Humans have always dreamed of traveling through space, fascinated by unknown worlds and the desire to explore distant galaxies. The greatest obstacle to space travel is the vast distances. From our human perspective, it isn't easy to comprehend how enormous the universe is. Therefore, in this article, we aim to illustrate the immense size of the universe, and the best way to do that is by calculating how long it would take to travel to different objects in space using various modes of transportation and spacecraft.
How long would it take to reach nearby planets or the nearest star if we could travel through space by car? How long would commercial airplanes travel to the Moon or Mars take? How fast is the fastest spacecraft ever built by humanity? If we could travel at the speed of light, how much would travel time be shortened, and how deep into space could we venture? How fast are the spaceships from the popular Star Trek franchise? How long would it take to travel aboard Captain Picard's powerful Enterprise to the nearest star? The answers to all these questions and much more are brought to you in this article.
Traveling through space in a car
Let's imagine that we can travel through space in a car. In many countries, the maximum speed limit on highways is 130 km/h or 80 mph, so we used this speed for our calculations. Among the space destinations, the only one we could reach by car is the Moon. The journey would take approximately 123 days. Traveling to Mars would take a long 48 years when Mars is closest to Earth. The journey could extend to 352 years when Mars is farthest from Earth. The New Horizons spacecraft took 9.5 years to reach Pluto, the dwarf planet at the edge of the solar system. By car, this journey would take at least 3,750 years. Proxima Centauri, the nearest star, is 4.24 light-years away from Earth. It would take 35 million years to drive to this star by car.
Pluto Colorful Composition. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Traveling through space in a commercial airplane
Most large commercial airplanes cruise up to 900 km/h (around 560 mph). If we fly through space in an aircraft, it would take 17.8 days to reach the Moon, 6.92 years to reach Mars, and 748 years to reach Pluto. The journey to the nearest star, Proxima Centauri, would take 5.09 million years. A plane ticket for this trip would undoubtedly be expensive.
Voyager 1 – The fastest human-made spacecraft traveling through space
Voyager 1, launched in 1977, is the fastest spacecraft created by humanity, traveling through space at approximately 61,000 km/h (around 38,000 miles per hour). However, Voyager 1 is not the fastest spacecraft ever built. The Parker Solar Probe reaches speeds of 700,000 km/h (about 430,000 miles per hour), but that speed is only achieved when it is closest to the Sun, using the Sun's gravity for acceleration. On the other hand, Voyager 1 is traveling through space and is currently the farthest human-made object from Earth. Voyager 1 left the heliosphere in 2012 and is now in interstellar space, more than 24 billion kilometers from Earth.
Voyager 1 Entering Interstellar Space Artist Concept. Credits: NASA/JPL-Caltech
So, how fast is Voyager 1, and how long would it take to travel through the vast cosmic expanses? Voyager 1 could travel from Earth to the Moon in about 6 hours at its current speed. The journey from Earth to Mars would take a manageable 37 days when Mars is closest to Earth, and the journey to distant Pluto would take eight years. Reaching Proxima Centauri, the nearest star to Earth, would take an astonishing 75,000 years. These calculations show that our current technological capabilities are barely sufficient for exploring the solar system and mostly without human crews. Perhaps shortly, we will be able to send humans to Mars, the planet closest to Earth. For now, our technology is not advanced enough to send probes to the nearest stars.
Traveling at the speed of light
The speed of light in a vacuum is approximately 299,792 km/s (about 186,282 miles/s), roughly equivalent to 1.08 billion km/h (around 671 million miles per hour). According to the laws of physics, as described by Einstein's theory of relativity, this is the maximum possible speed.
A Cauldron of Stars at the Galaxy Center. Credit: NASA/JPL-Caltech
According to relativity, it is theoretically impossible for objects with mass, such as spacecraft or humans, to travel at the speed of light. As an object's speed increases, its mass effectively grows, requiring ever more energy for further acceleration. According to current scientific understanding, accelerating a massive object to the speed of light would require infinite energy, making such travel impossible.
Let's disregard the laws of physics for a moment and assume that traveling at the speed of light is possible. If humanity had a spacecraft capable of traveling at the speed of light, how far could we go in space? Would the entire universe be within our grasp? Since the speed of light brings new possibilities, let's add a few more interesting objects in space to our list of potential destinations.
The star Tau Ceti is about 12 light-years from Earth and is very similar to the Sun. It is known for having a large debris disk and several potential exoplanet candidates, some of which are located in the habitable zone. This makes Tau Ceti one of the closest and most accessible systems for the search for potential life beyond our solar system.
