The search for a habitable Earth 2.0
Jan. 30, 2023.
4 min. read Interactions
In about 5 billion years, the Sun is due to turn into a red giant. But long before then, there are other concerns, such as asteroids, global warming, and nuclear destruction.
So there’s a long-range quest to find planets that orbit stars other than the Sun, referred to as “Earth 2.0.” As conceived by NASA, Earth 2.0 would be a habitable planet similar enough to Earth , intended to enable the existence of life as we know it. Assuming we could somehow get there, we would also require a “habitable zone” that:
- Is similar enough to Earth to enable existence of life as we know it.
- Is the right temperature for liquid water
- Orbits a nearby star with a steady supply of light.
- Ideally, is close enough that we could imagine going there or at least sending a probe to explore it.
Researchers at Rensselaer Polytechnic Institute have just received a grant from NASA to find out how. Or at least, find all such habitable-zone planets closer than 10 parsecs, or 192 trillion miles, the range of our technology. The researchers are leading a team in pursuit of an idea that could make it possible to find nearby, habitable, Earth-like planets — or prove that they are unlikely to exist.
Heidi Jo Newberg, professor of physics, applied physics, and astronomy at Rensselaer, has been named a NASA Innovative Advanced Concepts (NIAC) Program Fellow. She will join a prestigious group of innovative scientists whose visionary ideas have included new types of space propulsion systems, robots that are modeled after nature such as spiderbots, and technology that makes it easier for humans to live in space.
Three times the diameter of the James Webb Space Telescope — range: 192 trillion miles
The key technology, designed by Thomas D. Ditto, inventor of the “Dittoscope” (“Diffractive Interference Coronagraph Exoplanet Resolver” or DICER) telescope, would be three times the diameter of the state-of-the-art James Webb Space Telescope. It’s designed to find all habitable zone planets closer than 10 parsecs, or 192 trillion miles.
“With DICER, light from a faint planet would be collected by two 10-meter diffraction gratings, which are easier to pack up in a rocket to shoot into space than a telescope with conventional mirrors and lenses,” Ditto explained. “DICER uses a diffraction grating primary objective and that changes everything.”
To determine whether conditions on a planet are right for life or whether it has already started to develop, scientists look at the air that surrounds the planet. But DICER may even be able to detect if the newly discovered exoplanets have atmospheric ozone, a biomarker that may indicate the existence of life as we know it.
Is all this feasible?
“Nobody really knows,” Newberg says. “We could find zero or we could find 100 habitable exoplanets. But the discovery of even one oxygen-rich, terrestrial exoplanet in the local neighborhood of our own Sun would be among the most publicly engaging astronomical results of all time!
“The DICER technology is also scalable, so the potential exists to find exoplanets that are fainter or farther away in the future. So far, most exoplanets have been found because they pass in front of their host star and block some of its light, but DICER could find exoplanets that orbit in any orientation.”
Newberg and her doctoral student Leaf Swordy will collaborate with Shawn Domagal-Goldman and Richard K. Barry, astronomers at NASA Goddard Space Flight Center; and L and Frank Ravizza, optical engineers at Lawrence Livermore National Laboratory.
Update January 31:
Comments by legendary science-fiction author and astronomer Dr. David Brin sent to Mindplex
I doubt NASA wants to be directly cited as fostering notions of interstellar colonization.
1. Because of the distances … the nearest such world (if they exist at all) … would be a million times farther than NASA’s greatest current ambition.
2. A popular expression is “there is no Planet B.” If you talk about a backup world to Earth, you risk being denounced as someone willing to give up on saving Planet A.
I’d rewrite the opening to emphasize that.
While it is both fun and enthralling to speculate about our descendants someday crossing the vast interstellar gulfs to other habitable worlds, that is not the central goal of scientific campaigns to seek “Earthlike planets” out there. No such world can ever serve as a “Planet B” to escape from our duties, here in the Solar System. Still NASA and the European Space Agency and others have prioritized the search for life-bearing worlds circling other stars, in part because of great public and scientific interest. But another motive must be to gain information about alien ecosystems — both their similarities and differences — which might improve our models and our planetary management, here at home.