Who and when were Uranus, Pluto and Neptune discovered respectively? urgent

178 1 March13rd, British astronomer F. W. Herschel discovered Uranus with the help of his sister C. L. Herschel. 1March, 930 13, American astronomer Tom Bo announced that he had discovered Pluto. American scientist Lowell believes that there is an unknown planet besides Neptune. Lowell called this unknown planet "Planet X" and spent a long time looking for its "beautiful image", but until his death, this distant planet still did not appear. Young Tombo, a staff member of Lowell Observatory, finally found this star through hard and meticulous work. Because this planet is far away from the sun, it receives much less sunlight than other planets. Its star is a dark, cold and gloomy world. So people are named after Pluto, the god of the underworld who lives in the dark and cold in Greek mythology. Neptune, which we call Pluto today, is the eighth planet from the sun. It was discovered on September 23rd 1846 by its perturbation effect on the orbit of Uranus, which was calculated by French astronomer Le Ye Wei. German astronomer J.G. Galle was the first person to observe the planet according to the calculated position. This discovery is regarded as an example of the accuracy of the theory of planetary motion. Because Neptune is far away and its luminosity is dim, it is difficult to see its surface details even with a large telescope, so it is impossible to determine its rotation period by observing the movement of surface markers. In 1928, the rotation period was 15.8 1h by observing the Doppler shift of spectral lines. The current rotation period (see the table below) was determined by Bertone and others by analyzing about 300 infrared observations. Neptune's rapid rotation makes its oblateness reach 1/50 (that is, the equatorial radius is about 500 km longer than the polar radius)1On April 7, 968, Neptune eclipsed the stars. Through the observation of this event, it is found that its equatorial diameter is 50950km, which is quite different from the latest data. Neptune looks slightly green through the telescope. 1932 proves that the strong absorption line in the infrared region of Neptune's spectrum is caused by methane. Its atmosphere is rich in hydrogen and helium, and its atmospheric temperature is about -205℃, which is higher than the expected value calculated according to solar radiation, indicating that either Neptune has a greenhouse effect in the lower atmosphere or it has an internal heat source. 1846, W. Russell discovered the retrograde triton. According to calculations, it is approaching Neptune and may break into Neptune's ring in the future. 1949, triton was discovered. The average temperature of Neptune cloud is-193℃ to-153℃, and the atmospheric pressure is about 1-3 Pa. The radius of orbit around the sun is 4.5 billion kilometers, and it takes 165 years to make a revolution. Neptune brightness 7.85, etc. You can only see it through a telescope. Its diameter is 49,400km, which is 3.88 times that of the earth. Its equatorial radius is about 64 1 km longer than the polar radius. Neptune's volume is about 57 times that of the Earth, its mass is 17.22 times that of the Earth, and its average density is 1.66g/cm3. The acceleration of gravity on the surface is slightly greater than that of the earth, with two poles 1, 180cm/s2 and equator about 1, 100cm/s2. The escape velocity of surface objects is 23.6 km/s Neptune has six satellites and five rings. 3。 The acceleration of gravity on the surface is slightly greater than that of the earth, with two poles 1, 180cm/s2 and equator about 1, 100cm/s2. The escape velocity of surface objects is 23.6 km/s Neptune has six satellites and five rings. Because Neptune is a light blue planet, people call it Neptune according to the traditional naming method of the planet. Neptune is Poseidon, the god of the sea in Roman mythology, and holds the universe of 1/3, which is quite amazing.