Astrobiology Archives

March 13, 2008December 26, 2015 by Fraser Cain

Meteorites Can Be Rich With the Ingredients of Life

How did life arise on Earth? How did we get from rocks and water to the abundance and variety that we see today? Perhaps the raw ingredients for life, amino acids, were delivered to Earth by a steady bombardment of meteorites. Researchers have turned up space rocks with concentrations of amino acids 10x higher than previously measured, raising hopes that the early Solar System was awash in organic material.

The study was done by Marilyn Fogel of Carnegieâ€™s Geophysical Laboratory and Conel Alexander of the Department of Terrestrial Magnetism with Zita Martins of Imperial College London and two colleagues, and will be published in Meteoritics and Planetary Science.

If you’re like me, the astronomy stuff’s fine, but the biology news is a little baffling (I forward the kids’ biology questions to my wife). Amino acids are organic molecules that form the backbone of proteins, which make much of life’s structures and drive chemical reactions in cells. Amino acids are naturally occurring, but they somehow came together to make the first proteins in the Earth’s early days.

The researchers took samples from three meteorites collected during recent expeditions to Antarctica. The meteorites are from a type called CR chondrites, which are through to contain ancient organic materials that date back to the earliest times of the Solar System. At one point, these meteorites were part of a larger “parent body”, which was later shattered by impacts.

One sample had few amino acids, but the other two had the highest concentration ever seen in primitive meteorites.

“The amino acids probably formed within the parent body before it broke up,â€ says Alexander. â€œFor instance. ammonia and other chemical precursors from the solar nebula, or even the interstellar medium, could have combined in the presence of water to make the amino acids. Then, after the break up, some of the fragments could have showered down onto the Earth and the other terrestrial planets. These same precursors are likely to have been present in other primitive bodies, such as comets, that were also raining material onto the early Earth. â€

So this points to the conclusion that the early Solar System was a much richer source of organic molecules than researchers previously believed. And the constant rain of amino acid-laden meteorites would have delivered this material to the primordial soup where life first emerged.

Exactly how the amino acids became the first proteins… that’s still one of the biggest mysteries in science.

Original Source: Carnegie Institution for Science News Release

March 11, 2008December 26, 2015 by Ian O'Neill

Germs Living in Space “Almost Three Times as Likely to Cause Disease”

In one experiment on board Space Shuttle Endeavor (STS-123) launched early this morning (at 2:28 am EST), the reaction of terrestrial bacteria to zero-G will be tested. When compared with test bacteria bred here on Earth, previous studies suggest that germs bred in space are far more potent and are more likely to cause illness to people in space. The Endeavor mission will continue this experiment in the aim to find some way to prevent these microscopic astronauts causing too many problems to the continuing missions on board the International Space Station and future space tourism companies. Until a solution is found, don’t go ordering fish off the in-flight menu on your next spaceship ride…

Wherever humans go, a whole zoo of bacteria will follow. Most of the bacteria hitching a ride on our skin and inside our bodies live in symbiosis with us, but occasionallyÂ problem bugs like salmonella orÂ Escherichia coli (E-coli) can get out of control, causingÂ problems such as common food poisoning to more serious, life-threatening ailments such as tetanus, diphtheria, syphilis, cholera… (the list is pretty long.)

So, as humans venture into space, it is inevitable that bacteria will come too – the whole symbiotic and parasitic jungle – exploring space with us.

Bacteria will mutate, often very quickly, adapting to the environment surrounding the little microbes. Mutation is the difference between a bacteria being harmless to becoming deadly. Mutations help bacteria to survive and as an example, they can become antibiotic resistant. This is a huge problem in places where antibiotics are used very regularly (such as hospitals); genetic information is passed down the generations of bacteria (often doubling in population in a matter of minutes). If just one microbe has the genetic ability to survive a type of antibiotic, its number will multiply, creating a strain of “superbug” that can avoid being killed by antibiotics – one of the most basic examples of “natural selection”. Methicillin-resistant Staphylococcus aureus (MRSA) is one particular nasty strain of the otherwise benign Staphylococcus genus which has mutated to resist commonly used antibiotics.

It is of paramount importance to understand how bacteria react to space conditions, so problems with potentially dangerous forms of bacteria, such as MRSA,Â can be avoided.

