Holy Planets, Batman

The Google Doodle celebrating the TRAPPIST-1 system announcement on 22 February 2017

Hopefully you've already heard about today's announcement during a NASA press conference about the confirmation of discovery of 7 Earth-sized planets around the star TRAPPIST-1, three of which are in that star system's Goldilocks Zone for liquid water. This star system is only 39 lightyears away from Earth (coincidentally, that's 12 parsecs, so just within one good Kessel Run if you have the right ship). 39 lightyears is practically down the street in the context of our galaxy (which spans over 100,000 lightyears from one end to the other). This announcement isn't only exciting, but it also comes with a lot of implications for astrobiology. We have the capabilities right now to start observing these planets closely to look for signs of biosignatures in their atmosphere and that will only get better in the coming years (especially when the James Webb Space Telescope goes into operation). I'm still in the process of crunching out my Ph.D. dissertation, so I can't write up all of my thoughts about this incredible announcement right now, but definitely stay tuned to the exoplanet and planetary science community to see what more we can learn in the coming years about these world so close to our own. 

Credit: JPL/NASA

Answering the Question "Are We Alone?"

 A TEDx Talk by Shawn Domagal-Goldman

Shawn Domagal-Goldman may be one of the hippest of our current generation of astrobiologists. I've heard him speak several times and have found his manner of speaking profound and enjoyable. Domagal-Goldman's work has focused on global geochemistry of terrestrial worlds, including the Earth, as well as on how we can characterize extrasolar planets from afar to learn more about their surface conditions and possibilities for supporting biology. Here's a video of Domagal-Goldman's talk from TEDxMidAtlantic 2015 where he considers how NASA is currently going about answering the all-important question "Are We Alone?":

Kepler-452b: One of the newest discovered kids on the block may be similar to our Earth

An artist's concept of what Kepler-452b might look like from orbit (NASA Ames/JPL-Caltech/T. Pyle)

We've now confirmed the existence of nearly 2,000 exoplanets in our neighborhood of the galaxy. There are still another three thousand or so possible finds that are awaiting confirmation, but there's a good chance many of them will turn out to be real planets as well. We still estimate maybe 160 billion (or more) planets exist in our galaxy alone (averaging 1.6 planets per star). These numbers are incredible, especially for those of us who remember a time when we had not yet confirmed the existence of planets around other stars. 

Most of the worlds we have confirmed were first detected by the Kepler space telescope. Kepler was launched and entered service in 2009, immediately getting to the work of hunting for alien worlds. The mission had a highly successful lifetime of 3.5 years and was even granted a mission extension, but then, in 2013, a second of four of the reaction wheels within the spacecraft had broken (the reaction wheels are what allow such spacecraft to orient themselves in space without the need for fuel). Since that time, an ingenious repurposing of the spacecraft for a new planet-hunting mission called "Second Light" (a.k.a. K2) has been undertaken. Second Light has been operating since early 2014 and has been slowly building upon the list of potential exoplanets out there.

From all of the worlds discovered through Kepler's original mission and the Second Light mission, none has been as exciting for the general public as one that was just announced this past week. On July 23rd, researchers announced 521 more planet candidates, including 11 worlds that are close in their size and orbital distances from their stars as is our own Earth. One of those eleven is a world currently known as Kepler-452b. This exoplanet orbits a G2 star (one that is in the same spectral class as our Sun), it has an orbit that is similar in size to the Earth's (Kepler-452b's year is only 20 days longer), and this alien world is only about 1.6 times larger than the Earth. The following infographic from Space.com gives some fantastic details on what we've recently discovered about this exoworld:

The discovery of another world very similar to our own Earth is very suggestive that we are on the right path to discovering extraterrestrial life. Since my birth, we've now determined that there are billions of planets in our galaxy and we now know that some of them, like Kepler-452b, are very similar to our homeworld in their size and orbit (and some even orbit similar stars!). With current improvements in telescope technology and the development of exoplanet atmosphere research, it seems more and more like it really is only a matter of time before we start seeing abundant evidence for worlds that are habitable. Following that, how long might it be before the first detections of biosignature gases on exoplanets? If life is abundant in our universe, then it seems like we are only around the corner from finally determining whether we are alone in the vast cosmos.

