For the past decade, Christiansen has studied the frequency of the planet's occurrence or how often and what kinds of planets are encountered in the galaxy as he examines extraterrestrial hunting data such as NASA's Kepler, K2, and TESS missions.
During a stellar party review at the California Institute of Technology, Christiansen explained how young the stars they were watching. Sky watchers watched the Pleiades, a bright young bunch of stars who are some of the youngest in our sky.
They are 13 million years old, which sounds ancient. Christiansen wanted to convey this astronomically, this is still a young age.
She told her fellow star stars that before they disappeared, dinosaurs would not even see these stars in the sky because they did not exist until millions of years after the event of extinction. And she told them that when dinosaurs roamed the Earth as our stegosaurus, our entire solar block was on the Milky Way opposite to the galaxy as it is now.
Kristiansen does not share new information, she said. But the fact caught everyone's attention because the motion of our solar system as it travels around the galaxy is not something that most people think about.
"You don't think about changing the sky," Christiansen said. "But the stars come and go, keeping up with our timing charts."
She wanted to share the idea that, although astronomical time charts were significantly different from our own, they actually coincided quite well with archaeological clocks.