Why are planetary scientists so fascinated by Mars? When there are at least 7 other planets, more than 200 moons, countless asteroids, etc. in our solar system, why spend so much time and money on this planet? To other worlds, and there are many missions to very exciting places in our solar system-exotic worlds such as ice volcanoes, ice rubble rings and huge magnetic fields.
There are currently 26 active spacecraft scattered in our solar system. Some of them orbit other planets and moons, some land on the surface of other worlds, some fly over to transmit images, and only half have visited Mars. Spacecrafts like Voyager-1 and Voyager-2, they are still active more than 40 years later, and now they have left the solar system, heading to interstellar space, and there are some lesser-known but equally strange spacecraft.
The most difficult masterpiece of astrodynamics was completed at the end of last year, when the Japan Space Agency not only landed a spacecraft on an asteroid, but also brought samples back to Earth with a spectacular sling. Hayabusa 2 did 2018 rendevous with asteroid 162173 Ryugu, surface detection and sampling. As of 2019, Hayabusa 2 has been using its ion thruster to change its orbit and return to Earth. On December 5, 2020, a 16 kg hatbox-sized sample return capsule passed through the Earth’s atmosphere and landed unscathed at the Woomera Proving Ground in Australia.
As JAXA continues to analyze the collected rocks and dust on the Ryugu asteroid, Hayabusa 2 stands upright again, this time encountering a second asteroid, 1998 KY_ (26), sometime in 2031. Our nearest planetary neighbor Venus. Despite the extreme heat and crushing surface pressure, NASA recently approved funding for two major missions to explore the origins of Venus and its atmosphere.
After the discovery of phosphine in the upper atmosphere, people believed that life could exist at the lowest and most habitable temperature at the highest altitude. The government tends to spend relatively small budgets on science and space exploration. They usually spend less than 1% of their budget on space missions, much less than social services or military defense.