Relative Sizes of the Planets and the Sun: Diameter of Earth - Windows to the Universe
Compare sizes for the planets and sort them by order from the Sun or by size. Planets' Number of moons, distance from the Sun and Earth, and composition. Moon Phase ChartMoon phases visualized in real time, the past or the future. miles, and 1 inch = cm ( meter) if you want to convert any units.) (That way you can ask the audience how big the moon is relative to the earth and Table 2a Solar System Scaled to 3-inch Sun Parameter Real Distance/ Size . Geographic magazine, written by K. F. Weaver and J. P. Blair (no relation !). Astronomical unit (AU, or au), a unit of length effectively equal to the average, or mean, of half of the maximum diameter—of Earth's elliptical orbit around the Sun. A simple trigonometric relationship incorporating this angular value and the.
It would be about feet that way, or about 60 or 70 meters, 60 meters. So you can imagine if the sun was this size, sitting on something like a football field, this little speck of an Earth, this little thing right here, would be sitting on the other yard line, 60 meters away. So you wouldn't even notice it.
- Navigation menu
- Kean University Continuing Education
- Keep Exploring Britannica
You might notice this from a distance, but you wouldn't even see this thing over here. And the other planets are even further. Well, not all of the other planets. Obviously, you have Mercury. I think most of us are familiar with these. But I'll just list them here, just in case. Mercury is the smallest of the planets where it's not debated whether it's a planet. Pluto is the smallest, but some people debate whether it's really a planet or just a large solar body or a dwarf planet or any of those type of things.
But then you have Venus, probably the closest in size to the Earth. Or it is the closest in size to the Earth. And then you have Mars. And then you have Jupiter. And just to give a sense of, once again, how far these things are, if I were to go back to the analogy of this being the size of the sun, then Jupiter is five times further than Earth.
So this would be-- If I were to actually do the scale distance, this would be meters away. So if I had a nice, big, maybe medicine-balled-size sun right over here, maybe basketball-sized. A little bit bigger than a basketball, this looks on my screen-- then this little thing that's smaller than a ping pong ball, I would put this three football fields away.
That's how far Jupiter is. And then Saturn's about twice as far as that. Saturn is about nine times the distance. So let me make it clear. The Earth is one astronomical unit away from the sun, roughly. It's not a perfectly circular orbit. Jupiter is approximately a little bit-- 5 plus astronomical units-- a little bit more than five times the distance of the sun to the Earth. And Saturn is approximately nine astronomical units, or nine times the distance from the sun to the Earth.
So once again, this would be nine football fields away. Or another way to think about it would be, essentially, a kilometer away. If we had kind of a medicine-ball-size sun, this little smaller than a ping pong balled Saturn would be a kilometer away. And I just want to really reiterate that because you never visualize it that way. Because just for the sake of being able to draw it on a page, you see diagrams that look like this.
And they really don't give you a sense of how small these planets are relative to the sun, and especially relative to their distance from the sun. And then after Saturn, you have Uranus and then Neptune. And obviously, these guys are even further. And just to give you a sense, it's very easy to start talking about galaxies and universes and all of the-- or the universe. But I really just want to get-- already, what we've talked about, we're talking about huge distances, huge scale.
We already talked about that it would take a jet plane 17 years to travel from the Earth to the sun.
Sizes and Distances
Multiply that by five, about years to go from Jupiter to the sun, years to go from Saturn to the sun. So you could have had Abraham Lincoln get into a jet plane, and if he left from Saturn, he still would not have gotten to the sun. So these are huge, huge distances. But we're not done with the solar system, there. Just to give a sense of scale-- so this right here, that's the sun.
And each of these planets are actually narrower than these orbits. So they just draw these orbits here, but you wouldn't actually even see the actual planets here at this type of a scale. But this is one astronomical unit right over here, the distance from the sun to the Earth. Then you have Mars. Then you have the asteroid belt. There you have the asteroid belt, which also has some pretty big things in it, itself. And it has these things that are kind of considered almost dwarf planets, things like Ceres.
You could look those type things up. And then you have Jupiter out here.
Size Scales in Astronomy
And once again, we said it would take years, or roughly years, for a jet plane to get from Jupiter to the sun. But even if you take this whole box here-- which is a huge amount of distance, of roughly about five astronomical units-- it would take about 40 minutes for light to get from the sun to Jupiter.
So this is a huge, huge distance. But even this huge distance-- we can put it into this little box right over here. So this whole box right over there can be fit into this box. And you need to do that in order to appreciate the orbits of the outer planets.
And so on this scale, Earth and Venus and Mercury and Mars, their orbits look pretty much-- you can't even differentiate them from the sun. They look so close.
They almost look like they're part of the sun when you look at it on this scale. And then you have you have the outer planets-- Saturn, Uranus, Neptune. And they we have a Kuiper belt. And this is more asteroids, but these are kind of more frozen. And when we think of ice, you always think of water ice. But out here, it's so cold. And it's relatively getting dark, now, because we're pretty far from the sun that things that we normally associate as gases are going to be in their solid form out here.