Scientists have discovered that the fairly common salmonella bacteria, usually responsible for terrible food poisoning outbreaks here on Earth, is far more likely to cause serious disease in space and has a much faster rate of reproductionÂ in zero-G. The virilence of salmonella increases drastically in the absense of gravity. The findings from the 2006 Space Shuttle Atlantis mission showed that space-borne bacteria are three times more likely to cause harm to humans in space than humans on the ground, further work was obviously needed to address this potentially deadly barrier to the success of space missions.

The project leader of these experiments, Dr. Cheryl Nickerson (at the Center for Infectious Diseases and Vaccinology, Arizona State University’s Biodesign Institute), hopes to find ways of blocking potentially deadly bacteria from multiplying so quicklyÂ in space and find out why zero-G is such a good environment for bacteria to grow. She headed the 2006 experiments on Atlantis.

“We are very fortunate to get a follow up flight opportunity, because in spaceflight, you only get one shot for everything to go just right […] We saw unique bacterial responses in flight and these responses are giving us new information about how Salmonella causes disease. NASA is giving us the opportunity to independently replicate the virulence studies of Salmonella typhimurium from our last shuttle experiment and to do a follow-up experiment to test our hypothesis about new ways this bacteria causes disease in this unique environment.” – Cheryl Nickerson.

This is obviously a high priority experiment for NASA and the future of manned missions into space. More precautions and safeguards need to be put into place so humankind can adapt to this new, microscopic threat, not from unknown alien bacteria, but from our own germs.

Source: EurekAlert

March 5, 2008December 26, 2015 by Fraser Cain

Do Advanced Civilizations Communicate with Neutrinos?

It’s one of the biggest questions in all humanity: are we alone in the Universe? Either way, the answer is significant. And so, scientists are searching for intelligence out there. Huge arrays of radio telescopes, like the Allen Array scan the skies for radio broadcasts. And researchers have also proposed that aliens might be using lasers to communicate with us. A Russian researcher is proposing another way that aliens might be communicating with us – with neutrinos.

To borrow a quote from the Hitchhiker’s Guide to the Galaxy, “Space is big. You just won’t believe how vastly, hugely, mind- bogglingly big it is.” When you’re attempting to communicate across the vast distances of space, you need huge amounts of energy. Just look at a star, even though it’s generating an incomprehensible amount of energy every second, the brightness drops dramatically with distance.

Instead of broadcasting in all directions, the other strategy is to focus your communications towards a specific location. A targeted beam of radio waves or laser light towards another star still requires an enormous amount of energy, but it’s less.

To save energy, alien civilizations might not be using radio or optical light at all, they might be communicating in a completely different way, with neutrinos.

Researcher Z. K. Silagadze at the Budker Institute of Nuclear Physics and Novosibirsk State University recently posted this idea to the Arxiv pre-press mailing list. His article is called SETI and Muon Collider.

It might sound like science fiction, but scientists are starting to understand how to generate beams of neutrinos – by creating beams of muons. Beams of these unstable particles can be generated in large particle accelerators. The muon beam decays quickly into a focused beam of neutrinos that can travel for light years and still remain remarkably coherent. A beam fired at relatively nearby star Tau Ceti, 12 light-years away, would open up to about 600 astronomical units across – enough to bathe the whole system in neutrinos that could be tracked back to a specific source star.

Finding neutrinos here on Earth is difficult. We’ve got an incredible amount of neutrinos stream towards us from the Sun. In fact, you’ve got billions of neutrinos passing through your body every second and you never feel them because never interact. It takes a huge vat of water, protected underground from other radiation and a suite of sensitive detectors. And even then, they only turn up a few thousand neutrinos a year.

In fact, a neutrino can pass through light-years of pure lead and not even notice.

But there are some advantages. Neutrino detectors are omnidirectional – they don’t have to be targeted in a specific direction to “tune in” a signal coming from a star. If the stream of neutrinos is passing through the Earth, we should be able to detect it, and then track back the source after the fact.

Neutrino detectors are also sensitive to many different energy levels. They don’t have to scan specific frequencies, they can detect high energy neutrinos as easily as low-energy ones.

