Scientists discover how life may have arrived on Earth


One of the many mysteries of the universe surrounds the existence of the first forms of life on Earth.

A clue has come from a group of scientists in Japan, whose new findings indicate the elementary components of life on Earth came from meteorites.

Researchers led by Astrochemist Professor Yasuhiro Oba from Japan’s Hokkaido University began analysing carbon-rich meteorites and uncovered evidence of various compounds needed for DNA or RNA.

After analysing carbon-rich meteorites a group of researchers uncovered evidence of various compounds needed for DNA or RNA, providing clues about the origins of life on Earth.
After analysing carbon-rich meteorites, a group of researchers uncovered evidence of various compounds needed for DNA or RNA, providing clues about the origins of life on Earth. (AP)

Professor Oba and his team analysed extracts from three different meteorites.

The first was the Murchison meteorite, which fell in Australia in 1969 near the Victorian riverside town of Murchison, 167km north of Melbourne.

The second was the Lake Murray meteorite, which fell in 1933 and was found on a farm in Carter County in Oklahoma. It’s ranked as the fifth largest meteorite in the world.

The last meteorite used was the Tagish Lake meteor, which fell on a frozen lake in the middle of winter in north-western British Columbia in Canada on January 18, 2000.

In the journal paper released about the study titled ‘Identifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites’, Prof Oba and his fellow scientists said, “a diverse suite of exogenous meteoritic organics, including nucleobases, may have been delivered to the early Earth during the late heavy bombardment period (~4.0–3.8 billion years ago)”.

“The influx of such organics is considered to have played an important role in the chemical evolution of the Earth’s primordial stage.”

The Murchison meteorite was used in the study by scientists who found DNA molecules on meteors that landed on Earth.
The Murchison meteorite was used in the study by scientists who found DNA molecules on meteors that landed on Earth. (Nick Moir/SMH)

The four main nucleobases, or building blocks of DNA, are adenine, thymine, cytosine and guanine – all of which were found on the meteorites.

A nucleobase of RNA, considered to be the sister molecule of DNA, uracil was also discovered by scientists on the space debris.

Researchers said advances in technology have allowed them to be able to extract the evidence from the meteorites.

“Recent advances in analytical techniques and instruments have enabled the detection and quantification of nucleobases in mixtures of complex organic molecules such as meteorite extracts and organic residues in interstellar ice analogs,” they said.

The scientists said there are still several molecules that remain unidentified in the meteorite extracts.

But they said in the future, model simulation studies and laboratory-based analysis will help detect more molecules in meteorites and connect them to the origin of life on Earth.

“We are now approaching a more complete understanding of the molecular distributions of meteoritic organics, including nucleobases and their formation pathways.”

https%3A%2F%2Fprod.static9.net

What the world’s tallest mountain looks like from space

Read the full article at: 9news.com.au


Leave a Comment