Breathable Oxygen Spotted in Another Galaxy for the First Time, Scientists Say

Astronomers have discerned the presence of molecular oxygen in a remote galaxy, marking the inaugural instance of this pivotal element’s detection beyond the confines of the Milky Way.

This significant milestone, termed the “first detection of extragalactic molecular oxygen,” in a recent publication in The Astrophysical Journal, carries profound implications for comprehending oxygen’s pivotal role in the evolutionary trajectories of planets, stars, galaxies, and the genesis of life.

Oxygen, ranking third in cosmic abundance following hydrogen and helium, represents one of the fundamental prerequisites for life on Earth. Molecular oxygen, manifested as the predominant gaseous form comprising two oxygen atoms, designated O2, is indispensable for respiration across numerous organisms, including humanity.

Despite its omnipresence and criticality to habitability, scientists have grappled for prolonged periods to discern molecular oxygen beyond our terrestrial confines.

Presently, a consortium led by Junzhi Wang, an astronomer affiliated with the Shanghai Astronomical Observatory, reports the identification of molecular oxygen within the resplendent galaxy dubbed Markarian 231, situated at a staggering distance of 581 million light years from the Milky Way.

Employing ground-based radio observatories, the team unveiled molecular oxygen emissions “in an external galaxy for the first time,” through meticulous scrutiny facilitated by the IRAM 30-meter telescope in Spain and the NOEMA interferometer in France.

The Earth’s atmosphere acts as a hindrance, absorbing an array of wavelengths essential for oxygen detection, thereby complicating endeavors to pinpoint this element amidst the atmospheric shroud enveloping our planet.

Consequently, the exclusive sightings of molecular oxygen within the Milky Way were accomplished via spaceborne telescopes unimpeded by atmospheric interference. In recent decades, satellites have successfully discerned molecular oxygen within the Rho Ophiuchi cloud and the Orion Nebula, positioned respectively at distances of 350 and 1,344 light years from Earth.

The signature of molecular oxygen was deciphered by Wang and associates, facilitated by the redshifted illumination emanating from Markarian 231. This phenomenon, characterized by the elongation of wavelengths during traversing cosmic expanses, rendered Earth’s atmosphere less proficient in impeding oxygen emissions, compared to instances involving proximal sources.

Markarian 231, initially identified in 1969, has remained an enigmatic subject of scientific scrutiny owing to its designation as the nearest known quasar, a class of hyper-energetic entities inhabiting the galactic core. Quasars, categorized as active galactic nuclei (AGN), represent luminous celestial bodies of immense potency within the cosmic tableau.

While Markarian 231 encapsulates the identical oxygen variant essential for human respiration, it is imperative to underscore that inhalation of this extragalactic reservoir akin to a quasar-derived coursing hound is implausible. This arises from the absence of requisite proportions of nitrogen, carbon dioxide, methane, and myriad other molecules essential for rendering Earth’s atmosphere breathable to terrestrial life forms.

The team envisages promising prospects in targeting energetic systems akin to Markarian 231 for subsequent endeavors aimed at extragalactic molecular oxygen detection. The study delineates a revelation of approximately 100-fold greater oxygen content within the distant galaxy compared to antecedent Milky Way detections, predominantly dispersed tens of thousands of light years into the galactic peripheries by the tumultuous quasar of Markarian 231.

This discovery “furnishes an optimal instrument for exploring” molecular outflows originating from quasars and other AGNs, as articulated by the team within the study. “O2 may emerge as a pivotal refrigerant for molecular gases within regions influenced by AGN-driven effluences,” the researchers accentuate. “Novel astrochemical frameworks are requisite to explicate the implied elevated molecular oxygen abundance within regions spanning several kiloparsecs distant from galactic cores.”

In light of these developments, the researchers advocate for the utilization of next-generation radio observatories, exemplified by the Next-Generation Very Large Array (ngVLA), to expedite novel extragalactic oxygen detections.

Subsequently, a scientific discourse may be initiated to unravel the enigmas surrounding this element’s impact on planetary, stellar, and galactic evolutions—alongside elucidating its precise contributions towards fostering habitability.