Tag Archives: meteorites

Illustration of early Earth. Credit: Harvard University.

Meteorites impacting ancient Earth could have formed the basic ingredients for life

Artistic depiction of the Hadean.

If you’d travel back in time four billion years ago, you would surely be shocked by what you’d see around you — through the visor of a life-support suit you’d need to survive.

Instead of peaceful blue skies and an oxygen-rich atmosphere, the Earth is covered in a haze of noxious fumes, seas of lava, and a never-ending onslaught of asteroid and meteorite impacts. Welcome to the Hadean Earth!

Fittingly, this geological era was named after Hades, the Greek god of the underworld, and also the Hebrew word for hell. Perhaps the most chilling realization is that there are no lifeforms to speak of, not even the tiny microscopic bacteria.

Is this truly hell?

Well, almost. In a puddle of bubbling liquid nearby, inconspicuous amino acids are assembling into proteins, which will eventually give rise to the first single-celled organisms. But where did these amino acids come from?

The origin of life is perhaps the most debated existential question out there, known for giving scientists and philosophers angst and headaches for centuries. Today, the consensus seems to be that the emergence of amino acids can be pinned down to either endogenous formation or extraterrestrial delivery via meteorites.

It this latter scenario that Japanese researchers at Tohoku University, National Institute for Materials Science (NIMS), the Center for High Pressure Science & Technology Advanced Research (HPSTAR), and Osaka University have explored by simulating the chemical reactions involved when a meteorite crashes into the ocean.

Single stage propellant gun used for the simulation of impact-induced reactions. Credit: Yoshihiro Furukawa.

Using a complex experimental setup that employed more carbon dioxide and nitrogen in order to mimic the Hadean atmosphere, the researchers fired a single stage propellant gun to simulate the impact of an iron-rich meteorite.

Strikingly, these environmental conditions and the force of impact triggered chemical reactions that led to the formation of amino acids such as glycine and alanine, the main building blocks of proteins.

 “Making organic molecules form reduced compounds like methane and ammonia are not difficult, but they are regarded as minor components in the atmosphere at that time,” Yoshihiro Furukawa, a researcher at Tohoku University and the corresponding author of the new study, said in a statement.

“The finding of amino acid formation from carbon dioxide and molecular nitrogen demonstrates the importance in making life’s building blocks from these ubiquitous compounds,” he added.

It’s quite likely that carbon dioxide and nitrogen were also major constituent gases of Mars’ ancient atmosphere. Up until two billion years ago, Mars hosted oceans of liquid water and may have been very much Earth-like. If Mars ever harbored life, the same essential building blocks may have been seeded similarly to how it may have happened on Earth — at the very least, the new study shows that such a scenario is plausible.

Previously, other studies found that phosphates, essential ingredients for DNA-based life forms, may have originated from space. NASA scientists also found that hydrothermal vents are plausible hotspots that can enable the spontanous generation of molecules required for life.

The findings appeared in the journal Scientific Reports.

Comet.

Building blocks of life can spontaneously form in outer space

Space may be the final frontier, but it may have also been the first.

Comet.

Image via Pixabay.

Researchers at NASA’s Ames Research Center found new evidence in support of the view that asteroids carried the basic ingredients of life to Earth. In a new study, they report that such compounds can spontaneously form in the conditions of outer space with substances commonlt found the interstellar medium.

From whence we came. Maybe

We actually don’t know that much about how life started on Earth. In fact, we don’t even know if life started on Earth — at least, not its constituent parts. Two main theories compete in this regard. One holds that life emerged in hot springs or deep-sea thermal vents because such areas are rich in the right ingredients. The other states that those ingredients formed up there (way up there) and then crash-landed on the planet on the back of meteorites or comets.

The Ames Research Group team found evidence supporting the latter. They found that one of the fundamental building blocks of life — sugars — can and will spontaneously form in outer space. Sugars are important both from a nutritional value (they pack a lot of energy) as well as a biochemical one: 2-deoxyribose, for example, is a fundamental component of DNA (and also a sugar).

In a lab setting mirroring conditions in outer space, the team managed to spontaneously create 2-deoxyribose. The team cooled a sample of aluminum substrate in a freezer and cooled it down to nearly absolute zero. Afterward, they placed the sample in a vacuum chamber; all in all, this rig was a close simulation of conditions in deep space, they report.

Next, the researchers pumped small quantities of a water and methanol gas mixture similar to that found in the interstellar medium (to simulate its chemical makeup) and blasted the whole thing with UV light (to simulate radiation levels in outer space).

