Scientists have detected several sugars essential for life in the samples brought back from asteroid Bennu, NASA announced on Tuesday (Dec. 2).

Analyzing pristine fragments of the asteroid delivered to Earth by NASA's OSIRIS-REx spacecraft in 2023, a team led by Yoshihiro Furukawa of Tohoku University in Japan found ribose, a crucial building block of RNA, and glucose, an energy-rich sugar used by nearly all life on Earth.

Although the researchers stress that these sugars are not evidence of life itself, their presence suggests that the basic chemical ingredients needed for biology were common throughout the early solar system.

"They were everywhere," Danny Glavin, an astrobiologist at NASA's Goddard Space Flight Center in Maryland and a co-investigator on the OSIRIS-REx mission, said in a NASA video announcing the finding.

If materials like these were widespread, he added, then places such as Mars or Jupiter's icy moon Europa may also have been seeded with the same raw ingredients. "I'm becoming much more optimistic that we may be able to find life beyond Earth, even in our own solar system."

Pristine extraterrestrial chemistry

Because the OSIRIS-REx spacecraft scooped and sealed the Bennu samples directly in space, the grains never touched Earth's environment. Scientists say that allowed them to study pristine extraterrestrial chemistry, something not possible with meteorites that crash to Earth and quickly become contaminated.

For the new study, published on Tuesday in the journal Nature Geoscience, Furukawa's team analyzed about 600 milligrams of powdered Bennu material. After soaking the grains in water and acid to extract any sugars, the scientists used highly sensitive lab instruments to detect chemical "fingerprints" matching ribose, glucose and several other sugars, according to the paper.

The researchers say the most exciting of these is ribose, a sugar that forms the backbone of RNA — a molecule that stores genetic information, helps build proteins, and carries out many of life's essential chemical reactions. The prevailing scientific consensus is that RNA arose before DNA in early life, making ribose a key piece in theories about how life began.

Furukawa's team also discovered glucose, the primary fuel source for modern life, marking the first time this sugar has been identified in an extraterrestrial sample.

"These sugars complete the inventory of ingredients crucial to life," Furukawa and his team wrote in the new paper.

The results suggest the sugars formed inside Bennu's long-lost parent asteroid more than 4.5 billion years ago, when pockets of salty water reacted with simple organic molecules inside the rock. That parent body later drifted into the inner solar system, broke apart in the asteroid belt, and eventually reassembled into the rubble-pile asteroid now known as Bennu.

The researchers also note that they did not detect a type of sugar used to build DNA, called 2-deoxyribose, whose absence supports the long-standing "RNA world" hypothesis that early life relied on RNA first, with DNA and proteins evolving later.

Scientists say they're now checking whether similar sugars appear in samples from Ryugu, a nearby asteroid sampled by Japan's Hayabusa2 mission. "I wouldn't be surprised if we found them there as well," Glavin said in the video.

More to come

The sugar detections were one of three major Bennu findings announced on Tuesday.

A second team, co-led by Zack Gainsforth of the University of California, reported discovering a type of "space gum" in the Bennu samples — an unusual, polymer-like material never before seen in space rocks.

"It was like nothing we had ever seen," Gainsforth said in a NASA statement. "For months we were consumed by data and theories as we attempted to understand just what it was and how it could have come into existence."

Once soft and flexible but now hardened, the substance forms tangled molecular chains rich in nitrogen and oxygen, according to the study, which was published in Nature Astronomy. Because it appears to have formed very early in the asteroid's history, scientists say it may be an early chemical precursor that helped set the stage for life on Earth, and perhaps one of the first alterations preserved inside Bennu.

A third study, led by Ann Nguyen of NASA's Johnson Space Center in Texas and also published in Nature Astronomy, found that Bennu contains six times more dust from ancient exploding stars than any other known space material. These fragile grains indicate that Bennu's parent body formed in a region of the early solar nebula enriched in dust of dying stars, scientists say.

"On this primitive asteroid that formed in the early days of the solar system, we're looking at events near the beginning of the beginning," Scott Sandford, an astrophysicist at the Ames Research Center in California, who co-led the analysis with Gainsforth, said in the NASA statement.

