How many light years nearest star

By we should know whether or not there would be habitable planets around Alpha Centauir A and B. They are both very close to what our star, the Sun is. We are thinking too small and too short term. Also Proxima Centauri is doo-doo. For another. Too short term: witihin the next 50 years, we should have effective immortality for humans through medical advances. That changes all the rules about how long you can take to get there.

Take a planet. Mars might be big enough. Either live underneath the surface or make an artificial sun. Plan B, consider taking the Sun and all the major planets. Everyone needs to pause a bit and think about the motivation for the article. The article is a valid discussion of the distances and times it would take to travel to another star using diffenert technologies. Remember, around years ago, a fast ship would take about 9 months to travel from England to Australia.

I often wondered about this very question — so thank you to the author. It seems so simple at first — only four point something light years away — but we all know that is still a very long way. I point to the technical, ethical and financial constraints that surround the present day discussions of travelling to the Moon or Mars to stress my point.

I think our first step is to colonize the solar system, that will give us better experience in developing faster propulsion systems. I hope its within our life time. Imagine travelling 80 to 1, years to the nearest star, and then finding out there is absolutely nothing of interest there. It seems to me that for Humans and all the other alien species out there, we are all stuck in our own little solar systems. We are fine. Nothing really happened since our last communication 2, years ago.

We received your communication 1, years ago and we are glad you are fine. The author has ignored the Nerva and Phoebus nuclear rocket engines for upper stages and the D-He-3 fusion reaction to provide 10million times as much energy per particle as in chemical systems. See John Luce and John Hilton paper. Far more efficient than Orion. Soviets have operated 3 dozen nuclear reactors in space for electricity production.

At 1G it only takes a year to get to near c. Imagine doing the best telescopic study from this solar system you can, first. And possibly sending robotic probes after that, befor committing people…just like here. Alpha Cen A and-or B would seem more stable, luminous stars with a better likelihood of habitable planets or moons orbiting gas giant planets. We could learn a lot by just looking at all the fantastic space technology that was developed 50 years ago.

Are there any theories relating to what space would be like between solar systems? MC, both ideas go kablooie. Space is a near vacuum anywhere you go, even in a nebulae.

There are no meteor storms to watch out for in interstellar space. Nothing to keep them together It would be like watching out for meteorites while you are driving…not a major concern.

The Milky way affects us here the same way it would outside our solar system. The heliopause affects atomic size particles, not spaceships. There is a radioactive belt or two surrounding the earth even now. Space is filled with radioactivity.

Nasty place. As described in one post, bomb detritus would spread to near nothingness in little time. It would probably take off from moon orbit anyway. Too big to launch from earth surface. And the blast absorbtion plate would have to be enormous? Where does that thinking come from? The blasts are smallish and continuous. I think anti-matter will probably be the answer that gets us there.

Massive energy from smallest quantity, and lacking in need for extra-dimensional travel which will probably always remain a tantalizing theory at best. Within two or three decades, we should have sufficient molecular manufacturing technology to create extremely efficient, small, light and highly intelligent robots, as well as small nanofactories capable of creating any object from patterns stored in computer memory. Sending them out to the nearest stars would take far less energy than sending humans.

If a robot arrived at a suitable exoplanet, it could use the nanofactory to construct a laser receiving station or similar device , as well as living accommodations for humans. The same technology that would allow the construction of the robots and nanofactories should allow us to disassemble human beings and reassemble them. This may allow us to store entire humans as digital information.

We could then beam the information to the receiving station on the exoplanet. The nanofactory would reassemble the human patterns, creating exact duplicates of the original human templates, and those humans would have living accommodations already waiting for them.

Of course that would still take a while: probably hundreds or thousands of years to get the robots to the exoplanets, then at least a few years to establish a connection with Earth beaming info at lightspeed , and then a few more years to beam the human patterns to the exoplanets.

So…forget it. At least for now. Maybe some AI will come up with a way to shorten the trip, so just wait a few decades and find out. Thanks so much for the article and reader comments.

Exciting visions. Always dreamt of such possibilities as a small boy. Unfortunately, nowadays, the negative consequences of global warming accelerate faster than the development of interstellar propulsion engines. Trying to be realistic, I only hope that there will be human astronauts after or so to board space ships.

Maybe we could travel to other planets with our mind rather than our bodies. To: Peter K. A couple of probes NASA has lost contact with over the years comes to mind. Another thought, for mankind to do any serious space traveling, it would be necessary to develop a means to exceed the speed of light several magnitudes.

Maybe we need to learn to live on this planet before we go to another? Planet starbucks haha…. Did anyone mention suspension, cryonic or other?

Wake up 20, years later orbiting a strange planet …. If you have ever had the chance to look at stars through an actual telescope, not the internet pictures, taking the time to just look at some random name-unknown group of stars, it is fascinating. I am enthralled by the fact that I am looking at real suns live minus light year distance of course. There is something about it that overwhelms. I am not one who would immediately plant a carbon copy of human society on another planet.

