They say "a journey of a thousand miles begins with a single step." Well now you can go much farther. And all it takes are a few clicks of the mouse with Starry Night and SkySafari. This is a journey from your backyard to the farthest reaches of the universe. Here, each successive step increases your distance from the ground by a factor of ten.
A backyard or park, much like yours . . .
Lifting off from the surface of the Earth. Hovering ten meters (33 feet) above the ground. Looking down, objects on the surface appear a bit smaller but not by much.
Elevator going up, ladies and gentlemen, by another factor of ten. Things begin to look really tiny when you look down. It's like being on the 27th floor of a high-rise building.
Now, your virtual observation deck is twice the height of one of the world's tallest freestanding structures—the CN Tower in Toronto (553 meters / 1,814 feet).
At this elevation you might bump into a glider plane or two. PS - Help us spread the word about the amazing New Horizons mission to Pluto by downloading our free, kid-friendly, Pluto Safari app for iOS and Android.
At this altitude you'd better have your own oxygen supply. Here you stand eye to eye with climbers of Everest, the highest mountain on Earth. From this height, the curvature of the Earth is readily apparent. Commercial jets cruise at these altitudes.
You are looking down on your backyard from a height one-quarter of the distance to the International Space Station.
Anyone who flies this high gets to be called an astronaut (or a Russian cosmonaut, or a Chinese taikonaut). In the early 1960s, the U.S. X-15 Aircraft was flown up to 108 kilometers (64 miles). The pilot received his "astronautical wings," in recognition of becoming an astronaut.
Large portions of the continents become visible.
Thousands of artificial satellites are in orbit around the Earth at this height: satellites for communications, environmental sensing, weather prediction, global positioning systems, and scientific research. There is even a LightSail up there!
From this perspective, they are brighter than many of the stars in the background. Of course, satellites don't emit light on their own; we see them because they reflect light from the sun.
At this distance, the Earth, our home in space, fills the view.
It's about 12,760 kilometers (7,656 miles) in diameter—the fifth-largest planet in our solar system.
As it spins counterclockwise on its axis, its residents experience night turning to day turning to night . . . But you're now up in the realm where night and day have no meaning.
You are now just over a quarter of the way to the moon. Only the Apollo astronauts have ventured this far out into space. In 1969, Apollo 11 astronauts Neil Armstrong and Buzz Aldrin became the first humans to set foot on another world.
Our moon orbits the Earth in 29.7 days at an average distance of 384,000 kilometers (230,000 miles).
The orbit of the Earth around the sun looks like a nearly straight line at this distance, although you probably know that it's really a huge ellipse. That's it there, running from lower left to upper right.
Notice, too, that the moon orbits Earth in a counterclockwise motion; the same direction that Earth rotates and revolves!
Now the Earth is becoming the "pale blue dot" written of by Carl Sagan and Ann Druyan.
Many Near Earth Objects (NEOs) pass through this region of space. And several groups of astronomers have begun systematic searches to detect NEOs that may threaten Earth.
An object two kilometers (1.2 miles) or larger likely strikes Earth about once every million years on average. The asteroid that struck Mexico's Yucatan peninsula 65 million years ago may have been responsible for the extinction of the dinosaurs.
You are now seeing the Inner Solar System and the orbits traced out by Mercury, Venus, Mars, and Earth. Our home world orbits the sun at an average distance of 150 million kilometers (93 million miles).
The region between the planets is mainly empty space. There are some particles of dust and molecules of gas very sparsely sprinkled between the worlds. But there are also a few thousand small asteroids that have come together from the material left over from the formation of the inner planets.
You can see more of those asteroids now. Most of them cruise in a ring called the Main Belt flanked by the orbits of Mars and Jupiter.
The Main Belt lies between 2 and 3.5 AU from the sun (that's between two and three-and-a-half times Earth's average distance from the sun).
Astronomers once thought that the Main Belt was the debris from a destroyed planet. This turns out not to be the case. Scientists now think that Jupiter's gravity prevented a planet from forming out of the initial clump of matter in this region of the solar system.
All the planets in our solar system come into view. But at this distance, only Jupiter and Saturn would be visible with the naked eye.
Faraway dwarf planet Pluto orbits the sun at an average distance of 5.9 billion kilometers (3.7 billion miles). Pluto was the first of a large collection of small worlds, now known as the Kuiper Belt, to be discovered.
Dr. Kuiper's Belt begins just outside the orbit of Neptune, at a distance from the sun of 30 to 100 AU. There are probably more than 35,000 objects here with diameters greater than 100 kilometers (60 miles). There could be 100,000 or more!
You can follow the historic New Horizons mission to Pluto with our free Pluto Safari app for iOS and Android.
Most periodic comets—those that return on predictable orbital timetables—come from the Kuiper Belt. The most famous example is Comet Halley.
Here, all the planets are hidden in the glare of the sun and invisible to the naked eye.
Now the sun is but a bright dot among other stars. You have entered the region of the Oort Cloud. This is the remnant of the original cloud of dust and gas that formed our solar system.
