Searching for life in the universe: how will we know it’s life?



Earlier this year I reported here on a December 2016 astrobiology workshop held by the National Academies’ Space Studies Board (SSB), at NASA’s request. The National Academies has now published the proceedings of this workshop, “Searching for Life Across Space and Time.” At 132 pages, it’s a dense but fascinating read, if you’re interested in the subject matter.

The subject matter is how to look for, identify, and verify evidence of extraterrestrial life.

The more we learn about life as we know it, and the more we speculate about life as we don’t know it, the more we explore other planetary environments in our solar system, and the more we discover about a wildly diverse population of extrasolar planets, the more complex the task of extraterrestrial life detection becomes.

The astrobiology community is focused on identifying reliable biosignatures – that is, signs of life that can’t be signs of something other than life. (Recall the 1996 claim of fossil evidence of microbial life in the martian meteorite ALH 84001 – a claim that continues to be disputed.) The primary challenge here is that there is no simple answer to the question, “What is life?”

At the SSB workshop, experts focused on four approaches to the search for evidence of life beyond Earth: in-situ detection of life as we know it on solar system bodies; remote detection of life as we know it on extrasolar planets; in situ detection of life as we don’t know it (a.k.a. “weird life”) on solar system bodies; and remote detection of life as we don’t know it on extrasolar planets.

Research into the origin (or origins) of life on Earth has yet to reveal exactly how non-life becomes life. At the workshop, astrobiologist John Baross suggested four approaches to the study of the origin of life: a “paleogenetics” approach, working backward in time by studying fossil evidence of ancient biology and prebiology; a “prebiotic chemistry” approach to identifying the chemical pathway (or pathways) to the simplest first life; the astrobiology approach, searching the cosmos for evidence of an independent genesis of life beyond Earth; and a synthetic biology approach, aimed at designing and building life in the laboratory.

Systems biologist Eric Smith posed these questions to the workshop: Is life a cosmic imperative? How would thermodynamics force life into existence? Is the existence of a biosphere an inevitable result of thermodynamics?

Astrobiologist Morgan Cable described three types of extraterrestrial plumes that could be sampled for evidence of life: volcanic plumes, cometary plumes, and plumes emitted by ocean worlds. Would it be possible to detect extant life by plume fly-throughs at several kilometers per second? She discussed some possible sampling techniques that might (or might not) be successful.

Rather than writing a long blog post, I’ve cherry-picked a few topics covered in this report, topics of particular interest to me. If you’re interested in learning more, take a look through the report’s table of contents, or read Chapter 7, which summarizes previous chapters.


Hurricane Irma: my observations

iss053e003631Hurricane Irma approaching south Florida, as seen from the International Space Station. Credit: NASA

On Tuesday September 12, it’s a beautiful mid-hurricane-season day here in Sarasota, Florida, where I now live. My partner David and I, relocated here from the Washington, D.C., area just three months ago, came through Hurricane Irma unscathed.

Miraculously (I know, not a very scientific word), we did not lose power. We suffered no damage to our (rented) property. Even our pool cage is intact. We were not worried about flooding, as we are about eight miles way from the Gulf of Mexico, equidistant from rivers in the area, and at 30 feet above sea level – the highest elevation in Sarasota County (higher than all but one of the county’s emergency shelter locations). Near the peak of the storm, David worried that our pool would overflow and possibly flood the house, so he went outside (in 50-mph winds) and drained some water out of it.

Our neighbors on both sides spent Sunday night elsewhere. They’re all home now, and all is well. I spoke to another neighbor this morning, who spent Sunday night in a shelter with 3000 other people and 1000 dogs (including her own). She said all were very well behaved.

Nonetheless, it’s been a terrifying time here. Today is the first time in at least a week that I feel free of fear and anxiety.

We are not in a flood/evacuation zone where we live (“know your zone” is a message we heard from multiple sources over and over again.) Nonetheless, at the urging of family and friends, we left our Sarasota home Thursday morning Sept. 7 at 8 am, with the aim of reaching northern Virginia by Friday evening. We brought our 20-year-old cat, Giovanni, with us. Six and a half hours later, we’d traveled 150 miles on I-75 north. We pulled off the highway for gas and found that some stations were already out of fuel.

When we did find a truck stop with fuel, of course it was mobbed. The stop had a single entrance/exit – one lane each way. Panicked drivers were entering the stop in both lanes, making it impossible for vehicles to exit the stop. In the midst of this madness, David spoke with the truck-stop operator, who said he was in contact with other truck-stop operators going several states north. They were reporting that the situation was gridlock all the way.

