While scientists are expecting life to continue on Earth another 1.78 billions years, humans could become extinct long before that. According to a study published in the magazine Astrobiology, astrobiologists are predicting that Earth will move out of the solar system’s “habitable zone” and become too hot for all but the most primitive, extreme-weather-loving bacteria. The solution? Hop on over to Mars.

The habitable zone—nicknamed the Goldilocks zone—refers to the area around a star (such as our sun) where planets with the right atmospheric pressure can support liquid water. “We estimate Earth will cease to be habitable somewhere between 1.75 billion and 3.25 billion years from now,” said Andrew Rushby, of East Anglia University. “After this point … the seas would evaporate. We would see a terminal extinction event for all life.”

According to Rushby, humans’ only hope lies in Mars. “It’s very close and will remain in the habitable zone until the end of the sun’s lifetime – 6 billion years from now,” Rushby said. How long a planet can be inhabited dictates how complex life evolves, again according to Rushby. For example, insects have been around 400 million years, dinosaurs 300 million years, but humans have only been around 200,000 years, indicating that it takes a very long time for intelligent life to evolve.

Humans may be the most intelligent species on the planet, but according to Rushby, we may also be the least capable of handling drastic changes in the Earth’s climate and atmosphere, which is being accelerated by climate change. “Humans would be in trouble with even a small increase in temperature,” Rushby said.

Scientists had first believed that the Sun’s habitable zone starts at about 0.95 astronomical units (AU), which is far enough away from the Earth’s orbit at 1 AU. However, another body of work by James Kasting and colleagues at Penn State University, NASA and the University of Bordeaux has found that the inner edge of the habitable zone is actually much farther out at 0.99 AU, uncomfortably close to Earth’s orbit.

The Earth has been moving out of the inner edge of the sun’s habitable zone, according to Kasting and his research team. Moving out of this habitable zone would result in the planet experience a “moist greenhouse” climate that could increase the drastic changes we already face in our atmosphere, according to the study.

Kasting believes the information is sobering. “If you are this close to [the] inner edge of the habitable zone, it is not as difficult to push yourself over…[and] that is catastrophic,” he says.