NASA researchers have found the building blocks of DNA, the genetic molecule that is essential to all life forms, in meteorites, pieces of space rock that have fallen to Earth. The discovery suggests that similar meteorites and comets may have impacted Earth and assisted in life formation here.
With minimal chance for contamination of the meteorite samples, scientists are confident that these meteorite specimens were formed in space. “People have been discovering components of DNA in meteorites since the 1960's, but researchers were unsure whether they were really created in space or if instead they came from contamination by terrestrial life,” Michael Callahan, lead author of the study on the discovery, said in a statement.
The research team analyzed twelve carbon rich meteorites, nine of which were from Antarctica, to positively identify the basic elements of the chemical compounds they extracted from the samples. Testing revealed adenine and guanine, two fundamental components of DNA called nucleobases.
DNA is shaped like a double helix, or twisted ladder, and the rungs of that ladder are each comprised of two nucleobases, either a pairing of adenine and thymine or of guanine and cytosine. The ladder is essentially a long string of genetic code that tells cells in an organism which proteins to make. Those proteins then play critical roles in organism growth and function, making everything from hair to enzymes.
Scientists also found hypoxanthine and xanthine, two other chemicals used in biological processes and found in muscle tissue.
The meteorites also contained trace amounts of three molecules associated with nucleobases, called nucleobase analogs, but two of those are almost never seen in biology, providing the necessary proof that these DNA components were actually created in outer space.
In fact the only record of any of these nucleobases in biologic processes is within a virus. Callahan said in the NASA press release that “if asteroids are behaving like chemical 'factories' cranking out prebiotic material, you would expect them to produce many variants of nucleobases, not just the biological ones, due to the wide variety of ingredients and conditions in each asteroid,” and that is exactly what these researchers found. He says the nucleobases found, biological or not, can also be created in a lab setting, using the basic compounds hydrogen cyanide, ammonia, and water.
This finding contributes further to the growing collection of evidence that asteroids and comets are comprised of the proper chemicals to generate the building blocks of life. Some seem to have the ideal internal chemistry for the job.
“In fact, there seems to be a ‘goldilocks’ class of meteorites,” Callahan said in a statement, “the so called CM2 meteorites, where conditions are just right to make more of these molecules.”
The National Oceanic and Atmospheric Administration (NOAA) is keeping an eye on a set of solar storms and explosions that could disrupt satellite, telecommunications and electric equipment here on Earth in the next few days.
While activity had reportedly returned to somewhat normal levels when solar winds calmed Monday morning, another explosion Tuesday was three times larger than the February 15 flare, which, until now, was the most significant flare of this solar cycle.
The real forecast worth taking a look at, however, is the one for 2013, when solar activity levels are expected to peak with the next "solar maximum" within the 11-year activity cycle. Electric and magnetic interference from solar storms blasting electrically charged particles into the Earth’s magnetic field can cause major interferences on earth. Already this year, there have been reports of lost high-frequency radio communication with aircraft near the Arctic, along flight paths where pilots depend on such communication for flight safety and guidance.
Scientists at the Herschel Space Observatory in Pasadena, California, have found oxygen– in space. Using the facility’s large telescope and state-of-the-art infrared detectors, the European Space Agency project has provided the first confirmed findings of oxygen molecules in space. Individual atoms have been allegedly spotted before, but the breathable molecular form of oxygen has never been seen before.
“Oxygen gas was discovered in the 1770s, but it's taken us more than 230 years to finally say with certainty that this very simple molecule exists in space,” said project scientist, Paul Goldsmith, according to the Herschel press release.
The launch window for NASA’s next mission, one the agency is calling a “five-year cruise to Jupiter”, opens next week, and scientists are hoping it will answer some giant questions about the giant planet.
Juno, named after the god Jupiter’s wife in Greek and Roman mythology, has been in the making since the early 2000s. In the ancient Roman stories, Jupiter, the god of the sky, pulled a veil of clouds around himself to hide his mischief, and only his wife was able to peek through and see him as he truly was.