Sometimes personal affairs intervene for all of us, and they have now for your Many Worlds writer and his elderly father.  But rather than remain off the radar screen, I wanted to repost this column which has a new import. 

It turns out that versions of the instrument described below — a miniature gene sequencing device produced by Oxford Nanopore — have been put forward as the kind of technology that could detect life in the plume of Enceladus, or perhaps on Europa or Titan. 

Major figures in the astrobiology field, including Steve Benner of the Foundation for Applied Molecular Evolution (FfAME) and Chris McKay of NASA Ames Research Center see this kind of detection of the basic polymer backbone of RNA or DNA life as a potentially significant way forward.  Three different “Icy Moon” teams are vying for a NASA New Frontiers mission to Enceladus and Titan, and this kind of technology plays a role in at least one of the proposed missions.

Early Earth, like early Mars and no doubt many other planets, was bombarded by meteorites and comets. Could they have arrived “living” microbes inside them?

When scientists approach the question of how life began on Earth, or elsewhere, their efforts generally involve attempts to understand how non-biological molecules bonded, became increasingly complex, and eventually reached the point where they could replicate or could use sources of energy to make things happen.  Ultimately, of course, life needed both.

Researchers have been working for some time to understand this very long and winding process, and some have sought to make synthetic life out of selected components and energy.  Some startling progress has been made in both of these endeavors, but many unexplained mysteries remain at the heart of the processes.  And nobody is expecting the origin of life on Earth (or elsewhere) to be fully understood anytime soon.

To further complicate the picture, the history of early Earth is one of extreme heat caused by meteorite bombardment and, most important, the enormous impact some 4.5 billion years of the Mars-sized planet that became our moon.  As a result, many early Earth researchers think the planet was uninhabitable until about 4 billion years ago.

Yet some argue that signs of Earth life 3.8 billion years ago have been detected in the rock record, and lifeforms were certainly present 3.5 billion years ago.  Considering the painfully slow pace of early evolution — the planet, after all, supported only single-cell life for several billion years before multicellular life emerged — some

A DNA helix animation.