{"id":174322,"date":"2026-09-09T09:26:39","date_gmt":"2026-09-09T15:26:39","guid":{"rendered":"https:\/\/tecscience.tec.mx\/en\/?post_type=sciencecommunication&p=174322"},"modified":"2026-09-14T09:29:01","modified_gmt":"2026-09-14T15:29:01","slug":"astrobiological-molecules","status":"publish","type":"sciencecommunication","link":"https:\/\/tecscience.tec.mx\/en\/science-communication\/astrobiological-molecules\/","title":{"rendered":"The Signatures of Life That Telescopes Search for in Space"},"content":{"rendered":"\n

By Ana Margarita G\u00f3mez<\/strong>, Mariel Romero Mu\u00f1oz<\/strong>, and Javier Eugenio Icaza<\/strong> | CIENCIA AMATEUR<\/p>\n\n\n\n

Reviewing authors:<\/em> Edgar Andr\u00e9 Ram\u00edrez Alonso<\/a><\/em> and<\/em> Alejandro Parra C\u00f3rdova<\/a>.<\/em><\/p>\n\n\n\n

A molecule<\/strong> can have a kind of \u201cright hand\u201d and \u201cleft hand\u201d: two forms that are mirror images of each other but cannot be superimposed. These forms, known as chiral<\/strong>, are of particular interest to astrobiology<\/strong> because life on Earth<\/strong> shows a strong preference for one of these two forms.<\/p>\n\n\n\n

This phenomenon, known as homochirality<\/strong>, raises a fundamental question about the origin of life: How did nature come to favor one of these two molecular forms, and what connection might this have to the emergence of the first organisms<\/strong>? [1]<\/p>\n\n\n\n

The projects *\u201cSimultaneous search of five chiral molecules in Orion KL (OMC-1)\u201d<\/a><\/em> and \u201cExploraci\u00f3n de cinco mol\u00e9culas quirales de inter\u00e9s astrobiol\u00f3gico en la nube molecular de Ori\u00f3n KL (OMC-1)\u201d<\/a><\/em> investigated five chiral compounds of astrobiological interest\u2014propylene oxide, \u03b1-aminoethanol, glyceraldehyde, 2-aminopropionitrile, and cyanooxirane\u2014in Orion Kleinmann\u2013Low (Orion KL)<\/strong>, a star-forming region within the OMC-1 molecular cloud known for its extraordinary chemical richness [2].<\/p>\n\n\n\n

These compounds cannot be observed directly. Instead, astronomers identify them through the spectral fingerprints<\/strong> they leave in radiation<\/strong>. Each can emit or absorb radiation at specific frequencies<\/strong> as its bonds and structure rotate and vibrate. Together, these frequencies form a spectral pattern<\/strong> that acts, in a way, like a molecular fingerprint<\/strong>.<\/p>\n\n\n\n

Astrobiological molecules: How do we find them?<\/h2>\n\n\n\n

Looking for life<\/strong> in space<\/strong> is a long way from looking for living organisms. It means searching for molecules that could have been part of the chemistry<\/strong> that preceded life. In this case, the goal was to determine whether any of the five chiral molecules<\/strong> could be identified in Orion KL from the signals they leave in radiation.<\/p>\n\n\n\n

The researchers compared theoretical fingerprints<\/strong> with real archival observations<\/strong> collected by the Atacama Large Millimeter\/submillimeter Array (ALMA)<\/strong> radio telescope in Chile. To generate the expected fingerprints for each compound, they produced synthetic spectra<\/strong> under Local Thermodynamic Equilibrium (LTE) conditions using CASSIS software and spectroscopic data<\/strong> from the Cologne Database for Molecular Spectroscopy<\/em> (CDMS) and the Jet Propulsion Laboratory<\/em> (JPL).<\/p>\n\n\n\n

The theoretical spectra<\/strong> were then compared with signals detected by ALMA. CARTA<\/strong>, a software tool for analyzing and visualizing radio astronomy<\/strong> data, allowed the team to examine the observations and zoom in on regions where the compounds were expected to produce detectable signals.<\/p>\n\n\n\n

The basic idea sounds simple: if a molecule is expected to produce a spectral line at a particular frequency and the telescope<\/strong> detects a peak there, the molecule could be present. But Orion KL turns that task into a genuine puzzle. The region contains an enormous number of molecular species<\/strong>, so many spectral lines overlap.<\/p>\n\n\n\n

That means a single peak may be produced by more than one molecule<\/strong>, and an isolated match is not enough to establish that a particular species is present.<\/p>\n\n\n\n