We’d been listening to public radio stations all along the way, and we were not hearing any useful information about traffic conditions, hotel accommodations, fuel supplies moving north. I checked numerous web sites on my phone: Sarasota Highway Patrol, Florida DOT, I-95 web site, I-75 web site. Ditto.

David and I discussed and discussed and discussed the pros and cons of continuing north or turning around and heading back south, as we inched ahead at 10 miles per hour. We finally agreed that the risks of continuing north were equal to, or perhaps even greater than, the risks of returning home. So we returned. My level of anxiety dropped considerably – until Saturday….

On Thursday evening, our neighbors invited us to dinner and provided us with a lot of tips for storm preparation (for example: release the parking brake on your car, put it in neutral and gently roll it up against the inside of your garage door, for extra reinforcement). My friend Rob, who lives in Houston and just went through Hurricane Harvey (relatively unscathed), gave me a lot of good tips too – such as, have an axe ready in case you have to hack you way out through the roof of your home. Other friends advised us to stash important documents and other valuables in our dishwasher.

On Friday we continued preparations for Irma. At the urging of my friend Theresa in Venice, Florida, I went out in search of a car charger for my iPhone. I’d ordered one online that morning, but Theresa said, “Get one now, you won’t regret it.” At 6 pm on Friday, Best Buy was out of them, but Target came through.

Saturday and Sunday were terrible days. I was sick with fear. David was watching CNN and getting panicked. I begged him to switch to our Sarasota news channel, Suncoast News Network (SNN) – or better yet, to step away from the TV for awhile. By Sunday he’d been switching back and forth between CNN and SNN and looking out the window and realized that our local TV news staff, especially the two on-air meteorologists – Justin Moseley and Marco La Manno – were much better informed about local conditions than anybody else on the air. Even our local public radio station, based in Tampa, was only mildly helpful to us. Tampa and Sarasota are very different places, geographically and demographically.

As the Sarasota Herald Tribune reported yesterday, “By the time Hurricane Irma reached Sarasota County Sunday evening, conditions were more on par with a severe tropical storm than a major hurricane. The maximum sustained winds reported in Sarasota County fell between 40 and 50 mph, with gusts topping 70 mph at Sarasota-Bradenton airport and 80 mph in Venice, according to the National Weather Service. The area saw 5.31 inches of rain, somewhere between the initially predicted 0.86 inches and later forecasts of more than 8 inches. And the six to 10 feet of storm surge that was mentioned at every press conference about the hurricane manifested as 1.7 feet of storm surge at Port Manatee. That was not the way meteorologists predicted it would go.”

I try to avoid clichés, but in this case, it’s apt to say that we dodged a bullet.

I took a walk around our neighborhood this morning. I saw lots and lots of plant debris on the ground – to be expected, as our local environment is lush with vegetation. I saw one live-oak tree uprooted and toppled – but it did not damage any homes. That’s it. Roads are clear. Some gas stations here were pumping gas yesterday. Supermarkets are open today. Trash collection resumes tomorrow (Wed.).

In the course of my work with NASA’s Planetary Defense Coordination Office (PDCO) (and past work with NASA’s Planetary Protection Office), I’ve paid close attention to issues in emergency and risk communication. And I’ve paid VERY close attention to communications about Irma during the past week, as Florida prepared for the storm and as it’s now beginning to recover.

How did state and local officials do on emergency and risk communications? How did the media do?

Florida governor Rick Scott stayed on message for days and days before Irma made landfall here. He met with the press every day. Message #1: If you are subject to mandatory evacuation, go as soon as possible. “We can’t save your property but we can save your lives.” Message #2: If you are told to evacuate and do not do so by the deadline we’ve established, we will not be able to rescue you during the storm. Plan for the worst. Local officials stayed on message too. (Another message from local officials: Once wind speeds reach 70 mph, emergency vehicles will be called off the road.) I give them an A. (I’m sure that over the next few weeks we’ll be hearing stories about communication failures here and there, and that’s okay, because it will help us all do better the next time around.)

Our daily paper, the Sarasota Herald Tribune, was an excellent source of information on how to prepare and what to expect. The paper removed its paywall for the duration of Irma and its aftermath. The paper delivered its Sunday edition on Saturday night. (This morning, Tuesday, the Monday edition was delivered.) The paper’s local news staff did their best to keep up with what was happening. Information on shelter locations, free sandbag distribution sites, what to expect at shelters and what to bring with you, and other “news you can use” ran in the paper for several days up to the storm, as did plans for school, airport, and other closings. I give them an A.