Kepler-452b excites many people because of how similar it is to our world. Might there be a geophysical processes occurring on that world that are similar to ours? Might there be plate tectonics, continents, oceans...

We have a tendency to think that we need to find worlds like our own to find life (though this may not truly be the case), and that's why Kepler-452b is so exciting. I'm glad to know that so many people in the general public have been excited by this new finding. It might be that Kepler-452b is another Venus (a hothouse world devastated by a runaway greenhouse), or maybe the surface of Kepler-452b is simply a barren wasteland. Yet it's fun to imagine some of the more intriguing possibilities. 

Maybe Kepler-452b has a surface covered in microbial mats that generate large amounts of gases that are far from equilibrium with the atmosphere. Maybe that world has gigantic creatures like walking trees, dinosaurs, or giant floating blobs. Maybe there are intelligent beings on that world that have also discovered math and science and who have orbiting space telescopes that are peering out into their galactic neighborhood. Maybe, if that's the case, then just maybe they're also holding exciting press conferences to share their findings of new exoplanets around other stars. Maybe they've even had a meeting to discuss this new planet that is just like theirs in it's orbit around a similar star. Maybe that planet is just a bit smaller. Does it also have life?

An artist's illustration of a possible surface of newfound planet Kepler-452b (SETI Institute/Danielle Futselaar)

NASA and University Researchers Discuss the Search for Life in the Solar System & Beyond at AbSciCon 2015

Image taken from the NASA Astrobiology Roadmap

Last week, at the Astrobiology Science Conference (AbSciCon) in Chicago, NASA convened a press briefing to feature some of the lead figures within the realm of astrobiology and to promote discussion of what we're doing right now in astrobiology as well as what will be coming next. You can find the video of that briefing at the bottom of this post!

The panel for the briefing consisted of the following four people:

-John Grunsfeld, former astronaut and now Associate Administrator for Science at NASA Headquarters

-Alexis Templeton, Principal Investigator for the NASA Astrobiology Institute's Rock-Powered Life team

-Britney Schmidt, Principal Investigator for the NASA-funded project Sub-Ice Marine and Planetary Analog Ecosystems (SIM

-Vikki Meadows, Principal Investigator at the University of Washington's Virtual Planetary Laboratory

Left to right: Vikki Meeadows, Britney Scmidt, and Alexis Templeton. Image posted to Twitter by NASA NExSS

I've never met John Grunsfeld in person, but I love the energy and enthusiasm he presents when he talks. I have met Vikki Meadows, Britney Schmidt, and Alexis Templeton. They are impressive researchers and wonderful people. 

Britney and Alexis are especially kick-ass women. Britney has quickly climbed to fame within the sciences as a lead expert on the icy worlds of our solar system. She's travelled to Antarctica to study icy analog environments and a paper that she authored in the journal Nature in 2011 rocked icy-worlds research with the conclusion that the chaos regions on Europa may be caused by shallow subsurface fluids. 

I was abundantly overjoyed to see Alexis Templeton on the panel. She's one of the most renowned researchers in the realm of geobiology, she knows more about the connections between microorganisms and the variety of environments present on the Earth than anyone else I've ever met, and she is my graduate research advisor! Here's a picture of Alexis and I taken by John Spear while we were working at our field site, Borup Fiord Pass, in the Canadian High Arctic during the summer of 2014:

Alexis has been involved in many research projects that seek to characterize the myriad ways that microorganisms interrelate with their environments. Research that has been conducted in her lab over the years has included looking at the microbial alteration of basalt on the seafloor, characterizing metal oxidation by microbes in the depths of the Earth, and working on our NASA-funded project to understand microbial sulfur cycling and the formation of sulfur biosignatures at an Arctic analog to icy extraterrestrial environments. 

Most recently, Alexis has become the Principle Investigator of a team that goes by the handle Rock-Powered Life (RPL). This team, funded by the NASA Astrobiology Institute, seeks to characterize the pathways through which water and rock can react to form the simplest ingredients for living processes on Earth. They're also considering what these reactions mean for the habitability of extraterrestrial environments, such as those in the subsurface oceans of Europa and Enceladus. 

The NASA press briefing last week went very well. All of the members of the panel gave fantastic introductions to what we're doing right now in astrobiology to better understand life on Earth and the potential for life in our solar system and beyond! I highly recommend checking out the briefing video below: