How long would it take to travel to neighboring solar systems?

The nearest exoplanet is 4.5 light years away

This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. (Credit: NASA)

NASA's newest spacecraft TESS is designed to find more sun-planet systems like our own.

Since 1993, astronomers have confirmed the existence of thousands of planets orbiting stars outside our solar system, known as exoplanets. Some exoplanets are orbiting their stars within a habitable zone, meaning they are not too far and not too close to their stars, and are rocky, or terrestrial worlds, similar to Earth.

That's exciting news, because it means some of these other worlds could support life. The bad news is that these newly discovered worlds are light-years away and the technology doesn't exist yet to send a robotic mission, let alone a crewed spacecraft to meet our nearest neighbors.

There are innovators currently working toward finding a way to reach those neighboring planet systems.

Breakthrough Starshot, a $100 million program co-founded by Yuri and Julia Milner, and officially announced by the late Stephen Hawking, is working toward ultra-light travel at 20 percent the speed of light in an attempt to make a flyby mission to one of the nearest planet systems, Alpha Centauri. 

Discovered in 2016, the planets orbit the red dwarf star Proxima Centauri, and are more than four light-years away.

The initiative would use ground-based light beams to push tiny spacecraft attached to light sails, powered by the sun, to speeds of up to 100 million miles an hour. The innovators behind the program estimate that would allow a flyby mission to reach Alpha Centauri in about 20 years after launch. However, many engineering challenges lay ahead to make a mission like that possible.

The distance light travels in one year is about 5.9 trillion miles. Even if we had the technology to travel at the speed of light, it would take more than four years to get to Alpha Centauri.

Joe Harrington, a University of Central Florida physics professor of planetary science, who specializes in exoplanets, said how fast the technology is developed to make a mission like Starshot happen depends on multiple factors.

"Where we are in 20 years depends very strongly on general public interest, (and) wealthy people who want to invest," Harrington said. 

Funding is big a problem, Harrington said. He said the commercialization of rocket launchers is helping bring the cost down, but he doesn't see those same companies launching scientific missions on their own.

"If they were going to do that they would have done it," Harrington said of billionaires like SpaceX founder Elon Musk and Blue Origin's Jeff Bezos.

Read on to find out how long it would take to make the trek to our solar system's nearest neighbor.


Read more about how the MIT-led mission TESS will find exoplanets below and follow our launch coverage of the spacecraft here.