What difference does it make what planet you watch TV on? It is the chance to leave this society behind and be out there with no one else except the stars that draws me like nothing else in life. Pick any one star, no matter how far, and head for it. Perhaps by launching the nukes ahead of the starcraft, or maybe by some other means.

We could always build a massive coil gun, preferably orbiting one of the outer planets. Realistically, we can get a lot higher speeds and lower mass crafts by using robotics rather than manned voyages.

This method reduces the problem of on-board fuel. It all depends on how much power we can store, and what velocity we can accelerate the projectile to. We now can accellerate a stream of particles to How much energy would it take to accelerate a larger object to those speeds. Also the G forces from just the curvature of the earth would be enough to destroy any device we send around. But I propose that we create an orbital TRACK, one that works just like a particle accelerator that pushes an object around untill we reach the right velocity then it opens upon on end to let it fly.

We could get a robot or transmitter to a distent star pretty fast, however there would be NO way to slow it down. We would need on accelerator to throw and another at the destination, to catch. But heaven forbid we should miss. I suggested the coil gun over at NewMars.

The unfortunate thing about it is how long it takes to get up to speed without killing its occupents and such. So I suggested launching Ion beams instead. Others suggested Aluminum pellets. Those could work to, if they could perhaps be vaporised to form high speed Ions hitting the craft. Decelerate at the target system using a combination of MagSail and Orion. From a mission perspective and not from a propulsion perspective. Optics make it impossible for us to see what the planet actually has to offer us as far as living conditions goes.

Is the planet habitable? I think the first mission s around our local star group should be of the flyby variety. Gaining speed from day one and slowing down only after half our local group is visited for the return home. We may only be in a solar system for a few productive days, but we would gain more information about planets in that system than any kind of optical examination from Earth or Earth orbit.

This kind of mission reduces the cost of slowing up for each system and decreases the time it takes to examine all the local stars near us. We could send a burst signal with data if a system is suitable for human life as the mission progresses. This type of trip will most likely be a generational trip. But it also has the advantage of being able to be aborted if we find out we can actually move faster than light at some future time.

And if the scientists and engineers get smarter over generations, who knows. Skip to content. Over exoplanets have been identified, many of which are believed to be habitable. Credit: phl. Since its arrival, the spacecraft turned around to point the blue glow of its ion engine in the opposite direction.

A Helios probe being encapsulated for launch. Credit: Public Domain. Credit: NASA. Credit: bisbos. Credit: Adrian Mann. Credit: futurespacetransportation. What matter and antimatter might look like annihilating one another. Like this: Like Loading The algorithm then repeats each mission times to determine the likelihood of this size of crew reaching its destination.

A key question is what degree of inbreeding can be allowed. One option is to limit inbreeding to less than 5 percent, so partners have to be more distantly related than first cousins. Another option is to stipulate that partners cannot be related at all, so that inbreeding is 0. Marin and Beluffi use this second scenario in their simulation. The algorithm then determines the likelihood of success over missions for different initial crew sizes.

The results make for interesting reading. The Heritage algorithm predicts that an initial crew of 14 breeding pairs has zero chance of reaching Proxima Centauri. Such a small group does not have enough genetic diversity to survive. Researchers have observed with animals that the genetic diversity of an initial population of 25 pairs can be sustained indefinitely with careful breeding.

But when the Heritage algorithm uses this as the starting crew—25 men and 25 women—it predicts a 50 percent chance of dying out before reaching the destination.

The chances of success, according to Heritage, do not reach percent until the initial crew has 98 settlers, or 49 breeding pairs. For example, fertility rates in deep space may turn out to be quite different from those on Earth.

And the chances of a healthy child resulting from a successful pregnancy may also be much lower because of higher mutation rates due to radiation. The chances of catastrophe because of accidents or plagues may turn out to be much smaller than the chances of catastrophe caused by social factors such as conflict. All this could be programmed into a more advanced version of Heritage.

Indeed, these issues have already been explored by science fiction writers. For example, in the book Seveneves , the author Neal Stephenson imagines a future in which humanity passes through a population bottleneck and all individuals are descended from seven women. But it is surely important to consider the scenario given the multiple threats that our civilization faces. Ref: arxiv. This is because your eyes are separated from each other by a few inches - so each eye sees the finger in front of you from a slightly different angle.

The amount your finger seems to shift is called its "parallax". Astronomers can measure parallax by measuring the position of a nearby star very carefully with respect to more distant stars behind it, then measuring those positions again six months later when the Earth is on the opposite side of its orbit.

If the star is close enough to us, a measurable parallax will be seen: the position of the star relative to the more distant background stars will have shifted. The shift is tiny - less than an arcsecond even for the nearest star.

Imagine the Universe has more information on calculating parallax. Stars are not actually stationary objects! The Galaxy is rotating, and the stars are in orbit around its center.

Not every star moves at the same rate - how fast they orbit can depend on where the star is located within the Galaxy. Our Sun, being fairly far from the Galactic Center, takes over million years to circle the Galaxy once. Some of the stars near us are moving faster than us, and some slower. As Phil Plaitt, from Bad Astronomy says, " They change positions, slowly, but measurably.