Earths Beyond Earth: The Search for Other Worlds In early 1990, the firstextrasolar planet was detected, surprising everyone by its strangeness. Moreplanets have now been discovered outside our solar system than in it. Theseplanets present many great mysteries to the astronomical world.
Extrasolarplanets are planets that exist outside our solar system; they are orbiting astar other than our Sun. So far, eighteen have been found, all of them defyingwell-established theories about planets and how they operate (Winters, 46). AsStephen Maran said, The new discoveries remind us that ignorance is not justbliss, it is also a lack of imagination. The newfound planets show us not onlythat a solar system is not a rare commodity, but that ours may be plainvanilla. (73) Finding extrasolar planets is both difficult and complicated.The average star, for instance, is one hundred million times brighter than anyplanet orbiting it (De Grasse Tyson, 87). Picking out a planet against theglare of a star is like trying to spot a 100-watt light bulb next to a100-billion-watt searchlight, says Michael Lemonick (54). Also, earth-sizeplanets are too small to have any significant effect on their star, so they arealmost impossible to detect (De Grasse Tyson, 88).
There is, however , a way tofind extrasolar planets without using direct sight: the Doppler Effect. When astar has a planet in its gravitational field, it makes the star appear as if itis wobbling by stretching the light waves and slightly changing thestars color (Maran, 75). A second method of finding a planet is to searchthrough a disk of debris surrounding a star, such as Vega. Chances are that aplanet will exist there (De Grasse Tyson, 87). Out of the detected planets, onlya few have actually been seen, being found by accident by either theHubble Space Telescope or the Infrared Space Observatory (Lemonick, 53).
Inshort, planets can only be found in a limited number of ways, and under veryspecific conditions. In general, most extrasolar planets are alike in that theyare all very odd compared to what humans are accustomed. For example, most ofthem orbit around sun-like stars no further than 100 light years from the Sun.Also, they are gas giants, almost all of them being larger than Jupiter, andhave temperatures up to 1800 degrees Fahrenheit (Maran, 74).
On the other hand,these planets all have very different orbital patterns; some of them have orbitsthat are extremely close to the star that they orbit, while others have oddelliptical orbits (Naeye, 45). Either way, almost all of these planets differsignificantly from the planets in our solar system. Very little specificinformation is known about most extrasolar planets, but a few have beenresearched extensively and found to have interesting characteristics. Forinstance, 51 Pegasi (all planets being named after their host stars) was thefirst extrasolar planet found, being discovered by Swiss astronomers Mayar andQueloz. This planet is half the mass of Jupiter (seventy-five times more massivethan Mercury), and has the least mass of any of the new planets (Maran, 74).
Also, it is 5 million miles from its star, but still manages one orbit in only alittle more than four days (Flamsteed, 80). 70 Virginis, another odd planet, issix times the mass of Jupiter, has extreme weather conditions, and orbitselliptically (Lemonick, 53). Likewise, 47 Ursae Majoris has fierce hurricanes,and is also larger than Jupiter. The planet with the most elliptical orbit knownto man is 16 Cygni B; it travels from 56 million to 250 million miles of itssun. In contrast, 55 Cancri B is an example of a tight-orbiting planet, circlingthe sun closer than mercury is to our sun (Maran, 74). In summary, what we knowabout these planets shows that they are very diverse and strange. Thoughstrangeness may promote curiosity, a major goal in searching for extrasolarplanets is to discover one that resembles ours or possibly harbors life.
Thoughstrangeness may bring curiosity, the main motive behind finding extrasolarplanets is to discover one that resembles ours or possibly harbors life (DeGrasse Tyson, 86). “The Holy Grail,” says Alan Boss, an Astronomer atCarnegie Institute, “is to find an extrasolar planet that is capable ofsupporting life” (Lemonick, 56). However, out of the planets discovered sofar, none are thought to be compatible with life for various reasons. First,planets that orbit close to their sun are too hot for life.
Second, Pulsars,stars that are most likely to host Earth-like planets, give off too much deadlyradiation. Third, elliptical planets are gaseous and unstable, being up to tentimes more massive than Jupiter. One hope for the possibility of life is if thelarge gas planets have moons like that of Jupiter. Scientists believe that thesemoons may have conditions which would be conducive to support life (Maran, 74).Though the chances of there being life on one of these planets is extremelyslim, we may someday detect one that is suitable. Although there has been agreat deal of speculation and optimism about these newly discovered planets,some irrational scientists still refuse to believe in their existence. In the1600s, Giordano Bruno was burned at the stake for saying that there was otherworlds outside our solar system (De Grasse Tyson, 86). Todays punishment isnot nearly as harsh, but often planetary scientists are ridiculed for theirdiscoveries, because in the opinion of some scientists there is a lack ofsubstantial evidence (Maran, 75).
How can we be so silly as to assume that weare the only planetary island in a vast ocean of stars? Also, many theories arebeing eliminated by extrasolar planets, causing stubborn astronomers to becomeuneasy. One instance is the theory of a stars formation; when a star is beingmade, strong winds blow away all debris orbiting near it. The presence of largeplanets with tight orbits contradict this theory. There are also some doubtsabout the Doppler effect, in that it may simply be the result of fluctuations ofthe stars surface, and not planets at all (De Grasse Tyson, 88). Whatconstitutes most doubt, however, is the existence of Brown Dwarf Stars.
BrownDwarfs are stars in elliptical orbits around other stars that do not have enoughmass for nuclear reactions in their cores (Winters, 47). They “bridge thegap in mass between stars and planets,” as Robert Naeye says (45), andalmost always have elliptical orbits (Winters, 46). In fact, brown dwarfs wouldexplain many of these odd “planets” that have been located. Thus,extrasolar planets are not only unstable in structure, but in existence as well,being doubted and contradicted just as much as supported and proven. Theextrasolar planets that have been found raise more questions, rather than givinganswers.
They have shot down theories, confused speculators, and left us withpuzzle pieces that simply do not fit together, according to current theories. Atthe same time, they have opened up doors to new possibilities, expanded ourknowledge, and given us hope for life elsewhere. These new discoveries help usto realize how ignorant we are to the processes of the universe.BibliographyDe Grasse Tyson, Neil. The Search for Planets. Natural History Oct.1997: 86-9. Flamsteed, Sam.
Impossible Planets. Discover Sep. 1997: 78-83.
Lemonick, Michael. Searching for Other Worlds. Time Feb. 1997: 52-7. Maran,Stephen. Planets Around Other Stars are Hot Hot Hot. Smithsonian Sep.
1997: 72-6. Naeye, Robert. The Strange New Planetary Zoo. Astronomy Apr.1997: 42-9. Winters, Jeffrey. Planets by the Dozen.
Discover Jan. 1997:46.Astronomy