Sun Distance to Earth: Key Physics Explained

We know that our solar system is huge and found to be one of the massive systems in the milky way galaxy. In the solar system, the sun is found to be at one of the foci and all the planets are revolving around it in their respective orbits. There is a lot of empty space between the planets, and they are at a specific distance from the sun (which is measured in the astronomical units of light-years). 

The influence of the sun is found to be strongest on these planets and all other celestial objects, for example, voyager-1 which was launched 40 years ago is still orbiting and couldn’t escape from the influence of the sun. Our planet Earth orbits around the sun at an average of 92,955,807 miles (which is about 149,597,870 kilometers). The sun distance to earth or the distance from the earth to the sun is also known as an astronomical unit, or AU, which is used to measure distances throughout the solar system. 

In this article, we will learn about the what is distance between earth and sun and how to measure it, and we will make a note of the pattern of the sun and earth distance, i.e., whether is the distance between sun and earth decreasing, or increasing, etc. 

What Is The Distance Between Earth And Sun?

When we study our solar system we notice that the planets are not random but placed in a particular order, planets close to the sun to planets away from the sun, every planet is having a specific distance from the sun. According to Kepler’s law of planetary motion, we know that the sun is considered to be placed at one of the foci and all other planets are revolving around the in an elliptical orbit. All these elliptical orbits are placed at a particular distance measured in terms of astronomical units. 

Now, what is the distance between earth and sun? The distance between the earth and sun in cosmological terms is known as the astronomical unit and it is abbreviated as the AU. An astronomical unit (AU) is found to be around 93 million miles (150 million kilometers), which is approximately 8 light minutes.

⇒ 1AU = 92,955,807 miles ≈ 93 million miles

Since Earth’s orbit isn’t perfectly circular, but it’s oval in shape, thus the Earth’s distance will be changing throughout the year. Many cosmologists have said that the Earth’s changing distance throughout the year is relative to the astronomical unit, too. For example, when the Earth is at perihelion, which is its nearest position to the sun for the year, in January, and at this point, the sun and distance are about 0.983 AU from the sun. When our planet reaches the position of the aphelion which is its farthest point and it will be in July. At the aphelion, the sun and earth distance are about 1.017 AU away from the sun.

Drifting of the Earth-is Distance Between Sun and Earth Decreasing?

Our solar system is filled with amusing facts and processes one such amazing fact is the drifting of the earth, i.e., is the distance between sun and earth decreasing?

According to a recent cosmological report on January 3, 2019, the Earth reached the point of its orbit closest to the Sun: perihelion. Each object orbiting a single mass (such as our Sun) forms an ellipse, containing the closest approach point that is unique to that particular orbit, known as periapsis. For the past 4.5 billion years, the Earth has orbited the Sun in an ellipse, as have all the other planets orbiting their stars in all other mature solar systems in the galaxy and the Universe. 

But there is something you might not expect or appreciate that happens anyway: the orbital path of the Earth does not stay the same over time, it spirals outward. And in the year, 2019, our perihelion was 1.5 centimeters which were higher than the previous year, which was farther than the previous year, etc. It's not even just the Earth; each planet is moving away from its parent star.  

The force responsible for each planet's orbits around each solar system in the Universe is the same: the law of universal gravitation. Whether you look at it in Newton's terms, where every mass attracts every other mass in the Universe, or in Einstein's terms, where mass and energy fold the fabric of space-time through which other masses travel, the larger mass dominates. the orbit of everything influences. . 

If the central mass did not change and was the only factor in play, the force of gravity would remain constant over time. Each orbit would continue forever in a closed and perfect ellipse, and would never change. 

Of course, that's not what happens. There are other masses present in every solar system: planets, moons, asteroids, centaurs, Kuiper belt objects, satellites, and more. These masses serve to disturb the orbits, causing them to process. This means that the closest point of approach - periapsis in general or perihelion for one orbit relative to our Sun - rotates over time. 

(Image will be uploaded soon)

Orbital mechanics, in various ways, influences the precession of the equinoxes. The Earth, for example, had its perihelion and December solstice aligned just 800 years ago, but they are slowly separating. With a period of 21,000 years, our perihelion precedes in such a way that it alters not only the closest point in our orbit but also the position of our polar stars.

Today, the Earth (and all the planets) are so far from the Sun and surrounded by so little matter that an inspired time scale is trillions to quadrillion times longer than the current age of the Universe. Since the protoplanetary disk completely evaporated about 4.5 billion years ago, there is almost nothing left to dissipate our angular momentum. The biggest effect that contributes to our inspiration is the emission of the solar wind, that is, of the particles of the Sun, which collide with our planet and stick together, making us lose some angular momentum. 

In general, the Earth does not even spiral towards the Sun; it is rotating outward, away from him. So are all the planets of the Solar System. With every passing year, we find individually slightly (1.5 centimeters, or 0.00000000001% of the Earth-Sun distance) farther from the Sun than the previous year.

Did you know?

• With a diameter of 109 times the size of the Earth, the Sun forms a very large sphere. You could fit approximately 1.3 million Earths inside the Sun, in other words, we can flatten 11,990 Earths to cover the Sun's surface. It's big, but there are much larger stars out there. For instance, the largest star we recognize would almost reach Saturn if it were placed within the Solar System.

• It takes eight minutes for sunlight to reach the earth. The average distance from the sun to the earth is about 150 million km. Light travels at 300,000 km per second, so it divides 500 seconds into one: eight minutes and twenty seconds. This energy can reach the earth in a few minutes, but it takes millions of years to get from the core of the sun to its surface.

This is all about what is distance between earth and sun and how to measure it, drifting of the earth (is distance between sun and earth decreasing), Astronomical unit, etc…