What planet is closest to earth right now? Has this question ever boggled you? Reading about the universe, the solar system, and the numerous galaxies can be overwhelming. It makes you feel like a tiny entity in a gigantic universe.
The earth’s position among other planets, its distance from them and the sun, and its similarity to other planets are some hot topics for which most people want answers. If you are wondering what planet is closest to earth right now, it could be either Venus or Mars, but most times, it’s Mercury. Keep reading to learn more.
What Planet Is Closest to Earth?
The obvious answer to which planet is closest to Earth will be either of the planets flanking the earth. So, it could be either Venus that comes before Earth — when you place them chronologically from the sun — or Mars that comes after Earth.
So, to find out, you need the following readings:
• Radius of Earth’s orbit (RE)
• Radius of Venus’s orbit (RV)
• Radius of Mars’s orbit (RM)
To find the distance between any two planets, you need to subtract the smaller radius from the bigger radius. Among the three planets, Venus has the smallest radius as it is closest to the sun, and Mars has the largest.
So, the distance between Venus and Earth is RE-RV, and the distance between Mars and Earth is RM-RE.
On subtracting, the smaller value will be the closest pair. And among the two, that’s Venus. So, the correct answer must be Venus.
But when you ask what planet is closest to earth right now, Venus may or may not be the right answer. But it is not Mars, either.
So, which planet is closest to the earth, if not Venus or Mercury? And why is the above reasoning not giving us the right answer?
The thing is, Venus is closest to Earth when you put the planets in a straight line. And in reality, that is never the case. Earth will cross paths with Venus only for minimal durations and after determined periods. So, Venus will not be close to Earth at any given time, as it can be anywhere in its orbit, even diagonally opposite to Earth.
To understand the concept thoroughly, you need to consider the full picture. You need to take into account the mutual position of the planets throughout their orbital journeys.
So, let’s see why and why not Venus.
As mentioned above, Venus has the smallest orbital gap to Earth. It is technically the closest planet to Earth and gets closer to it than any other planet can ever get. When the two planets are closest, they are 23.6 million miles apart, the closest any planet ever gets to Earth.
But Venus has its own orbit, and it can get as far as 160 million miles while orbiting. This is when Venus is on the opposite side of the Earth from the Sun. So, Venus, at any given time, can be anywhere between 38 and 160 million miles away from the earth.
So, when Venus is this far, some other planet is closer to Earth. Could it be Mars?
You will be amazed to know that at its closest, Mars is 33.9 miles away from Earth. But when it is far, it can get as far as 249 million miles.
So, whether it is Venus or Mars, the closest planet to Earth is the one whose orbit is in direct alignment with the orbit of the Earth.
So, can both Venus and Mars be quite far away from Earth? Yes, and this is the case most of the time.
When this happens, the closest planet is the one with the smallest orbit — Mercury.
It is closest to the sun and thus has the smallest orbit (it has an orbit of just 88 days!) This means it completes one full rotation around the Sun in just 88 days), which aligns it with all the other planets in the system quite frequently.
So, even though it may not be closest to Earth, it is never very far either. And this is the case with almost every other planet in the Solar System. Mercury is the closest planet to virtually every other planet.
Confused? Let’s dig a bit deeper.
You may have understood how Mercury overtook Venus and Mars, taking the number one spot in the competition for the closest planet to Earth. But understanding how it is closer to other planets may be confusing.
As the planets move farther from the sun, their rotational orbits also increase. So, their orbits are so big that their adjacent neighbors may take hundreds of years to cross paths. Mercury has a small orbit, aligning itself with the planets more frequently. So, Mercury is often the closest planet to the Sun, Jupiter, Mars, Venus, Saturn, Neptune, and Uranus.
So, when you calculate the shortest distance between two planets, the least distant or the nearest will be either of the adjacent planets. But the shortest distance in real time is Mercury for most planets, including Earth. This is because of Mercury’s proximity to the sun and its small orbital radius, as a result.
So, on average, Mercury is closest to Earth. So if anyone asks you which planet is closest to Earth right now, the right answer will most often be Mercury.
To understand better, here is the orbital distance of the planets:
• Mercury: 88 days.
• Venus: 224 days.
• Earth: 365 days.
• Mars: 1.88 years.
• Jupiter: 11.86 years.
• Saturn: 29.46 years.
• Uranus: 84 whole years.
• Neptune: 164.79 years.
• Pluto: 248.59 years.