Scientists have observed what they believe could be the precursors of life in the region around a distant star.
But don't start writing that interstellar pen pal quite yet. What researchers are seeing is a disc of red dust around a star about twice the size of our own sun. The eight-million-year-old star, known as HR 4796A, is believed to be in the late stage of planet-building.
Using instruments on the Hubble Space Telescope, researchers from the Carnegie Institution and the University of Arizona found that the spectrum of light reflected from the dust disc appears very red, different from what would be observed with common molecules such as iron oxide, but just right to be an indication of large organic carbon molecules called tholin.
We don't see tholins on Earth today, because they would quickly be destroyed by the oxygen in our atmosphere. However, scientists believed they may have existed here early in the planet's history, and they have been detected on comets and on Saturn's moon Titan. Some scientists believe that tholins were precursors to the biomolecules that make up living organisms here on Earth.
The team's observation was the first time tholins have been seen outside the solar system, and indicate that "the basic building blocks of life may be common in planetary systems," the researchers said.
HR 4796A is about 220 light years from Earth. A paper on the findings is being published in the current issue of Astrophysical Journal
Letters.
Red Dust in Planet-Forming Disk May Harbor Precursors to Life [Carnegie press release]
Complex Organic Materials in the Circumstellar Disk of HR 4796A [ArXiv.org]
(Image: Red and near infrared wavelengths from the dust disk surrounding the star HR 4796A. Credit: John Debes)
