Реферат: Extra Solar Planets Essay Research Paper Earths

Extra Solar Planets Essay, Research Paper

Earths Beyond Earth: The Search for Other Worlds In early 1990, the first

extrasolar planet was detected, surprising everyone by its strangeness. More

planets have now been discovered outside our solar system than in it. These

planets present many great mysteries to the astronomical world. Extrasolar

planets are planets that exist outside our solar system; they are orbiting a

star other than our Sun. So far, eighteen have been found, all of them defying

well-established theories about planets and how they operate (Winters, 46). As

Stephen Maran said, ?The new discoveries remind us that ignorance is not just

bliss, it is also a lack of imagination. The newfound planets show us not only

that a solar system is not a rare commodity, but that ours may be plain

vanilla.? (73) Finding extrasolar planets is both difficult and complicated.

The average star, for instance, is one hundred million times brighter than any

planet orbiting it (De Grasse Tyson, 87). ?Picking out a planet against the

glare of a star is like trying to spot a 100-watt light bulb next to a

100-billion-watt searchlight,? says Michael Lemonick (54). Also, earth-size

planets are too small to have any significant effect on their star, so they are

almost impossible to detect (De Grasse Tyson, 88). There is, however, a way to

find extrasolar planets without using direct sight: the Doppler Effect. When a

star has a planet in its gravitational field, it makes the star appear as if it

is ?wobbling? by stretching the light waves and slightly changing the

star?s color (Maran, 75). A second method of finding a planet is to search

through a disk of debris surrounding a star, such as Vega. Chances are that a

planet will exist there (De Grasse Tyson, 87). Out of the detected planets, only

a few have actually been ?seen,? being found by accident by either the

Hubble Space Telescope or the Infrared Space Observatory (Lemonick, 53). In

short, planets can only be found in a limited number of ways, and under very

specific conditions. In general, most extrasolar planets are alike in that they

are all very odd compared to what humans are accustomed. For example, most of

them 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, and

have temperatures up to 1800 degrees Fahrenheit (Maran, 74). On the other hand,

these planets all have very different orbital patterns; some of them have orbits

that are extremely close to the star that they orbit, while others have odd

elliptical orbits (Naeye, 45). Either way, almost all of these planets differ

significantly from the planets in our solar system. Very little specific

information is known about most extrasolar planets, but a few have been

researched extensively and found to have interesting characteristics. For

instance, 51 Pegasi (all planets being named after their host stars) was the

first extrasolar planet found, being discovered by Swiss astronomers Mayar and

Queloz. This planet is half the mass of Jupiter (seventy-five times more massive

than 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 a

little more than four days (Flamsteed, 80). 70 Virginis, another odd planet, is

six times the mass of Jupiter, has extreme weather conditions, and orbits

elliptically (Lemonick, 53). Likewise, 47 Ursae Majoris has fierce hurricanes,

and is also larger than Jupiter. The planet with the most elliptical orbit known

to man is 16 Cygni B; it travels from 56 million to 250 million miles of its

sun. In contrast, 55 Cancri B is an example of a tight-orbiting planet, circling

the sun closer than mercury is to our sun (Maran, 74). In summary, what we know

about these planets shows that they are very diverse and strange. Though

strangeness may promote curiosity, a major goal in searching for extrasolar

planets is to discover one that resembles ours or possibly harbors life. Though

strangeness may bring curiosity, the main motive behind finding extrasolar

planets is to discover one that resembles ours or possibly harbors life (De

Grasse Tyson, 86). «The Holy Grail,» says Alan Boss, an Astronomer at

Carnegie Institute, «is to find an extrasolar planet that is capable of

supporting life» (Lemonick, 56). However, out of the planets discovered so

far, 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 deadly

radiation. Third, elliptical planets are gaseous and unstable, being up to ten

times more massive than Jupiter. One hope for the possibility of life is if the

large gas planets have moons like that of Jupiter. Scientists believe that these

moons 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 extremely

slim, we may someday detect one that is suitable. Although there has been a

great deal of speculation and optimism about these newly discovered planets,

some irrational scientists still refuse to believe in their existence. In the

1600s, Giordano Bruno was burned at the stake for saying that there was other

worlds outside our solar system (De Grasse Tyson, 86). Today?s punishment is

not nearly as harsh, but often planetary scientists are ridiculed for their

discoveries, because in the opinion of some scientists there is ?a lack of

substantial evidence? (Maran, 75). How can we be so silly as to assume that we

are the only planetary island in a vast ocean of stars? Also, many theories are

being eliminated by extrasolar planets, causing stubborn astronomers to become

uneasy. One instance is the theory of a star?s formation; when a star is being

made, strong winds blow away all debris orbiting near it. The presence of large

planets with tight orbits contradict this theory. There are also some doubts

about the Doppler effect, in that it may simply be the result of fluctuations of

the star?s surface, and not planets at all (De Grasse Tyson, 88). What

constitutes most doubt, however, is the existence of Brown Dwarf Stars. Brown

Dwarfs are stars in elliptical orbits around other stars that do not have enough

mass for nuclear reactions in their cores (Winters, 47). They «bridge the

gap in mass between stars and planets,» as Robert Naeye says (45), and

almost always have elliptical orbits (Winters, 46). In fact, brown dwarfs would

explain 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. The

extrasolar planets that have been found raise more questions, rather than giving

answers. They have shot down theories, confused speculators, and left us with

puzzle pieces that simply do not fit together, according to current theories. At

the same time, they have opened up doors to new possibilities, expanded our

knowledge, and given us hope for life elsewhere. These new discoveries help us

to realize how ignorant we are to the processes of the universe.

De 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:


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