A planet that orbits a star outside the solar system.
In 1988 Bruce Campbell, the Canadian astronomer, not the American actor, was credited with the first confirmed exoplanet discovery. Since then, both techniques and technology have grown in sophistication and scope to now having confirmed over 3500 exoplanets in our little corner of the galaxy.
On average every star we’ve studied has had at least one planet circling. Many are gas giants like Jupiter but 1 in 5 suns like ours have earth-like planets, that is rocky hard planets, in the habitable or “Goldilocks” zone. This zone is where the planet is warm enough to have liquid water and cool enough not to boil it all off.
In a galaxy the size of the Milky Way, that translates to roughly 11 billion planets like ours.
Every day our technology grows and only recently have we been able to directly observe an exoplanet.
Astronomers can determine what if any atmosphere is composed of on a planet by how the starlight behaves passing through it.
This same method can show the presence of life-giving water.
The closest exoplanet Proxima B, orbiting the star Proxima Centauri is 4.2 lightyears away and is thought to have a liquid ocean. Scientist are scrambling to verify the results as more and more planets are discovered each day.
NASA chief scientist Ellen Stofan , said recently, “I think we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years.”