In the five billion years since it first came together, that dust and gas has slowly been building itself into deep-frozen comet cores, probably billions of them! But they're all much too far away to be seen with any telescope we've built yet.
Once in a very long while, a passing star—or other disturbance in the force . . . of gravity!—jostles a comet core loose and sends it on a trajectory towards the sun.
As these so-called non-periodic comets move toward the sun, they pick up speed and can enter the region of the planets traveling at incredible speeds!
Worse, they can hit a planet (like Earth) moving in a direction opposite to the planet's motion around the sun and add the planet's speed to the force of the impact.
All this makes them very dangerous characters, indeed, and very difficult to predict because, although they may actually be periodic, their orbital period may be more than one million years!
Welcome to the void between the stars. You are about one light-year from the Earth. It takes light one year traveling at nearly 300,000 kilometers (186,000 miles) per second to make it this far. This region is vacant. Scientists call it very hard vacuum.
You've arrived at a distance of about ten light-years from your backyard. The sun's nearest neighbors live here; a community of eleven stars.
Closest to the sun is Proxima Centauri—or at least that's what we humans call it. If there's anybody living in the P. Centauri system, they probably have a different name for their star. Actually, we should say their stars. All of the stars here—except the sun—are multiple stars. Each has a companion star locked with it in a dance of gravity.
The neighborhood has become a town. Thousands of stars, including our sun, make their homes within this distance.
At about 1,000 light-years, you can begin to see a large chunk of the Orion spiral arm of our galaxy, the Milky Way. Spiral arms are named according to the constellation in which they appear brightest. So the sun is said to be located in the Orion Arm of the Milky Way galaxy. This region is also home to the Great Orion Nebula.
But, you are about to leave the disk of the Milky Way.
You are hovering outside the disk of the Milky Way galaxy. The cluster of stars you see inside it represent the 100,000 or so closest stars to the sun. These are all the stars for which we have accurate information. Everything else you see here is a guess, based on the overall shape of the band of light in the sky we know as the Milky Way.
Seen from high above, the Milky Way galaxy resembles a pancake with a bulge at the center. The pancake is about 100,000 light-years in diameter. The sun is 26,000 light-years—or about two-thirds of the distance—from the center of the pancake. In this part of the galaxy, the Milky Way is about 3,000 light-years thick.
The stars in our galaxy orbit around its center in much the same way the planets move around the sun. But they actually bob up and down—like horses on a merry-go-round!
The time it takes for a star to make one trip around the galactic core depends on its distance. The sun, moving at 250 kilometers (150 miles) per second, takes a whopping 220 million years to make one trip. The sun, and hence our solar system, has made fewer than 25 such journeys since its hydrogen-fusion fire ignited.
Our Milky Way is not alone; it is not the "island universe" once envisioned by astronomers and philosophers. But it is "the biggest animal in the valley." And, that animal is a predator! Our Milky Way is right now actually gobbling up at least two smaller galaxies.
Of those that haven't yet been "eaten," the closest is called the Canis Major Dwarf. A bit further out you find the Large and Small Magellanic Clouds. These small, irregular galaxies are less than 200,000 light-years away. All the galaxies are collectively known as the Local Group.
But beyond the Local Group, all the other points of light you are seeing are actually thousands of other galaxies. The space between them is a very, very hard vacuum.
Making the next jump to a distance of ten million light-years from where you started, we now see a cluster of several hundred galaxies.
This condensation of gravitationally bound galaxies is known as the Virgo Cluster. At its heart is a truly huge elliptical cannibal of a galaxy that's been eating everybody it can get.
Jumping now to the almost unimaginable distance of 100 million light-years, you can clearly see clusters of galaxies and clusters of clusters (called, naturally, super-clusters).
But notice that the clusters are either clumped together in groups, or connected to one another by long thin filaments. And between them there are huge bubbles of absolutely nothing! The bubbles are called voids and contain the most perfect vacuum known—only one lonely atom per cubic meter.
You are actually seeing the very structure of the universe itself; a foamy texture often called the cosmic web.
There's more: You are now viewing a cube that encompasses 700 million light-years of space. Every point is a galaxy of a group of galaxies. 700 million light-years sounds like a huge volume of space—and it truly is. But it's only three percent of the total volume of the universe (we think)! Just three percent of the way to the beginning of time . . .
But wait! The cube seems to have a wedge-shaped section taken out of it. Is this some deep structural defect in the universe?
No, it's an illusion; it is what scientists call "an artifact of the data." It's happened because what you're seeing here is all that we can see from the vicinity of Earth.
And we cannot see through the dense core of our own galaxy, the Milky Way. So the "butterfly" or "wedge" is actually just missing data. We're pretty sure there are galaxies there, but we won't be able to see them until we can send a telescope a few million light-years away from Earth. Or, maybe, until we hear about it from the intelligent extraterrestrial astronomers via the intergalactic Internet . . .
No, it's not over yet.
Welcome to the unknown.
Our telescopes are not powerful enough—nor our understanding of physics complete enough—to peer into the region where space-time itself is curved. This is the edge, if there is an edge. This is the end, but it's also where time began . . .
... ok, you can come back to your backyard now.
If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app. It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.
Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram.