There have been journeys to the inner planets: the Messenger, Magellan and Mariner spacecraft to Mercury and Venus. There have, too, been expeditions to Jupiter and Saturn and their colorful flocks of moons. Asteroids and comets and the sun itself have also been studied up close. Many of the missions are ongoing.
In short, a visit to another planet by a human crew is possible, but some are easier to explore than others. Each planet is different and has a unique set of challenges. For example, the largest planet in our Solar System, Jupiter, is a 'gas giant' mainly composed of hydrogen and helium gas.
Visiting Venus
Venus lies just outside the sun's habitable zone. That zone has temperatures that could keep liquid water stable on a planet's surface. No spacecraft have landed on the surface of Venus since 1985. A few orbiters have visited Earth's neighbor in the past decade.
Not yet, but we've sent rovers, landers, and orbiters to. gather the information we'll need to keep future. astronauts safe, and with NASA Artemis, we're.
Mankind has been studying Jupiter for more than 400 years. But we've only been sending spacecraft there since the 1970s! Nine spacecraft have visited Jupiter since 1973, and they've discovered a lot about the planet. Flip through the slideshow below to find out about these spacecraft and what they've discovered.
Surface. As a gas giant, Jupiter doesn't have a true surface. The planet is mostly swirling gases and liquids. While a spacecraft would have nowhere to land on Jupiter, it wouldn't be able to fly through unscathed either.
New Horizons was the first spacecraft to encounter Pluto, a relic from the formation of the solar system. By the time it reached the Pluto system, the spacecraft had traveled farther away and for a longer time period (more than nine years) than any previous deep space spacecraft ever launched.
Sole Encounter
The only spacecraft to visit Pluto is NASA's New Horizons, which passed close by in July 2015.
As an ice giant, Uranus doesn't have a true surface. The planet is mostly swirling fluids. While a spacecraft would have nowhere to land on Uranus, it wouldn't be able to fly through its atmosphere unscathed either. The extreme pressures and temperatures would destroy a metal spacecraft.
The technology required to travel between galaxies is far beyond humanity's present capabilities, and currently only the subject of speculation, hypothesis, and science fiction. However, theoretically speaking, there is nothing to conclusively indicate that intergalactic travel is impossible.
Light-year is the distance light travels in one year. Light zips through interstellar space at 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year.
So, to leave our Galaxy, we would have to travel about 500 light-years vertically, or about 25,000 light-years away from the galactic centre. We'd need to go much further to escape the 'halo' of diffuse gas, old stars and globular clusters that surrounds the Milky Way's stellar disk.
After a descent lasting two hours and 27 minutes, the Huygens probe successfully landed on Titan on Jan. 14, 2005.
Technology that helps humans travel and survive in space has improved since that first trip to the Moon-so why haven't we traveled to any other planets? The answer lies in size and distance. Compared to the rest of our solar system, Earth is just a tiny dot surrounded by a whole lot of empty space.
So why haven't astronauts been back to the moon in 50 years? "It was the political risks that prevented it from happening," Bridenstine said. "The program took too long and it costs too much money." Researchers and entrepreneurs have long pushed for the creation of a crewed base on the moon — a lunar space station.
While a spacecraft would have nowhere to land on Saturn, it wouldn't be able to fly through unscathed either. The extreme pressures and temperatures deep inside the planet would crush, melt, and vaporize any spacecraft trying to fly into the planet.
There have also been studies for a possible human mission to Mars, including a landing, but none have been attempted. Soviet Union's Mars 3, which landed in 1971, was the first successful Mars landing. As of 2022, the Soviet Union, United States, and China have conducted Mars landings successfully.
Jan. 24, 1986: NASA's Voyager 2 made the first - and so far the only - visit to Uranus. The spacecraft came within 50,600 miles (81,500 kilometers) of the planet's cloud tops. Voyager discovered 10 new moons, two new rings and a magnetic field stronger than that of Saturn.
The Cassini mission launched in 1997 and spent seven years traveling to Saturn, arriving in 2004. Cassini is the first spacecraft to orbit Saturn, and has provided a treasure trove of data and images of the entire Saturnian system.
One Voyage There. Voyager 2 is the only spacecraft to have visited Neptune. No spacecraft has orbited this distant planet to study it at length and up close.
The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.”
Tough Place for Life
It is unlikely that life as we know it could survive on Mercury due to solar radiation, and extreme temperatures.
The exploration of Mercury has a minor role in the space interests of the world. It is the least explored inner planet. As of 2015, the Mariner 10 and MESSENGER missions have been the only missions that have made close observations of Mercury. MESSENGER made three flybys before entering orbit around Mercury.
Have astronauts from Earth ever stepped foot on Mercury? No, Mercury has been visited by spacecraft from Earth, but no human has ever gone into orbit around Mercury, let alone stepped on the surface.