What was discovered?
Cracks in the surface of Enceladus allow water vapour and ice to shoot through, high into the sky. This is precisely where negatively charged water molecules, with an extra electron, were found.
How?
The Cassini space probe recently swept past the moon, collecting data with its plasma spectrometer (CAPS).
This instrument can measure the density,
flow velocity and temperature of ions and electrons that enter it. Originally it was intended to gather data on Saturn's magnetic environment, but this new data is exciting too!
In addition to negatively charged water, negatively charged hydrocarbons were also found.
Why is it important?
Wherever there is water, carbon and an energy source, there is the potential to build some of the molecules of life!
What is a plasma spectrometer?
The Cassini plasma spectrometer (CAPS) is a sophisticated instrument that includes
a) an electron spectrometer,which measures the energy of incoming electrons,
b) an ion beam spectrometer, which can find the energy to charge ratio of an ion, and
c) an ion mass
spectrometer.
What are the major building blocks of life?
Defining life is a difficult task, but let's start by saying that a membrane would be needed around the outside of the cell, controlling what goes in and out, and inside there must be chemical reactions, or 'metabolism' as it is known.
Membranes are made from many phospholipids, themselves being made of glycerol joined to two fatty acids and a phosphate group. Within the membranes are found proteins, formed by many amino acids joined together in a long chain by peptide bonds.
Proteins also make enzymes, needed to speed up chemical reactions. Sugars often provide the energy needed for enzymes to do their work.
But of course a 'bag' with reacting molecules on its own cannot be considered living. It must be able to reproduce... and for that a much more complicated molecule is needed... can you guess what kind of molecule?
Which molecules can act as genetic material?
You guessed it... nucleic acids do the job very nicely! They can store instructions for making proteins, which include all the enzymes inside cells, so in that way they control metabolism, or what the cell can do if you prefer to think of it like that.
But they can also be copied precisely so that the information can be passed to two new cells if the first cell splits in half.
Importantly, our genetic material can change - we call such changes "mutations" - so that cells can change and hopefully survive better as the environment changes with time.
Have the molecules of life been found on Enceladus?
No, they haven't!
But that does not stop us marvelling at the recent data and what it tells us!
Current rating
