NASA Kepler’s Scientists Are Doing What Seems Impossible: Turning Pixels Into Planets
“It isn’t the image itself that gives you this information, but rather how the light from image changes over time, both relative to all the other stars and relative to itself. The other stars out there in our galaxy have sunspots, planets, and rich solar systems all their own. As Kepler heads towards its final retirement and prepares to be replaced by TESS, take a moment to reflect on just how it’s revolutionized our view of the Universe. Never before has such a small amount of information taught us so much.”
When you think about exoplanets, or planets around stars other than the Sun, you probably visualize them like we do our own Solar System. Yet direct images of these worlds are exceedingly rare, with less than 1% of the detected exoplanets having any sort of visual confirmation. The way most planets have been found has been from the Kepler spacecraft, which gives you the very, very unimpressive image of the star you see featured at the top. Yet just by watching that star, the light coming from it, and the rest of the field-of-view over time, we can infer the existence of sunspots, flares, and periodic “dips” in brightness that correspond to the presence of a planet. In fact, we can figure out the radius, orbital period, and sometimes even the mass of the planet, too, all from this single point of light.