\r\n \r\n \"\"\r\n <\/picture>
Theoretical transitional emission spectrum, calculated using the LTE model and OMC-1 parameters, for the compounds propylene oxide (orange), \u03b1-aminoethanol (blue), glyceraldehyde (brown), 2-aminopropionitrile (green), and cyanoxirane (purple), in the 100\u2013200 GHz range. (Prepared by Mariel Romero Mu\u00f1oz.)<\/figcaption><\/figure>\n\n\n\n

The findings<\/h2>\n\n\n\n

Propylene oxide<\/strong> showed the strongest evidence. Several of its spectral transitions<\/strong> matched signals detected by ALMA, making it the most promising candidate for further analysis. The researchers also found signals consistent with some transitions from \u03b1-aminoethanol<\/strong> and glyceraldehyde<\/strong>, but the matches were less conclusive and could also be explained by other molecular species.<\/p>\n\n\n\n

By contrast, cyanooxirane<\/strong> and 2-aminopropionitrile<\/strong> did not produce signals clear enough to be considered candidates. This does not mean that these compounds are absent from Orion KL or that they do not exist elsewhere in space. It simply means the data analyzed do not provide enough evidence to identify them<\/strong>.<\/p>\n\n\n\n

\r\n \r\n \"\"\r\n <\/picture>
Expanded spectral regions around 145 GHz in Orion KL, based on selected candidate transitions. Spectral data obtained from Wilkins et al. (2024), ALMA project \u201cHigh-Resolution Imaging of Deuterated Methanol (CH\u2082DOH) in Orion KL.\u201d<\/em>
(a)<\/strong> Region 145.08\u2013145.105 GHz, showing limited alignment with the predicted transitions, including those of glyceraldehyde and aminoethanol, with no conclusive assignment due to the weak agreement and possible overlap.<\/em>
(b)<\/strong> Region 145.11\u2013145.14 GHz, where several predicted transitions show better alignment with the observed spectral peaks, particularly for glyceraldehyde and propylene oxide. (Prepared by Ana Margarita G\u00f3mez, Mariel Romero Mu\u00f1oz, and Javier Eugenio Icaza.)<\/em><\/figcaption><\/figure>\n\n\n\n

New observations<\/h2>\n\n\n\n

This distinction is crucial in molecular astronomy: a match is not enough to confirm<\/strong> a molecule is present, but its absence from the data does not mean the molecule does not exist<\/strong>.<\/p>\n\n\n\n

The search for the \u201cmolecule of life\u201d is still far from a definitive answer. At this stage, it has led to a better question: Which molecules can survive, form, or transform within the clouds where stars and planets are born<\/strong>?<\/p>\n\n\n\n

Answering that question will require new observations<\/strong>, better models, and many more spectral lines<\/strong>. But every match, every ambiguous signal, and every unidentified peak may be another piece of the same puzzle: understanding how cosmic chemistry<\/strong> may have prepared the stage for life<\/strong>.<\/p>\n\n\n\n

\r\n \r\n \"\"\r\n <\/picture>
From left to right: Omar Salda\u00f1a Penetro, Ra\u00fal Naranjo, and Ana Margarita G\u00f3mez Romo at the Gran Telescopio Milim\u00e9trico Alfonso Serrano (GTM) facilities on Sierra Negra, Puebla. (Photo: Omar Salda\u00f1a Penetro.)<\/em><\/figcaption><\/figure>\n\n\n\n
Refer<\/strong>ences<\/h6>\n\n\n\n
    \n
  1. McGuire, B. A., Carroll, P. B., Loomis, R. A., Finneran, I. A., Jewell, P. R., Remijan, A. J., & Blake, G. A. (2016). Discovery of the interstellar chiral molecule propylene oxide (CH\u2083CHCH\u2082O)<\/a><\/em>. Science, 352<\/em>(6292), 1449\u2013145<\/li>\n\n\n\n
  2. Cunningham, M. R., Jones, P. A., Godfrey, P. D., Cragg, D. M., Bains, I., Burton, M. G., \u2026 & Shobbrook, R. (2007). A search for propylene oxide and glycine in Sagittarius B2 (LMH) and Orion KL<\/a>. Monthly Notices of the Royal Astronomical Society, 376<\/em>(3), 1201\u20131210. <\/li>\n<\/ol>\n\n\n\n

    .<\/p>\n\n\n\n

    Scientific Forums<\/strong><\/h6>\n\n\n\n

    Los resultados del proyecto para rastrear estas mol\u00e9culas astrobiol\u00f3gicas <\/strong>se presentaron en dos foros cient\u00edficos: el TecScience Summit 2026<\/strong>, en el marco de Next-Gen Scientist<\/strong><\/a>, y la reuni\u00f3n de la American Chemical Society<\/strong> en Atlanta. <\/em><\/p>\n\n\n\n