Chapter 4 covers the Viking missions. We learn much about Carl Sagan and something of the hidden politics that damaged his career. We also meet Wolf Vishniac and his proposed experiment to look for microbial life on Mars nicknamed "Wolftrap". It was dropped, but another experiment flown on Viking detected active bacterial metabolism. 'We were so excited, we sent out and got champagne, cigars,' Gulliver's lead recalled (p 70). Gulliver is actually the Labelled Release (LR) experiment, whose leader was Gil Levin. But without turning to the fine print in the endnotes, a reader would never even learn his name.
Chaper 5, "Stone from the Sky" tells the story of the Allen Hills meteorite (ALH84001). In 1996, NASA geologist David S. McKay and co-workers reported that it contained good evidence for past life on Mars. But after much excitement, skepticism took over. Johnson pronounces that neither the LR experiment nor the analysis of ALH84001 produced anything conclusive. Both projects came before her active involvement, so she is likely just relaying NASA's official position. I think it's whitewashed.
By the time Opportunity and Spirit rovers were launched for Mars, Johnson was on the team. Right away, in 2004, Opportunity photographed tiny shapes that clearly resemble fossilized crinoid pieces. She has studied fossilized crinoids and she is well aware of that image, but now she ignores it. Later Mars missions like Phoenix and Curiosity didn't include life-detecting experiments. Not even the current one, Perseverance. This intransigence is quite puzzling. Is hidden politics also at work at NASA?
But Johnson's book is really a memoir. She fell in love, she almost died, and she is ever enchanted with the wonders of Mars. Her own story is engaging and the writing excellent. If she writes another one, I'll read it!The Sirens of Mars: Searching for Life on Another World by Sarah Stewart Johnson, ISBN:9781101904817, Crown/Penguin Random House, 07 Jul 2020.
Thanks, Mark Frederick at the Memphis bookstore, Novel.
Life on Mars! has background with links about Viking and ALH84001.
Sea Lilies on Ancient Mars: a poster about the fossilized crinoids.
Mars Helicopter Flight Delayed to No Earlier than April 14, NASA/JPL, 10 Apr 2021.
Environmental DNA Can Be Pulled from the Air by Amanda Heidt, TheScientist, 07 Apr 2021.
Time-resolved comparative molecular evolution of oxygenic photosynthesis by Thomas Oliver et al., doi:10.1016/j.bbabio.2021.148400, Biochimica et Biophysica Acta (BBA) - Bioenergetics, 01 Jun (online 19 Feb) 2021.
Photosynthesis could be as old as life itself by Hayley Dunning, Imperial College London +ScienceDaily, 16 Mar 2021.
Thanks, Martin Langford. In mainstream darwinian theory, genetic programs are composed gradually, by trial-and-error. Genomic sequences have been accumulating exponentially, so clear examples of that process should be abundant by now. They aren't. Instead, genes seem to come abruptly, whole or in large pieces, as expected in cosmic ancestry. Sometimes the parts arrive long before they are deployed, as it seems here. Many more examples of genes that appear precede their deployment are discussed and linked from:
Metazoan Genes Older Than Metazoa?
Genes Older Than Earth?