Tag Archives: Abiogenesis

31 Days – Sugar in Space

Soon after I posted yesterday about life ratcheting its way into existence, I came across the video below. It turns out that if life were to arise in space, there might be food waiting for it!

Here’s the description from the YouTube page.

A team of astronomers has found molecules of glycolaldehyde — a simple form of sugar — in the gas surrounding a young binary star, with similar mass to the Sun, called IRAS 16293-2422. This is the first time sugar been found in space around such a star, and the discovery shows that the building blocks of life are in the right place, at the right time, to be included in planets forming around the star. The astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect the molecules.

This video starts with a broad panorama of the spectacular central regions of the Milky Way seen in visible light. It then zooms in to the Rho Ophiuchi star-forming region in infrared light, highlighting IRAS 16293-2422. Finally, we see an artist’s impression of glycolaldehyde molecules, showing glycolaldehyde’s molecular structure (C2H4O2).

More information and download-options:
http://www.eso.org/public/videos/eso1234a/

Credit:
ESO / Nick Risinger (skysurvey.org) / S. Guisard (www.eso.org/~sguisard) / L. Calçada & NASA/JPL-Caltech/WISE Team
Music: Disasterpeace

31 Days – Ratcheting

We have only 3 days left in this month’s 31 Days of Wonder, and I’ve saved a good one for you. I call it the ratcheting effect, and we owe our existence to it.

First let’s play cards.

If you were to shuffle a deck of cards perfectly (completely randomizing it) over and over again, how long do you think it would take until, by chance, it fell into order? (“Order” in this case means Ace through King of Spades, followed by Ace through King of Hearts, and so on — one specific order.)

Well, there are about 8 * 1067 possible ways to arrange 52 cards. By comparison, the universe is only about 4 * 1017 seconds old.  If you were to shuffle once every 5 seconds, you would have to shuffle for incalculably many lifetimes of the universe before you’d expect even one perfect ordering.

Now suppose we change the game. This time, each card has the unusual property that if it happens to get shuffled next to its correct neighbor, then the two will ride together for all the remaining shuffles.

How long do you think it will take before the deck is in order?

Last night, I wrote a little computer program to perform this experiment. On average, it took only 55 shuffles to put the deck in order. You could do that in less than 5 minutes — a lot less than even one age of the universe.

When something that’s “right” sticks, the situation can ratchet toward a desired outcome very quickly.

So what does this have to do with us? How do we owe our existence to the ratcheting effect?

Some people think the chance formation of even a single cell is wildly improbable. And so it would be if it had to form in one step, but that’s not the way it happened. Just as the cards in our second deck stuck together to form sub-units, which then coalesced further until the deck was ordered, life ratcheted up in steps, each of which was naturally preserved.

In fact, the more experiments we do in this area, and the more Earth-like planets we discover, the more likely it seems that we are not alone in the universe. Now that’s something to wonder about!

31 Days – Life from Meteorites?

I saw four shooting stars this morning! It was the last of the Perseid display so I hauled myself out of bed and sat on the grass under a clear, pre-dawn sky.

MeteoriteSitting there surrounded by trees, it was hard to imagine that Earth was once as barren as Mars. How did life get started? There are several credible hypotheses , but watching meteorites fall to earth brought to mind the recent news that nucleobases have been found on meteorites.

What’s a nucleobase and why is that a big deal? You’ve heard of the famous nucleobases. They go by the nicknames A, G, C and T, and are the building blocks of DNA – the molecule that carries the code for life as we know it. Some of our DNA’s nucleobases were found in the meteorites, but more intriguing were the “related but exotic nucleobases never seen before,” according to NASA, as reported by the Washington Post.

Furthermore, the exotic molecules were absent from the surrounding dirt and ice. “The detection of the exotic nucleobases, and their absence from surrounding material, helped rule out contamination,” the Post continued.

The NASA team led by Michael Callahan have also shown by experiment that it’s fairly simple to produce nucelobases from ammonia, water and hydrogen cyanide, which are all found on meteorites.

Although nothing is proven, it’s eerie to think that the building blocks of life might have arrived on this planet from the same sorts of meteorites I saw this morning.