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Space Exploration: We Need To Travel Near The Speed of Light For It To Be Practical

Melvin is an avid reader and a retired chemist after working for a major pharmaceutical company for 32 years.


If we are going to explore anything beyond our solar system and out into the vastness of the universe in a spaceship or probe; we need to seriously increase the speed of our space flight to do it. There is a tremendous difference in distant we travel locally here on earth when compared to the distant we must travel just to get from here to our nearest star, the sun, and beyond. We must come close to the speed of light, which is 186,000 miles per second to transverse the vastness of space if we want to get to the nearest star with an earth-like planet orbiting it. To get a better understanding of speed I will start with speeds we are familiar with and work my way up to the speed limit of our universe, the speed of light.

The Cosmos

The Cosmos

Speed As We Understand it on Earth

Speed on earth is pretty slow to transverse the vast distant of space. For starters, the fastest sprinter maximum speed is just under 28 miles per hour. A racehorse maximum speed on the track is about 50 miles per hour. To go ever faster we need something with power such as a stock car, which reaches a maximum speed of about 240 miles per hour and with more power such as fighter jet we begin to approach speeds of 1000 miles per hour. The International Space Station orbiting the earth is moving at an astounding speed of 17,000 miles per hour and the New Horizons probe just sped by Pluto at a speed of 52,000 mph. This is the fastest speed a man-made object have traveled and even at this speed it took the probe about 9 years to get there. Even at 52,000 miles per hour this speed is still not enough to do serious space exploration in a spaceship or probe.

NASA recently announced that the Voyager 1 space probe launched in 1977 to explore the outer planets in our solar system finally left the solar system after traveling for nearly 37 years. It finally left the region of particles from the Sun known as the heliosheath, a distant of about 11 billion miles from earth, at a speed of about 38,000 mph and is currently entering interstellar space. At this point and speed it would take Voyager another 40,000 years to reach the nearest star to us.

Now let us look at speed from a different and familiar perspective, in terms of distance. If we had a fast car such as a Lamborghini and travels about 3,000 miles across the United States from New York City to Los Angeles at a constant speed of 100 miles per hour it would take us approximately 30 hours to complete that trip. If we travel to the moon at that speed it would take us about 14 weeks to get there. The moon’s center is about 238,000 miles (average distance) from the earth’s center. And to travel to the last planet in the our solar system, Neptune, at 100 miles per hours it would take an incredible 3,100 years to get there. Obviously, 100 miles per hour is nothing to the vast distance of space. We need something much faster like the speed of light.

Nothing in the universe is faster than the speed of light even though a recent experiment was conducted that indicated neutrinos might travel faster than light. However, further investigations of the results of the experiment indicated the speed of the neutrinos particles was less than the speed of light. After all they were talking about measurements in nanoseconds. For clarity, a nanosecond is one-billionth of a second or a second divided into one billion equal size slices. That is an extremely short period of time.

Light Speed, the Universe Speed Limit

As I mentioned before, the speed of light in miles per hour in a vacuum is an incredible 670 million miles per hour or 186,000 miles per second. At that speed light will travel a distance of about 6 trillion miles in one year or a distant equal to one light-year, a term used by astronomers to define the vast distant light travels in the cosmos. To put this in a different perspective, a beam of light can travel back and forth between New York City and Los Angeles 75 times in a second. It can circle the earth seven times a second. When we look up at the sun the light and heat that we are seeing and feeling left the sun eight minutes ago. Another way of looking at this is if the sun for some reason was to disappear on us we will not notice it until eight minutes later because it take light and heat (infrared light) eight minutes to traverse the 93 to 96 million miles distant from the sun to the earth. In other words, the sun is eight light-minutes from the earth in astronomical terms.

A Serious Need For Speed

Now, if we start looking at the stars and galaxies in the night sky the distant from earth to the stars and galaxies increases dramatically. Everything that we see happening in the night sky already happened millions or even billions of years ago because that is how long it took light even at its speed to travel through the vastness of space to get here. Just to leave our own solar system will take a large and massive spaceship with a lot of fuel to reach the speed of light. Going from zero to the speed of light is not an instantaneous feat. A lot of energy is required to do that. If the spaceship left Earth it will take some time to accelerate to the speed of light. The spaceship would take 1 year to reach Pluto while accelerating to the speed of light and even after passing Pluto it would only be moving at half the speed of light. On the other hand, starting at the speed of light from Earth the spaceship will pass Pluto in a little less than 7 hours. Light from the nearest star, Proxima Centauri, would take a little more than 4 years to reach earth and light from the nearest star, Epsilon Eridini, with a planet similar to earth would take at least 10 years to get here.

Going off the subject a little, the previous statement pretty much explains why earth probably have not been visited by any visitors even from our very own galaxy and they must also have the capability (intelligence) to do so even if there is life out there. Once we go beyond our galaxy the probability of this ever happening seems highly unlikely because the next galaxy is two and half million light years away if they can travel at 99 percent the speed of light. Any speed less than light speed would make it virtually impossible for some form of life to tranverse intergalactic space.

Getting back on track, to get to the edge of our galaxy, the Milky Way, would take us approximately 24,000 years traveling at the speed of light. Any speed less than that will take us almost practically forever just to leave the Milky way to reach intergalactic space; the space between the galaxies out there. And to get to the nearest spiral galaxy, the Andromeda Galaxy, will take us an incredible two and a half million years to get there from earth as previously mentioned. Currently, the twin Voyager probes launched more than 30 years ago are just reaching the point where they will be in interstellar space after passing the wall where the particles from the Sun are stop by the particles originating from interstellar space. This point in space is the edge of our solar system. These probes are traveling at a speed of about 58,000 miles per hour but nowhere near the speed of light.

Our nearest spiral galaxy, Andromeda Galaxy (M31)

Our nearest spiral galaxy, Andromeda Galaxy (M31)

One form of propulsion

One form of propulsion

Spacecraft with sails for propulsion

Spacecraft with sails for propulsion

At the speed of light we will not see streaks of light like this, instead we will see distant stars and galaxies as points of light since they are so far away.

At the speed of light we will not see streaks of light like this, instead we will see distant stars and galaxies as points of light since they are so far away.

To Get More Speed We Need More Power

Obviously, to get more speed we need more power. The astronauts would not have made it to the moon without the tremendous amount of power needed to send their rocket there. The space shuttle needs 3 million pounds of rocket fuel to send it into orbit every time it is launched. The weight of that fuel is 20 times the weight of the shuttle. Just imagine how much fuel we need to go beyond the moon. Researchers are currently coming up with alternative means of propulsion for space exploration. There are right now two promising methods; one involves using the particles injected from the sun, which will propel space vehicle equipped with large sails on them. The momentum from these high-speed particles will be transferred to the sails thus giving the spacecraft the boost needed to move through the solar system at much higher speeds. The other method involves using powerful magnets to re-direct ejected high-speed streams of hot plasma gases out of the nozzles of rockets called magnetoplasma rockets to propel the spacecraft at speeds greater than 50,000 miles per hour. Even at this speed space exploration would be limited to just our solar system.

Strange Things Happen To Us At the Speed of Light

If we ever develop the technology to send humans on a spacecraft near the speed of light to explore space they would experience strange events. They would also encounter a very serious and potentially deadly problem traveling at such a high speed.

If a spaceship is moving near the speed of light and impact something out there it would be a catastrophic event. The impact would create an explosion similar to an atomic bomb explosion because the mass of the object would be so great at that speed that it would release an incredible amount of energy (remember the equation E=mc squared) after the collision with another object. Traveling at the speed of light would only be possible in intergalactic space after the spaceship cleared the space within the galaxy.

Strange things happen when it come to speed near the speed of light. The laws of physics behave differently at light speed versus the relatively slow speed we experience on earth. For example, if two cars were each traveling at 50 miles per hours as they approach each other from opposite directions they will pass each other at 100 miles per hours. This is why head on collisions are generally deadly. In the second example, if two cars are traveling in the same direction, one at 40 miles per hours and the other at 50 miles per hours, the faster car will go by the slower car at a relative speed of only 10 miles per hours. Guys you see this effect all the time on the highway you do not pass the other car that fast unless it is not moving.

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Now, if you do these same experiments at the speed of light the out come is completely different. In the first example if the two cars each were traveling toward each other at the speed of light from opposite directions they will pass each other at the speed of light, 186,000 miles per second, not double the speed of light. In the second example, the faster car will pass the slower car which is going a little slower than the speed of light, will pass it at the speed of light. This phenomenon happens because the speed of light does not change in the vacuum of space it is always moving along at a constant speed of 186,000 miles per hour so time slows down to keep the cars from passing each at speeds greater than the speed of light. The other effect humans will experience is the time dilation effect of moving at the speed of light. If an astronaut left earth for a 20-year trip into space and back at 99.9% the speed of light he would be surprise to see that 1,000 years have gone by on earth since he left and he will be basically the same in appearance when he left. Our astronauts today experience this time dilation effect when they are in orbit around earth on the space shuttle or space station. When they return to earth they are a fraction of a second younger than everyone on earth because they are moving at 17,000 miles per hours for a few days. I am sure no one noticed that when they return.

The Time Dilation Effect

The Time Dilation Effect


As you can see, there are benefits of traveling at the speed of light you will stay young longer, but to achieve this speed will be an incredible achievement in itself if we ever develop the technology to do it. It look like it is going to be a while before we can leave the boundary of our solar system to do some serious space explorations physically.

References: Wikipedia, National Geographic Channel

© 2010 Melvin Porter


Melvin Porter (author) from New Jersey, USA on August 07, 2019:

Besarien, thanks for your comment.

Besarien from South Florida on August 04, 2019:

Nice article! We could also work on digitizing ourselves into zero mass light-encoded information that can be relayed at the speed of light. I wouldn't want to be the first one to test it.

Loreal Harris from Crown Point, Indiana on November 24, 2014:

Amazing article there! Well stated about space also. I love outer space, mostly on account of how it inspires me for most of my books. Take it from an author who knows ;)

love for science on May 09, 2014:

space is a large mine of energy . many explosions took place this generated energy can be used as the roket to go faster near meteorit.. the warm generated by this meteorit is energy and to have alight not loaded vehicle apilar to reach ahigh speed next time i ll have more details science science and science

love for scince on May 09, 2014:

yes we could reach the light speed we have first the speed of meteorit we could use it as natural space vheicle to travel around galaxy secodly we could use the explosion which took place in the space to move faster as light and to hav e an idea about the limeted space.

tali shepard on December 16, 2013:

thank you melpor for the answer ..

so if that's the case with our lifetime i mean human life time is around 70-80-90 at best case 100 years(maybe in the future we will able to live more) and we will sand full grown human then we could explore only about 30-60 ly from earth the galaxy still become mystry for us..unless we find some way to put us on some type of coma or freeze the body.

ive read some article that said if you travel in lightspeed then time is freezes for you or slow down rapidly..(you set of at age 40)so even if you travel for 2ly in space and arrive to your destination im guessing you'll be at the age of 42 (not speaking about earth or anything )?

Melvin Porter (author) from New Jersey, USA on December 15, 2013:

Tali, thank you for reading my hub. Yep, if you traveling to a planet and it takes 2 light years to get there then you would have been traveling for 2 years. You are just traveling at the speed of light for 2 years but time will slow down for you. However, time for everybody not on your spaceship will move along at the usual rate (faster with respect to your time on the ship), therefore, thousands of years will go by for them.

tali shepard on December 15, 2013:

i found this very interesting and helpful thank you =]

but i cant stop thinking about what if lets say im on spaceship that can go 99.9% of speed light and to get to the planet i need, it will take for ly lets say 2 ly so ..when ill travel there will it take me 2 years of my life??or does it take me few moments perhaps hours?

if it does take me 2 years from my life..then im afraid we'll never be able to travel and explor other solar systems let alone other planets that's like 60-100 ly ahead..and the fact the the milky way is 100k-120k ly..and i do believe that there is other civilizations out there ive heard and read about michio kaku the milky way is full of surprises that we never dreamed to find out.

Melvin Porter (author) from New Jersey, USA on February 21, 2013:

Ib, thanks for your comment. I am using examples of various speeds from common everyday things for comparison to help my readers understand how fast light moves through the vacuum of space. The only thing that comes close to the speed of light on earth are the particles being artificially pushed to nearly 99% the speed of light in the particle accelerators in the world.

Brad Masters from Southern California on February 20, 2013:

You need to use some up to date examples of speed.

A car has broken the sound barrier.

The current rockets the escape our world travel at about 25,000 miles per hour.

We should start by increasing that speed to get to the moon in just a couple of hours before we consider leaving the earthly neighborhood.


Jim Dorsch from Alexandria, VA on February 21, 2012:

Nicely done, up and sharing.

Melvin Porter (author) from New Jersey, USA on December 08, 2011:

Weestro, again thanks for reading my hub. Space travel is a very interesting area of research, but we are going to need a lot more speed before we are able to go beyond our own solar system. That space probe that is traveling to Pluto at this moment will take 9 years to get there at a speed of about 52,000 miles per hour. The distant to Pluto is just so large.

Pete Fanning from Virginia on December 08, 2011:

Very interesting, I'll leave the scientific aspect to you and the others posting. I do find this fascinating! Great Hub, voted up!

Melvin Porter (author) from New Jersey, USA on December 05, 2011:

You are right Credence2. I forgot about that one. But anyway it would still require a lot of energy to push a spaceship near the speed of light. Thanks for reading my hub.

Credence2 from Florida (Space Coast) on December 05, 2011:

Melpor, regarding possible propulsion scenarios, what about ion propulsion, which while providing small thrust can eventually reach speeds far in excess of those available with our current rockets? Cred2

Melvin Porter (author) from New Jersey, USA on October 31, 2011:

Elixir, thanks for your comment about the time it takes to get to Pluto at the speed of light. I added a few sentences to clarify this and made some corrections. Thanks for catching this error.

Melvin Porter (author) from New Jersey, USA on October 31, 2011:

Elixir, this is the amount of time it will take light just to get out of the neighborhood of our solar system, not pass pluto. Light from the sun will pass Pluto in about 7 hours.

Elixir on October 30, 2011:

A whole year to reach Pluto at the speed of light? I don't understand...

Melvin Porter (author) from New Jersey, USA on October 16, 2011:

Chamilj, thanks for stopping by to read my hub. I appreciate your response.

chamilj from Sri Lanka on October 15, 2011:

Voted up! Thanks for the clear explanation of speed.

uday on October 07, 2011:

Logically...only other means which we can travel faster than light is mind...our mind travels faster than light and so little we know how our brain functions....we dream at night...we remember everything but we dont remember the start of any dream we arrived there at first on earth our memories cant recollect before 3-4 yrs as kid...this is a dream...and to come back to reality is thru death and to travel is thru mind....travelling at speed of light does not make sense..since it looks like earth is an island in the vacuum space and we all are stranded on the island....

uday on October 07, 2011:

...we are in big dream...and death is the only way to get back to reality...

Melvin Porter (author) from New Jersey, USA on September 13, 2011:

James, thanks for reading my hub. Yes, the universe is huge but it is also made of atoms just as we are. That is not the reason why the universe is large. The universe is large because we happen to be one of the trillions of objects in it. The problem with portals is that they are just theories. Some scientists bring up the idea of wormholes but the problem is they are microscopic and exist at the sub-atomic level. Creating a large wormhole is basically unstable, it will collapse immediately and require a lot of energy even to produce one. Right now traveling near the speed of light is the only way to transverse the large distances in space. As I mentioned in this hub traveling near the speed of light will take us one year just to go pass Pluto in our own Solar System. It is highly unlikely we will see or encounter anything beyond our Solar System anytime soon.

James on September 13, 2011:

The Universe is huge to humans, but I believe it is much smaller from someone's else perspective far beyond our comprehension. We are atoms, molecules. Picture a basketball, hold it up, and look around it. We are inside this basketball held up by something FAR beyond our comprehension. Another theory is beyond religion. Are we aliens? Did we choose to come here? Like going to a library and saying basically let's go here and anything goes? You can't remember leaving but here we are. When we die we go back to that place.? The Speed of light is NOT in my opinion the way to travel through space. There are portals, but where? How? Doors? That exist.

Melvin Porter (author) from New Jersey, USA on August 18, 2011:

Carcro, thanks for stopping by to read my hub. The universe is a very vast place. Until we develop another method of traveling we will not be going beyond Mars anytime soon and people need to stop talking about aliens from another world because they are in the same situation as we are if they are out there. It will be a while before we see anything from another world. Forget about wormholes they are too small for anything larger than an atom to come through.

