There is no indication of life on Mercury. Temperatures during the day can reach 430 degrees Celsius (800 degrees Fahrenheit) while at night can dip to -180 degrees Celsius (-290 degrees Fahrenheit). Life (as we know it) is unlikely to exist on this planet.
However, some scientists believe that there might be water under the surface of the planet's moon. If this is true, then perhaps life could have evolved earlier on Mercury than we thought.
The temperature is 800 degrees Fahrenheit. Mercury's temperatures are quite high. During the day, surface temperatures can approach 800 degrees Fahrenheit (430 degrees Celsius). Because there is no atmosphere to keep the heat in, nighttime temperatures on the planet's surface can reach minus 290 degrees Fahrenheit (minus 180 degrees Celsius).
All things considered, it is a very hot planet.
This high temperature is due to its proximity to the Sun. The closer a planet is to the Sun, the hotter it gets. As well, more distant planets take longer to orbit the Sun, which means they experience more hours of darkness than does Earth and thus have more time to heat up.
Also contributing to Mercury's high temperature is that it has no influence from other planets or moons. There are many other factors that come into play when considering the total environment of a planet, but without a doubt, distance from the Sun is one of the most important ones.
Earth's average temperature is 50 degrees Fahrenheit (10 degrees Celsius). Venus is 900 degrees Fahrenheit (500 degrees Celsius). It is the hottest planet in our solar system. Mercury is 800 degrees Fahrenheit (425 degrees Celsius). It is also the closest planet to the Sun. These facts about Venus and Mercury show us how important it is to have an atmosphere to protect you from the heat of the Sun.
Plants require consistent temperatures. Mercury's temperatures range from 400 degrees Celsius during the day to -200 degrees Celsius at night. Any vegetation, living or dead, on its surface would either freeze or catch fire. That's a resounding no.
Mercury is uninhabitable because it lacks an atmosphere and has temperatures ranging from 212 to 1,292 degrees Fahrenheit (100 to 700 degrees Celsius). It is also highly toxic. Humans can survive on Mercury for a few days but then begin to suffer serious health problems including neurological damage and cancer.
The temperature range of Mercury makes it impossible for there to be surface water or ice. There are many small craters around the planet that appear to have once been lakes, but they have long since dried up.
In addition to being extremely hot, Mercury has very little gravity; objects weigh much less there than on Earth. This means that people could travel at high speeds without injury or death. However, normal body functions would be difficult to maintain at such speeds.
The most important factor in determining whether Mercury is habitable by humans is its atmosphere. Although most of the oxygen has been removed over time due to the high levels of solar radiation, there are some areas where Oxygen molecules remain trapped under certain conditions. If human explorers were able to find these pockets, they might be able to live there indefinitely.
Another possible source of oxygen is the Sun. During periods of low activity, Mercury does not absorb enough solar energy to cause any significant change in its climate.
The conditions on Mercury would make life difficult. See how in this infographic from Space.com. (Image courtesy of Infographics Artist Karl Tate) Mercury's MESSENGER pictures suggest that the planet possesses water ice at its poles, which are permanently black. The presence of ice at these locations could not be confirmed, but it is believed to form a crust that prevents any water beneath from being exposed to solar radiation.
These facts about Mercury show that it is the most hostile planet out of the eight planets in our Solar System. Any living organism would find it difficult to survive there.
However, some species have been known to successfully adapt to these harsh conditions. One example is the human being who has been able to live and work on Mercury for several years now when sent by NASA there in 2010.
It is also worth mentioning that because Mercury is so close to the Sun, it experiences very high temperatures and very little air pressure. All these factors combine to create a very dangerous environment for living organisms.
Still, it's amazing that anyone would want to live there!
Even though Mercury's daytime temperatures may reach 750 degrees Fahrenheit (400 degrees Celsius), ice can form in craters that are shaded from the sun. There, the surface is exposed to chilly space at around minus 330 degrees Fahrenheit (minus 200 C). Over time, this cold weather causes water molecules in the air when the planet reaches its closest approach to the Sun to freeze into solid crystals that accumulate in the depressions of these craters.
Like the Moon, Mercury has a lot of energy trapped inside it. This power comes from the heat generated when its core of iron and nickel rocks up against the outer layer of silicon and oxygen. The friction between these layers creates enough energy to keep the planet's surface warm even though there is no source of light other than the sun. However, because mercury is so close to the sun, only a little energy is needed to melt all the way through its skin and reach its hot interior.
When scientists first discovered signs of water on Mercury, they thought it must be leftover material from when the planet was formed. But more recent studies have shown that the ice is actually buried under many feet of rock and soil. It's just that small amount of heat leaking out from deep within the planet's body is enough to cause the water vapor in the air above it to freeze into frozen droplets that can be seen from space.
People have been to Mercury, but not many.
Mercury is also the only planet in our solar system that does not have a tilt, hence it does not have seasons. It does, however, have a very elliptical orbit, which creates a version of summer and winter. During the day, when Mercury is closest to the sun, it may reach 427 °C. At night, when it is most distant, it drops to -153 °C.
However, because Mercury has no real atmosphere or oceans, these extremes are just that: extremes. The core of the planet is probably close to 500°C all the time, with temperatures fluctuating slightly depending on how close or far away it is from the sun. The surface probably averages about 45°C year round.
It is likely that water may exist beneath the surface, but we will never know unless we go there.
Summer on Mercury lasts for about half of each orbit, from May to July. Winter on Mercury lasts for the other half of each orbit, from November to May.
This means that the average temperature on Mercury is around 150°C, although the coldest point is probably below 300°C and the hottest point is probably above 400°C.
All this energy comes from the sun. If Mercury was farther from the sun, then it would be too hot and if it was closer to the sun, then it would be too cold.