When he was about to land, Hua Feng received a summary material, which briefly introduced what he had learned and consolidated recently.

He casually flipped through the test and got ...... Among the interchangeable satellites: Titan and Titan will interchange satellites: Titan and Titan.

The two satellites will switch places!

us) and Titan (Epimetheus) are two small moons of Saturn that are reversed as they orbit their home planet. The separation of the radius of the orbit of the two satellites around Saturn is less than the radius of the satellite itself, which is about 50 kilometers. In the beginning, one of the satellites leads the way in front of each other, and the distance gradually decreases under the gravitational pull of each other, and every few years, they pass by and switch places. This peculiar dance of moons has led astronomers to suspect that Titan and Titan were originally a larger moon that later split into two. In the image above, the two moons are orbiting Saturn outside of Saturn's F ring, and the Cassini spacecraft that took this image is also orbiting Saturn.

Titan (S/1980 S 3), also known as Epimetheus, is the fifth closest known moon of Saturn. Epimetheus was the son of Iapetus, the brother of Prometheus and Atlas, and the husband of Pandora. It means "hindsight" in Greek.

Titan itself is a little smaller in diameter than Titan (181 km), almost the same distance from Saturn as Titan (orbital radius of 151,000 km, a difference of only 30~50 km), and rotates synchronously along a common orbit. In close proximity to each other (once every 4 years), they exchange pulses and change positions: the inner satellites switch to the outside, the outer satellites to the inside, they always face Saturn on the same side, just as the Moon faces the Earth, and therefore always orbit forward in one direction, with a week of 0.694 days. Scientists believe that Titan and Titan share a common "ancestor". Titan was discovered in 1966 by French astronomer A. Dolphy, while Titan was discovered by Ja Fontein and his colleagues when the Voyager-1 probe flew by Saturn in 1980.

Its surface has many craters (craters) with a diameter of more than 30 km, as well as large and small mountains and ravines. It is widely believed that Titan must be very old.

The volume of Titan (ep-ee-MEE-thee-us) is 114 x 108 x 98 cubic kilometers. This composite close-up, taken by Cassini's Saturn probe, emphasizes its uneven surface and irregular shape through the use of exaggerated shading. Titan orbits 91,000 kilometers above Saturn's cloud top, but it is not the only moon. Titan is close in size and orbits only 50 kilometers from its orbit. this

The two satellites actually meet every four years, but the encounter is not a collision, they deftly switch orbits and then go their separate ways.

Titan is a small moon of Saturn, about 140×100 kilometers in size, discovered in 1980. Titan is a so-called "co-orbital" satellite, which means that its orbit is practically identical to that of Titan, another Saturnian moon. The difference in the average radius of the orbits of the two satellites is very small, with the average radius of Titan orbiting being 151422 km and the average half-diameter of Titan orbiting being 151472 km.

Titan and Titan were most likely a celestial body at some point that disintegrated after being hit by another celestial body. The irregular shape of the two satellites favors this hypothesis, except that Titan is slightly larger than Titan, measuring 220×160 km. As can be clearly seen from the photographs shown, Titan has been hit by asteroids many times, and there are quite a few craters on its surface due to the impacts.

John Cavelas, an astronomer at McMaster University, is known for the myth of Iji

aq) as its English name, which for the first time broke away from the habit of naming satellites after characters from Greek or Roman mythology. When he discovered the satellite, he began to look for a proper name for it, hoping for a name that would be a blend of cultures and representative of Canada, but after months of thinking and asking many humanities scholars, he was unable to find a proper name.

It wasn't until March 2001, when he was reading an Inuit storybook to his children, that he discovered that Ijerak was a monster who liked to hide, just like all the little moons of Saturn, and that the Inuit lived in the Arctic Circle, which was very cold, just like Enceladus. Therefore, he took Iapetus as Ijerak.

On June 18, 2011, NASA, the European Space Agency and the Italian Space Agency jointly developed the Cassini Saturn probe and flew past one of Saturn's moons: Titan Hele

e (Helen), about 6,968 kilometres (4,330 mi) above the surface of Titan, was the second close-range flight after reaching 1,931 kilometres in 2010. Hele

The orbit of the E satellite is somewhat special, with an average distance of 370,000 kilometers from the surface of Saturn, which is about the same distance as the distance between the Moon and the Earth. From the outside, the satellite appears to be irregularly shaped, measuring about 22 x 19 x 18.6 miles (36 x 32 x 30 km).

The route of the Cassini probe this flight is from Hele

The shadow side of the E satellite flies towards the sun, and the surface of Titan is unusually smooth, but it also shows the presence of ridges and hills in some areas, as well as the presence of impact craters. And scientists estimate that Enceladus most likely collided with a larger celestial body at some point before, leaving a huge gap in its surface. Except to be to Hele

After the topographic mapping of the E satellite, the focus was on observing the gully-like structure on the surface, which will help to understand the formation history and geological structure of the satellite, which is only 35 kilometers wide.

Figure 1: This color image is a composite image superimposed with the original images taken by the red, green, and blue monochrome visible filters on board the Cassini spacecraft. Some blurring is evident on the image, and this is because of Hele

There is a slight shift in position in each frame of the image, but scientists in the Cassini detector image control room believe that the composite image does a good job of capturing light and the color changes on the surface of the satellite.

