths of light. By being able to view stars in other galaxies, scientists have been able to determine the age of the universe and the way that galaxies form.
Throughout the twentieth-century, reflecting telescopes became larger, but they still encountered a major obstacle. The Earthβs atmosphere bent light in unpredictable ways, which affected the sharpness of the image. In the 1990s, scientists began launching telescopes, such as the Hubble Space Telescope, into space and placing them in orbit around the Earth. From space, the images captured are clearer because they are not affected by Earthβs atmosphere. These telescopes allow astronomers to view the universe in all wavelengths of light. By being able to view stars in other galaxies, scientists have been able to determine the age of the universe and the way that galaxies form.
Hubble Space Telescope
The Hubble Space Telescope is a reflecting telescope.
Along with the illustration of the Hubble Space Telescope (HST) in Figure 1, can you use your understanding of reflecting telescopes to describe how the HST works?
Because the HST is in space, light is not distorted by Earth's atmosphere, resulting in very high quality images. The HST did not always produce excellent images; when it was first put into space, it was discovered that the main mirror was made incorrectly, and a mission was required to fit it with corrective optics.
The HST has been responsible for many discoveries. It has allowed us to see the formation of new galaxies and learn that there is an immense black hole at the centre of most galaxies. Thanks to the HST we also have a better understanding of dark energy and how the universe is expanding.
The Hubble Space Telescope is a reflecting telescope.
Along with the illustration of the Hubble Space Telescope (HST) in Figure 1, can you use your understanding of reflecting telescopes to describe how the HST works?
Because the HST is in space, light is not distorted by Earth's atmosphere, resulting in very high quality images. The HST did not always produce excellent images; when it was first put into space, it was discovered that the main mirror was made incorrectly, and a mission was required to fit it with corrective optics.
The HST has been responsible for many discoveries. It has allowed us to see the formation of new galaxies and learn that there is an immense black hole at the centre of most galaxies. Thanks to the HST we also have a better understanding of dark energy and how the universe is expanding.
Figure 1 β The Hubble Space Telescope
Watch
To learn more about the HST, watch the following video.
Try It!
Practice Worksheet: Telescope Advantages Chart 2
- DOWNLOAD this practice worksheet (S9_UE_S2_L6_telescope2). If you prefer to use a Google Drive or PDF version of the worksheet, click here.
- Answer the questions on the worksheet as you work through the readings and videos in this lesson.
- When you are satisfied with your responses you can check your work by clicking on the "SUGGESTED ANSWERS" button below.
Wait! Don't view the suggested answers first. This practice work is not for marks, it is meant to help you check your understanding. Check the answers AFTER doing the questions! Keep the practice worksheet for study purposes. If you don't understand something, contact your teacher!
Figure 2 β The HST has allowed for the collection of many incredible images.
