Laboratory Ice Links Comets with Life On Earth

Artist impression of the nucleus of Comet Tempel (NASA)

It is an established theory that comets may have, in some way, seeded life on Earth. Some extreme ideas support the panspermia concept (where bacterial organisms hitched a ride on comets, asteroids or some other planetary debris, spreading life throughout the Solar System), while others suggest comets may have contributed the chemical building blocks essential for life to form 4 billion years ago. We know these icy bodies are also awash with organic compounds, so it’s not a huge leap of the imagination to think comets may have donated life-making material to the early Earth.

In an effort to study cometary material and its possible influence for nurturing early life on Earth, Prof. Akiva Bar-Nun of the Department of Geophysics and Planetary Sciences at Tel Aviv University has been creating his own comets in the laboratory. By doing this, Bar-Nun is hoping to gain a better perspective on how comets acquired their composition of the noble gases Argon, Krypton and Xenon.

The proportion of these elements are found in the Earth’s atmosphere, but are not thought to have originated from the rocky material our planet consists of. By understanding the proportions of these elements that formed in the icy laboratory environment, if the proportions match that of what we’ve measured on Earth, it goes to some way in explaining how comets formed in space and how they delivered organic compounds to the surface.

Now if we look at these elements in the atmosphere of the Earth and in meteorites, we see that neither is identical to the ratio in the sun’s composition,” said Bar-Nun. “Moreover, the ratios in the atmosphere are vastly different than the ratios in meteorites which make up the bulk of the Earth.”

So we need another source of noble gases which, when added to these meteorites or asteroid influx, could change the ratio. And this came from comets.”

Prof. Bar-Nun and his team carried out the research using a comet-making machine unique to Tel Aviv University, and although the original press release is light on the details, it is assumed the chemical composition of the early Solar System was recreated and then deep-frozen.

Comets bombarded the Earth 4 billion years ago. Organic chemicals were therefore deposited, possibly kick-starting life (NASA)

Comets bombarded the Earth 4 billion years ago. Organic chemicals were therefore deposited, possibly kick-starting life (NASA)

Comets formed some distance from the Sun (and a vast number of them populate the Oort Cloud), water vapour would have condensed and frozen, in temperatures as low as -250°C, trapping a primordial collection of chemicals inside their dusty, icy interiors. Some time after, these comets may have fallen into the inner Solar System, many impacting the Earth. Amino acids may have been introduced to the surface and oceans, or vital chemical components from the comets combined with chemicals already on Earth and life was sparked. When this happened, these comets would have left a chemical fingerprint.

Bar-Nun’s team were successful in creating their own synthetic comet, freezing water vapour, creating a natural ratio between the three elements. Then a link could be made, from the laboratory comet, with the very definite noble gas proportions, and the proportions of these gases found in the atmosphere.

The pattern of trapping of noble gases in the ice gives a certain ratio of Argon to Krypton to Xenon, and this ratio — together with the ratio of gases that come from rocky bodies — gives us the ratio that we observe in the atmosphere of the Earth,” added Bar-Nun.

Judging by the information available (the paper is published in the journal Icarus), Bar-Nun’s research has provided evidence that comets left a unique ratio of stable noble gases in the atmosphere, a ratio of necessary materials for life to eventually form.

Source: Tel Aviv University, EurekAlert via @Avinio

About these ads

The Russian Rocket-Powered Lander. What Could Possibly Go Wrong?

russian_spaceship_next

Let’s face it, Soyuz is getting old. It’s not that the spaceships themselves are getting rickety, there have been many incarnations, but the original Soyuz design was first conceived in 1966, so the Russian space agency (Roscosmos) is feeling it’s about time for a change. Soyuz has carried out the most manned missions into space out of any other space flight system (over 100 since the 1960s), so Russia has every right to be proud of its achievements.

So what system does Roscosmos want to replace Soyuz with? Perhaps a bigger version of Soyuz? Perhaps a revolutionary winged spaceplane? Nope. They are currently looking at plans for a Soyuz-esque capsule that will re-enter the Earth’s atmosphere much like before. But due to political pressure (spawning the need to move Roscosmos’ operations out of Kazakhstan), engineers must find a way to land the return vehicle in a minuscule area. Measuring only 2×5 km (yes, that’s a tight 10 km2), the landing strip will be as unforgiving as the new method to land the descent vehicle.

There will be no parachutes and no wings; the new concept will use a rocket-powered landing system alone, creating the first ever rocket-powered Earth-lander. If you thought that was a rather extreme design specification, you might be surprised to hear that engineers want to start firing these landing thrusters when the descent module is only 600-800 metres from the ground
Continue reading

Cassini Detects Salt: Enceladus Probably Has a Liquid Ocean

The small icy Saturn moon might have liquid sub-surface oceans after all (NASA)

In October 2008, Cassini flew very close to the surface of Saturn’s icy moon Enceladus. From a distance of only 50 km from the moon, the spacecraft was able to collect samples of a plume of ice. In an earlier “skeet shot”, Cassini captured detailed images of the cracked surface, revealing the source of geysers blasting the water into space. At the time, scientist were able to detect that it was in fact water ice, but little else would be known until the molecular weight of chemicals in the plume could be measured and analysed.