Initially, the test seemed to be a dud — only water ice formed on the sample. After a while, however, the strong UVs melted it down, and subsequent chemical analysis revealed that a small quantity of  2-deoxyribose had formed along with some other sugars. Fresh on the scent, the team then analyzed samples from several carbonaceous meteorites. They found traces of alcohols and deoxysugar acids on these space rocks which.

Although that’s not exactly 2-deoxyribose, the team notes their samples were drawn from a small number of meteorites. It’s quite possible, they add, that others would carry traces of these substances.

The findings add more weight to the to the theory that life got jump-started by space-stuff. However, that isn’t to say it’s definitive proof, or that the two scenarios didn’t take place at the same time, or in tandem. It is, however, a good indicator that the chemical building blocks of life are out there and, given the right environment, they can lead to life.

The paper “Deoxyribose and deoxysugar derivatives from photoprocessed astrophysical ice analogues and comparison to meteorites” has been published in the journal Nature Communications.

The Search for Alien Life: We Have Been Looking in the Wrong Places

SETI Initiative. Source: Traces Online.

Humanity has pondered the existence of alien life for centuries. However, it has been in just the past 100 years or so that modern science has backed some of this thinking. Scientists of the late 1800’s and early 1900’s believed that objects appearing on the surface of Mars were canals constructed by aliens. Particularly, astronomer Percival Lowell believed this concept and promoted it in works such as the book Mars As the Abode of Life (1908).

This belief in the scientific community led to a huge amount of pop culture based around the concept of extraterrestrials. This has resulted in some people even believing in the existence of aliens like the ones in the movies. Who knows? They could be out there. But some wonder how probable their existence is.

With aliens constantly being depicted in entertainment, even after the Martian alien canal hypothesis was busted, scientists considered communicating with otherworldly life forms. The first scientists looking for a close encounter believed the best bet was to use radio waves as the communication medium. The first of such proposed experiments was conducted in 1960 by astronomer Frank Drake.

One of the most eye-opening quotes about extraterrestrial alien life comes from the book Time for the Stars by Alan Lightman. The author states, “Are we alone in the universe? Few questions are more profound… Extraterrestrial contact would forever change the way we view our place in the cosmos” (Lightman 21).

Drake would definitely not be the last scientist to attempt to summon a response from an alien. But this was the first modern example of tests which would now be referred to as part of SETI, the search for extraterrestrial intelligence. In 1980, to bring more of a public interest to SETI, the legendary astrophysicist, astronomer, and astrobiologist Carl Sagan and several others formed The Planetary Society. In more recent years, other programs with goals similar to SETI’s have been established such as METI, messaging extraterrestrial intelligence.

Apart from radio waves, humans have tried other ways of communicating with hypothetical aliens. One example is a plaque which was attached to the Pioneer 10 probe in 1972. This plaque would be a unique kind of “message in a bottle,” except the ocean it was doomed to drift in was far more vast than any sea on Earth. It was inquired of Carl Sagan about sending such a message several months before the scheduled departure of the craft. So Sagan went to work, and assisting him with this undertaking was none other than Frank Drake, the man who had conducted the first modern SETI tests in 1960. The fruit of numerous labors and laborers, the Pioneer 10 plaque that was sent into space depicted a man and a woman and several objects. Through the imagery, the scientists were trying to give any aliens who might see this plaque an idea of what humans are like and where Earth is located.

This could be the first big mistaken researchers are making. They are looking to make contact. They are putting their faith in a sci-fi movie concept. What these scientists are attempting to do is call up and have a conversation with an alien or, better yet, a race of aliens. This is not to say that SETI is pointless, but it might not be the most opportune method for seeking alien life.

Perhaps scientists should strive to discover life in its simpler forms. As Lee Billings of Scientific American states in a recent article, if you were able to travel to another planet it is likely “you would find a planet dominated by microbes rather than charismatic megafauna.” Many scientists are now suggesting microscopic organisms could be more plentiful throughout the cosmos than macroscopic creatures.

Microbes Are a Realistic Form of Alien Life. Source: Joi Ito’s PubPub.

A specific search for such minuscule life forms is not a new practice. Bacteria are, of course, microbes. Astrobiologists like Richard Hoover and Dave McKay have examined certain meteorites. Some of the microscopic structures found embedded in or on the space relics resemble bacteria. They have released their findings in past years. They have admitted that even though the fossilized structures appear to be remnants of bacteria there is still some skepticism as to whether those structures are alien in origin. This is because bacteria from Earth could have been attached to the meteorites once they entered our atmosphere.

