CAMBRIDGE, England — Astrophysicists don finally gather strong evidence say extraterrestrial life fit dey far away beyond our solar system. Dem observations on K2-18b, a planet 124 light years from Earth, show say chemical fingerprints of two compounds wey only life fit produce don appear.
Dis finding, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), no mean say dem don find proof say alien life dey exist, but e fit get us closer to understanding whether we dey alone in the universe. “This na di strongest evidence we don get for biological activity beyond di solar system,” Prof. Nikku Madhusudhan, wey lead di research, talk. “We dey cautious so we gatz question whether di signal dey real and wetin e mean,” he add.
K2-18b, wey dey inside Leo constellation, dey nearly nine times di size of Earth and orbit for habitable zone of its star, wey na cool red dwarf wey small pass di sun. As di Hubble Space Telescope spot di planet, scientists come declare am di “most habitable known world” wey dey beyond di solar system.
Pretending water signal turn out to be methane during follow-up observations by Madhusudhan’s group for 2023, dem still believe say di planet profile fit mean say e get vast ocean. Some skeptics still dey argue about di overall conditions for K2-18b and whether di chemical compounds fit be reliable biosignatures.
To study di planet atmosphere, scientists dey track di planet as e dey move across di face of di host star and measure di light wey comot from di atmosphere. Di latest observations show say di wavelengths wey DMS and DMDS dey absorb suddenly drop as K2-18b enter front of di red dwarf. “Di signal come through strong and clear,” Madhusudhan talk. “If we fit detect these molecules for habitable planets, na di first time we don fit do am as a species… e no easy to believe say dis fit happen.”
Di findings publish for The Astrophysical Journal Letters show say di concentrations of DMS and DMDS dey thousands of times stronger than wetin dey for Earth, wit a “three-sigma” level of statistical significance (0.3% chance say dem happen by chance). Although dis no meet di gold standard for discoveries for physics, e still dey generate excitement.
“There fit be processes wey we no sabi wey dey produce these molecules,” Madhusudhan talk. “But I no think say any known process fit explain wetin we dey see without biology.” Dis insight dey challenge, as di scientific community still dey argue about di true conditions of di planet.
“Life na just one of di options, but e fit remain among many,” Dr. Nora Hänni, wey be chemist for di University of Berne, share her perspective. “We gatz strictly rule out all di other options before we claim life dey.”
Some scientists believe say measuring planetary atmospheres go continue dey hard to find conclusive proof for life. “Technosignatures, like intercepting message from advanced civilization, fit be better evidence, regardless of di likelihood,” Dr. Caroline Morley from di University of Texas, Austin, talk.
Dr. Jo Barstow, wey dey work for di Open University, say di detection dey significant, but he advise caution: “My skepticism for any claim wey relate to evidence of life no dey low, not because I no believe say life dey out there, but I feel say di burden of proof gatz high.”
At 120 light years away, di debate no fit resolve through close-up observations, but Madhusudhan remind say dis no stop discovery of black holes and other cosmic phenomena. “For astronomy, di question no be about going there,” he conclude. “We dey try establish if di laws of biology dey universal in nature. I no see am as: ‘We gatz go swim inside di water to catch di fish.’”
Di research don provide new hints say maybe K2-18b fit be inhabited, but independent astronomers urge say dem need more data to confirm di findings. “These na di first hints we dey see of alien world wey fit dey inhabited,” Prof. Madhusudhan talk at a press conference, add say e hope say dem go confirm di signal within one or two years.
“K2-18b na two and a half times di size of Earth and e dey seven hundred trillion miles away from us. Di JWST na powerful telescope wey fit analyze di chemical composition of di planet’s atmosphere from di light wey pass through from di small red Sun wey e dey orbit.”
