Penn astronomer to give talk about finding life on other planets

As part of a monthly program at the Franklin Institute, James Aguirre, of Penn's Department of Physics & Astronomy, will talk about the hunt to find nearby planets like our own.

red sun
One of the best places to hunt for exoplanets is around small, dim stars called red dwarfs. This artist’s concept illustrates three planets orbiting one of these stars. Photo by NASA/JPL-Caltech

On Thursday, Jan. 12, James Aguirre, an associate professor in the Department of Physics & Astronomy in the School of Arts & Sciences, will give a talk as part of the “Philly Loves Bowie Week” edition of Night Skies in the Observatory at the Franklin Institute. The talk will focus on the hunt to find nearby planets like our own. The event begins at 6 p.m. in the Joel N. Bloom observatory. Tickets are $5 for members and $10 for non-members.

Aguirre primarily conducts research on the evolution of galaxies and how they are related to the larger scale picture of the universe. He says his talk will be a bit outside his comfort zone.

The idea for the talk originated from another project Aguirre is working on called STARFIRE, which will use detectors more sensitive than any ever built to look at the universe in infrared and map a large chunk of the sky, looking as far back in time as four billion years after the big bang.

One special aspect of these detectors is that they can be made to count individual particles of light, or photons, and measure their energies so that in addition to knowing where the light came from, scientists would also know its color.

A colleague pointed out to Aguirre that an array of these detectors would be able to find exoplanets. That’s because one way scientists search for exoplanets is by looking for something called a Doppler shift, which occurs when a planet tugs on a star and changes the wavelength of light you see from it. These detectors would be able to tell exactly which wavelength of light landed where.

Locating exoplanets that are relatively close to us represents a big leap in humanity’s quest to answer the question of whether there is life elsewhere in the universe.

“If we found something else in the universe that was like us—that was intelligent and wanted to communicate—it would clearly be kind of a watershed moment where we know that whatever else the purpose of the universe is, it also has to include whatever this other intelligent species is,” Aguirre says. “But at this moment, we have this funny situation where we really don't have any other examples of life. Maybe there’s something under the sands of Mars or in the oceans of Europa [one of Jupiter’s moons], but as of now we haven't yet seen life at all.”

Aguirre says that if our ideas of biogenesis and the theory of evolution are right, we should expect there to be more places where life would emerge. It would be an important step to go from just circumstantial evidence and plausibility arguments to having actual evidence of life on other planets.

“We’ve had tropes in science fiction for so long about beings everywhere so I don’t know if anybody would be so surprised, but there’s a real excitement to know that it’s not just a story that we make up that seems reasonable but is actually true,” he says.

Originally published on .