Leading astronomers will use the just-launched Roman Space Telescope to search for Earth doppelgängers across the center of the Milky Way, Shown here are the seven Earth-like planets in the TRAPPIST-1 star system, originally discovered via the TRAPPIST telescope, and then confirmed via NASA’s Spitzer Space Telescope. Three of the planets orbit in the habitable zone of their M-dwarf star. (Photo digital Illustration by NASA/NASA via Getty Images)
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The picture-perfect launch of NASA’s Roman Space Telescope could push forward the American space agency’s overarching search for life across the Milky Way, says a leading scientist who helped develop the cutting-edge observatory.
Astronomers pointing the fantastical telescope toward the center of the galaxy, which is rich with ancient stars and planets born billions of years before the solar system formed, hope to find twins of Earth that orbit in the habitable zone of their sun, says Vanessa Bailey, part of the Roman Telescope team of scientists for nearly a decade.
Dr. Bailey told me in an interview that some searches conducted via the Roman Observatory could seek out rough doppelgängers of the entire solar system.
Earth analogue planets that orbit in the optimal zone around their star, with temperatures ranging between 1 and 99 degrees Celsius and liquid water across their surface, carry a higher chance of hosting some alien life forms.
NASA is partly gearing its Roman observations of the galactic center to finding and characterizing Earth 2.0s.
A generation ago, after astronomers simulated variations on the solar system as potential models for other sections of the Milky Way, many were shocked when the first cannonade of exoplanet discoveries turned up radically different planet-star configurations, says Bailey, who conducted postdoctoral research at Stanford University after obtaining a doctorate in astronomy.
Starting with the first confirmed detection of an exoplanet around a Sun-like star in 1995, many of the earliest alien worlds uncovered were gas giants that tightly orbited their star, and became so ubiquitous across the field of astronomy they were nicknamed “Hot Jupiters.”
Many exoplanets discovered so far have been “Hot Jupiters,” or gas giants that orbit in close proximity to their star. Shown here is a Hot Jupiter about to partially eclipse its sun. AFP PHOTO NASA/ESA/K. SAHU (STScI) AND THE SWEEPS SCIENCE TEAM (Photo credit should read -/AFP via Getty Images)
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These Hot Jupiters, Bailey says, meant that the earlier, prevalent solar system simulations could not account for the wide range of actual planet-star groupings that were being discovered with generations of observatories including the Kepler Space Telescope and the orbiting Hubble Telescope.
A radically expanded atlas of simulations needs to be developed to account for the alien planet configurations being uncovered, she says.
But NASA will still search for star systems that resemble the earlier models.
“I think it’s likely that there’s no exact twin to our Solar System,” Bailey told me in an interview.
“But I’m interested in the question: how common are similar systems?”
Before the first exoplanet was discovered in 1995, astronomers created simulations of star-planet configurations that might populate the Milky Way that were all based on variations of the Solar System (Photo credit should read IAU/AFP via Getty Images)
AFP via Getty Images
“That’s a question Roman will go a long way toward answering, with its Galactic Bulge Time Domain Survey, using the [300-megapixel camera] Wide Field instrument and the microlensing technique,” says Bailey, who has played a pivotal role in perfecting the Roman Space Telescope as a scientist at NASA’s leading-edge Jet Propulsion Laboratory in Pasadena, California.
The JPL lab is operated by the California Institute of Technology, one of the top science universities in the U.S. and globally.
The uncovering of a torrent of Hot Jupiters was tied to the two dominant planet detection methods being used by scientists over the past three decades, Bailey says.
Both the transit method, which detects a planet by measuring the partial eclipse of its star’s light when it passes between the star and the remote astronomical observer, and the radial velocity method, which tracks the gravitational pull a planet exerts on its sun, are biased in favor of giant planets that orbit in close proximity to their sun, she says.
By switching to the gravitational microlensing method, she says, Roman Telescope scientists will be able to detect smaller terrestrial planets that orbit farther away from their star.
The picture-perfect launch of the Roman Space Telescope aboard a SpaceX Falcon Heavy rocket from NASA’s Kennedy Space Center in Cape Canaveral, Florida. (Photo by Joel Kowsky/NASA via Getty Images)
NASA via Getty Images
Gravitational lensing is an application derived from Einstein’s General Theory of Relativity, which postulates that massive bodies can warp the fabric of spacetime.
Just over a century ago, Einstein posited that giant objects like galaxies, or even stars, could act as a lens that magnifies line-of-sight star systems behind the lens, or even create multiple images of a single lensed galaxy.
These cosmic lenses are built into the physics of the cosmos, and sprinkled across the universe, and can aid astronomers in observing distant star systems magnified by an intervening star cluster.
Gravitational microlensing can bolster the detection of stars and even planets and moons amplified by a fortuitously positioned lens.
Astronomers using the Roman Telescope might start by mapping out an atlas of lenses to aid in their survey of the galaxy’s center.
Gravitational lensing on a grand scale. A gravitational lens occurs when light from a very distant, bright source (such as a quasar) is bent around a massive object (such as a galaxy) situated between the source object and the observer. Gravitational lensing was predicted by Einstein’s General Theory of Relativity. (Photo by Oxford Science Archive/Print Collector/Getty Images)
Print Collector/Getty Images
Using microlensing, Bailey predicts, Roman astronomers might discover tens of thousands of new planets, potentially including Earth analogues studded across the Milky Way.
Meanwhile, Vanessa Bailey said during a NASA Curious Universe podcast, in a sensational show hosted by Jacob Pinter, that the overwhelming prevalence of gas giants in exoplanets discovered to date means that: “The planet formation model that produced our solar system is not the only type of planet formation that happens in our galaxy.”
“Our solar system is not the universal blueprint.”
Some astronomers hypothesize that there might not be a universal blueprint for solar system formation.
Every star system discovered into the future might be entirely unique, like the endless outpourings of one-of-a-kind snowflakes that have been produced for aeons.
Yet with NASA estimating there are hundreds of billions of stars across the Milky Way, near-looking-glass versions of the solar system might still be discovered.
“The Wide Field instrument will use the microlensing method,” she said during the Curious Universe show, “to get the most complete census to date of smaller planets orbiting at distances more like Earth, Mars, Jupiter.”
Vanessa Bailey, a leading scientist who helped develop the Roman Space Telescope, is based at NASA’s cutting-edge Jet Propulsion Laboratory, operated by the California Institute of Technology. (Photo by Mario Tama/Getty Images)
Getty Images
Joshua Roth, an astrophysicist at Princeton University who headed a recent search for exoplanets that discovered a remarkable 10,000 candidates based on observations using the Transiting Exoplanet Survey Satellite (TESS) space-based telescope, told me in an interview that the Roman Observatory might uncover even more planets orbiting alien stars.
Roth said his international team of astronomers ultimately found a treasure trove of exoplanet candidates using the transit method of detection, which turned up mostly “Hot Jupiters.”
These Jupiter analogues accounted for nine-tenths of all of his team’s newly discovered planets.
With the new space-based super-telescopes coming online, Roth says, a new golden age of exploring the cosmos is unfolding, and he predicts that an explosion of new candidate planets could be uncovered over the course of the next decade.
He forecasts the Roman Space Telescope will discover a gushing torrent of new planets, but adds that the microlensing technique to be used in tandem with the observatory potentially holds one drawback.
Most of the Roman Telescope’s newly detected planets, he says, “will be around very faint stars (much fainter even than the ones we searched in our transit search), and thus, it will be exceedingly difficult to confirm how many of those candidates are true positives.”
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