So how do scientists narrow down the search for alien life even further? Billings’ piece may give us the best idea available at the moment. He informs his readers that one of oxygen’s properties is that it tends to descend from an atmosphere in the form of mineral oxides. It does not remain in its gaseous phase for long. Because of its nature, in an atmosphere such as Earth’s, the oxygen has to be reinstituted on a regular basis.

Astrobiologists have to accept oxygen may be one of the least familiar elements they come upon when studying potential life-supporting bodies. For example, atmospheric chemist David Catling has said the atmosphere of a world dominated by microscopic life could be largely comprised of methane and carbon dioxide gases. Keeping this in mind, this will hopefully narrow down the most likely planet candidates for life.

Study: Mars got its water the same place Earth did – meteorites

A study conducted by researchers from the Carnegie Institution for Science concluded that both Earth and Mars got their water from the same source chondritic meteorites. However, unlike Earth, Martian rocks containing atmospheric volatiles such as water don’t get recycled into the planet’s deep interior.

 

The origin, history, and evolution of Martian water are pretty much a hot topic of debate. Although the Red Planet’s canals practically scream “we had water”, that terrain is pretty ancient, so while early Mars might have been all warm and wet, not, it’s just cold and dry.

Researchers analyzed water concentrations and hydrogen isotopic compositions trapped inside crystals within two Martian meteorites known as shergotites; one of the meteorites was rich in rich in elements such as hydrogen, and the other depleted. The two meteorites, pristine samples of various Martian volatile element environments, contain trapped basaltic liquids. However, the rich one of them has a hydrogen isotopic composition similar to that of Earth, and it appears to have changed little on its way from the Martian mantle up to the surface of Mars. The other one, however, appears to have sampled Martian crust that had been in contact with the atmosphere. So one of them had samples from the deeper parts, when Mars originally formed and had water, and the other one resembled recent Mars, with a dry environment.

“There are competing theories that account for the diverse compositions of Martian meteorites,” says researcher Tomohiro Usui. “Until this study there was no direct evidence that primitive Martian lavas contained material from the surface of Mars.”

“The hydrogen isotopic composition of the water in the enriched meteorite clearly indicates that they have been overprinted, so this meteorite tells scientists more about the Martian crust than about the Martian mantle,” he added. “Conversely, the other meteorite yields more information about the Martian interior.”

Since the hydrogen isotopic concentration was very different, the team believes that Martian surface water has had a different geologic history than water from the interior. The concentration of pure water are also very different – one of them had 10 times more water than the other one, so it’s becoming increasingly clear that Mars had two different stages in its evolution.

“To understand the geologic history of Mars, more information about both of these environments is needed,” Carnegie’s Conel Alexander said.

Via RedOrbit

NASA slams alien life claims

Two days ago, the whole world was teeming with excitement, after some NASA researchers reported finding traces of alien life in meteorites; now, even their employer distances itself from them, and the whole scientific world seems to frown upon this work. However, in what is a very unusual move, NASA has denied any involvement with the paper, and even the Journal of Astrobiology refused to published the paper.

However, lead author Richard Hoover, engineer at NASA’s Marshall Space Flight Center in Huntsville, Alabama did publish his research in the online Journal of Cosmology, a publication which supports the idea that life came from outer space. Of course Fox News, in their usual and disturbing way, made big (and biased) news from this report, which led to NASA condemning the study; and it didn’t take long until other scientists followed too.

Paul Hertz, chief scientist of NASA’s science mission directorate issued a statement which left little to interpretation, stating that:

“NASA cannot stand behind or support a scientific claim unless it has been peer-reviewed or thoroughly examined by other qualified experts…. NASA was unaware of the recent submission of the paper to the Journal of Cosmology or of the paper’s subsequent publication.”

Now, the Journal of Cosmology is not your average publication; the 2 year publication claims to be peer reviewed, but this time, they published the report BEFORE having other peers review it, which is highly unprofessional and unethical. The journal was reported to be closed on Monday, being “killed by thieves and crooks” at the journal Science and other subscription-based periodicals. I’m not really sure at all what the situation is, but in this particular case, they messed up – if you want to ensure the accuracy of a publication, you have to peer review it before publishing it.

Biologists from all over the world have dashed and bashed the paper, claiming that other structures similar to those of the bacteria can easily be found in nature, and contamination cannot be ruled out either.

“Move along folks. There’s nothing to see here,” wrote Rosie Redfield, a microbiologist at the University of British Columbia,

Mister Hoover was unavailable for comments.

Picture source