Debra Fischer

Generally speaking, exoplanets can be any size, and they are found in a wide range of orbits. Some have massive gas atmospheres; others are smaller with an icy or rocky composition. ”

One of the first thoughts I had, when doing early exoplanet research, was that Earth and its many companions seemed very different from the planetary systems we were detecting. ”

Once we see stars with three times the metal content of our sun, the planet detection rate goes up to 20 per cent. ”

The gas-giant planets in our solar system all have large moons. ”

It now seems logical that all the stars, like our own sun, must have formed with a system of planets around them. ”

Before 1995, the only planets we knew about were the planets in our solar system. ”

Because Alpha Centauri is so close, it is our first stop outside our solar system. There's almost certain to be small, rocky planets around Alpha Centauri A and B. ”

Further ahead, I'd like to see tiny spacebots - smaller than your cell phone - travel outside our solar system to the nearest star system, Alpha Centauri. By keeping the mass of those spacebots low, we could more easily accelerate them. ”

In 1999, my team discovered that the star Upsilon Andromedae was circled by three gas-giant planets - the first distant multiplanet system ever found. That same year, other researchers observed the first 'transit' of an exoplanet - a planet blocking out a small fraction of the starlight as it passes in front of the star. ”

As our sensitivity improves, we are finally seeing planets with longer orbital periods, planetary systems that look more like our solar system. ”