Is There Life on Other Planets?

 Last Sunday, May 25, 2008, the Phoenix cleaved through the Martian atmosphere and landed successfully on the planet’s northern polar region.  In what was obviously a very historic moment, the lander sent back crisp, clear pictures of the region’s polygon-cracked terrain.  It sent shivers down my spine.

             The Phoenix Mars lander is a robot spacecraft that was launched on August 4, 2007, which contains instruments that will search “for environments suitable for microbial life on Mars, and to research the history of water there.”   In short, it is an attempt to search for life outside Earth.  Mars is the likely first stop.

The red planet has fascinated me, as it has to a lot of inquiring minds, ever since I was gifted by my mother with an astronomy book entitled “Secrets of Space” when I was about nine or ten years old.  The book abruptly opened my mind to the unlimited wonders and possibilities that the universe, in all its greatness, could bring.  Which brought out the big question, the possibility; as what has been, in the last century down to the present, the subject of countless films, books, articles, and all forms of literatures.

             I never forget the words of Ellie Arroway, played by Jodie Foster, in the epilogue of the movie adaptation of Carl Sagan’s “Contact”—when she talked to a group of children about the SETI project and the infinite vastness of space:   “So if it’s just us… seems like an awful waste of space, right?”

             So the questions “Are we alone?” or “Is there life out there?” are becoming more and more familiarly conventional questions in this age of rapidly increasing, and enlightening, scientific discoveries; we’ve definitely come a long way from the time Galileo was disgraced by the Church for claiming that the Earth is not the center of the universe.            

             How big really is the universe?  You’d probably say, it’s really, really big.  But really, how big?

 Perhaps, it would help to employ a methodical push of the imagination by asking how big the sun and the solar system is, and yet how considerably insignificant it is to the immensity of the galaxy, and the galaxy to the universe.

 Our planet, the third from the Sun, is one among nine (recently, eight, as per the new definition of “planet” which excludes Pluto as it is now classified as a “dwarf planet”) that revolve around the Sun.   The Sun and all the celestial objects bound to it by gravity make up the solar system. Apart from the eight planets and their 166 known moons, these celestial objects also include Pluto and two other dwarf planets and their four known moons; and billions of small bodies, such as asteroids, Kuiper belt objects, comets, interplanetary dust and meteoroids.

 The Sun, with a minimum approximate distance of 146,900,000 kilometers from Earth, is found close to the inner rim in the Orion Arm of our galaxy—the Milky Way, a barred spiral galaxy with an estimated diameter of about 100,000 light years.  In astronomy, the distance is usually measured in astronomical units or AU.  The distance between Earth and Sun is 1 AU.  From Pluto to the Sun, the distance is 39.4 AU.   A light year is the distance traveled by light in a vaccum for one year, or approximately 10 trillion kilometers or 63,241 AU.

 Our solar system orbits the center of the Milky Way which takes about 225-250 million years to complete one revolution—or one galactic year.  Our Sun is just one of about (take a deep breath) 400 billion stars that are contained in our galaxy, the Milky Way.   Our galaxy (take a deeper breath) is just one of at least 80 billion galaxies in the observable universe, which contains approximately 30 to 70 billion trillion stars—more than the number of grains of sand of all the Earth’s deserts and beaches!

So, if we truly are alone in this great, big universe–indeed, what an awful waste of space.