Can We Ever Get To Earth 2.0?

Recently, astronomers discovered Kepler-452b, calling it the "most Earth-like planet ever discovered". It is a place that has enough sunlight to perhaps sustain the crops and house plants of life forms like the earth's, according to nbcnews.

However, though it sounds like an attractive vacation spot, it's a bit far off.

Just 1,400 light-years away.

And another discovery of the "closest confirmed rocky exoplanet to Earth", that one with the rather attractive name of HD 219134b, was also announced by NASA on Thursday.

Now this one is closer, as it is 21 light-years away.

But what makes that Earth 2 more alluring is that it's a "Goldilocks planet." It seems to be the most habitable, as its temperatures are not too hot or cold for liquid water to form.

On the other hand, HD 219134b is a boiling planet that sticks too close to the sun for any water or life to exist.

Kepler-452b probably has a rocky surface and thick atmosphere, which seems closest to the earth. However, to travel 1,600 light years, you need a ship to travel faster than the speed of light, which is tough. With existing technology, one trip to Kepler-452b may take too long to complete in one lifetime.

NASA's New Horizons probe would involve 20,000 years to travel one light-year, according to Jeffrey Bennett, astronomer and author of "What Is Relativity?: An Intuitive Introduction to Einstein's Ideas, and Why They Matter." That kind of rocket would involve 28 million years to reach Kepler-452b, Bennett told NBC News.

What looks more feasible is the electrically-powered ion engine on NASA's Dawn orbiter, which would be way more efficient than the chemical thrusters used by past spacecraft. With NASA Evolutionary Xenon Thruster (NEXT), it is hoping to "propel future spacecraft as fast as 90,000 miles per hour, rather than the current speed of 9,600 miles per hour.

Still, it would take 10.5 million years to reach Kepler-452b.

Another possibility is what was proposed in 1958, by physicist Freeman Dyson for Project Orion, using pulsed nuclear explosions to move a giant ship forward at around 5 percent the speed of light. Still, it would take 28,000 years to reach Kepler-452b from Earth. Now that would be an improvement, but still impossible to get people going on such a journey.

So what we would really need is an antimatter engine, which is matter with the electrical charge reversed. For instance, an antiproton is a proton with a negative rather than a positive charge. With antimatter meeting matter, it could create so much energy that it would power a rocket engine or even a bomb. NASA said that it would take $100 billion to create one milligram of antimatter in a particle accelerator.

"Creating a spacecraft engine with the stuff would require finding a way to make tons of it, then harnessing the intense energy from a matter/antimatter reaction. If human beings figured that out, some scientists believe an antimatter engine could propel a spacecraft forward at 70 percent the speed of light. In that case, it would take a 2,000 years to reach Kepler-452b," according to nbc.

"That is a long time," said Charles Liu, an associate in astrophysics at the American Museum of Natural History, told NBC News. "Two thousand years ago, the Roman Empire was around."