Gliese 667 Cc is an exoplanet orbiting the red dwarf star Gliese 667 C, part of a triple star system about 23.6 light-years away. Gliese 667 Cc is a super-Earth located in its star's habitable zone, meaning liquid water could exist on its surface.
The nearest black hole, V616 Monocerotis, is 3,300 light-years from Earth.
The center of our galaxy is 26,000 light-years away. The center of the galaxy is located in the direction of the constellation Sagittarius, where the supermassive black hole known as Sagittarius A* is found.
Andromeda is the closest large galaxy to the Milky Way, and according to astronomical estimates, it is approaching our galaxy, potentially colliding with it in a few billion years. The distance from Earth to the Andromeda galaxy is approximately 2.537 million light-years.
At the speed of light, it would take just 1.28 seconds to reach the Moon, 3 minutes to reach Mars, and 4 hours to reach Pluto. The speed of light would be ideal for fast travel within the solar system. But is the speed of light enough for interstellar travel? Proxima Centauri, the nearest star to us, is 4.24 light-years away. This means that light takes 4.24 years to reach Proxima Centauri, and the return journey would take the same time. Such journeys could have human crews, but passengers on such a spacecraft would have to spend a significant portion of their lives in space.
At the speed of light, a journey to the star Tau Ceti would take 11.9 years, and to the exoplanet Gliese 667 Cc, 23.62 years. It would take 3,300 years to reach the black hole V616 Monocerotis, 26,000 years to reach the center of our galaxy, and 2.537 million light-years to reach Andromeda.
There are about 50 stars within a radius of 15 light-years from Earth. A spacecraft capable of traveling at the speed of light would allow us to explore this part of space, most likely with unmanned probes. We can conclude that traveling at the speed of light would allow us to explore the nearest stars but not to travel to the farthest parts of the Milky Way or other galaxies.
Faster-than-light travel
In the globally popular science fiction series Star Trek, spacecraft travel at speeds much greater than the speed of light. This is made possible by the fictional warp drive. The warp drive in Star Trek allows starships to travel faster than light by creating a "bubble" that warps space-time around the ship. This way, the starship does not violate the laws of physics that prevent faster-than-light travel within space but instead moves the space-time around itself. Although this drive is fictional, scientists have developed a theoretical model of a drive based on a similar idea.
The Alcubierre Drive
The Alcubierre drive is a theoretical concept that proposes a method for faster-than-light travel by warping space-time. According to this idea, a spaceship would not actually travel faster than light, but it would create a "bubble" around itself that contracts space-time in front of the ship and expands it behind. In this way, the starship would effectively move through space-time while remaining stationary relative to the space within the bubble. The theory suggests the need for exotic matter with negative energy, which scientists have yet to discover or create. You can read more about the Alcubierre drive here.
Star Trek and Warp Drive
While scientists are solving all the obstacles to building the Alcubierre Drive, let's return to Star Trek and travel at warp speeds. In Star Trek, starships traveled using warp drives. As technology advanced, warp speeds became faster. Warp 1 allows for travel at the speed of light, Warp 2 is ten times faster than the speed of light, Warp 3 is 39 times faster, and so on. We selected three well-known Star Trek starships for which data on their maximum speeds is available. Although starships in the series could not continuously travel at maximum warp, we will use the maximum speeds they are capable of for our calculations.
The starship of Captain Jonathan Archer from Star Trek: Enterprise
This ship is designated NX-01. It is the first ship in the Enterprise series, crucial for space exploration and laying the foundation for the future Federation. Its maximum speed is Warp 5, which is 214 times faster than the speed of light. With this Enterprise, the journey from Earth to Pluto would take only a minute and a half. It would take seven days to reach the nearest star, Proxima Centauri. The trip to the star Tau Ceti would take 20 days and 39 days to get the exoplanet Gliese 667 Cc.
It would take us 15 years to reach the nearest black hole, V616. The journey to the center of our galaxy would take 121 years, while the trip to Andromeda would still take a staggering 11,853,271 years.
This ship could cover approximately 17 light-years in 30 days. Within a radius of 17 light-years from Earth, there are approximately 50–60 star systems with about 100 stars.
The starship of Captain Jean-Luc Picard from Star Trek: The Next Generation
Captain Jean-Luc Picard's starship from Star Trek: The Next Generation was the USS Enterprise (NCC-1701-D). It was the fifth ship in the line to bear the name Enterprise and is one of the most famous ships in the Star Trek franchise. Its maximum speed is Warp 9.6, which is 1,909 times faster than the speed of light.
Picard's Enterprise would reach Proxima Centauri in just 19 hours and 28 minutes. It would take only about two days to reach the potentially interesting star Tau Ceti and about four days to reach the exoplanet Gliese 667 Cc.
