By Jeffrey T. (8th Grader)
Guess many people like me are curious about the weird, wonderful worlds outside of our earth.
My today’s science story is about exoplanet-our future home.
The terms exoplanet means a planet outside our solar system, a planet that doesn’t orbit our sun. Most orbit other stars, but some are just sunless wanders out in the space between the stars.
Here is the thing about exoplanets, they are everywhere. In fact, from our observation so far, we know there are more planets than stars. So, there’s our solar system. Then there are all the billions of planetary systems in our galaxy, the Milky Way. Then there are all the billions of other galaxies.
We’re still trying to understand which kinds of stars provide long last stable conditions that could allow life a chance to take hold and evolve like it did here on Earth.
Have you seen the movie called WANDERING EARTH? When the sun dies out, the people of Earth build giant thrusters to move the planet out of orbit and sail to a new star system. It’s kind of super earth, the potential future home.
Gliese 581G, discovered in2010 is such kind of earth-like exoplanet, a rocky planet 3 times the mass of earth. It is an unconfirmed (and frequently disputed) exoplanet claimed to orbit within the Gliese 581 system, twenty light-years from Earth.
We think the most life-ready planets are the ones most similar to Earth. And being at the right distance from their stars to have liquid water on the surface. There are many factors that affect habitability. Gliese581g easily meet the requirements- tidal locking/water/temperature/atmosphere
Just as Earth’s Moon always presents the same face to the Earth, the length of Gliese 581g’s sidereal day would then precisely match the length of its year.
The researchers said that the planet always has one side facing its parent star-Gliese581, and the other always in darkness. The region of habitability would likely be on the line between shadow and light.
Another important factor is Gliese581g orbits an red dwarf star called Gliese581,it is much smaller than our sun.
Because of it’s cool temperature and small mass, the habitable zone of Gliese581 lies much closer than ours does from our sun. Our Sun is an yellow dwarf star which means the temperature on Gliese581g may be more suitable for human to live.
Because Gliese581g is locked by the tide of its parent star, there is always a half face to Gliese 581 and half is back to the star which means the temperature of its habitable zone is about dozens of degrees. It is thought to be near the middle of the habitable zone of its star. That means it could sustain liquid water——a necessary for all known life.
The huge weight of it causes the distance of its atmosphere and the greenhouse effect which means the probability of existing life is very high. If the planet has a dense atmosphere, it may be able to circulate heat. The actual habitability of the planet depends on the composition of its surface and the atmosphere.
Gliese581g is only 20.5 lightyears from Earth. Although traveling 20 lightyears would take about 180,000 years using current propulsion methods. But a man can dream, right?! If people are possibly work out a kind of spacecraft close to the speed of light, it would take 20 years to make the journey.
To today, NASA confirmed there are more than 5000 exoplanets found by human being. We are incredibly luck or that there are many habitable systems than we ever thought.
We can believe that there must be the “second Earth”. Let’s keep looking up and exploring.
(Image Sourced from Internet)