Paul Cronin from Winnipeg on August 18, 2011:

Voted Up and Interesting, space travel is the most interesting of all subjects, just because we know so little. Distance and speed are things so hard to comprehend when it comes to the vastness of space. Great hub, thanks for sharing.

Melvin Porter (author) from New Jersey, USA on July 26, 2011:

Venzkhvam, thanks for the comment and for stopping by. I will check out some of hubs.

VENZKHVAM from Milk way galaxy, trying to find a more adventurous place in another galaxy with my great followers on July 26, 2011:



Melvin Porter (author) from New Jersey, USA on May 22, 2011:

Ione77star, again you are right there is a slight misinformations on my part. The astronaut will physically age 20 years despite the fact 1,000 years have passed by on Earth by he was traveling. Time is only going by slower to him with respect to people I will correct that error in my article as soon as possible. Thanks for bring that to my attention.

Rod Martin Jr from Cebu, Philippines on May 22, 2011:

Hi, melpor. Interesting stuff, but there may be an error in your portrayal of Relativity and time-dilation. If an astronaut goes out on a 20-year trip (if it is 20 years to him), then he will age 20 years. That will make him look quite different (not the same). I agree that something like 1,000 years will pass by on Earth, but the astronaut will experience some time going by. In your example, 20 years of it. That's a lonely 20 years!

Einstein was great for thinking outside the box and bringing it back down to reality. He is an inspiration to us all.

Thinking outside the box, what if there is a better way for space travel than using the brute force of Newtonian physics and the reliance on relativistic effects? Just because we don't know this is possible, doesn't mean it isn't.

With the political ebb and flow on Earth, getting behind a generational ship or a near-light-speed juggernaut to the stars could prove fiscally impossible. If, however, we find an Einstein-caliber breakthrough in the study of spatial manipulation, inertial shielding and the like, para-light speeds might become possible. Galvanize the public imagination with faster return on their investment, and it might prove far easier to fund a mission to the stars, especially to those potentially habitable systems near our own.

Melvin Porter (author) from New Jersey, USA on April 24, 2011:

Ss Sneh, once again thanks for stopping by to read my hub. Thanks for the comment.

ss sneh from the Incredible India! on April 24, 2011:

Hi! Beautiful article!

...especially about my childhood friend and my boss's theorem!

Well, to travel to other solar systems...I don't think we need to achieve near lights speeds as Stephen hawking thinks...

but to be smaller...

smaller to the quantum levels...

precisely speaking to the inner space!

Or to be be like Bose-Einstein condensate.

Fast forward 50 years... and (I hope) we will know them clearly!

-- Thanks

Melvin Porter (author) from New Jersey, USA on March 05, 2011:

Nick, that is true. There is not enough funding from the government for space travel. NASA is depending on private investors to continue space exploration and depending on Russia to ferry US astronauts and supplies to International Space Station in the future after the retirement of the Space Shuttles.

Nick drew on March 05, 2011:

Melpor sorry

Nick drew on March 05, 2011:

Thanks for the article melter. I remember reading an article where it said that there is not enough investors these day so money is a problem for space travel. Is this true?

Melvin Porter (author) from New Jersey, USA on February 18, 2011:

Paul, yes space is huge. This is why I wrote this hub. It will be a while before we explore anything beyond our own solar system. The next closest star to us is more than 4 light years away traveling near the speed of light.

Paul Scanlon from Birmingham, UK on February 18, 2011:

Great article melpor. It always amazes me just how big space is. Look forward to more hubs.

Melvin Porter (author) from New Jersey, USA on November 26, 2010:

A M Werner, tanks for your comment. I agree with your comment. Space exploration will be a very limited area for us for awhile to come. Also this is the reason why it is highly unlikely we have been visited by aliens form another world because they most likely will have the same limitation as we have to travel through deep space.

Allen Werner from West Allis on November 26, 2010:

melpor, I remember reading an article not too long ago, but I can't remember where, but that the conclusion was, that until science discovers more powerful (quicker) methods of travel, space exploration will be very limited. Thanks for all the incredible information. Peace.

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