Between Earth and the sun, you can find two planets. These two planets are Venus and Mercury. They are effectively neighbors, with Venus being the second planet from the sun, with Earth obviously as its other neighbor. Mercury, on the other hand, is the closest planet in our solar system to the sun, with Venus being one neighbor and the sun itself being the other. So, these planets are obviously located in a relatively similar area of our solar system, The Milky Way. But how does this influence the comparison between the two planets? What do these two planets share in common? What are their significant differences? And why do these come to be? These are the all-important questions that we’ll be finding the answers to today as we compare Venus against Mercury!
So, what are the main differences between Venus vs. Mercury? When comparing Venus with Mercury, there are significant differences to be found in relation to their size, orbit, temperature, and many other characteristics. Venus is a bigger planet than Mercury, and it’s also hotter, but then again, it is the hottest planet in our solar system. Mercury takes much less time to orbit the sun than Venus does, but then again, it takes the least amount of time to complete this action compared to any planet in our solar system.
What Are The Differences Between Venus and Mercury?
Mercury and Venus are different when you compare their size, orbit, temperature, axle tilt, rotation time, aesthetics, and terrain.
So, it would seem that there are quite a lot of noticeable differences to be found in the comparison of Mercury with VenusSpoiler alert.
One by one, we’re going to explore these key differences in more detail.
Size and Mass
The Milky Way is full of planets of all different sizes.
Both Mercury and Venus are placed at the ‘small planet’ end of the spectrum.
And yet there is still a significant difference in size when you compare these two planets.
Venus is the bigger planet.
Venus has a diameter of 12,104km compared to Mercury’s diameter of 4,879km.
Venus has a surface area of 460.2 million square kilometers compared to Mercury’s surface area of 74.8 million square kilometers.
And finally, Venus has a mass of 4.867 × 10^24 kg compared to Mercury’s mass of 3.285 x 10^23 kg.
These figures make Venus the sixth biggest planet in our solar system, which means they’re only bigger than Mars and Mercury itself, which is the smallest planet in our solar system.
Orbit of the Sun
These two planets are the closest in our solar system to the sun. Venus is the second closest, and Mercury is the closest.
Distance from the sun plays a big part in determining how long it takes a planet to complete one orbit of the sun. The closer a planet is to the sun, the less time it takes for it to orbit it.
By this logic, you would assume that Mercury takes less time to orbit the sun than Venus does…and you’d be correct to assume this.
Venus takes 225 days to orbit the sun. That’s pretty quick.
But not as quickly as Mercury which only takes 88 days to orbit the sun.
Venus is hotter than Mercury when it comes to surface area temperature and core temperature.
Mercury’s surface temperature is approximately 332 degrees Fahrenheit (167 degrees Celsius). Venus’s surface temperature is approximately 887 degrees Fahrenheit (475 degrees Celsius). So, Venus is clearly the warmer temperature on its surface. Mind you; Venus is warmer on its surface than any planet in our solar system.
We also measure how warm planets are at their cores. Venus is still warmer in this regard, as it has a core temperature of 9392 degrees Fahrenheit (5200 degrees Celsius). This is much higher than Mercury’s core temperature of approximately 2912-5792 degrees Fahrenheit (1600-3200 degrees Celsius).
Axial Tilt and Rotation
You’ll find that the planets in our solar system tilt on different axials.
Sometimes comparisons can be very stark, whilst other times, they can be very similar.
When it comes to Venus Vs. Mercury, their tilts are very similar. With that being said, there is still a difference between these two planets.
Mercury has an axial tilt of 2 degrees, whilst Venus’ is 3 degrees. See what I mean? A very fine margin.
But what isn’t a fine margin is a comparison to be made between the varying lengths of time it takes for these planets to complete one rotation on their axial.
In other words, how long it takes for these planets to complete what we humans call ‘a day’.
The truth is that both of these planets complete this rotation very slowly. We shall judge how slow their rotation times are by measuring them in terms of Earth days.
So, Mercury completes one rotation of its axial in 58.65 days.
Quite a long time, right? Well, it’s not the longest rotation time in our solar system.
