Scientists have found all the bases of DNA in meteorites. Now, there’re good chances of life on exoplanets. Here’s all
Article by: Andacs Robert Eugen, on 30 April 2022, at 06:30 am Los Angeles time
Scientists have confirmed for the first time that meteorites and space rocks that have recently fallen to Earth contain all 5 bases that store information in DNA and RNA. And among these, scientists also found 30 nitrogen heterocyclic molecules in the meteorites.
The 5 bases are in order: adenine, guanine, cytosine, thymine, and uracil. They combine with sugars and phosphates, making up the entire code of life on Earth.
This discovery makes us think a little about how life came to be on Earth.
Researchers claim that the new discovery is in addition to the many pieces of evidence that show that all this code of life that is now, breathes, and thinks on Earth, came from space.
However, there is also the possibility that only certain "ingredients" came from space, and that the creation of codes that are now in our DNA began on Earth.
But something clearly comes from space and is not the first discovery to show that meteorites may have brought the necessary elements from space to create life on Earth, but it is the most complex discovered to date.
Since 1960, researchers have detected adenine, guanine, and other organic compounds in meteorites, including uracil indices.
However, only now have they clearly detected that cytosine and thymine are present in meteorites.
About the new discovery:
All the study began a few years ago when geochemist Yasuhiro Oba of Hokkaido University in Sapporo, Japan, and his colleagues found a new method of separating compounds from liquefied meteorites that is much more efficient than what was known to date.
Until then, acid was used to separate the compounds, but Oba and his colleagues found a way to pour cold water, not acid.
"Our detection method has orders of magnitude higher sensitivity than that applied in previous studies," Oba says.
"Three years ago, the researchers used this same technique to discover ribose, a sugar needed for life, in three meteorites." he continued.
After discovering this method, Oba collaborated with NASA scientists to discover something in meteorites - all 5 bases in DNA and RNA also called nucleobases, mentioned above.
And, they succeeded!
"We've completed the set of all the bases found in DNA and RNA and life on Earth, and they're present in meteorites," says astrochemist Daniel Glavin of NASA's Goddard Space Flight Center in Greenbelt, Md.
Also, the method that Oba and his colleagues discovered is also approved by NASA scientists and was very useful in this study.
"We're finding this extraction approach is very amenable for these fragile nucleobases," Glavin says. "It's more like a cold brew, rather than making hot tea."
After Oba and the other scientists came up with this method and discovered the 5 bases for life codes, they wanted to measure and bring data in favor of the theory that meteorites brought life to Earth.
They analyzed a lot of meteorites that fell a few decades ago in Australia, Kentucky, and British Columbia, as well as their sites.
Thus, they found that in some cases meteorite compounds are larger than soil compounds, suggesting that these rocks brought these compounds to Earth.
However, some sites contain compounds up to 20 times more than meteorites, which could indicate Earth contamination, according to Michael Callahan of Boise State University in Idaho. That is, they spread and multiplied on Earth.
"I think [the researchers] positively identified these compounds," Callahan says. But "they didn't present enough compelling data to convince me that they're truly extraterrestrial." Continued Callahan, a scientist that worked at NASA and collaborated with Glavin and others to measure organic materials in meteorites.
Nature magazine says that the compounds may have been brought to Earth by larger space rocks or meteorites at a time when the Earth was massively bombarded about 3.8-4 billion years ago.
Thus, falling so many space rocks and meteorites brought these compounds to Earth in very large quantities.
And various compounds that are found more in a place where a meteorite fell than the meteorite itself, have spread creating Earth contamination.
But now the possibility of life on other exoplanets is much more convincing. If "life" was brought to Earth from space, we should ask ourselves the following questions:
"Where was it brought from?" and "If it was brought to Earth, then it could be brought by meteorites to any other planet, so if an exoplanet is in a habitable zone, can there be life there?"