So this isn't just rocky elements. This will also be things that we normally associate as gases, like methane, frozen methane. But even here, we're not done. We're not even out of the solar system yet. And actually, just to give you a sense of the scale we're operating right here, I have this chart right here from the Voyager mission. So the Voyager missions-- Voyager 1 and actually, Voyager 2 left a little bit earlier, a month earlier.
Voyager 1 is just traveling faster. At this point, depending on the audience and the overall goals of your presentation, you can take the further step of describing the relative size and distance of the sun on this same scale see Table above. Again, exact numbers are less important than the overall effect.
A distinctive landmark at approximately the right distance adds a nice touch. For instance from Hopkins Homewood campus I would probably say, "On this scale, the sun is a big ball of glowing gas about feet in diameter sitting in the Inner Harbor!
It can be used in conjunction with the above, or as a separate demonstration, again depending on size and age of audience and amount of time available. In this demonstration, we use the diameter of the sun as our yardstick, and look at the solar system on this scale.
The tables below gives some of the basic information for two different scalings of interest, although by no means do these both have to be used in a given presentation. Next nearest star 4.
Since we are interested in "relative" distances, I choose to keep the table as simple as possible and scale distances relative to this yardstick. Also, Pluto's orbit is relatively non-circular, so the number given is an average. Again, start by setting the stage: A tennis ball or lacrosse ball is about right, but I have also used a small orange or tangerine to good effect especially since the Florida Orange Growers Association would have us believe that oranges are "captured" sunshine!
Now go through a few steps from the table above. It is good to include the earth as a reference point, and Jupiter because it is the largest planet.
Including Saturn the next planet out from Jupiter is nice because it shows how quickly the distances get very large for the outer solar system, and Pluto, for better of for worse, is recognized as the most distant planet although no longer considered to be the "edge" of the solar system--but that is another topic.
That Pluto is more than three football fields away from the "orange" sun can be made even more effective if you are standing on or near a football field at the time! Also, reinforce the idea that these distances are the radii of the orbits--that each planet sweeps out a big "circle" in its trek around the sun. The zinger here, of course, is if you make the last step in the table above to the NEXT nearest star. Pictures of star clusters or nearby galaxies are misleading in a sense because the true distances between objects are not often placed in the proper context.
Our Galaxy, the Milky Way, is a huge spiral of stars aboutlight years across. The sun and its nearest stellar neighbors are quite similar in size and temperature, and so the "orange" remains a good size reference.
However, the distance is another matter altogether. Instead of using feet or football fields, we must increase the yardstick to miles or kilometers.
The next nearest star to the sun is another orange-sized object more than miles away! I leave the possibility of describing the size of the Milky Way on this scalely, which scales to 33 million miles! Other Scalings You can generate other scalings to your heart's content; really all you need is a good astronomy textbook with some numbers and a few props of the right approximate dimension.
Here I mention just two others: I have used the following scaling and effectively combined some highlights from both of the above demonstrations into one presentation with good results. In this one, we let the earth be scaled down to 3-inches instead of the sunwhich keeps most of the sizes and distances within the realm of understanding. I find it particularly effective to use an earth "ball" or paperweight with the continents marked.
Squishy earth balls of about the right dimension are available in many gift or toy shops at very reasonable prices. In this presentation, you can still do the "earth-moon separation" demonstration from above to good effect, but the "shuttle above the earth" part less than 0. Likewise, the nearest star beingmiles on this scale gets rather large, but in combination with Pluto being only 22 miles from the sun it may still have the desired effect.
As we try and step out from the regions adjacent to the sun, to the scale of our Galaxy, the nearby galaxies, and finally the distant Universe, it becomes very difficult for most people to fathom the true immensity of the distances involved.
Scale of solar system (video) | Khan Academy
Obviously "miles" or "kilometers" are no longer useful units, and even the venerable "light year" becomes only marginally acceptable. Even the nearest large galaxy, the "Andromeda" galaxy also known as Messier 31, or M31 is at a staggering distance of some 2 million light years away with the hopefully obvious connotation that the light from even this "nearby" galaxy takes about 2 million years to reach the earth!
That this distance is deemed almost inconsequential compared with the most distant objects known in the Universe, which are roughly 10 BILLION light years away or times the distance to our "neighbor," M31 should give an idea of the magnitude of the problem. To provide an inking of what these distances are like, I have used the following description with general audiences to good effect, especially in conjunction with one or more of the above to give it the proper perspective.
This has been adapted and updated from a section of an article called "The Incredible Universe," in the May National Geographic magazine, written by K. It is particularly timely given the recent release of a new, very sensitive image obtained with the Hubble Space Telescope showing an essentially "empty" region of sky to be literally littered with galaxies of all types, shapes and colors!
Estimates based on this image indicate that there may be 5 or more times as many galaxies in the Universe as was thought previously, based on the best available data!