Neo Earth

Saturday, May 7, 2011

Exosolar Planets

An Exosolar planet is a planet that is not in orbit
around our star.

How they are formed
Planets are formed from the protoplanetary disk surrounding a star soon after its formation. The disk is mainly composed of dust particles. Over time the these particles attract each other and the dust to clump together creating planetesimals( a planet-like form to small to be considered a dwarf planet or a planet). Eventually (time can vary for different planets) the planetesimals can form into full planets.


The image shows the evolution of planets from dust to planets.

Types of planets

Terrestrial


Examples

all the inner planets(Mercury, Venus, Earth, and Mars)

Composition
Core and Mantles of molten metals
Crust of metals and rock
Atmosphere of Carbon dioxide, Nitrogen, Oxygen

Gas Giant
Examples
Jupiter, Saturn

Composition

Core of Ice
Mantle of Metallic Hydrogen (caused by pressure)
Envelope of gasses (Hydrogen & Helium)


Examples
Uranus, Neptune


Composition
Core of rock and ice

Mantle of water, methane, and ammonia
Envelope of gasses (helium, methane)

Note: most data on water worlds and gas giants is theoretical only


If you want to find out more follow the links at the end to watch a National Geographic episode on the formation of our solar system and why the planets are what they are and where they are.
Part I
Part II

Part III
Part IV
Part V

Detection

Doppler Shift (Stellar Wobble)

When the star is moving closer to the observer the light given off turns red, but when it goes away from the star it turns blue. By the amount of wobble scientists can determine the size and mass of the planet and its distance from the star. Based on this the type of planet can be determined

A real life example of this is if you are standing on a sidewalk as an ambulance goes past. When the ambulance is approaching you the sound you hear is a different pitch than it is when it is moving away from you. This example uses sound instead of light but the principal is the same.

Land based telescopes are used for this method


This image shows a land based telescope picking up the light wave from a star as it orbits a central point in space.

Transit Method

If a planet moves directly between the observer and a star the stars brightness dims.Scientists then determine the mass, size and distance from the star by how large the dip was and how long it lasted.

You can see this anytime if you hod an object that is smaller than the light between you and a light source
.

Telescopes in space use this method

In the image you can see the stars usual brightness the planet entering the observation line and the planet directly in front of the star.

Corona Graphing (Direct Detection)

By putting a physical mass to block a stars sunlight we can see the corona of that star. Then without the stars light in the way planets orbiting that star are illuminated by the corona and we can directly see them.

This was originally invented for the purpose of studying our stars corona without he need to wait for a solar eclipse. One of these could be tried at any time the sun is shining.

Both land and space telescopes use this method.

In the image there is a physical mass blocking the stars light and the corona is illuminating the planet that the scientist is looking at.

If you want to learn more or need a better explanation go to either of these two links.
Text
Video
Missions

Kepler -current

  • Uses Transit Method
  • Launcehed March 6 2009
  • one meter diameter telescope
  • monitor approximately of sky covered by an hand held at arms length( two big dipper scoops)
  • NASA funded

Hubble-current

  • uses transit method
  • Launched April 1990
  • monitors amount of sky covered by a grain of sand at arms length
  • NASA, ESA CSA funded
  • Extreamly famous for pictures of nebule

James Webb-future

  • infa red imaging
  • can observe atmospheric composition
  • gathers data on planets
  • planed launch 2013
  • NASA, ESA, CSA developed
  • 6.5 meter telescope





Naming process

The name of the star -(letter in order of discover starting with b)(-a is the star)

Because of order of discovery naming it can you can end up where e is closer to the star than b


Examples

Gliese 581g

Located 20 light years

Announced by NASA on September 29th 2010

Terrestrial planet that may support water

11 years of observation was put into the discovery and analysis effort An artist rendition

has multiple other planets in the system

Most likely discovered planet to support life

Fomalhaut b

Located 20 light years away in the southern fish

Gas giant

Announced by NASA November 13th 2008

First exosolar planet to be photographed

one year on Fomalhaut b is equivalent to 872 earth years

Still a protoplanetary disk in around the star

The first real image taken of an exosolar planet the actual image is in the little box, its those bright red dots.



Kepler 10b

560 light years away

Terrestrial and first that is most defiantly rocky

only 40% larger than earth

orbit distance is 1/20 of Mercuries

called a scorched planet

Artist rendition of Kepler 10b

Interesting facts

main reason for interest is to see if we are alone in the universe

PSR 1257+12 B was the first exosolar planet ever discovered

PSR 1257+12 B orbits a pulasar

Over 530 exosolar planets have been found

Most planets are huge (many times the size of Jupiter)

4 comments:

  1. Hi Bryce!
    This is a great post! You have great information, no spelling/grammar mistakes, etc etc etc. The few things you could have changed are not having an extremely long and complicated National Geographic video, you should try to find something more simple, even though you found a good video about corona graphing. You also need to have some more "exciting" voice. Your science looks great, and your pictures are captioned. Great job! :)

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  2. Bryce - great job on this post. You have covered everything you discussed in class and incorporated a picture for each topic, although some of them are missing their caption. Your links are excellent, especially the National Geographic information and all of them work! Your scientific explanation, especially of the three detection methods, is clear and understandable - congratulations on that, as this is a difficult topic. Some things you could have improved are spelling & grammar - there are a few errors here. Plus, you did not add your date in the title, nor did you include labels. But the media you used really was your strong point. Well done! ~Ms. D.

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  3. Hello Bryce,
    this is a very good post. You've done a terrific job in choosing the different pictures, links, videos and scientific data for Exosolar planets.
    I especially like the videos about the creation of planets and the universe, but your layout is a bit confusing for the reader. You should watch out for your subtitles, titles and different sizes of font, so the reader could know what is more and less important etc. You asked me what program I used to design my blog post. It is CorelDRAW, a graphic editing program. You can practice during the summer, so you could become the best blogger in your future school. Good luck! Dave :-D

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  4. Actually, you have a grammatical error of "hod" which should be changed to "had".
    Additionally, the light emitted when a star approaches the observer is blue, and when it recedes the star emits red light (longer wavelength). You have stated the reverse.

    ReplyDelete