It would take about one year and nine months to travel to the black hole V616 Monocerotis, 13 years and seven months to reach the center of our galaxy, and 1,328 years to reach Andromeda.
In 30 days, this ship could cover 156 light-years. Within a radius of 156 light-years from Earth, there are approximately 40,000 to 60,000 stars.
The starship of Captain Kathryn Janeway from Star Trek: Voyager
The starship of Captain Kathryn Janeway from Star Trek: Voyager is called the USS Voyager (NCC-74656). It is an Intrepid-class ship known for its mission in the Delta Quadrant. Its maximum speed is Warp 9.975, which is 5,126 times faster than the speed of light.
Voyager would travel to Proxima Centauri in just 7 hours. The journey to the star Tau Ceti would take only 20 hours and 38 hours to reach the exoplanet Gliese 667 Cc.
Voyager would take seven months to reach the black hole V616 and five years to reach the center of our galaxy. Andromeda is still out of reach, and it would take this starship 495 years to get there.
At maximum speed, this starship could cover 421 light-years in 30 days. Within a radius of 421 light-years from Earth, there are approximately 1.25 million stars.
The Future of Space Travel
The vastness of space represents a limiting factor for space travel. The spacecraft we are currently capable of building can reach distant parts of the solar system and objects like Pluto by traveling for 10 or more years. Interstellar travel is presently not feasible, as it would take Voyager 1, our fastest spacecraft, 150,000 years to reach the nearest star and return. For now, we are limited to space travel within our solar system. To achieve interstellar travel, our technology would need to reach at least 20% of the speed of light so a probe could reach the nearest star in about 20 years. There are plans to build such a spacecraft that would be accelerated using powerful lasers from Earth. The data collected by such a probe would take another four years to reach us.
Milky Way galaxy and the neighboring Andromeda galaxy. Credit: NASA Goddard
To successfully explore the nearest stars, we would need to achieve speeds close to the speed of light. This would make about 50 stars within 15 light-years of Earth accessible. Such journeys would be very long, and it would take decades to receive data from probes. Space is so vast that even spacecraft capable of traveling at the speed of light would only allow us to explore the nearest stars.
If the speed of light cannot be achieved, and faster-than-light travel is not feasible, the chances of encountering an advanced extraterrestrial civilization are extremely slim. The universe may be full of life, but the vast distances in space make contact between civilizations almost impossible, at least in our part of the universe. The exception could be stars within star clusters, such as globular clusters, where stars can be as close as 0.1 light-years apart. However, even such a small distance is incredibly large for a civilization like ours. It would take Voyager 1 about 1,769 years to reach a star that is 0.1 light-years away.
Is faster-than-light travel possible?
Theoretically, faster-than-light travel is fascinating, but according to current scientific understanding, particularly Einstein's theory of relativity, objects with mass cannot travel faster than light. However, several theoretical ideas suggest the possibility of "bypassing" this limitation:
The Alcubierre Drive
This concept, proposed by physicist Miguel Alcubierre in 1994, is based on creating a "bubble" around a spaceship, within which space-time remains intact. The bubble would contract space in front of the ship and expand it behind, thus allowing for faster-than-light travel. The spaceship itself wouldn't actually travel through space faster than light, but the space around it would be warped. The problem is that this would require exotic matter with negative energy, which has not yet been proven or discovered.
Wormholes
Wormholes are hypothetical tunnels through space-time that could connect distant points in the universe. Traveling through a wormhole could provide an effective "shortcut" through space, meaning that the traveler would not have to traverse the entire distance between two points.
Although wormholes are mathematically possible within general relativity, there is no evidence that they exist or would remain stable long enough for practical use. Additionally, maintaining them might require exotic matter.
Tachyons
According to theory, tachyons are hypothetical particles that always travel faster than light. However, their existence has not been proven. If tachyons existed, they would violate some fundamental laws of physics, such as causality, which could lead to paradoxes, like traveling backward in time.
Warp Drive
In Star Trek, warp drive uses a concept similar to the Alcubierre drive, where the spaceship doesn't travel faster than light in the traditional sense but rather distorts space-time around it. Although fictional, this idea has inspired real-world physicists to explore the possibilities of warping space-time.
Quasicrystal Spaces or Higher Dimensions
In some theories, such as string theory, the universe has more dimensions than we can perceive. Traveling through higher dimensions could potentially allow "shortcuts" in three-dimensional space. This idea is still highly speculative but theoretically intriguing.
Although these ideas are interesting, most of them are still within the realm of theory and science fiction. Currently, we do not have the technology or materials needed to achieve faster-than-light travel, but ongoing research into exotic matter, space-time, and quantum physics continues to offer new possibilities for the future.