which planet is hotter, Mercury or venus?

Question

my 7 y.o. twin boys are curious about it,

Answer 1

mercury. aw, cute. 7 year old twin boys! im a twin!

Answer 2

Venus is hotter. You might think Mercury is, since it's closer (most of the posters thought this). In fact, per square meter, mercury receives far more thermal radiation. However, Mercury has no atmosphere. That radiation hits the surface, and heats the rock until the rate at which the heat continues to warm the rock (conduction) equal the rate at which the sunlight is bounced back and/or re-radiated back into space.

Venus has an atmosphere, comprised of greenhouse gases. Now the radiation (sunlight) is not only conducted through the rocks, the heat is convected through the atmosphere. Also, because of the greenhouse gases, the heat cannot be re-radiated out into space - it remains trapped in the atmosphere. Eventually an equilibrium is reached, but not before the surface temperature is hellish, the hottest in the solar system, enough to melt lead.

BTW, you may want to tell your kids the greenhouse gases are responsible for the runaway global warming, a situation not unlike what is starting to happen on Earth.

Answer 3

Most people would say Mercury, since it is closer to the Sun, but they are WRONG! Venus is actually warmer because of its atmosphere. The atmosphere traps hot air in and stops it from getting out which creates a greenhouse affect. Mercury, however, does not have an atmosphere, so when the Sun shines on it, the moment it goes away, the moment Mercury freezes. Therefore, Venus is warmer than Mercury and is the warmest planet in the Solar System.

Answer 4

"Temperature variations on Mercury are the most extreme in the solar system ranging from 90 K to 700 K. The temperature on Venus is slightly hotter but very stable."

"This dense atmosphere (of Venus) produces a run-away greenhouse effect that raises Venus' surface temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is actually hotter than Mercury's despite being nearly twice as far from the Sun."

Answer 5

Venus is... Mercury might be closest to the sun... but that doesn't change the fact, Mercury doesn't have ANY atmosphere.... But ... Venus has a thicker atmosphere than any other planet in our solar system.... It's called a "Greenhouse Affect" .... What it is is the heavy atmosphere of Venus is made up of Carbon Monoxide .... Carbon Dioxide ..... Water Vapor, And many more gases... This makes it very hot... hotter than Mercury...The reason why is.... What Venus atmosphere does is it basically Sucks in ALL of the heat it can get.... so.... it's like a Greenhouse...It's gets all of this heat... but can't get rid of any of it...So... it makes it hotter than any other planet. There you go... hope I helped.... I.M. me if you have any other questions about Venus and/or Mercury... :)

Answer 6

Mercury is NOT hotter than Venus dispite being closer to the sun. As you can see even it's hottest recorded temperatures (on any part of Mercury) fall below the average on Venus.

Venus
Min .... Ave .... Max
228 K 737 K 773 K

Mercury
90 K 440 K 700 K


Even on it's sunny side which warms up as it turns slowly from the sun only reaches about 623 K on average which is still vastly less than Venus' average temp over it's entire surface! Mercury's average on the night side is a chilly 103 K.

Mercury DOES outdo Venus in it's variation in temperature as you can see. It has practically no atmosphere so it has a hard time holding the heat in. On Earth the heat that warms our surface takes time to escape as it is held in by our atmosphere. On Venus where the surface is practically invisible because of the thick clouds of sulfer dioxide and sulferic acid that hover over the CO2 layer, the heat takes even longer to escape. Venus suffers from a runaway greenhouse effect... it is heated more and more but not enough of this heat is able to escape.

Answer 7

Mister (above) is wrong - Mercury does not have one side always facing the Sun. People thought that a long time ago, but we know better now. Mercury actually rotates 3 times for every 2 times it orbits the Sun.

Venus is hotter than Mercury, even the sunlit side of Mercury.

Answer 8

Woo. Nice question.

Venus' hot atmosphere makes it the hottest planet in our Solar System..

Your questions has brought out a lot of opinions and shown people that their first idea can be wrong! It also showed that people can even find wrong answers on the Internet when they look at information that is still there after new information was discovered. There is no easy way to update the millions of pages of information that become obsolete!

New satellites are making discoveries about the Sun, Mercury and Venus. There are lots of ideas that are being overturned.



;-D Astronomy and Astrophysics are alive and well.

Answer 9

oh no no, I think most of you are wrong,

True Mercury is closest to the sun, but it has no atmosphere, its all been blasted away by solar radiation, plus its pretty small too. so without an atmosphere it cant retain any heat.

Venus is different, it has a very thick atmosphere of gasses that are very good at absorbing the sunlight and also keeping in the heat. (a bit like the greenhouse effect on Earth gone mad!) So I believe that it actually gets hotter than Mercury.

Answer 10

Overall average, Venus is hotter because the whole planet is hot. Mercury is hot on the side toward the sun, extremely cold on the night side, because it has no atmosphere to hold heat in.

Answer 11

The surface temperature on Venus is hot enough to melt lead! It is actually otter than the surface of Mercury, even though Mercury is closer to the sun. (It does not ever enter the sun, that is completely false.)

There is also the sunlit side of Mercury, which is very hot, and the dark side which is very cold. The rotation of the planet actually makes a day on Mercury exactly a Mercury year and a half long! (The year is 88 Earth days long.)