Here we are at the end of the year 2016, having discovered in total thousands of exosolar planets. The next question to ask is, “Which ones may contain life?”
Will we one day detect a biomarker in the atmosphere of an exoplanet say in the form of oxygen or even ozone? Perhaps, yet the first step to finding life on other planets is to visualize the planets.
This turns out to be quite hard. To date nearly all discoveries of exoplanets are indirect. That is to say, we see the effect of the orbiting exoplanet(s) on the star, and yet unfortunately we cannot point to the planet itself.
There have been many recent breakthroughs in a field of astronomical imaging called “adaptive optics” that enable some of the first direct imaging of exoplanets. Even so, it is painstaking work. Astronomer Sara Seager at M. I. T. leads a new effort to make it easier to see the exoplanets named “starshade.”
Starshade is a NASA project in which a large metallic satellite is inserted into space which literally has the shape of a flower. It works like this: the starshade is aligned very nearly in between the observer on Earth and that star with the planet(s) under investigation. Note the starshade will not be situated exactly inbetween so it will not physically obstruct the light from the star.
By using a starshade we will be able to take pictures of the exoplanets which will turn them into ‘dots’ instead of ‘points.’
The study of these dots in different colors, in turn, will inform us as to which exoplanets should be habitable. Whether from the ground or in space, the year 2017 will take us one step closer in our search to answer the question, “Are we alone?”