The Sun’s gravity holds together our Solar System, keeping planets, asteroids, meteoroids, as well as microscopic debris in orbit around it. At its core lies nuclear fusion processes which turn hydrogen into helium; all this heat makes up our star.
This video from BBC Planet Earth series, hosted by David Attenborough.
Volume
Comparing planet sizes is crucially dependent upon their volumes as much as on their diameters; their space-occupying abilities play a pivotal role in how much heat energy remains from their formation billions of years ago, thus increasing mass and speeding rotation on its axis.
Our star, the Sun, is by far the largest object in our solar system with the greatest volume. Accounting for 99.8 percent of its mass and roughly 109 times bigger than Earth, Sky at Night Magazine noted that even if all Earth were compressed into one sphere it would still only constitute one millionth of Sun’s volume!
Planet volumes are determined by their composition and assembly process. Earth, for instance, is made up of rock and ice with an atmosphere made up primarily of water comprising about 2/5 of its volume; remaining gasses include nitrogen and oxygen.
Planets are nearly perfect spheres; however, those which spin rapidly often bulge slightly at their equators due to inertia pulling material away from its rotation axis and leading to noticeable differences at their equators. Saturn and Jupiter can easily be recognized with their Great Red Spot or rings of plasma; consequently their volume can often be determined using this formula: volume = (p/6)x diameter cubed
Jupiter, for instance, has an 11 times larger diameter than that of Earth and boasts 343 trillion cubic miles in volume – meaning over 1300 Earths could fit inside Jupiter according to NASA estimates.
Uranus and Neptune do not compare closely in size with Earth; however Venus stands out as being closer. With an estimated volume of 1.08×1012 cubic kilometers, Venus could contain nearly 63 Earths; enough space to cover every grain of sand!
Mass
The Sun is an immense ball of fire, yet not the biggest star in our galaxy. Its diameter is 936 times greater than Earth but only has one fifth of its volume – enough room to fit over one million Earths inside its interior!
The Sun derives its energy from nuclear fusion in its core, where hydrogen atoms combine to form helium, producing tremendous amounts of light and heat as well as heavier elements like carbon, oxygen, nickel and aluminium that make up our universe. Stars like our Sun are responsible for creating all these heavier elements.
A planet’s mass is defined as its density or how much matter it contains, with orbital paths having an effect. A popular way of describing this number is as its total mass which includes any natural satellites it may possess.
Gravitational force of attraction between two objects is directly proportional to their combined mass and inversely related to distance; its formula for measurement is F = G where M1 and M2 represent their masses and R is their distance apart.
For spherical objects, the total mass can be easily represented by their center of gravity (CoG). The CoG for Earth can be found approximately 34 of its radius away from its surface.
Even as our Sun loses mass through nuclear fusion, this does not directly impact planets such as Earth. Indeed, Earth stands alone amongst Solar System planets in its ability to sustain liquid water on its surface due to its high density – thus making conservation of resources and environmental protection so crucial.
Diameter
Understanding the diameter of Earth is essential when studying this vast celestial body. This measurement indicates how far light from the Sun can reach from its surface; larger planets typically have greater diameters than their smaller counterparts; for instance, Jupiter has an impressive 3,100 mile (5,500 kilometers). Furthermore, its iconic Great Red Spot provides evidence of atmospheric activity within its orbital plane.
Scientists must first measure a planet’s equatorial and polar radius before being able to accurately determine its diameter. Unfortunately, due to mountains and ocean trenches which can distort this measurement process, measuring an accurate diameter requires using a standard formula that adds together these two measurements until arriving at an average or mean diameter.
Eratosthenes, an ancient Greek mathematician, made some calculations that came close to modern figures for Earth size; however, his numbers were 0.4% larger than what we know is true today. Additionally, there are regions on Earth such as mountains or oceans which alter planet’s radius calculations significantly.
Once we know the diameter of a planet, we can start to estimate how many Earths could fit inside of the Sun. While our Sun is unquestionably the biggest object in our solar system, compared with all of the hundreds of billions of other stars comprising our Milky Way galaxy it would require approximately 1.3 million Earths to fill its volume.
To put things into context, 57 Earths would be needed to cover the volume of Neptune, our fourth largest rocky planet in our solar system; but keep in mind this number does not include empty space within its orbit. Meanwhile, 8 Earths would suffice in filling Saturn, our sixth-largest planet.
Radius
The radius of planet earth is an essential variable in many scientific calculations, including gravity, atmospheric studies and geodesy. It also plays an integral part in navigation systems and satellite orbits as well as helping us gain a better understanding of the structure and size of our solar system. A planet’s radius can be calculated by dividing its diameter by circumference at some perpendicular point to Earth’s surface – however as its radius varies across its circumference. Also since our world is rounder than a globe its radius increases at certain locations with greater equatorial radius being slightly larger than its polar radius compared with our own solar system!
The Sun is one of billions of stars in our Milky Way galaxy and can be classified as medium-sized due to its size and mass relative to others. It generates enough gravitational force to keep all planets orbiting it – including our Earth! To match its mass, Earth would need to be approximately 3.3 million times larger in terms of both diameter and volume.
Even though it’s difficult to accurately measure the Sun, we do have an idea of its diameter and radius. The Sun is almost perfectly circular with only slight deviation between its equatorial radius and polar radius differences (6.2 miles/10 km). Furthermore, on average the distance from its center to the rim of its disk averages 864,450 miles (1.392 million kilometers).
The Sun is made up of seven elements in addition to hydrogen and helium; these include oxygen, carbon, neon, nitrogen, magnesium and iron. Its core can reach temperatures exceeding one million degrees Celsius, where nuclear fusion takes place which converts simple hydrogen molecules into heavier elements such as helium. Stars perform this fusion process throughout their lives in order to generate energy and remain alive.
The Sun continues to expand and heat up as its core converts hydrogen to helium, and will eventually reach its helium-burning stage and transform into a red giant, becoming so large as to engulf Mercury, Venus, and Earth in its embrace.