When I’m trying to express to someone how cool my friend Sarah Ballard is, I always add in the same detail: Sarah discovered four planets before she turned 30.
“The first two were Kepler-19b & c. Then I have Kepler-61b. And then the one, just recently, was Kepler-93b.”
Dr Sarah Ballard is an Seattle astronomer and NASA Carl Sagan fellow and when I spoke with her about astronomy, I could feel my brain stretching and growing, trying to comprehend the vastness of space. So let’s make your brain grow and stretch and talk about space for a while.
Sarah says it wasn’t until 1995 that a planet was identified outside of our solar system.
“At that period of time, if you discovered a planet you went on David Letterman. Now you find a planet, it’s like, whatever.”
There have since been thousands of planets discovered. Sarah’s method starts with pictures taken in space.
“For the NASA Kepler space telescope, it’s just staring at one patch of the sky and not blinking for four years. Except once every three months it would turn and point it’s antennae at the Earth and download the data through the Deep Space Network. There are people who, their full time job was to try to figure out how to extract the best quality data from what was coming down from the instrument.”
Then Sarah takes that photo data and searches for planets.
“The vast majority of the time you indirectly detect the planet, by which I mean you detect something that’s going on with the star and then you infer that what’s happening is that it’s due to a planet. So with the Transit method, the planet will actually pass around the host star, from your point of view, and the host star will look dimmer. It will look some tiny amount dimmer every time the planet goes around.”
Just like what happens every 365 days when the earth makes its way around our sun.
Sarah says she might not put any more work into finding planets, since they’ve determined that virtually every star has one. Instead, she would research how planets form, and the possibility of life in other solar systems. She says most planeteers believe there’s at least molecular life out there.
“The thing that’s most persuasive to me about life on other planets actually isn’t from other planets at all, it’s here on Earth. And it has everything to do with so-called extremophiles. Life that lives in extremely inhospitable environments. For example, you have life at the very bottom of the ocean that will never see a single particle of light. So how does it subsist? In these thermal vents. So it makes use of the heat that’s emanating from the Earth’s core up through the bottom of the ocean. Or in the Atacama Desert where it just doesn’t rain, period. And yet there are bacteria who live under these tiny rocks where a minuscule amount of moisture will condense out of the air, under the rock, and then there’s bacteria. If you give life a chance then it will find a away.”
She says the only way we would know if there’s intelligent life out there is if we go to another planet, or if aliens come here. But she says aliens might have a hard time detecting us.
“The truth is we are actually quite dark now. We used to be sending out a lot of radio waves, but we don’t broadcast TV by radio anymore. A lot of communication now is fiber optic and that’s not sending anything. To an alien species it would look like there was intelligent life for 20 years and then all of a sudden it turned off the light.”
Sarah never intended to get a PhD in astronomy. She started out a gender studies major at UC Berkeley, and a general ed astronomy class piqued her interest.
“Plenty of young women get goose bumps about science. So the question is, who pursues science as a career? So the National Academy of Science did a survey. For men, they report going to graduate school in the sciences because they really like it or because they think they’re good at it or because they feel they can make a contribution. For young women it’s overwhelmingly because somebody encouraged them to. And that somebody doesn’t have to be a scientist. Somebody that matters to them encouraged them to.”
Sarah had lots of encouragement all the way through school, so she encourages any girls or women interested in, or struggling with the culture of science, to message her to ask questions. I asked her why it’s harder to be a woman in the field.
“That’s a complex question. The single answer is probably that you can’t see yourself being one. When you look around you, there’s nobody who looks like what you look like and there’s nobody that has a life that you want to have. If you look at female tenured professors they are three times more likely to be single and not have children. When you look around and you see, oh, there is a woman professor here, but she made a lot of sacrifices to do this. It would be foolish to imagine that women don’t perceive that. That if I pursue this career other things I want to do with my life.”
Sarah doesn’t have any children, so her parents choose to dote on her planets.
“My parents call them their grandplanets. It’s precious. And that’s all they’re going to have for a long time so laugh it up.”