In the fall of 1995, the very first planet outside our own planetary system was discovered. Both Swiss astronomers Michel Mayor and Didier Queloz found a gas planet orbiting star 51 Pegasi, 50 light years away.

Before they made their discovery, we could not know for sure whether planetary systems are common in the universe, or if we are on a globe that is a solitary exception in an empty space.

There are other worlds

But with the discovery of the planet around 51 Pegasi, we were confirmed for the first time that there are other worlds out there - and with it also increased the opportunity to find life beyond our own earth. Today, about 4,000 planets have been discovered.

Exoplanets are so far unable to see directly, not even the sharpest telescope can discern the faint glow from a distant planet. The light of the planet is submerged in the light of the star. It's like distinguishing a single cell phone's flashlight on a concert scene that is soaked in floodlights.

Swing back and forth

But planets can reveal their existence in ways other than illumination. Michel Mayor and Didier Queloz discovered the planet by observing how it affected its sun, 51 Pegasi. The planet causes the star to swing back and forth, and that movement is observable.

The fact that the Nobel Prize now goes to the discovery of exoplanets is a long-awaited prize for many. The universe has not been the same since October 1995 when the very first planet was discovered.

Is there a third early planetary explorer

What is surprising is that not a third person was allowed to participate in the prize for the planetary discovery, namely American Geoffrey Marc. He confirmed the planetary discovery and only two months later, in December 1995, he presented another discovery of several exoplanets.

But the Royal Academy of Sciences seems to be taking the challenge first.