NASA and the journal Nature made announcements this week which increase the odds of life beyond Earth significantly.
NASA’s announcement is the bigger of the two. Scientist’s found life in California’s Mono Lake that is unlike all other known life on Earth. Until now, all life we knew about on Earth was made up of six components: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. A few scientist has suggested there may be other combinations, but we had not found any that did.
Until now, that is. This week, Nasa Announced:
Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.
Phosphorus is a critical part of cellular structure. It is part of the chemical makeup or RNA and DNA. Phosphorus is required in the molecules for carrying energy in cells. And it is part of the material for cell membranes.
Arsenic is chemically similar to phosphorus. This causes major problems with most life on Earth since it is able to bind with other chemicals disrupting metabolic pathways. While scientist have found microbes which can breathe arsenic, this is the first microbe discovered which is building parts of itself using arsenic.
The search for life beyond Earth has largely focused on looking for the six essential components in an area where they can readily mix as they have here on Earth, in liquid water. Certainly, the search will now go beyond the primary six.
"If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?"
- Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team’s lead scientist.
The announcement just published in Nature and reported in Gizmodo this way, “new observations on the red end of the optical spectrum at the W. M. Keck Observatory in Hawaii show an overwhelming population of red dwarfs in eight massive nearby elliptical galaxies. The team has discovered that these galaxies hold twenty times more red dwarfs than the Milky Way.”Van Dokkum says that "there are possibly trillions of Earths orbiting these stars" which are "typically more than 10 billion years old." According to him, that’s long enough for complex life to evolve, which is "one reason why people are interested in this type of star."
Carl Sagan explains why life and in particular intelligent life is more likely with the discovery of more stars similar to our Sun and more combinations for how life can form.