Besides Earth, Mars would be the easiest planet to live on. Mars has liquid water, a habitable temperature and a bit of an atmosphere that can help protect humans from cosmic and solar radiation. The gravity of Mars is 38% that of the Earth.
Earth is the best planet. Earth developed around the same time and the place as all the other planets, but it's the only one we know of that managed to produce such a robust expression of life.
So far, the only life we know of is right here on our planet Earth. It is because of the hostile conditions of other planets in the solar system. Essential elements of life- oxygen, water, air, etc. - are lacking on other planets.
In composition, size, in atmosphere, etc? Venus and Mars are the most like Earth, but in different ways. In terms of size, average density, mass, and surface gravity, Venus is very similar to Earth. But Mars is the planet that is most similar to Earth in other ways.
Mars is the best planet because Mars and Earth have more in common than any other worlds in the solar system. It cowers next to humongous Jupiter, but unlike that gas giant, its hard surface beckons visitors.
The planet Saturn is probably the best known and most beautiful planet in the Solar System. Saturn's rings are far more extensive and more easily seen than those of any other planet.
Potential for Life
Uranus' environment is not conducive to life as we know it. The temperatures, pressures, and materials that characterize this planet are most likely too extreme and volatile for organisms to adapt to.
The order of the planets in the solar system, starting nearest the sun and working outward is the following: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and then the possible Planet Nine.
Water vapour has been detected on a potentially habitable super-Earth known as K2-18b, located about 110 light years away. The exoplanet was first spotted in 2015 by Nasa's Kepler spacecraft but analysis of data has revealed new details that have not been seen on a super-Earth before.
The surface of Mars today doesn't seem like the sort of place hospitable to life. It is dry and cold, plunging down as far as -220 degrees Fahrenheit. Its thin atmosphere cannot block ultraviolet radiation from space, which would devastate any known living thing on the surface of the planet.
At the current rate of solar brightening—just over 1% every 100 million years—Earth would suffer this "runaway greenhouse" in 600 million to 700 million years. Earth will suffer some preliminary effects leading up to that, too.
It is unlikely that life as we know it could survive on Mercury due to solar radiation, and extreme temperatures.
Mars does have an atmosphere, but it is about 100 times thinner than Earth's atmosphere and it has very little oxygen. The atmosphere on Mars is made up of mainly carbon dioxide. An astronaut on Mars would not be able to breathe the Martian air and would need a spacesuit with oxygen to work outdoors.
Named GJ 504b, the planet is made of pink gas. It's similar to Jupiter, a giant gas planet in our own solar system. But GJ 504b is four times more massive. At 460°F, it's the temperature of a hot oven, and it's the planet's intense heat that causes it to glow.
Among the stunning variety of worlds in our solar system, only Earth is known to host life. But other moons and planets show signs of potential habitability.
Jupiter's environment is probably not conducive to life as we know it. The temperatures, pressures, and materials that characterize this planet are most likely too extreme and volatile for organisms to adapt to.
Ingredients for Life? Jupiter cannot support life as we know it. But some of Jupiter's moons have oceans beneath their crusts that might support life.
Although you might think it would be cool, humans could not live on the moon! (Maybe one day in the future…) The moon has almost no atmosphere, so there's no air for us to breathe. There is no water on the moon either, and we need to drink water to survive.
Kepler-69 is a two planet system discovered by Kepler. Kepler-69 c, the outer planet, is orbiting the star every 242 days and might be in the habitable zone. It is 70 percent larger than Earth. Not much is known about its composition.
Astronomers have announced the discovery of the 100th planet known to inhabit another solar system. The star is 100 light years from Earth in the southern constellation Grus, or The Crane. The planet, one and a half times the mass of Jupiter, has a roughly circular orbit, like those of the sun's family of planets.
Potential for Life
The surface of Pluto is extremely cold, so it seems unlikely that life could exist there. At such cold temperatures, water, which is vital for life as we know it, is essentially rock-like. Pluto's interior is warmer, however, and some think there could even be an ocean deep inside.
Additionally, Titan's rivers, lakes and seas of liquid methane and ethane might serve as a habitable environment on the moon's surface, though any life there would likely be very different from Earth's life.
ROUTES OF EXPOSURE: Elemental mercury is toxic primarily through inhalation of mercury vapors. It is only slowly absorbed through the skin, although it may cause skin and eye irritation.