The smallest planet in the solar system?

Of the nine planets, Pluto is the farthest from the sun and has the smallest mass. It hobbles in the cold and dark space 5.9 billion kilometers away from the sun, which is very similar to proto, the god of the underworld in Roman mythology. So people call it Pluto, which is the first two letters of the English name of Pluto in astronomy, and the abbreviation of the name of Lovel, an American astronomer who promoted the discovery of Pluto.

The picture on the left is the best photo taken by the telescope on the ground;

The picture on the right is the space telescope image;

The following figure is a schematic diagram of their orbits.

Pluto and its satellite1February 2, 9941space telescope image.

The small image is that original image of the space telescope;

The big picture is a ghost after computer processing.

Wangxing surface

Pluto is the latest planet to be discovered. Compared with the discovery of Uranus and Neptune, the discovery of Pluto is "a lot of trouble". Pluto's brightness is very weak, only 15 and so on. Even in the photos taken by large telescopes, it is no different from ordinary stars. Finding it among thousands of stars is like looking for a needle in a haystack.

In the process of searching for Pluto, Lovel, an American astronomer who is an astronomy enthusiast, calculated the position of this unknown planet in detail and searched it carefully with a telescope, which took more than ten years. Until19161.0616 suddenly died.

1925, Lovel's brother donated a large-field photographic telescope with a diameter of 32.5 cm, which provided excellent conditions for continuing the search for new planets. From 65438 to 0929, the director of Lovel Observatory invited clyde william tombaugh to join the search for unknown planets. They searched one by one, photographed a large number of negatives, and examined each one carefully. This job is hard and boring. 193065438+1October 2 1 day, Tang Bo finally found this new planet in the negative of Gemini.

Underground world

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Mass: 0.0024 Earth mass

Radius:1350km

Period: 90465 days

Half-length diameter of orbit: 39.87 astronomical units.

Track eccentricity: 0.256

Orbit inclination: 17. 1.