On Thursday, the National Aeronautics and Space Administration announced that it had discovered the Earth’s “older cousin”, Kepler 452-b, 1,400 light years away from the Earth’s solar system.
Greek Reporter spoke to a young Greek scientist that works in NASA to get a better understanding of what the discovery means for the potential development of life beyond our planet.
Anezina Solomonidou, who is from the island of Milos and grew up in Korydallos, Athens, joined NASA’s Jet Propulsion Laboratory (JPL) as a Postdoctoral Fellow in February 2014.
“I am really thrilled to be involved in this field at this exciting time. I believe that planetary and space sciences have been making giant leaps and discoveries in habitability and astrobiology studies over the past decade,” Solomonidou said.
Although Solomonidou has not been directly involved in the Kepler mission, which discovered the new planet, she is working on the Cassini-Huygens mission that studies Saturn and its satellites. Similar to the Kepler mission, the Cassini-Huygens also studies the habitable potential of faraway worlds, among other things.
“The Kepler mission consists of a space telescope, which through the use of a photometer continually monitors the brightness of stars in Deep Space. It is specifically designed to discover and study Earth-sized planets within the limits of the habitable zone. The Kepler 452-b planet is that kind of a discovery,” she said.
The Kepler 452b is an exoplanet- a planet orbiting a star different than the Earth’s sun- in the constellation of Cyngus. It orbits a Sun-like star every 385 days and the distance at which it orbits its star is also a significant factor for drawing comparison with the Earth.
“Kepler 452 is a G2-type star, which is the same type as our Sun, with comparable mass and temperature. It seems that the exoplanet Kepler 452-b orbits its star at a distance similar to the one Earth orbits our Sun, which is measured as 1 AU (Astronomical Unit). This distance is within what we call the habitable zone, which corresponds to the distance from the star where physical conditions allow for liquid water to exist on the surface,” she said.
However, Solomonidou pointed out that to actually prove that life similar to that of Earth could develop there, the planet must fulfil certain habitability criteria.
“The presence of an energy sources, nutrients, and most importantly liquid water which is necessary for life as we know it on Earth. Unfortunately, the Kepler telescope is not equipped to perform such kind of investigations. We will have to wait for new enhanced future missions with spectroscopic capabilities to give us answers to such fundamental questions,” she said.
The Greek scientist also noted that the Kepler 452-b could give us insight about the Earth’s composition and history. More specifically, comparative planetology, which Solomonidou called “one of her favorite fields in planetary science”, could tell us how the Earth’s atmosphere has changed within the 4 billion years of its existence.
Although the exact composition of the exoplanet is unknown, NASA knows that it is 60 percent bigger than the Earth. The similarity in size is especially important because it is the first similar sized planet in the habitable zone around a Sun-like star.
“Most of the exoplanets known today in addition to the large planets of our solar system like Jupiter and Saturn are giant balls of gaseous atmospheres and lack any rocky surface. Rocky planets like the ones of our inner solar system (Venus, Mars etc.) tend to be small and Kepler-452b’s size seems promising for the existence of a surface made of rocky materials,” she said.
Solomonidou noted that following such such a discovery, NASA will process and analyze data. Time is necessary for scientists to extract all the possible information. The data analyses will allow NASA to assess different hypotheses and to build models that will help make discoveries in the future possible.
“Even though it (the planet) offers an excellent exotic laboratory for an ‘aged-Earth’ for theoretical studies, we need to discover the ‘next-Earths’ in terms of habitability and astrobiology closer to us,” she said. “Examples of such worlds are the outer solar system satellites such as Europa, Enceladus and Titan. There is a tremendous need for future missions to these destinations.”
But will humans be able to settle on a different planet anytime soon?
“Space colonization is a big challenge to implement and our closest planetary neighbors, Mars and Venus, are very inhospitable to maintaining a human life presence, says Solomonidou.
“Although unmanned spacecraft missions and space observatories are currently our main ‘tools’ for space exploration, the human space flight program beyond the moon tremendously inspires our imagination and might move closer to reality during our lifetime.”