Frozen complex organic molecules have been discovered for the first time as ices around a young protostar in a galaxy other than our own, thanks to the observing power of the James Webb Space Telescope (JWST).

Astronomers led by Marta Sewiło of the University of Maryland used the JWST's Mid-Infrared Instrument (MIRI) to detect myriad complex organic molecules (COMs) in ice that encase grains of dust around the massive protostar ST6 in the Large Magellanic Cloud (LMC), which is a neighboring dwarf galaxy about 163,000 light years away. COMs are classed as carbon-bearing molecules containing more than six atoms, and many COMs are the chemical precursors to the building blocks of life as we know it.

The frozen COMs that were confirmed to exist around ST6 include acetaldehyde, acetic acid, ethanol, methanol and methyl formate. On Earth, methyl formate and acetaldehyde are used as industrial chemicals, methanol and ethanol are alcohols, and acetic acid is in vinegar. But they are also the backbone of even more complex, "second-generation" molecules that build the likes of amino acids and RNA molecules.

At least 14 other absorption lines were also detected by JWST, but so far Sewiło and her colleagues have been unable to confirm their identity.

"We have only just started exploring the dependence of complex organic chemistry on the environment," Sewiło told Space.com in an interview.

JWST is breaking new ground in the study of chemistry in environments where stars and, later, planets form.

Stars form when massive clouds of frigid molecular gas begin to fragment and collapse, producing dense cores where stars begin to coalesce. At first, these cores are cold, less than 100 kelvin (i.e., 100 degrees above absolute zero) and complex molecules exist as ices on dust grains. It is only later, when the core grows hotter, that the ice sublimates and releases the COMs as gases.

Whereas COMs in their gas phase have been detected multiple times around young stars in both the Milky Way galaxy and the LMC — for example, both methanol and methyl formate had previously been found in their gas phase around protostars in the LMC — they have been far harder to spot when in the earlier, cold ice phase.

"JWST has enabled the detection of COM ices, but to date there are only four protostars in the Milky Way where we have detected icy COMs, and only one in the LMC — ST6," said Sewiło.

By detecting the COMs in their frozen states, astronomers get an indication of how far evolved the chemistry of the material surrounding protostars is at the earliest stages of star formation.

Their presence around a young, massive protostar in the LMC is also intriguing, given the differing conditions there compared to our Milky Way galaxy. The LMC has properties in common with galaxies that existed when the universe was much younger, namely a lower abundance of elements heavier than hydrogen and helium and a stronger ultraviolet radiation field. The lack of heavy elements could impact the abundance of COMs, while the ultraviolet radiation could affect the rate of chemical reactions.

Therefore, understanding the organic chemistry of the LMC can also help teach us about the organic chemistry of the early universe, in particular how soon the building blocks of life were able to form. This could help place limits on how early, theoretically, life could have formed in the universe.

The dearth of heavy elements in the LMC does seem to have impacted the abundance of COMs around ST6.

"The COM ice abundances with respect to water ice that we measured for ST6 are lower than those measured for the four protostars in the Milky Way for all COMs, as expected, except for acetic acid," said Sewiło. "The overabundance of acetic-acid ice is likely the result of the higher ultraviolet flux in the LMC."

Among the unknown absorption lines in ST6's spectrum could be glycolaldehyde, which is a chemical precursor to ribose, which is a component of RNA molecules.

"We have found evidence that several of the unidentified absorption features could be attributed to glycolaldehyde, but the detection remains inconclusive since more laboratory spectra are needed to verify it," said Sewiło, alluding to the fact that the star's spectrum is compared to those of different molecules taken in laboratory conditions to identify which absorption lines belong to which COMs.

"It is likely that more COMs are present in the ices around ST6, and our results highlight the need for more laboratory experiments."

As the protostar evolves and heats up, the ice on the dust grains nearest the star will sublimate and the COMs will move into their gas phase, as has previously been detected.

It is in the gas phase that more chemical reactions can take place, triggered by ultraviolet radiation from the protostar and the wider environment, "leading to larger and more complex molecules important for life such as propanol and propanal, and possibly amino acids, but we've not detected them in ST6 yet," said Sewiło.