According to Silagadze, the newly developed IceCube neutrino observatory being built in Antarctica should have the sensitivity to spot neutrinos generated on purpose by alien civilizations – whether they’re targeting us specifically, or we’re just overhearing their conversations.

It has been suggested that advanced civilizations might deliberately choose neutrinos for communications because it shuts out the very young, and not mature civilizations from the galactic conversation.

But give us a few years, and we’ll be listening.

Original Source: Arxiv

February 29, 2008December 26, 2015 by Ian O'Neill

First Experiment Starts in ISS Columbus Module Testing Plant Growth

The brand new ESA Columbus Module installed on the International Space Station (ISS) by the STS-122 crew last week is beginning a first run of biological experiments. This first experiment tests the reaction of root growth in different gravitational states. Of particular interest is how the roots of seeds develop in space when compared to terrestrial conditions. This has obvious applications for growing plants in space, underpinning agricultural science in some of the most extreme and challenging environments man will experience.

Today saw the first ever experiment on the ESA Columbus Module on board the ISS. European astronaut LÃ©opold Eyharts activated the Waving and Coiling of Arabidopsis Roots at Different g-levels (WAICO) experiment, comparing two types of arabidopsis seed (one wild and one genetically modified) in gravity conditions from zero to one Earth gravity (or 1G). The arabidopsis seed is derived from the arabidopsis thaliana plant which copes very well in restricted space and thrives in hostile surroundings.

The WAICO experiment will last for 10 to 15 days and the sprouted seeds will be returned by the STS-123 Space Shuttle mission due for launch on March 11th so the results can be analysed. Throughout the experiment, using the brand new “Biolab” equipment (pictured), the advanced telemetry of the Columbus Module will relay real-time video of seed development to ESA scientists in Germany.

The development of the root growth will be scrutinized; especially the amount of “waving” and “coiling” that occurs as a reaction to different gravity conditions. These experiments will also help terrestrial farming methods, giving farmers the opportunity to optimize plant growing conditions.

Source: ESA

February 27, 2008April 26, 2016 by Nancy Atkinson

Earth Life Forms Ejected on Asteroid Impact Could Survive and Return Again

Does this mean that, perhaps, we can go home again?

If an asteroid or comet impacted Earth, the resulting ejection of materials could contain life forms. According to a study published in the journal Astrobiology, these life forms could survive and then seed another planet or moon with life. Additionally, Earth could also be re-seeded with life by those same life forms.

Ah, there’s no place like home.

If rock fragments containing embedded microorganisms were ejected into space, at least some of those organisms might survive and reseed Earth or seed another planetary surface able to support life. This scenario, which is called lithopanspermia was examined in studies called systematic shock recovery experiments designed to simulate this type of situation where microorganisms are transported between planets via meteorites.

The researchers sandwiched dry layers of three kinds of biological test ingredients, including bacterial endospores, endolithic cyanobacteria, and epilithic lichens, into rocks analogous to rocks from Mars. They then simulated the shock pressures Martian meteorites experienced when they were ejected from Mars and determined the ability of the organisms to survive the harsh conditions.

The organisms are hardy examples of microbes that can withstand extreme environmental stress and represent potential ‘hitchhikers’ within impact-ejected rocks.

“Given that impacts have occurred on planetary bodies throughout the history of our solar system,” says Sherry L. Cady, PhD, Associate Professor in the Department of Geology at Portland State University, “the hypothesis that life in rock could have been transferred between planets at different times during the past 3.5 billion years is plausible.”

And not only is it plausible that Mars rocks could be transferred to Earth and vice versa, but ejected rocks from Earth could possibly return and land back on their home planet. Given the contemplation of the destruction of life on Earth, it’s somewhat comforting to think that we could perhaps start over again from our own ingredients.

Original News Source: Astrobiology Press Release

February 13, 2008December 26, 2015 by Ian O'Neill

Titan has “Hundreds of Times More” Liquid Hydrocarbons Than Earth

According to new Cassini data, Saturns largest moon, Titan, has “hundreds” times more liquid hydrocarbons than all the liquid fossil fuel depositsÂ on Earth. This is impressive as Titan’s 5150 km diameter is only about 50% larger than Earth’s Moon and only a little larger than the planet Mercury. Titan’s hydrocarbons cycle into the atmosphere, fall as rain and collect in lakes creating massive lakes and dunes.

