Beyond Hubble
① Over the past half century, the world’s most powerful ground-based astronomical telescope was once the patented title of the Hale Telescope on Palomar Mountain in California. , but compared with the Hubble Space Telescope, the Hale Telescope still pales in comparison.
②The 5-meter mirror of the Hale Telescope can observe celestial objects billions of light-years away. Although Hubble's aperture is only 2.4 meters, it can observe celestial objects 14 billion light-years away. . The 5-meter reflector can only see stars as faint as magnitude 23, which is equivalent to seeing the brightness of a candle 3 kilometers away; while Hubble can observe faint objects as dark as magnitude 29, which is equivalent to seeing the brightness of a candle 500 kilometers away. . Importantly, Hubble provides images that are 10 times clearer than those observed from the ground.
③ However, in the past few years, technological advancement has allowed new ground-based astronomical telescopes to replace the Hale telescope on Earth. The new ground-based telescopes are also expected to surpass those traveling in space in terms of functionality. Hubble telescope.
④ On the Mauna Kea volcano in the United States, there are now the New Emperor Telescope and the Gemini North Star Telescope with a mirror diameter of more than 8 meters, as well as the king of telescopes on this mountain - the two Keck telescopes. The diameter of the mirror reaches 10 meters. In addition, powerful astronomical telescopes are also located in the mountains of Arizona, Texas and South Africa. In the Andes Mountains in northern Chile, five telescopes with a diameter of more than 8 meters have been completed or are nearing completion. These telescopes are large and operate smoothly. Any one of them can obtain astronomical images comparable to Hubble's, and under the right astronomical conditions, their clarity can even reach a higher level.
⑤ Among these ground-based telescopes, the Keck telescope is the best. George Cholgovsky, a professor of astronomy at the California Institute of Technology who participated in the development of the Keck telescope, said: The research radius of the Keck telescope has reached 10 billion light-years, and the special instruments equipped in the telescope system can help researchers obtain large-scale observations. A clearer image with a telescope. Cholgovsky once used the light waves emitted by the infrared electron camera on the Keck Telescope to filter out the dust in the universe and see a perfect image of the core of the Milky Way.
⑤ Currently, telescope designers are still conceiving the next generation of super ground telescopes, which will have a diameter of 30-100 meters. At the same time, a new generation of adaptive optical systems is being developed. With the assistance of this technology, future astronomical telescopes are expected to surpass Hubble, thus revolutionizing astronomy again.
1. Based on the content of paragraph 2, several aspects of the comparison between the Hale Telescope and the Hubble Telescope are summarized below.
Comparison one: __________________________________________________
Comparison two: __________________________________________________
Comparison three: __________________________________________________
2. What is the purpose of using the comparative method of explanation in paragraph 2?
Answer: _______________________________________________________
_______________________________________________________________
3. Hale, New Emperor, Gemini North Star, Keck, and Hubble are all ________ telescopes. According to the classification explanation method, divide them into two categories. One type is a ________ telescope, such as _________; the other type is a ________ telescope, such as _________.
4. The underlined sentence in paragraph 5 uses the explanation method of _______________. Using this explanation method, the _______________ is explained in detail.
1(1) The 5-meter mirror of the Hale Telescope can observe celestial objects billions of light-years away. Although Hubble’s aperture is only 2.4 meters, it can observe objects 14 billion light-years away. distant celestial body.
(2) The 5-meter reflector can only see stars as dim as magnitude 23, which is equivalent to seeing the brightness of a candle of 3 kilometers; while Hubble can observe faint objects as dim as magnitude 29. It is equivalent to seeing the light of a candle 500 kilometers away.
(3) What is important is that the images provided by Hubble are more than 10 times clearer than those observed on the ground.
2 illustrates the function of Hubble Telescope and its observation effect is very strong.
3 Ground-based astronomy Ground-based Hale Space Hubble.
Four columns of numbers: The next generation of super ground telescopes will have larger apertures and clearer observations