Amino acids have, however, been found in comets and meteorites in our solar system. Comets and meteorites are ancient bodies, formed 4.5 billion years ago when our sun was a protostar. The implication is that amino acids are the end result of a pathway of chemical reactions that begin with the kinds of COMs discovered around ST6.

The research was published on Oct. 20 in Astrophysical Journal Letters.

Correction 11/10: COMs have been seen in other galaxies before — this is the first time they've been detected as ices. The absorption lines referred to in the article may also not necessarily indicate 14 different molecules. This article has been updated to reflect that.

Complex organic molecules that form part of the chain of chemical reactions that can result in life's building blocks have been found in the watery geysers of Enceladus, almost twenty years after the plumes were first sampled by NASA's Cassini spacecraft.

Cassini's mission to the ringed planet Saturn ended in 2017, but scientists are still making findings buried deep in its treasure trove of archived data.

The discovery of these organic molecules ("organic" meaning they contain carbon) strengthens the case for the icy moon Enceladus being of astrobiological interest. In 2005, Cassini discovered that plumes of water vapor were spraying into space from huge fissures in Enceladus' surface. These fissures are believed to lead to a subsurface ocean within the 310-mile-wide (500-kilometer-wide) moon of Saturn, and it is this ocean that provides the water for the plumes. While some of the material from the plumes snows back onto the surface of Enceladus, most of it escapes into space where it forms a diffuse ring, called the E-ring, encircling Saturn at a greater distance from the planet than most of the rest of its system of rings.

"Cassini was detecting samples from Enceladus all the time as it flew through Saturn's E-ring," Nozair Khawaja of the Freie Universität Berlin and the University of Stuttgart in Germany said in a statement. "We had already found many organic molecules in these ice grains, including precursors for amino acids."

However, there has always been caution over the findings from the E-ring, because charged particles trapped in Saturn's magnetosphere bombard the icy particles in the E-ring, instigating chemical reactions. It had been unclear whether the organic molecules present in the ring had come from Enceladus' ocean or whether they had been formed by the reactions triggered by the radiation.

However, Cassini also flew directly through some of the plumes, so Khawaja went back to archive data from 2008 and the results from the spacecraft's Cosmic Dust Analyzer (CDA), which was an instrument led by scientists at the University of Stuttgart. With painstaking precision, Khawaja's team took apart the CDA data, and their new analysis found evidence for organic molecules that had been missed the first time around.

When Cassini flew through the plumes, icy grains struck the CDA's detector at 11 miles (18 kilometers) per second, which is faster than the 7.5 miles (12 kilometers) per second in the E-ring. These grains, only just spewed out of the ocean, contain pristine material that had not yet been altered by radiation.

"The ice grains contain not just frozen water, but also other molecules including organics," said Khawaja. "At lower impact speeds, the ice shatters and the signal from clusters of water molecules can hide the signal from certain organic molecules. But when the ice grains hit the CDA fast, water molecules don’t cluster and we have a chance to see these previously hidden signals."

The results showed that the same organic molecules present in the E-ring are also in the plumes, which tells scientists that they must originate from the ocean and are not a product of space radiation. Khawaja's team also found a variety of other organic molecules that had not been detected before in relation to Enceladus' plumes. These include aliphatic, (hetero)cyclic ester/alkalines, ethers/ethyl and possibly nitrogen- and oxygen-bearing compounds. On Earth, these molecules are part of a chain of chemical reactions that lead to life's building blocks.

"There are many possible pathways from the organic molecules we found in the Cassini data to potentially relevant compounds, which enhances the likelihood that the moon is habitable," said Khawaja.

There is a note of caution, however.

Recent research led by Grace Richards of the Istituto Nazionale di Astrofisica e Planetologia Spaziale (INAF) in Rome has found the bombardment of radiation that scientists had been so concerned had altered the material in the E-ring can also create organic molecules on the surface of Enceladus. This includes on the ground in and around the fissures, called "tiger stripes," from which the geysers emanate. If Richards is correct, this would seriously confuse the issue and there would be no way to know whether the organic molecules detected by Cassini in the plumes are from the ocean or produced by radiation in the tiger stripes and are dragged into space by the plumes.