Figure 2: This Hele

In the image of the E satellite, the North Pole is downward, and this is because the Cassini probe was taken upside down. Hele at the same time

3D image of the e satellite, this image was imaged by the Cassini probe Pat in the control room

ick Ruthe

fo

d mission expert post-processing, if you have red/blue 3D eyes, you can clearly see the three-dimensional structure of the entire satellite.

In addition, Titan Hele

e is also known as the Trojan asteroid of Titan. A Trojan object is a celestial body whose orbit coincides with the orbit of a larger planet or moon. and is located near the Lagrange point 60° in front of or behind the orbit of a larger planet or moon. Originally, Trojan objects were used to represent asteroids located near Jupiter's Lagrange point, where the asteroids would not collide due to their balanced gravitational pull.

Therefore, the reason why Titan is called the Trojan asteroid of Titan is because its orbit is similar to that of Titan

e is the same, located 60 ° in front of it. Among Saturn's moons, Titan (Tethys), Titan (Telesto) and Titan (Calypso) form a group of Trojan moons. Together, these Trojan moons form Saturn's spectacular constellation of moons, and are another iconic sight of Saturn in addition to its impressive ring system.

The largest satellite system in the solar system. The outermost Titan is a retrograde moon, and from Titan to Titan there are 8 regular moons. Titan, the largest moon second only to Ganymede, was the first moon to discover an atmosphere, its atmosphere is five times denser than the Earth's atmosphere, its main components are nitrogen and methane, and its surface is viscous hydrocarbons.

There are also several strange phenomena of several satellites in the same orbit in the Titan system, such as Titan 13 and 14 are 60 degrees before and after Titan, forming two regular triangles, while Titan 10 and 11 are sometimes very close together, and several satellites are located in the ring, which is also one of the reasons for the complex and changeable structure of Saturn's rings.

Saturn's rings and its moons. ESA Image: Saturn, with its beautiful rings, has a large number of moons, 34 of which have been named, and their exact data is not known because there are so many objects orbiting it in such a wide orbit. More recently, an observation made in the second half of 2000 discovered 12 other moons with strange orbits, suggesting that they were originally fragments of a large celestial body that were later captured by Saturn's gravitational field.

The most notable of Saturn's moons is Titan, the only moon in the solar system with a dense atmosphere.

On Christmas Day, December 25, 2004, Cassini released the Huygens, who embarked on a three-week solo trip to Titan. The Cassini-Huygens probe entered orbit around Saturn on July 1, 2004. The Cassini-Huygens mission also increased the number of satellites to be discovered.

At least 10 of Saturn's moons have been confirmed. In order of distance from Saturn, they are: Titan, Titan, Titan, Titan, Titan, Titan, Titan. On September 1, 1979, it was reported that the interplanetary probe Pioneer 11 discovered a new moon, tentatively named Pioneer Rock (Pio).

ee

ock) or 1979S1, but it has not yet been confirmed.

The distance between Titan and Saturn is only 159,500 kilometers, which is only 2.66 times the radius of Saturn's equator and is close to the Loch limit. Iapetus's orbital plane is 14°7 with Saturn's equatorial plane, and its orbital plane is 16°3 with Saturn's orbital plane, which is an irregular moon, and Titan orbits Saturn in an elliptical orbit with an eccentricity of 0.1633, and its orbital plane is about 150° with Saturn's equatorial plane, which is also an irregular moon.

With the exception of Titan and Titan, Enceladus to Titan and Titan are regular moons that orbit Saturn in a near-circular orbit near Saturn's equatorial plane.

Of the 10 Saturnian moons from Enceladus to Titan, Titan is the only retrograde moon because its orbital plane is at an angle of 174°42┡ to Saturn's orbital plane, and its rotation around Saturn is in the opposite direction to Saturn's rotation around the Sun.

Among the Titan systems it is worth mentioning Titan, Enceladus and Titan. Titan is also known as Tita

）。 With a radius of about 2,575 kilometers, it is the second largest moon in the solar system, second only to Ganymede and larger than Mercury, the closest planet to the Sun. It orbits Saturn once or so every 16 days or so. Because of its mass and distance from the Sun, it may have an atmosphere based on its escape velocity.

In 1944, Kuiper discovered methane lines in Titan's spectrum, and learned that it did have an atmosphere. The main components of its atmosphere are methane and hydrogen, and the atmospheric pressure is about 1.5 Earth's atmospheres. Titan's surface may be ice, with a temperature of about 125 K. In September 1979, Pioneer 11 took pictures of the satellite 356,000 kilometers away.

Titan is orange. The moon's atmospheric clouds are composed of methane, ethane, acetylene (and possibly nitrogen), which are dissociated by the sun's ultraviolet radiation. Pioneer 11 also measured the temperature of Titan's upper atmosphere at -200°C, which is about the same temperature as Saturn's rings.

How many moons does Saturn have? In 1996 it was 18, in 2000 it rose to 24, in 2003 it was 53, in 2005 it was 60, and later it was found that there were 62.