Orange Sun? Purple Trees? 'Superhabitable' Planets May Be Better for Life

Imagine landing on a world where a larger sun glows orange in an amber sky. On this planet, the days and nights last longer. And the plants and trees sprout dark leaves. Their colors are dark purple and charcoal black. 

Sounds weird, doesn’t it? But such a planet might be better for life than our Earth, scientists say. It's a possible “superhabitable” world imagined circling around an orange “K-dwarf” sun. No such planet has been found. But scientists have found possible ones that might be like it. They circle these stars within habitable zones. They may have liquid water. That's needed for life.

"We are so over-focused on finding a mirror image of Earth that we may overlook a planet that is even more well-suited for life," Dirk Schulze-Makuch told Space.com. He's a Washington State University space scientist. 

Scientists say such a world would revolve much closer to a cooler star. A nearby planet might have more land for animal and plant life as a result. It could also have seas with many more species because of its shallow waters. The climate would be more temperate and stable. And life on that world would have had billions of years longer to evolve. That's because a K-dwarf star is more stable than our sun. Also, the trees and plants would be darker because they would need to absorb every scrap of light from a dimmer star to survive, scientists say.

In 2023, astrobiologist Iva Vilović grew garden cress in a Berlin lab under simulated K-dwarf sunlight. To her delight, the plant grew faster and taller, sprouting bigger and deeper green leaves, though not as dark as the colors imagined on alien planets. 

“I like to believe that statistically speaking, in the realm of the universe, it is likely that life exists,” Vilović told The New York Times, “especially on superhabitable planets.”  

Reflect: What is a mystery about the universe you would most like to see solved in your lifetime?

Photo of an artistic depiction of an orange K-dwarf planet from Reuters.