One way to solve the issue would be to land on Enceladus and sample fresh ice directly. Indeed, this is the plan, with the European Space Agency considering a mission that would feature an orbiter/lander combo arriving at Enceladus in 2054. Only by getting ground truth can scientists know for sure whether Enceladus' ocean really does feature the kind of complex chemistry that can potentially lead to life.

The new results from Cassini's Cosmic Dust Analyzer were published on Oct. 1 in the journal Nature Astronomy.

Asteroid Ryugu is proving to be one of the most scientifically valuable time capsules in the solar system.

A recent study of microscopic grains collected from Ryugu by Japan's Hayabusa2 spacecraft found the tiny space rock harbors minerals that formed long before Earth itself — minerals that have been preserved in pristine condition for billions of years.

Using cutting-edge X-ray imaging tools, researchers from the Brookhaven National Laboratory examined the chemistry of the asteroid samples in extraordinary detail, revealing a mixture of minerals and elements that trace back to the asteroid's ancient parent body, according to a statement from the laboratory.

"These clues begin to tell a story about the starting materials of the asteroid and their early interactions with fluids," officials said in the statement. "This information helps to better define the sequence of fluid activity and processes that led to the current composition of Ryugu and other carbonaceous asteroids."

Ryugu is a carbon-rich near-Earth asteroid thought to have originated in the cold outer reaches of the solar system. More than 4.7 billion years ago, its parent body was gently warmed by a chemical process known as radioactive decay. That subtle heating melted ices like water and carbon dioxide, releasing fluids that seeped through the rock. The fluids triggered chemical reactions that left behind a diverse mineral assemblage — some familiar to Earth, others entirely foreign.

Using only two tiny pieces of the asteroid — one grain from its surface and the other from its subsurface — researchers identified carbonates such as manganese-bearing dolomite and ankerite, iron-rich minerals like pyrrhotite and magnetite, copper sulfides, phosphorus-bearing hydroxyapatite, a mineral found in human teeth and bones, and a rare phosphide mineral not found on Earth. There were also traces of selenium, sulfur, silicon and calcium. The wide array of minerals points to a rich interplay of fluids and chemistry that unfolded in the asteroid billions of years ago, long before our planet's crust had stabilized.

Because Earth's earliest rocks have been destroyed by tectonics and erosion, Ryugu provides an unparalleled window into the conditions that existed during planetary formation. The returned samples could therefore also reveal whether the asteroid may have delivered water and organic ingredients that helped jump-start life on Earth.

"Earth is constantly changing, and, over time, its natural processes have erased most of the chemical clues about how the solar system first formed," officials said in the statement. "Asteroids like Ryugu preserve this important piece of the solar system’s history."

Asteroid sampling missions are rapidly gaining momentum as space agencies recognize the unmatched scientific value of returning pristine material from the early solar system. Japan's Hayabusa and Hayabusa2 missions set the stage, successfully retrieving samples from asteroids Itokawa and Ryugu, while NASA's OSIRIS-REx mission recently delivered material from asteroid Bennu — which researchers hope to study using the same X-ray techniques. Comparing Bennu and Ryugu could reveal key differences in how carbon-rich asteroids formed, altered and transported life's essential building blocks across the early solar system.

More asteroid sampling projects are on the horizon: JAXA's MMX mission will target the Martian moon Phobos, for instance, while future concepts aim to capture samples from metallic asteroids or even comets.

Findings about Ryugu's unique chemistry were published last year in the journal Geosciences.

New evidence has emerged suggesting that the building blocks of life were delivered to the primordial Earth from space by meteorites, a finding that could help scientists hunt for alien life.

These meteorites would have been the fractured remains of early "unmelted asteroids," a type of planetesimal. Planetesimals are small rocky bodies that served as the main building blocks of the solar system's rocky planets, including Earth. They were formed around 4.6 billion years ago in the disk of dust and gas around the infant sun as particles around our young star began to stick together, accreting more mass and making progressively larger bodies.

A team of researchers tracked the chemical element zinc in meteorites to determine the origin of Earth's "volatiles." These are elements or compounds that change into vapor at relatively low temperatures. They are important because they include six common chemicals vital for living things, including water.