At the European Geophysical Union meeting in Vienna this week, new results from the October Enceladus flyby were presented. Frank Postberg and colleagues from the Max Planck Institute for Nuclear Physics have discovered traces of sodium salts and sodium bicarbonate in the plume for the first time.

It would appear that these chemicals originated in the rocky core of the moon and were leached from the core via liquid water. The water was then transported to the surface where it was ejected, under pressure, into space. Although scientists are aware that the chemical composition in the plume may have originated from an ancient, now frozen, sub-surface ocean, the freezing process would have isolated the salt far from the surface, preventing it from being released.

It is easier to imagine that the salts are present in a liquid ocean below the surface,” said Julie Castillo of NASA’s Jet Propulsion Laboratory in Pasadena, California. “That’s why this detection, if confirmed, is very important.”

This is the best evidence yet that Enceladus does have a liquid ocean, bound to cause a stir amongst planetary scientists and re-ignite excitement for the search for life living in a salty sub-surface ocean.

Source: New Scientist

Every Reason Not To Worry About Doomsday In 2012

Image credits: Harold Edgerton (1964), NASA. Edit: Ian O'Neill

In today’s 365 Days of Astronomy, Cameron Hummels and Josh Schroeder from Columbia University, New York, discuss the 2012 doomsday hype. And it is awesome. The special thing about this podcast is that Cameron (who is working toward a PhD in astronomy) is clear, concise, and makes the whole crackpot 2012 doomsday scenario sound as petty as it really is.

In 10 minutes, the pair run through ancient prophecy, Mayan calendars, Planet X, galactic alignment and solar flares (to name a few) and carry out possibly one of the most comprehensive debunking efforts I have ever heard. They pretty much summed up all of my “No Doomsday in 2012″ articles with a huge helping of skeptical thinking, plus extras, pointing out that all the doomsday hype is driven by little more than a small group of irresponsible individuals wanting to make some fast money from people’s fear.

Congratulations Cameron Hummels and Josh Schroeder, you’ve just scored one huge point for rational thinking and produced a wonderful celebration of scientific endeavour!

Go to the 365 Days of Astronomy podcast page to listen in »

Show description:

An increasing number of people believe that December 21, 2012 will mark the end of the world. Proponents of this idea cite diverse astronomical reasons for an imminent apocalypse: the end of the Mayan long-count calendar; an alignment between the Solar System and the Milky Way; the solar sunspot cycle reaching an all-time high; the reversal of the Earth’s magnetic field; and a devastating collision with ‘Planet X’. Tune in to hear to the facts and controversy surrounding this purported impending disaster.

Did Dark Matter Reionize the Universe?

Did dark matter characterize our early Universe?

Immediately after the Big Bang, 13.72 billion (±120 million) years ago, the Universe was filled with energy. Nothing but energy. No protons, electrons, quarks or photons; just energy. Even the fundamental forces of nature (gravity, weak, strong, electromagnetic) were a confused mess and could not be distinguished, but that issue didn’t last for long. 10-43 seconds after the Big Bang the grand unification epoch began, when gravity is thought to have separated from the soup. Shortly after, the strong force separated from the electroweak force in a period called the electroweak epoch.
Continue reading

Flying Laser Ready to Begin Airborne Weapon Tests

The 747 plus ABL (USAF)

747 airliner? Check. Huge laser? Check. Huge-flying-missile-melting-laser? Nearly.

Actually, I’d want to fly the aircraft remotely, unmanned, and fire the oversized laser pointer at the 747 from a distance. Just to see how long it would take to melt. But that’s just me.

Boeing on the other hand, has succeeded in building a flying laser. Toward the end of 2008, the Airborne Laser (ABL) had been installed inside its Boeing 747 host and it was undergoing static tests. Sure enough, the megawatt laser had proven its worth and fired at a target, twice, in one-second bursts. Details are sketchy as to the damage the ABL caused, but Boeing and other US military contractors heralded the test as a success (if you ask me, the target probably looked like this afterwards).
Continue reading

2012 Is Coming… And All I Got Was This Lousy Fridge Magnet

Screenshot from the Flash animation "The End of the World" by Fluid

Just when I was getting bored of the endless stream of 2012 doomsday hype (tripe), my interest was suddenly reinvigorated when I saw this advertisement:

2012 Calendar Magnet

$2.99 + shipping

Our calendar magnet is a real 2012 calendar. So you can have it on the refrigerator for 3 1/2 years! The calendar magnet is 4.25 inches wide and 5.5 inches long. It is also very clear and easy to read (looks better than the picture above, but is smaller). The shipping cost within the U.S. is $0.79 and for International orders $1.89.

No way. Oh yes. Yes, they did! The most well-known 2012 protagonist website is selling doomsday fridge magnets depicting an Earth plus comet barrelling towards it.

I had to triple-check, just in case this was the doomsday blogging equivalent to Punk’d. No, this is real: fridge magnets.
Continue reading