We will look into the exploration attempts of all planets in the solar system...

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Spacecraft: Exploring our planets

The Solar System has eight official planets. We live and thrive on the 3rd planet, Earth. Due to our superior technology, we can observe the planets in the solar system. Yuri Gagarin's launch to space in Vostok 1 marked the beginning of the Space Age in 1961. Since then, we have sent lots of spacecraft to deep space. Let's look at the ones that have visited the other planets.

Solar System Exploration (By Google)

Sun: Sun? We may wonder, "Sun is a star and is tremendously hot. Comets that come near it have been obliterated. A spacecraft can't survive." Yes, that is right, but only one spacecraft has crossed these barriers. It was built with the best heatproof technology possible and is a success. It is none other than, The Parker Solar Probe, launched in 2021. This thing is so robust that it has ventured into the sun, intact and can picture the sun's interior.

Mercury: The first planet from the sun is hard to grasp. Since it revolves in 88 days, it is much quicker than the satellite's revolution. Only one lucky spacecraft has found its way around the planet and has clicked its pictures. It is Messanger 1. 

Venus: The hottest, as well as the closest planet to the Earth, is explored by the Venus Express, and Venera 1 has landed on the surface. The spacecraft eventually survived for only 23 seconds before promptly burning.

Mars: This planet has a long list of spacecraft orbiters and rover missions that have landed on it, where some have accomplished their assignment, some partially executed, and others are a failure. The first lander on Mars - the Viking 1, followed by Viking 2 by NASA, used to find any signs of extraterrestrial life. Others are Curiosity, Opportunity, Preservance and more.

Jupiter: This gas giant is not a rocky planet like Earth. It has no solid surface. This fact implies that swirling enormous clouds of gas all over the atmosphere make up Jupiter. Anything can merely dip inside the planet and get out off the opposite side. But the bad news is that the semi-solid core of Jupiter exerts high turbulence and not to mention the high doses of radiation surrounding the planet. It is certainly not a place for a human expedition, but a spacecraft has visited it, that is Galileo. This spacecraft is named after the Italian astronomer Galileo Galilei who discovered the Galilean moons, the four largest moons of Jupiter (Ganymede, Callisto, Europa, Io). The craft also released a probe into the atmosphere to analyse the gases.

Saturn: The Cassini-Huygens spacecraft has orbited this planet. Much like Jupiter, this planet has no surface. But the visible rings are its uniqueness and speciality. The craft has photographed its rings and has sent information like the rings, Encke gap and Cassini Division (These concepts are part of the upcoming post, so stay tuned for that!). The Huygens lander attached to its side dropped onto Titan when it orbited Saturn.

Uranus & Neptune: Now, we have covered the naked-eye planets. For years, we thought Saturn only was the solar system's boundary. We can't see the outer planets using the naked eye. Also, they have already been 'discovered' by astronomers such as Galileo, who found Neptune 238 years before the discovery and Sir William Herschel, who 'discovered' Uranus in 1781 but did not realise they were planets. We found Uranus by total accident. While astronomers tracked it, they found Uranus orbiting the sun in a different orbit. This orbit is different compared to their predicted rotation. It means a remote planet pulled Uranus. They calculated its location and trajectory, and when they saw it through the telescope, they found Neptune. The nuclear-powered Voyager 1 and Voyager 2. They flew by the planets and took their photographs. These two crafts are the only spacecrafts that have officially left the solar system and wandered into Interstellar space. Voyager 1 has travelled the most distance as compared to the other spacecrafts. 

But Neptune didn't have enough gravity to alter Uranus's orbit. Moreover, We found Neptune to be pulled by something else too! The minor bodies beyond the outermost planet, also known as eTNO (Extreme Trans-Neptunian Objects), are also affected by the pull of a mysterious body. It led to the theory of Planet X or Planet 9, lurking in the outskirts of the Oort cloud. It is a planet that impacted the orbit of eTNO, Neptune and Uranus. It is a mission for the daring Voyagers spacecraft.

Thank you for reading

Aditya VN Kadiyala