Habitable Zone of Imagination

We my not be as lonely as we think

After collaborating more than a decade’s worth of astronomical research, Astronomers of the Lick-Carnegie Exoplanet Survey have identified a planet in the Gliese 581 system that could potentially support life.  

The planet, called Gliese 581g for being the sixth planet discovered in the system, is the fourth planet from the star Gliese 581, a red dwarf located roughly 20 light years from Earth.  Because it is located outside of Earth’s solar system, Gliese 581g is known as an “exoplanet.”

Where Gliese 581 g would be located if it were in our solar system.
Model not to scale.  Graphic by Mike Choromanski

Gliese 581g intrigues astronomers because it falls within it’s stars habitable zone, an area close enough to provide proper heat energy, but far enough away to not be cooked, meaning that liquid water would exist there.  Liquid water may be common on earth, but it is very rare in the universe as a whole, and all known life on Earth requires water to survive.  Planets that exist in this “just right” zone are also know as “Goldilocks planets.”

According to the exoplanet survey team, Gliese 581g is roughly only three times the size of our own planet, and has a minimum mass indicative of a rocky planet with gravity strong enough to create a defined surface.  This also means that the Goldilocks planet would be able to hold in an atmosphere.

In many ways, It’s just like Mother Earth.

According to NASA, Gliese 581g was discovered using 11 years worth of observational spectroscopy data taken from the Keck I Telescope in Hawaii, gathered by analyzing Gliese 518’s radial velocity.  Since stars are pulled slightly by the gravity of their satellites, they vibrate slightly when they move across a line of sight as seen from Earth.  By observing this motion, astronomers can detect planets.

What is truly intriguing about Gliese 581g however, is that Astronomers like Stephen Vogt, professor of astronomy and astrophysics at UC Santa Cruz and co-discoverer of Gliese 581g, speculate that Earth-like planets may not be as rare of a phenomenon in the universe as people generally believe.

Vogt lead the exoplanet survey team along with Paul Butler of the Carnegie Institution. The team’s findings were published in The Astrophysical Journal.

In the journal, Vogt argues that if such potentially habitable planets are so rare, there would have been no way for astronomers to find a Goldilocks planet so quickly and so close to earth.  Due to this conclusion, Vogt speculates that a substantial percentage of star systems in the universe may contain habitable planets.

The location of Gliese 581 in the night sky.
Graphic by Mike Choromanski.

“If the local stellar neighborhood is a representative sample of the galaxy as a whole, our Milky Way could be teeming with potentially habitable planets.”  Vogt said.

While Gliese 581g cannot be seen by the naked eye, even an amateur can easily locate its location in the sky.  In for one to gaze into the general direction of Gliese 581, one must simply locate the constellation, Libra.  The goldilocks planet is located just above Libra’s beta star, Zubeneschamali.

If Vogt’s prediction is true, there’s no telling how many beautiful, Earthlike planets there could be drifting around in the cosmos.  The evolutionary possibilities of alien life would be endless, and many a sci-fi fantasy could become a reality.