最新研究：外星生命可能真的存在

导读 

据英国《每日电讯报》9月15日报道，来自利兹大学的科学家们发现年轻恒星周围有大量大型有机分子存在，这表明导致在整个银河系上出现生命的基本化学条件可能广泛存在，也就是说，我们银河系中出现外星生命的可能性比最初想象的要大得多。该研究结果近日发表在《天体物理学报》增刊系列中。

Chances of alien life in our galaxy are much more likely that first thought after scientists found "significant amounts" of large organic molecules surrounding young stars.

▲The image above shows four of the protoplanetary discs. Photo/University of Leeds

Dr John Ilee, a research fellow at the University of Leeds, who led the study, said the findings suggested that the basic chemical conditions that resulted in life on Earth could exist more widely across the Milky Way.

The team studied the discs of swirling material that surround stars and will eventually come together to form planets.

They found large reservoirs of precursor molecules that are "stepping stones" to complex molecules needed for life, such as sugars, amino acids and ribonucleic acid.

▲ An artist's impression of the gas and dust in the disk surrounding the young star. The inset image, right, shows a mix of both simple and complex molecules in the vicinity of still-forming planets. Photo/Centre for Astrophysics/Harvard & Smithsonian

Each molecule emits light at different wavelengths, producing a unique spectral "fingerprint" that can be picked up by telescopes.

The team studied data from the Atacama Large Millimetre/submillimetre Array (Alma) radio telescope in Chile, looking for the molecular fingerprints surrounding new stars.

Dr Ilee said: "Alma has allowed us to look for these molecules in the innermost regions of these disks, on size scales similar to our solar system, for the first time. Our analysis shows that the molecules are primarily located in these inner regions with abundances between 10 and 100 times higher than models had predicted."

Crucially, the disc regions in which the molecules were found are also where asteroids and comets form. Many scientists believe that life was seeded on Earth through bombardment by asteroids and comets containing large organic molecules.

It suggests that the same mechanism may be at work throughout the galaxy and beyond.

"The key result of this work shows that the same ingredients needed for seeding life on our planet are also found around other stars," said Dr Catherine Walsh, from the school of physics and astronomy at the University of Leeds.

"It is possible that the molecules that are needed to kickstart life on planets are readily available in all planet-forming environments."

The team now wants to find out whether more complex molecules exist in the star discs.

Dr Ilee added: "If we are finding molecules like these in such large abundances, our current understanding of interstellar chemistry suggests that even more complex molecules should also be observable."

The research was published in the Astrophysical Journal Supplement Series.

Source: The Telegraph  

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