Our local Suncoast News Network gets an A-plus – especially its meteorologists. (See above.) National media? B-minus to C. Moseley and La Manno emphasized the top message: if you’re told to evacuate, do not hesitate. At some point I heard La Manno explain in detail what to expect if worst came to worst. He is a Florida native and so has experienced many hurricanes. I especially appreciated his explanation of what a hurricane sounds and feels like (Rob in Houston has been very helpful on this point, too). La Manno said we’d be terrified by the sounds outside, but if we didn’t feel our house moving, we should stay put. He was very good at calmly and clearly explaining many scary things.

CNN, as to be expected, sensationalized (see above). I told David that this is the way cable news gets you to stay glued to the tube (watching all those commercials). National media are good at keeping us sitting in our seats, with loud music, scary video, and hyberbolic rhetoric, but they cannot provide much information in an emergency that’s useful at the local level. Watching cable TV during an event like Irma is like watching a disaster movie – except this time you feel like you’re in it.

As to social media, in a situation like the one we just experienced here, they are invaluable. I had family, friends, neighbors, our property manager, our realtor, and our power company (Florida Power and Light) in my cell phone. I’d signed up my phone number for Red Alert. (I did not receive any alerts during Irma.)

Texting is especially invaluable. Facebook, too. Our entire social network was in constant communication with us by phone, email, Facebook and Twitter before and after. As soon as I woke up Monday morning (at 2:50 am) and realized the coast was clear (figuratively speaking), I started texting everybody I could think of and emailing everybody else. Thanks to our “evil” telecommunications companies (in our case, Frontier and Verizon), lines of communication have remained fully functioning.

Interestingly, I heard nothing from FEMA directly during this period. I only went to the FEMA web site once, as I was getting all the information I needed from our newspaper, SNN, and the Sarasota County government. I’m assuming that our state and local officials were in constant communication with their FEMA regional colleagues.

David and I have had disagreements over which sources to trust. I tend to have more trust in government sources (“authority”) than he does. I’ve had to learn a lot about how government works in my decades of working in Washington. I’m a scholar of the media and know how to sort reliable sources and information from unreliable. David doesn’t trust my knowledge (“authority”). Thanks to my work with scientists who are finding, tracking, and characterizing asteroids, predicting their future orbits, and identifying those that might come close to Earth, I have a good understanding of how much uncertainty surrounds long-term predictions.

The same goes for hurricane forecasting. Forecasters were describing in very good detail how much uncertainty was involved in their predictions of Irma’s movement until, perhaps, 24 hours before landfall in Florida (or less). They did a good job of explaining why longer-term predictions were uncertain. Local media accurately reported forecasters’ explanations. But many people can’t get comfortable with uncertainty. What they want to know is: Is my house gonna blow, or not? Forecasters can’t answer that question, nor can anybody else. (My friend Stephanie just a few miles north of us has power. Her neighbor across the street does not. Such a situation is unpredictable.)

It’s going to be the same in the event of a predicted catastrophic asteroid impact with Earth. (First, rest assured that, as of today, no known asteroid is on an impact course with Earth over the next 100 years.) NASA, the Federal Emergency Management Agency, and many other federal agencies and departments are already working together to plan for an impact emergency (see the National Near-Earth Object Preparedness Strategy and the Charter of the Interagency Working Group for Detecting and Mitigating the Impact of Earth-Bound Near-Earth Objects). The best laid plans may go awry, though, if public trust in them is not strong. Reliable, informed, trustworthy spokespeople are critical resources in an emergency. It’s a challenge we have to work on.

It’s interesting to think about how differences in thinking about authority, legitimacy, trustworthiness, reliability play out from person to person, family to family, household to household in crisis situations.

During the Irma event, the local news sources I chose to trust did not mislead me or let me down. Monday morning, David was accusing CNN of reporting “fake news” on Sunday….

In terms of trustworthiness, my experience reinforces the idea that people tend to trust family and friends first, local leaders and government next, federal government last. I’m no fan of Governor Scott, but his messages were clear and sensible. I chose to heed them. In this case, I paid no attention to anything that might have been coming out of the White House, as I have no trust in the current administration.

I took a walk on Sunday morning, when all was still calm before the storm. I talked with a woman who was watching a flock of sandhill cranes. She was worried about what would happen to wildlife during the storm. I told her that since animals live outside all the time, they probably have ways of sheltering. We humans must continue to improve our ways of sheltering and taking care of each other, as sea surface warms and sea level rises.