Proxima Centauri b is the closest exoplanet to Earth, at a distance of about 4.2 ly.
The planet is about 1,800 light-years (550 pc) away from the Solar System. At the speed of the New Horizons spacecraft, at about 59,000 km/h (16,000 m/s; 37,000 mph), it would take approximately 30 million years to get there.
The closest extrasolar planet overall to Earth is Proxima Centauri b, a terrestrial and possibly habitable planet located 4.22 light years away.
Proxima Centauri is 4.2 light-years from Earth, a distance that would take about 6,300 years to travel using current technology. Such a trip would take many generations.
In 2020, Gilbert and others announced the discovery of the Earth-size, habitable-zone planet d, which is on a 37-day orbit, along with two other worlds. The innermost planet, TOI 700 b, is about 90% Earth's size and orbits the star every 10 days.
Among the stunning variety of worlds in our solar system, only Earth is known to host life.
This planet, named TOI-700 e, falls within its star's habitable zone, meaning the newfound planet could be capable of supporting life as we know it. The research team announced the finding Jan. 10 at the American Astronomical Society meeting in Seattle.
At the speed of the fastest space probes humanity has ever sent on their way out of the Solar System (the Voyager 1 and 2 spacecraft), covering the distance to the nearest star would take approximately 80,000 years. But all of this is based on current technology, which uses chemical-based rocket fuel for propulsion.
Using Voyager 1 technology, it would take us 80,000 years to travel to Proxima Centauri.
In short, at a maximum velocity of 56,000 km/h, Deep Space 1 would take over 81,000 years to traverse the 4.24 light-years between Earth and Proxima Centauri. To put that time-scale into perspective, that would be over 2,700 human generations.
That orbit suggests that Proxima d is too hot to host Earth-life surface life, if the planet does indeed exist (though the habitable zone is a squishy and tricky concept that should not be taken as gospel). (Like Proxima c, Proxima d still needs to be confirmed by follow-up observations.)
The most distant potentially habitable planet confirmed is Kepler-1606b, at 2,870 light-years distant, although the unconfirmed planet KOI-5889.01 is over 5,000 light-years distant.
If New Horizons were aimed toward the Alpha Centauri system, which it isn't, it would take this spacecraft about 78,000 years to get there. So, conventional rockets won't work because they are simply too slow. These 4 conventional spacecraft are headed out of the solar system.
Some parts of the world will be uninhabitable by 2050 due to climate change, according to NASA. NASA recently published a map of the world showing the regions that will become uninhabitable for humans by 2050.
So 1,400 light-years equals about 8.2 quadrillion miles. If we took one of our fastest probes to the planet, New Horizons, which is currently traveling about 36,000 miles per hour (50,000 km/h), it would take well over 26 million years to reach our destination.
In estimated one billion years the concentration of carbon-dioxide in earth's atmosphere will be too low to sustain plants or other phototropic organisms. Without plants also higher animals will have soon or later no food and starve to death.
Light-year is the distance light travels in one year. Light zips through interstellar space at 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year.
Remarkably, Alpha Centauri A and B are even older than the Sun, they have an age of 5 to 6 billion years, therefore they pass this test with glamour, too.
For most space objects, we use light-years to describe their distance. A light-year is the distance light travels in one Earth year. One light-year is about 6 trillion miles (9 trillion km). That is a 6 with 12 zeros behind it!
Nothing can travel faster than 300,000 kilometers per second (186,000 miles per second). Only massless particles, including photons, which make up light, can travel at that speed. It's impossible to accelerate any material object up to the speed of light because it would take an infinite amount of energy to do so.
So, while Earth will eventually leave the solar system one way or another, it's not something we will have to worry about for a few billion years yet.
Interstellar distances
As of January 20, 2023, Voyager 1, the farthest human-made object from Earth, is 159 AU away. The closest known star, Proxima Centauri, is approximately 268,332 AU away, or over 9,000 times farther away than Neptune.
By 2.8 billion years from now, the surface temperature of the Earth will have reached 422 K (149 °C; 300 °F), even at the poles. At this point, any remaining life will be extinguished due to the extreme conditions. What happens beyond this depends on how much water is left on the surface.
NASA recently announced the discovery of a new, Earth-sized planet in the habitable zone of a nearby star called TOI-700. We are two of the astronomers who led the discovery of this planet, called TOI-700 e.
Then, just last year, scientists discovered another Earth-like planet orbiting one of our closest neighboring stars, Proxima Centauri. Currently, this planet is the best candidate we have for supporting human life.