Titan is a planet-sized hydrocarbon factory. Instead of water, vast quantities of organic chemicals rain down on the moon’s surface, pooling in huge reservoirs of liquid methane and ethane. Solid carbon-based molecules are also present in the dune region around the equator, dwarfing Earth’s total coal supplies. Carl Sagan coined the term “tholins” to describe prebiotic chemicals, and the dunes of Titan are expected to be teeming with them. Tholins are essential for the beginning of carbon-based organisms, so these new observations by Cassini will stir massive amounts of excitement for planetary physicists and biologists alike.

The cold -179Â°C (-290Â°F) landscape of Titan is currently being mapped by the Cassini probe as it orbits the ringed gas giant, Saturn. Some 20% of the moons surface has been catalogued and so far several hundred hydrocarbon seas and lakes have been discovered. These lakes, individually, have enough methane/ethane energy to fuel the whole of the US for 300 years.

These new findings have been published in the January 29th issue of the Geophysical Research Letters by Ralph Lorenz from the Cassini radar team (Johns Hopkins University Applied Physics Laboratory, USA). Lorenz said on reviewing the Cassini data that, “we know that some lakes are more than 10 m or so deep because they appear literally pitch-black to the radar. If they were shallow we’d see the bottom, and we don’t.” He also steps into the life-beyond-Earth debate by pointing out: “We are carbon-based life, and understanding how far along the chain of complexity towards life that chemistry can go in an environment like Titan will be important in understanding the origins of life throughout the universe.”

The ESA Huygens probe separated from Cassini and dropped slowly through the Titan atmosphere in January 2005 analyzing the atmospheric composition and taking some breathtaking images of the surrounding landscape. To complement the huge amount of data assembled from Huygens decent, Cassini will flyby the moon again on February 22nd to take radar data of the Huygens landing site.

Source: Physorg.com

January 17, 2008January 24, 2021 by Fraser Cain

Has a Signal from ET Really Been Detected?

Have you heard the news? A television station in Oakland California was reporting that researchers working with SETI@home discovered a signal believed to be from extraterrestrials. Is it true? Has the most important discovery is the history of humanity been made? Do we have definitive proof that there are aliens out there with interesting things to say to us?

No.

Actually, I was going to give this the big write up, but Phil beat me to the punch. So, I’ll just point you over at his coverage.

January 12, 2008December 26, 2015 by Ian O'Neill

Radioactive Hot Spots on Earth’s Beaches May Have Sparked Life

We’ve heard about life being created in a puddle of primordial chemical soup, sparked by lightning strikes, or organic molecules falling to Earth from comets or planets, such as Mars. But now, there is an alternative. Early Earth was radioactive; the Moon also had a lower orbit, generating strong tidal forces. Due to the close proximity to abundant water, radioactive beaches may have possessed all the essential ingredients for organic compounds, and eventually life, to thrive.

Research by the University of Washington, Seattle, suggests that perhaps the highly radioactive environment of Earth some 4 billion years ago may have been the ideal time for life to form. The orbit of the Moon also had a part to play in this offbeat theory.

Through strong tidal forces by a Moon that orbited far closer to the Earth than it does today, radioactive elements accumulated on the beaches could be gravitationally sorted. The chemical energy in these beach hot spots was probably high enough to allow self-sustaining fission processes (which occurs in natural concentrations of uranium). The main product from fission is heat, therefore powering chemical processes and the generation of organic, life-giving compounds.

“Amino acids, sugars and [soluble] phosphate can all be produced simultaneously in a radioactive beach environment.” – Zachary Adam, an astrobiologist at the University of Washington Seattle.

This is a hard theory to understand, it is well known that radioactivity breaks down organic molecules and causes a whole host of problems for us carbon-based creatures. But in the early Earth, devoid of plants and animals, radioactive processes may have provided energy for life to begin in the first place.

This theory also partially explains why life may be a very rare occurrence in the universe: there must be the correct concentration of radioactive elements, on the surface of a water-dominated developing planet, with tidal forces supplied by a closely orbiting stellar body. The Earth may, after all, be unique.