"One of the most fundamental questions on the origin of life is where the materials we need for life to evolve came from," study team leader Rayssa Martins, from the Department of Earth Sciences at the University of Cambridge in England, said in a statement. 

"If we can understand how these materials came to be on Earth, it might give us clues to how life originated here and how it might emerge elsewhere," Martins added.

Related: The building blocks of life can form rapidly around young stars

Follow the zinc

Martins and colleagues from Cambridge and Imperial College London chose zinc because, when it is formed in meteorites, it has a unique composition that can be used to identify the origins of volatiles.

The team previously found that Earth's zinc seems to have originated from different regions of the solar system. Around half came from the inner region of the solar system, close to our planet and the other rocky worlds by the sun. However, the other half seems to have originated from out beyond the fifth planet from the sun, the gas giant Jupiter. 

This is possible to gauge because planetesimals aren't all the same. The planetesimals that formed in the earliest era of the solar system were exposed to high levels of radiation from the infant sun. This caused them to melt, thus easily losing volatiles through vaporization.

Planetesimals that came together later in the solar system's formative years weren't exposed to as much radiation, meaning they didn't experience as much melting and were able to hold on to more of their volatiles.

The team looked at zinc in a large sample of meteorites that originate from different planetesimals. They then traced the arrival of different types of zinc over the tens of millions of years that our planet was accreting material. 

They found that melted planetesimals accounted for around 70% of our planet's total mass but only delivered about 10% of its zinc content. That means 90% of Earth's zinc originated from "unmelted" planetesimals with higher amounts of intact volatiles. The consequence is that these unmelted space rocks must have also delivered a lot of volatiles to the forming Earth, too.

"We know that the distance between a planet and its star is a determining factor in establishing the necessary conditions for that planet to sustain liquid water on its surface," Martins added. "But our results show that there’s no guarantee that planets incorporate the right materials to have enough water and other volatiles in the first place — regardless of their physical state."

The research conducted by Martins and colleagues may have implications far beyond the reaches of our planet, assisting in the ongoing search for life elsewhere in the cosmos.

"Similar conditions and processes are also likely in other young planetary systems," Martins concluded. "The roles these different materials play in supplying volatiles is something we should keep in mind when looking for habitable planets elsewhere."

The team's research was published on Friday (Oct. 11) in the journal Science Advances.

A young protostar that bears a striking resemblance to a giant "space hamburger" contains the molecular building blocks of life, researchers discovered.

What astronomers call the "space hamburger" is actually a cloud of gas and dust that is collapsing to form a baby star. That baby star will eventually be surrounded by planets, much like Earth's own solar system. The hamburger is called Herbig-Haro object 212, or HH 212.

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, astronomers have identified complex organic molecules in the atmosphere around the protostar's accretion disk — the space hamburger's giant bun and patty, if you will. The types of molecules discovered in the protostar likely played a key role in the development of life on Earth, the researchers said. This finding suggests that the building blocks for life begin to form in the earliest phases of star formation, long before planets have the chance to form around their central star. [Meet ALMA: Amazing Photos from Giant Radio Telescope]

The atmosphere around the space hamburger contains methanol (CH₃OH), deuterated methanol (CH₂DOH), methanethiol (CH₃SH) and formamide (NH₂CHO), which "have been proposed to be the precursors for producing biomolecules such as amino acids and sugars," the researchers said in a statement.

"It is so exciting to discover complex organic molecules on an accretion disk around a baby star," Chin-Fei Lee, a researcher at the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan, who led the study, said in the statement.

"When such molecules were first found in the protoplanetary disk around a star in a later phase of star formation, we wondered if they could have formed earlier. Now, using ALMA's unprecedented combination of spatial resolution and sensitivity, we [can] not only detect them on a younger accretion disk, but also determine their location," Lee said. "These molecules are the building blocks of life, and they are already there in the disk atmosphere around the baby star in the earliest phase of star formation."

Scientists estimate that the space hamburger is only 40,000 years old, which pales in comparison to Earth's 4.5 billion-year-old sun. The space hamburger's radius is about 60 astronomical units, or 60 times the average distance between the Earth and the sun.