That title belongs to Venus, which takes 243 days to complete one rotation on its axial.
Aesthetic and Terrain
There is a difference to be discerned in terms of the aesthetics of these planets.
Venus appears as a yellowy-white color. It’s actually the brightest planet in our solar system.
Mercury is gray, in a similar way that the moon is.
Venus’ terrain is predominantly volcanoes and magma, whereas Mercury’s is predominantly rocky, consisting of a lot of sulfur.
What Are The Similarities Between Venus and Mercury?
Mercury and Venus are similar when you compare their chemical composition, orbit pattern, shape, the fact that they both have hotter central cores, they both have a gravitational pull, neither has any rings or moons, neither can support human life, and neither has been visited by humans.
It’s no surprise that these two planets have a lot in common, considering the fact that they are neighbors.
Once again, let’s explore the comparisons between these two planets from the perspective of what they have in common.
Although their terrain may differ, Venus and Mercury, both belong in the same planet category.
The eight planets in our solar system can be split into two separate planet categories, with four falling into one and four falling into the other.
Venus and Mercury fall into the terrestrial planets category.
Terrestrial planets are planets composed primarily of silicate rocks or metals. Earth and Mars join Mercury and Venus in the terrestrial planet category..
The other type of planet to be found in our solar system is the gas giant.
Gas giants are planets composed of gases, primarily hydrogen and helium.
The four gas giants in our solar system are Jupiter, Saturn, Uranus, and Neptune.
It is true that the time by which Venus and Mercury have completed an orbit of the sun varies significantly.
However, what doesn’t vary is the pattern these planets orbit the sun through.
Just like the rest of the planets in our solar system, both Mercury and Venus have circular orbits of the sun.
Both are Spherical
I said earlier that all planets come in different sizes. And I meant it.
But planets don’t come in different shapes. For example, we don’t have cubed planets. Or octagon-shaped planets.
All of our planets are spherical, and this includes Venus and Mercury.
Both Have a Hotter Central Core
Venus is the hotter planet when compared to Mercury.
What these two planets do share in common is that their core temperatures are warmer than their surface areas.
This is the case for all planets in our solar system.
Mercury and Venus possess a gravitational relationship with the rest of the universe.
They orbit in relation to other objects. Most notably, the sun.
This relationship is driven by the planets having a gravitational pull force.
For some planets, this gravitational pull force ensures that their moons and rings stay close to them within their orbit.
But this is only the case for planets that actually have moons or rings. This brings us to the next thing Venus and Mercury have in common…
Both Don’t Have Moons or Rings
What? No moons or rings? For either planet?
Yes, that’s correct.
Venus doesn’t have any moons or rings, and neither does Mercury.
Can’t Support Human Life
Venus or Mercury is not somewhere you want to visit…without the right technology.
Humans just aren’t designed to survive naturally on either of these planets.
Well, first of all, there isn’t oxygen on either of them. So we wouldn’t be able to breathe.
Second of all, the temperatures on the surface and in the atmosphere are too hostile for us to survive.
Humans Haven’t Visited
Even with the right technology and equipment to survive on Mars and Mercury, we still aren’t able to visit either of them.
Even though they’re not the furthest planets away from Earth in the solar system, they are still a really long way away.
Until we have safe and efficient travel means for getting to either of these planets, we won’t be able to visit them anytime soon.
No two planets are the same.
And that’s certainly the case when comparing Mercury and Venus.
But that’s not to say that they don’t have similarities. As you’ve discovered, they most certainly do!
Other planetary comparisons you may want to read:
- Venus vs Jupiter [How Do The Planets Differ?]
- Venus vs Neptune [How Do The Planets Differ?]
- Mars vs Venus [How Do The Planets Differ?]
Hey, my name is Jeremy. I’m a passionate and seasoned astronomer who loves nothing more than observing the night sky. I also love researching, learning, and writing all things Space and the Universe. I created Astronomy Scope to share my knowledge, experience, suggestions, and recommendations of what I have learned along the way while helping anyone to get into and maximize their enjoyment of the hobby.