WASHINGTON — Last week, we were captivated by NASA’s New Horizons spacecraft flyby of the dwarf planet Pluto and its complex system of moons.
Finally, the last of the nine classic planets had been explored, and we were not disappointed.
It’s been 20 years that we have known of planets orbiting other stars. To me, this is one of the biggest discoveries ever made in astronomy. Known as extrasolar or exoplanets, they come in a large variety of sizes, masses and orbits around their stars.
The discovery of an Earthlike exoplanet — or commonly known as Earth 2.0 — could be considered the Holy Grail in our search for exoplanets. Earth 2.0 would have to be similar in size and mass, have liquid water, an atmosphere comparable to ours and orbit a Sun-like star.
NASA on Thursday announced that its exoplanet hunting Kepler spacecraft discovered an exoplanet that is an older and bigger cousin to our own planet Earth. Known as Kepler 452-b, it is “the first near-Earth-size planet in the ‘habitable zone’ around a sun-like star,” according to NASA. The habitable zone as defined by NASA is “the area around a star where liquid water could pool on the surface of an orbiting planet.”
We know of 1,030 other exoplanets as of today, but many of them are gas giants like those in our solar system: Jupiter, Uranus and Neptune. Some exoplanet orbits are amazingly close to their star, which makes them very hot. Kepler also has another 4,696 exoplanet candidates it has discovered that require follow-up observations and analysis to verify they are actual planets. Research indicates that there may be billions of planets in our own Milky Way Galaxy.
To find an exoplanet a little larger than Earth, in the liquid water sweet spot around its Sun-like star, is quite a find. Astronomers have been able to determine the age of the parent star as being 6 billion years old, which makes the system 1.5 billion years older than ours.
Further observations need to be made of Kepler 452-b to see if it’s as rocky as Earth. And someday, we may be able to determine the composition of any atmosphere that the planet has.
Could Kepler 452-b have life? That’s certainly the $100 million question. On July 20, the 46th anniversary of Apollo 11 landing on the moon, we also saw the announcement of a bold new initiative in the search for extraterrestrial intelligence.
Breakthrough Prize Foundation and its founder, Internet investor Yuri Milner, made the 10-year, $100 million commitment to ‘Breakthrough Listen’ described as being “the most comprehensive scientific SETI project yet.”
Optical and radio telescopes will be used in the search for new exoplanets and searching for signals from other civilizations. Our local Robert C. Byrd Green Bank Telescope in West Virginia will be part of the effort.
There may come a time when we discover life beyond our planet. It is possible that our own solar system harbors life, which is why we must continue to explore our own backyard.
Life — including intelligent life — might also exist on orbiting planets of other stars. As we discover more worlds beyond our own, and listen for signals from other civilizations, we might truly discover Earth 2.0 someday.
Follow me on Twitter @SkyGuyinVA and my daily blog. You can email me at skyguyinva@gmail.com.
