They’re thinking a lot about extraterrestrial life these days over at the Pacific Science Center, where two new exhibits explore how scientists are working to identify far-away planets that may harbor life, and how we’re going to feed ourselves while we’re on our way to pay a visit.
The exhibit Mission: Find Life! opened up last month in the science center’s Portal to Current Research space. Erika Harnett, a University of Washington professor of Earth and Space Sciences who serves as the education and outreach lead for the UW’s Virtual Planetary Laboratory (VPL), was one of the key players in developing the content for the exhibit.
“We really wanted to connect the research being done by the Virtual Planetary Laboratory and some of the more cutting-edge science,” Harnett said.
It’s all in the biosignature
They decided to focus on examining the biosignatures of exoplanets. Harnett noted that we actually have the technology to take images of planets orbiting other stars, even though the images only amount to a pixel or two.
“From that single pixel you can actually glean quite a bit of information,” Harnett noted. “Scientists are trying to figure out if, from that, you can actually start to see if there are signatures of life on a planet, and really the initial work that they’re doing now is defining what are the signatures of life on Earth.”
The color of the light might tell you if you’re looking at ocean or continents. You might even identify the chemical components of a planet’s atmosphere or the types of molecules that are there.
Promotional material for the exhibit notes that, for finding life, “the color purple may be the key.” Harnett explained that that’s because red dwarf stars are plentiful in the universe, and they last a long time—long enough to give life plenty of time to develop. Whatever life appears would be faced with much redder light than we have here on Earth.
“Life will want to make use of it as much as possible, so it’s going to be either purple or black vegetation, instead of green, to be able to absorb as much electromagnetic radiation in the visible as possible,” Harnett said. She noted that, for the exhibit, they wanted to convey the speed of discovery—scientists verify new exoplanet discoveries practically every day. She also wanted to set expectations about what sorts of life might be found. Spoiler alert: it won’t likely be little green men like the ones on the socks Harnett wore when we spoke.
“It’s more likely that it’s going to be something like microbes or bacteria, because that’s actually what most of the life on Earth is. It’s not the most visible, but it’s the most plentiful,” she said.
Watch an exoplanet transit
One of the cool, hands-on features of the exhibit gives visitors a look at how scientists using the Kepler Space Telescope actually find exoplanets. A lighted globe represents a star, and you can spin a couple of planets around it.
“Then they have a sensor off to the side,” Harnett said—it’s actually inside a model of Kepler. “On a screen you can see the light from the star, and then as the planet transits you can see the dip” in the amount of light that arrives at the sensor.
“You get to actually play with that and explore what the change in signal associated with a planetary transit looks like,” she added.
Another interactive feature of the exhibit is a large touch screen that uses the NASA Eyes on Exoplanets program to let visitors explore planets.
The Mission: Find Life! exhibit is part of the VPL’s work funded by the NASA Astrobiology Institute, which requires that a portion of funds be reserved for education and public outreach. VPL has created several science-on-a-sphere shows and trained numerous graduate students to be science communication fellows.
“The Portal to Current Research project is the culminating part of our work,” Harnett said. She has been involved with the Pacific Science Center’s communication fellows program for about a decade and said she feels effective communication about science is important.
“If scientists do a better job of communicating their science there would not be quite as much mistrust of science,” she said. “Everybody needs to get out more into the community and be doing more communication and writing for the general public, as opposed to just writing the peer-reviewed articles that will go into a journal and ten people will see.”
Harnett said they’re working to line up astrobiologists to offer talks during the exhibit’s run, especially during Astrono-May at the science center. Mission: Find Life! runs through September 4, 2017 at the Pacific Science Center.
What’s for lunch?
Another new exhibit called Feeding Future Astronauts is just across the gallery from the Portal to Current Research space. Growing food in space will take a lot less energy than carrying a bunch of it along, and the exhibit highlights some of the things NASA is trying. In the test garden of the exhibit they’re growing “outredgeous” lettuce, “Tokyo bekana” cabbage, and “Red Robin” cherry tomatoes. The latter will be a challenge because tomatoes require pollination, and as far as we know there are no bees in space. ISS astronauts are experimenting with hand pollination and how it will work in microgravity. The Red Robin might be a good variety of tomato to try in your Seattle garden; the ones in the exhibit were doing great for early April with only artificial light.
Podcast of our interview with Erika Harnett: