Many people assume that the planets get bigger and bigger the further they are from the Sun. Whilst it is true that the planets that are closer to the Sun (the terrestrial planets) are generally much smaller than those further out (the Jovian planets), it doesn’t always work that way. So with this being said, what about Venus and Earth; is the fiery yellow planet smaller than our own? That’s what we’re going to take a quick look at.
How big is Venus compared to Earth?
Earth has a radius of 3959 miles, whilst Venus has a radius of 3760 miles – this means that Earth is larger than Venus, but only marginally. In fact, Venus is often referred to as earth’s twin or sister planet, as the size, mass and composition of the two are so similar to one another.
The radius is typically the best thing to look at if we want to see how large a planet is. In relation to both Mars and Mercury the smallest planet, Both Earth and Venus are significantly larger. However, they’re still both less than a quarter of the size of Uranus, which is actually the smallest of the four Jovian planets (Uranus, Neptune, Saturn, Jupiter).
We can also measure Venus and Earth against each other in a couple of different ways too, but looking at both their mass and their volume. The mass of the two planets is also very close to one another, with Venus having a mass of 4.867 × 10^24 kg, whilst Earth’s mass is very slightly more at 5.972 × 10^24 kg. So, there’s very little difference here too.
For the volume, the planets are again close, with Venus having a volume of 928.45 billion cubic km. When compared to Earth’s 1083.21 billion cubic km (just over a trillion), it’s easy to see why these two planets are often called twins. You can read more cool things about Venus, or stick with us and see how Venus and Earth are not always considered to be alike.
How are Venus and Earth different?
So, we can see here why the planets Venus and Earth are so similar to one another. There are many other celestial objects in the night sky, and NASA’s Magellan spacecraft discovered more on its way from Earth to Venus. But the truth is that no two planets are that alike, and there are some massive differences between us too, especially with Venus as it’s so different to that of Earth.
The first thing to take into account is the atmosphere. Earth actually has quite a thick atmosphere in comparison to Mercury and Mars, where it is almost non existent due to solar winds. But when it’s put up against the atmosphere of Venus, it doesn’t really compare. The atmosphere that surrounds Venus is much thicker than that of Earth’s, and it’s almost entirely made up of carbon dioxide.
It’s because of the atmosphere of Venus that it has such a dramatically different temperature to our planet Earth. It has the highest average surface temperature of any of the planets in our solar system, so it’s no surprise that we’re looking to go the other way when it comes to landing on a planet.
Although we have sent spacecrafts to the planet, landing on Venus with a manned craft would be impossible. This is because the dense atmosphere ends up making the planet extremely hot – if the planet had a thin atmosphere then it’d be much more possible for humans or other living beings to inhabit the planet.
One of the strangest things about Venus in comparison to the other planets is that it actually rotates in the opposite direction that it’s orbiting the Earth, which we call a retrograde rotation. It’s likely that this is a result of Venus’ close proximity to the Sun, which has a strong gravitational pull on the planet and therefore affecting its orbital pattern. It’s thought that at some point in time, the planet actually rotated in the same direction as the Earth and most other planets.
In conclusion, Earth is a little bigger than the smaller planet Venus, but it’s close. There are still things that we aren’t 100% sure on, like the inner compositions of Venus; however, astronomers think that it’s probably very similar to the inner core and mantle we have on Earth, as many of the other features the planets share are so similar.