Tag Archives: astrobiology

Astrobiologists meet to better their search for exoplanet life

The uncertainty of science: Astrobiologists are meeting this week in Seattle to discuss and refine their methods for detecting astrobiology on exoplanets.

The Seattle meeting aims to compile a working list of biosignature gases and their chemical properties. The information will feed into how astronomers analyse data from NASA’s James Webb Space Telescope, slated for launch in 2018. The telescope will be able to look at only a handful of habitable planets, but it will provide the first detailed glimpse of what gases surround which world, says Nikole Lewis, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland.

No single gas is likely to be a slam-dunk indicator of alien life. But Domagal-Goldman hopes that the workshop will produce a framework for understanding where scientists could trip themselves up. “We don’t want to have a great press release,” he says, “and then a week later have egg on everybody’s faces.”

A few years ago I was told by one astronomer that the field’s biggest and most exciting area of research in the coming decades will be the effort to study the thousands exoplanets they only just discovered. I agree. The Webb telescope might have been built to study cosmology, but the data it will produce about exoplanets will be much more real and less uncertain, thus making it more compelling and convincing.

Is it snowing microbes on Enceladus?

Is it snowing microbes on Enceladus?

“More than 90 jets of all sizes near Enceladus’s south pole are spraying water vapor, icy particles, and organic compounds all over the place,” says Carolyn Porco, an award-winning planetary scientist and leader of the Imaging Science team for NASA’s Cassini spacecraft. “Cassini has flown several times now through this spray and has tasted it. And we have found that aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth’s oceans.”

A group of researchers have failed to reproduce the earlier NASA result that suggested arsenic-based life was possible.

A group of researchers have failed to reproduce the earlier NASA result that suggested arsenic-based life was possible.

One interesting aspect of this story is that the research results were discussed openly, with regular updates as the work was on-going, on one of the scientists blogs.

Redfield and her collaborators hope to submit their work to Science by the end of the month. She says that if Science refuses to publish the work because it has been discussed on blogs, it will become an important test case for open science.

Scientists have found microbes inside a lava tube that can thrive in the freezing cold and low oxygen environment of Mars.

Scientists have found microbes inside a lava tube that can thrive in the freezing cold and low oxygen environment of Mars.

In a laboratory setting at room temperature and with normal oxygen levels, the scientists demonstrated that the microbes can consume organic material (sugar). But when the researchers removed the organic material, reduced the temperature to near-freezing, and lowered the oxygen levels, the microbes began to use the iron within olivine – a common silicate material found in volcanic rocks on Earth and on Mars – as its energy source.

Some detailed analysis by scientists of meteorite fossil paper

Here’s some detailed analysis by scientists of the meteorite fossil paper.

Once again, there is a great deal of skepticism, most of which appears reasonably and justified. Though a number of scientists have applauded his work, it really looks like Hoover does not have sufficient evidence to claim his samples are alien biology. However, this quote stands out:

It appears likely that Hoover’s study may soon be ignored by the majority of the scientific community, instead of enjoying a healthy debate such as that raised by McKay’s 1996 paper on the Mars meteorite. Redfield says that a microbiologist that she knows refused to read it. [emphasis mine]

That hardly seems the right response from an open-minded scientist.

Planetary scientists reject meteorite fossil paper — without reading it

Richard Kerr of Science is attending the annual Lunar and Planetary Science Conference in Texas, and has written a short article describing the reaction of planetary scientists to the meteorite fossil paper by NASA scientist Richard Hoover. Their reaction, hostile and disinterested, isn’t pretty. These two quotes will give you the flavor:

Whether they have closely examined the paper by astrobiologist Richard Hoover of NASA’s Marshall Space Flight Center or only heard about it in the hallways, the reaction is the same: not again.

Rather than taking a look themselves, researchers have other things in mind. One leading scientist half-jokingly suggested hanging Hoover in effigy in the conference center lobby.

» Read more

NASA Statement on Astrobiology Paper by Richard Hoover

In an unusual move, NASA has issued a statement on the alien fossil paper written by Richard Hoover. Key quote:

While we value the free exchange of ideas, data, and information as part of scientific and technical inquiry, NASA cannot stand behind or support a scientific claim unless it has been peer-reviewed or thoroughly examined by other qualified experts. This paper was submitted in 2007 to the International Journal of Astrobiology. However, the peer review process was not completed for that submission. NASA also was unaware of the recent submission of the paper to the Journal of Cosmology or of the paper’s subsequent publication.

This suggests that Hoover was having trouble getting published in one journal, and did an end-around to get published in a journal more agreeable to his conclusions.

Though this does raise questions about the validity of the research, it is always the research itself that matters. In this case I remain skeptical, but intrigued. I really would like to know why the peer-review process on Hoover’s paper was taking so long at the International Journal of Astrobiology. I would also love to read a critique of Hoover’s papers from scientists in the field.

Amino acids found on meteorite that crashed in the Sudan

Dead alien life arrives on Earth! Not really but still exciting anyway: Scientists have found the remains of space-born amino acids — essential to life — in the meteorite that crashed in the Sudan in 2008. Key quote:

“This meteorite formed when two asteroids collided,” said Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md. “The shock of the collision heated it to more than 2,000 degrees Fahrenheit [1,093 degrees Celsius], hot enough that all complex organic molecules like amino acids should have been destroyed, but we found them anyway.”

The discovery is further evidence that the basic elements of life can form in even the most hostile of environments.

The basic ingredients of life might exist in Titan’s atmosphere

Big news! In a simulation of the upper atmosphere of Titan at about 600 miles altitude, scientists have discovered the basic ingredients of life are quickly synthesized when exposed to the kind of hard radiation found there. Key quote from the press release, issued today at the 42nd meeting of the AAS Division for Planetary Sciences:

The molecules discovered include the five nucleotide bases used by life on Earth (cytosine, adenine, thymine, guanine and uracil) and the two smallest amino acids, glycine and alanine.

For those who don’t remember their high school biology, these nucleotides are the building blocks of DNA.

The abstract of the scientist’s work can be found here.

What the scientists did was recreate the basic ingredients of Titan’s upper atmosphere, comprised of nitrogen, methane and carbon monoxide. Cassini data has shown that within this atmosphere are very large molecules, as yet unidentified.

The scientists then bathed their recreation in the kind of intense radiation expected at that altitude, and amazingly produced the complex organic molecules that are basic to life. Moreover, the experiment was the first to produce these complex molecules without the presence of water, something that scientists have previously thought was required. These results suggest that in addition to forming in the oceans, life could also form in the upper atmospheres of planets.

This result also suggests strongly that it is incredibly easy to produce the basic building blocks of life, almost anywhere in the universe where organic molecules are present.