Source: Telegraph.co.uk

January 4, 2008December 26, 2015 by Nicholos Wethington

Organic Molecules Found Outside our Solar System

Organic molecules are thought by scientists to be instrumental in kickstarting life as we know it on Earth. Within our Solar System they can be found in comets, and they cause the redness of the clouds of Saturn’s moon Titan. New observations of a planet-forming disk around a star 220 light-years from Earth reveal for the first time that these molecules exist elsewhere in the Universe.

Astronomers at the Carnegie Institute have detected the presence of organic molecules in the dusty disk surrounding HR 4796A, an eight-million year-old star in the constellation Centaurus. Using Hubble’s Near-Infrared Multi-Object Spectrometer they analyzed the light coming from the disk and found that its red color is due to large organic carbon molecules called tholins. The analysis ruled out other causes of the red light, such as iron oxide.

â€œUntil recently itâ€™s been hard to know what makes up the dust in a disk from scattered light, so to find tholins this way represents a great leap in our understanding,â€? said John Debes of the Carnegie Institute’s Department of Terrestrial Magnetism, one of the authors of the study.

Just as in our early Solar System, the disk of dust is in the process of forming planets. The collision of small bodies like asteroids and comets creates the dust in the disk, and the organic molecules present on these objects could then be scattered on any planets orbiting the star. This discovery makes it clear that it is possible for organic molecules to exist in the early stages of planet formation, paving the way for the possible development of life later on.

Organic molecules are thought to be essential to the development biological organisms because they are made up of carbon, the building block of life on Earth. The discovery of these molecules elsewhere in the Universe does not mean that life exists there yet â€“ or even that it will in the future â€“ but it does increase the tantalizing prospect of life forming outside our Solar System.

The study was published in the current Astrophysical Journal Letters by John Debes and Alycia Weinberger of the Carnegie Institutionâ€™s Department of Terrestrial Magnetism with Glenn Schneider of the University of Arizona.

Source: Carnegie Institute Press Release

December 20, 2007December 26, 2015 by Fraser Cain

ET Would Know There’s Life on Earth

It seems impossible to believe, but astronomers are now making plans to reach for the brass ring of planet hunting: to find Earth-sized worlds orbiting other stars, and then to analyze them to see if there’s life. But you’ve got to know what you’re looking for. That’s why astronomers are considering what the Earth might look like from afar. What clues would our planet give to distant astronomers that there’s life here?

The number of discovered planets is up to 240 now and growing. In fact, the planetary discoveries are coming so fast and furious that many universities don’t even bother releasing press releases any more.

But these are all hostile worlds; larger than our own gas giants, and many orbit tightly to their parent star. We’re not going to find life on these “hot jupiters”. No, it’s going to be the Earth-sized planets, orbiting within the habitable zone of their star, where water can still be a liquid on the surface of the planet. These planets are going to have active weather systems, oceans and land masses.

Even with a telescope with many times the power of the Hubble Space Telescope, an Earth-sized world would appear as a single pixel in a vast empty space. You wouldn’t get any kind of detailed resolution.

Can a single pixel tell you anything about that world? Researchers say, “yes”. In a new paper published in the online edition of the Astrophysical Journal, they say that observers looking at the Earth from afar would be able to judge our rotation rate, the probability of oceans, weather, and even if the planet has life.

If distant astronomers were watching Earth, they’d see the brightness change over time as clouds rotated in and out of view. If they could also measure its rotation period, they’d know whether a certain part of the planet was in view, and start to deduce if there are oceans or land masses pointed towards them.

The researchers have created a computer model for the brightness of Earth over time, showing that the global cloud cover is surprisingly constant. There are usually clouds over the rain forests, and arid regions are clear.

Astronomers watching Earth would start to recognize the patterns, and be able to deduce an active weather system here. Compare this to the other planets in the Solar System:

“Venus is always covered in clouds. The brightness never changes,” said Eric Ford, a UF assistant professor of astronomy, and one of 5 authors on the paper. “Mars has virtually no clouds. Earth, on the other hand, has a lot of variation.”

To recognize these kinds of characteristics on another world will require a telescope with roughly twice the size of Hubble. And observatories like this are in the works.

Original Source: University of Florida News Release