HH 212 lies about 1,300 light-years away from Earth, so if life does eventually form there, even intelligent life, Earthlings will have nothing to worry about. The space hamburger would still be much too far away for any aliens (or humans) to travel between the two solar systems. Humanity would just have to sit back and watch life flourish from afar.

Email Hanneke Weitering at hweitering@space.com or follow her @hannekescience. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

A two-yearsurvey of enormous interstellar dust clouds has turned up eight organicmolecules in two different regions of space. One is a stellar nursery awash inlight while the other is a cold, starless void.

Thefinding, detailed in the current issue of Astrophysical Journal,supports other recent studies suggesting molecules important for life commonlyform in the gas and dust clouds that condense to form stars and planets.

Themolecules were discovered using the Robert C. Byrd Green Bank Telescope (GBT),a large radio telescope located in West Virginia.

"Findingeight [organic] molecules in the space of two years is quite remarkable,"said study leader Jan Hollis of NASA Goddard Space Flight Center.

Lifemolecules

The newlydiscovered molecules are made up of 6 to 11 atoms each and are classified asorganic because they contain carbon.

Five of themolecules were discovered in Sagittarius B2(N), a star-forming dust cloudlocated 26,000 light-years from Earthnear the center of the MilkyWay Galaxy. This stellar nursery is the largest known repository of complexinterstellar molecules.

The otherthree molecules were found in the Taurus Molecular Cloud (TMC-1), located only 450light-years away. TMC-1 is starless; it is cold and dark and has a temperatureof only 10 degrees above absolute zero.

"Thediscovery of these large organic molecules in the coldest regions of theinterstellar medium has certainly changed the belief that large organicmolecules would only have their origins in hot molecular cores," saidstudy team member Anthony Remijan of the National Radio Astronomy Observatory(NRAO). "It has forced us to rethink the paradigms of interstellarchemistry."

Just becausea molecule is organic does not mean that it is made by living things. In fact,many of the newly spotted molecules are poisonous to organisms on Earth, Hollissaid. But one of the molecules found in Sagittarius B2(N), called acetamide,contains a type of chemical bond important for linking together amino acids,the molecular building blocks of proteins.

Made up of9 atoms, acetamide "is the largest molecule found in space that has thatbond," Hollis told SPACE.com.

Spacetumbleweeds

The moleculesare thought to form by two main mechanisms. In the first, simple chemicalreactions add an atom to a molecule that is stuck to the surface of a dustgrain afloat in space. The second method involves chemical reactions betweenneutral molecules and highly reactive molecules called radicals.

Onceformed, the molecules are shaken loose from their dust-grain homes by rapidlymoving shockwaves. As the freed molecules tumble end-over-end in space, they can emitor absorb radiation at precise radio frequencies unique to each type ofmolecule. Astronomers identify the molecules based on these radio frequencies.

Within adust cloud, thousands of billions of molecules undergo the same types ofrotation, emitting and absorbing the same radio frequencies. The end result isa signal strong enough to be detected by instruments on Earth.

Thenewfound molecules bring the total number of biologically-relevant moleculesfound in interstellar space to 141. Scientists have previously found benzene,a ring-shaped carbon molecule important for life on Earth, around stars andintact amino acids in meteorites that have crash-landedon Earth.

Even morecomplex molecular creations might be possible in space, experiments suggest. Inone study, scientists simulated deep space conditions in the laboratory andcreated small structures resembling cell wallsin living organisms.

A casefor extraterrestrial life

Takentogether, the findings suggest that the chemical ingredients necessary for lifebegan taking shape long before our planet was formed.

Manyscientists now accept the notion that ancient meteorites and comets helpedjumpstart life on our planet by bringing a significant amount of water, organicmolecules and even amino acids to early Earth.

Scientistsnow think those imprisoned organic molecules were likely created in the massivedust and gas clouds that eventually coalescedinto planets and stars, comets and meteorites. Dust clouds are thought to formwhen events such as novasand supernovascaused chemical elements and molecules created during thermonuclear reactionsinside stars to be ejected into space.

Hollis sayshis team plans to keep using the Green Bank Telescope to continue searching forother biologically-significant molecules.

"Froma research and astrobiology point of view, it's been a goldmine," he said.

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