ou probably know the size difference (in numbers) between Earth and the other planets, but if you’d like to see images and compare all, this is specially for you. Earth is the third planet from the sun. Did you realize that it was one of the smallest planets in our solar system? There are nine planets that travel around the sun. In order of distance they are Pluto, Neptune, Uranus, Saturn, Jupiter, Mars, Earth, Venus, and Mercury. Together with the sun they make up our solar system. We came across these images ( very low resolution ) in the web. The source for this material is unknown and it was submitted without attribution. We offer thanks to the originator of the images. However, the images are most helpful as a tool to determine the scale of stars and planets so we decided to include them in this short article. First of all, let’s take a look at the size of Earth in relation to the other inner planets plus Pluto, now considered a dwarf planet as noted in the image at left. You can see why Venus is considered Earth’s ‘sister planet’ as they are similar in size. That fact though, is about as close as one can get to saying they have much in common because after the size similarity they differ significantly.
This image has all nine planets in our solar system somewhat to scale. Even if one is aware of the relative size of the planets this remains a fairly remarkable comparison between the gas/ice giants (Jupiter, Saturn, Uranus & Neptune) and the rocky inner planets (Mercury, Venus, Earth & Mars). Pluto again is a bit of an exception being the last planet in our solar system and way out in the Kuiper Belt with the gas giants between it and Earth. Pluto is quite small in comparison to even Mars and Mercury as viewed in this image.
Trying to fathom just how large our star is can be rather difficult to impart to average folks. After all it’s a yellow dwarf with a spectral classification of G2 V and fairly common – it’s one of perhaps more than 100 million G2 stars in our galaxy. However, it alone accounts for 99.9% of the mass of our solar system. This includes all the planets, satellites (moons), asteroids, meteoroids, comets and a plethora of dust and anything else that’s out there. Another point that makes it far from ordinary, common or typical… It is the only known star that supports life.
The ‘G2’ classification of our Sun indicates it has a surface temperature of approximately 10,000° Fahrenheit, about the middle of the temperature scale for stars, giving it a white colour. Because of atmospheric scattering this colour appears yellow. This is a subtractive effect, as the preferential scattering of blue photons (our blue sky colour) removes enough blue light to leave a residual reddishness that is perceived as yellow. The Roman numeral ‘V’ indicates that the Sun is typical in its class and is a main sequence star. In the meantime take a look at the comparative size in the next image below; it’s quite impressive.
Now that you have some idea of the size of our Sun in relation to the balance of our solar system, let’s compare it to some other stars. The image at right compares our Sun with Sirius (Alpha Canis Majoris), Pollux (Beta Geminorum) and Arcturus (Alpha Bootis). The scale is fairly astounding in my view, what do you think? Note the size of ‘giant’ Jupiter (only 1 pixel in this perspective)… And Earth wouldn’t even register on this scale.
Last but not least in our ‘perspective’, let’s compare our Sun to a few large stars in the heavens as indicated by the image at left. Note our Sun is a mere spec compared to some of these bad boys and mighty Jupiter doesn’t even warrant a glimpse… Betelgeuse (Alpha Orionis – this star should actually be the Beta star in Orion; the Bayer designation is incorrect in this case as Rigel is slightly brighter) is an M2Ib red supergiant and physically one of the largest stars known. If Betelgeuse took the place of our Sun its outer surface would extend between the orbit of Mars and Jupiter. Antares (Alpha Scorpii) is also a red supergiant and extremely large – about 700 times the diameter of our Sun and one of the brightest stars in the heavens. If you can’t read the small print, from left it reads as follows: ‘Jupiter is invisible at this size’; the ‘Sun (1 pixel)’ has an arrow pointing to it; the three stars noted below Antares are Sirius, Pollax & Arcturus. In any event, we hope this helps a bit to clarify perspective sizes in our solar system and universe. We think these images will make a handy tool when discussing comparative sizes of objects.
