First of all, I would like to thank the editor of Jiangsu Science and Technology Publishing House for giving me this book.

Since childhood, we have looked up at the starry sky, and countless twinkling stars in the night sky make us full of illusions about the universe. With their wisdom, the ancients realized astronomical phenomena such as the replacement of the sun, the moon and the sky and the shift of the stars, and gave birth to the oldest astronomy. Stonehenge in Britain, Itza in Chen Chi, and the pyramids in Mesopotamia are all places where ancient people watched the stars. Modern telescopes have also been used for astronomical observation for centuries. For a long time, people have used this ingenious device to spy on the mysteries of the sky. However, the idea of putting a telescope into space has only recently appeared. Astronomical observation and research on the earth's surface are limited by the interference and obstruction of electromagnetic radiation in the earth's atmosphere. Only electromagnetic signals of light and radio frequency will not be blocked by the atmosphere, and astronomical research outside the frequency range of light and radio waves is very important. For example, it is impossible to obtain X-rays on the surface of the earth, and the same infrared rays and ultraviolet rays are blocked by the atmosphere.

The protagonist of this book, Chandra X-ray Observatory, is one of the four space telescopes of NASA. The main difference between these four telescopes is that they observe different light bands.

Here, Zhang Shaoshao will talk about NASA's four big eyes in space by the way.

1, Hubble Space Telescope

The first is the famous Hubble Space Telescope,1launched on April 24th, 990, ranking first among the four space telescopes. Its name comes from the memory of astronomer Edwin Hubble, who discovered the expansion of the universe in the early 20th century. Hubble telescope was originally designed to observe only the visible and ultraviolet parts of the spectrum, and later added infrared observation capability to 1997. It can be said that Hubble is the closest space telescope to the human eye.

Briefly list a few Hubble achievements:

1 the birth of the universe: the farthest it can observe is the primitive galaxy that is 0/300 million light-years away from the earth. The light emitted by these galaxies comes from the early universe just after the Big Bang.

Black hole: One of the earliest core projects of Hubble Space Telescope is to establish the relationship between quasars driven by black holes and galaxies. Subsequent observations have also proved that massive black holes are everywhere in the universe-most of them appear in the center of galaxies.

Life span of the universe: With its help, astronomers observed the exact data of the expansion of the universe, and calculated the age of the universe as 65.438+038 billion years (the error is less than 3%).

4 Dark Matter: In March of 20 12, NASA's Hubble Space Telescope once again discovered a huge dark matter block in the Abel 520 galaxy cluster 2.4 billion light years away from the Earth. This unusual discovery puzzled astronomers, who suspected that there might be a mysterious "dark matter core" hidden in the dark matter block.

No matter which one is taken out, it will directly subvert our understanding of the universe and understand how small we are in the vast universe.

All good things will eventually have a home. As Hubble gets older, NASA has launched its successor, the Webb Space Telescope. Weber is much bigger than Hubble, and the 6.5-meter giant primary mirror has five times the light collection ability, even better than Hubble when observing distant stars.

2. Compton Space Telescope

Compton Space Telescope is a space telescope dedicated to observing gamma rays. It was launched in 199 1, and its name comes from Compton, a famous physicist who commemorates the future.

Compton Space Telescope is not as famous as Hubble Telescope because it mainly detects a kind of gamma ray that is invisible to human eyes. This powerful light is difficult to detect on earth. In the nine years of space travel, Compton also wrote a thick book of contributions. It detected the afterglow of solar flares, the burst of high-energy cosmic gamma rays, the antimatter "fountain" as high as 2940 light years in the center of the Milky Way, and a group of strange and powerful gamma ray sources that may be composed of small black holes. Astronomers previously thought that gamma ray bursts could only be detected in the Milky Way, but a few months after Compton's launch, scientists proved that gamma ray sources may be located in all directions of the universe.

3. Chandra Space Telescope

The Chandra telescope was launched on July 23rd, 1999/KLOC-0, and it is still in service.

Its main purpose is to observe the X-ray radiation of celestial bodies, named after Indian-American astrophysicist Chandra Sika. It is worth mentioning that the cost of Chandra telescope is as high as $65.438+55 billion, and the total cost of the project is as high as $2.8 billion. This is the most advanced and complicated space telescope ever built by mankind.

Its main achievements include: the discovery of medium-mass black holes in the galaxy M82, and the discovery of supermassive black holes with unprecedented high sky density.

Put some beautiful pictures in this book.

4. Spitzer Space Telescope

Spitzer Space Telescope is the last of the four space telescopes. It was launched in August 2003. It is the largest infrared telescope sent into space by human beings. Compared with optical astronomical observation equipment, Spitzer's infrared "eyes" can penetrate dust and gas and see the infinite mystery hidden behind.

The main achievements are as follows: the expansion speed of the universe is measured to be about 74.3 2.1(km/s)/MPC, and the star maps of the whole galaxy and the new 7-star galaxy are drawn.

Finally, I hope that Jiangsu Science and Technology Society can compile these four big eyes in space into a set of books, so that I can feast my eyes on this astronomy enthusiast.

The green hills do not change, and the green waters flow forever. I was forgiven.

Feel free to forward and reprint, please contact Zhang Shaoshao.