Inventive Minds explore the universe

How many planets similar to Earth are up there in space? Can it be 10 or 1,000 or millions? NASA is developing more search units to answer those questions and we may know in just a few years.

Until the 1920s, astronomers believed that there was only one planet like our Earth in the universe. They also seemed to know of no other galaxies like our Milky Way in the universe. Then Edwin Hubble started to explore the universe’s space with the largest telescope of the time in California, and he decided that another galaxy, like our Milky Way, existed. He called it the Andromeda Galaxy.

As he explored more, he discovered more galaxies and he discovered that they were all moving away in space. His findings were the first of their kind to be discovered and pronounced. And since then astronomers have been building larger and larger telescopes to search the universe for galaxies and stars and more.

How many solar systems and earths like ours exist in space? Astronomers don’t know now, but they have been exploring space and they have been finding more and more planets circling around more and more stars. If you think of how many galaxies exist and how many stars exist in those galaxies, you have to think in the trillions or more. And they are all very far from our Earth.

    u    u    u

In 1998 Geoff Marcy and his team at the University of California found the first sign of a giant planet, twice the mass of Jupiter, circling a star named Gliese 876 every two months. This was an important discovery that increased the search for other planets outside our solar system. Since then more than 300 planets have been discovered circling other stars. They have all been large planets with the exception of two, so far, that have been estimated at about four to eight times the mass of our Earth.

With the present telescopes and viewing systems we are unable to actually see the planets, and our detection is the result of the dimming of the stars around which they rotate. NASA and other astronomers are working hard to develop systems to make it possible to actually see the planets, especially the small ones that resemble Earth.

In December 2006, the French launched Corot, a 1,300-pound spacecraft, aimed at staring at stars to find planets circling them. Corot looks at over 5,000 stars for 150 consecutive days in order to find which ones dim from time to time. Corot’s device keeps the stars in view in the same place every day. It is a great system. Annie Baglin is the chief scientist of Corot.

An astrophysicist named William Borucki working with NASA launched a more powerful spacecraft called Kepler several months ago. Kepler has a much larger telescope than Corot and will be able to see more planets rotating around stars.

Borucki and his partner, Koch, first proposed their mission to NASA in 1994. It was rejected, and they proposed it again in 1996, 1998 and 2000. Finally Koch proposed naming the procession Kepler after the name of the discoverer of the laws of planetary motion many years ago. And in 2001 NASA finally approved the mission. Kepler has a telescope with fields of view more than 10 times as large as Corot. Borucki predicted that while Corot would find the first terrestrial-size planet, it will not be in the habitable zone and could not contain life. He said, “We’ll be the first one in the habitable zone.�

    u    u    u

Ground-based telescopes are now also at work searching for habitable earths, but their search concentrates on red dwarf Stars. The astronomers believe that planets are easier to find there. Jill Tarter, a leading thinker of alien life, and her colleagues convinced many researchers that red dwarfs are very good targets for earth hunters. Why? Because red dwarfs are the most common stars in the galaxy and happen to be the easiest targets for ground-based telescopes.

However, even if these ground telescopes find a habitable Earth-like world, it will take a space observatory to search for what we really want to know, and that is whether life exists on the planet. What seems most likely to happen is that within the next four or five years we will get to know whether there is life on other planets, where they are and how many have been identified so far.

The James Webb Space Telescope is slated to replace the Spitzer telescope in 2013. With its 21.3-foot mirror it is expected by some astronomers to open up new windows. And some feel that it will not happen. I am on the side of the astronomers who feel that it will find new things, especially habitable planets.

What would provide the best evidence for potential signs of life? Things such as water vapor and oxygen and vegetation are good examples. There is hope that the James Webb Telescope will be able to provide observations that would show these factors. And remarkably, more, and larger, telescopes are in the process of being created. Astronomers really want to discover life in space.

    u    u    u

My interest in astronomy has led me to discover that astronomers have decided that there are way more than 1 billion galaxies in the universe, and that the galaxies contain up to 2 billion or more stars. Think of the total number of stars up there. Multiply those two numbers. Think of the number of planets that exist up there. I find it difficult to believe that we are the only planet with life on it. As a matter of fact, within the multi-billion stars, I feel that even 1 million earth planets might be a small number. Time will give us this information. Be patient.

Sidney X. Shore is a scientist, inventor and educator who lives in Sharon and holds more than 30 U.S. patents.