Why search for life in outer space?


Figure 1: A gamma ray and neutron detector on board Dawn was used to determine the elements in the subsurface of the dwarf planet. It found water on the dwarf planet Ceres, located in the asteroid belt between Earth and Mars. Ceres. Credit: LA Times

In a recent LA Times news item it was reported that NASA’s Dawn spacecraft mission found life’s building blocks on the dwarf planet Ceres.1  However, the reality is that all that was found are possibly some biochemical molecules, molecules that are pre-cursor molecules to form the more complex chemistry in living cells.

Organic molecules are carbon based molecules and the chemistry of life is a special subset of those but from the spacecraft data no biochemical molecules were identified.  Those would be molecules like carbohydrates, lipids, proteins and nucleic acids.

The news item reports that this new spacecraft

… using its Visible and Infrared Mapping Spectrometer instrument, … has spotted organics lying on the surface.1

That is the only real fact in the report, that organic molecules of some sort have been found on Ceres.

While the scientists aren’t sure exactly what the compounds are, the fingerprint is characteristic of material containing carbon-hydrogen bonds, and may include components like methyl and methylene.(emphasis added)

But they don’t even know what the molecules are, and the research is hyped up in hope that scientists may find life–even just microbes–living on worlds other than our own.

We can now add this dwarf planet Ceres to other ‘space rocks’ that have been so hyped in the past few years in the quest to find life out there in the solar system. Examples are Mars,2 Enceladus (the sixth-largest moon of Saturn),3 Titan (the largest moon of Saturn),4,5 Europa (one of the 4 Galilean moons of Jupiter),6 and the asteroids.7 Continue reading