Date: January 7, 2011
Title: Finding Exoplanets, Part 1
Podcaster: Thomas Hofstätter
Description: This podcast discusses the topic of Exoplanets and life on other planets out of our solar system. If you have any questions, comments or suggestions to the podcast, feel free to write me an email to hidden-space (at) gmx (dot) at or visit me at my website at www.hidden-space.at.tf!
Bio: Born in 1993 near Vienna, Austria, Europe. Upper High School with focus on Computer Science.Interested in extreme small and extreme big, devious and uninvestigated things. My main aim is to bring astronomy to public and to establish secular interest in astronomy, physics and mathematics. Host of :: The Hidden Space Project :: at http://hidden-space.at.tf.
Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by — no one. We still need sponsors for many days in 2011, so please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at signup@365daysofastronomy.org.
Transcript:
Hello and welcome to this episode of 365 Days of Astronomy. My name is Thomas Hofstatter and I am the host of :: The Hidden Space Project :: at www.hidden-space.at.tf.
[Leon:] And I’m Leon Dombroski from the state of Connecticut in the United States.
In this and other episodes we are going to talk about Exoplanets. We will have a look at the origin of thinking of life in other planetary systems as well as the science and technology behind the discovery of planets like in our own solar system.
[Leon:] Let us start with a Definition of the word “Exoplanet”: It’s a planet that orbits a star outside the solar system.
As mentioned some times before, there are some basic questions Astronomy as a science is trying to answer. One of them is “Are we alone in the Universe”. Indeed, scientists aren’t able to answer this question exactly. Life in the universe needs at least a place to live – like a planet.
[Leon:] That’s where the story starts. Until the beginning of the last century, there were only eight known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. (Pluto was detected in 1930 but isn’t a planet any more since 2006.)
The earth is the only one to lie in the so-called habitable zone. That’s a ring around every star where the planet possible is able to support life. The habitable zone around our sun is about at the radius of earth. Venus and Mars are at its edge but don’t lie in it.
[Leon:] Only one of the planets in our solar system, our earth, was then known to support life. Nevertheless, SciFi authors never stopped writing about aliens and extraterrestrial civilizations. For them, other forms of probably intelligent life would be absolutely possible.
It’s not so long, that scientists even know how planets actually can form around stars. Nowadays, it’s quite sure that planetary systems form in a so-called protoplanetary disk or circumstellar disk. These disks are a collection of matter around a new-formed star. It’s a remnant of the process of star-forming. Due to the rotation of the star and the resulting centrifugal forces, the matter is formed to a disk that can span up to 2000 times the distance from earth to the sun wide.
[Leon:] In 1994, the Hubble Space Telescope discovered a high number of protoplanetary disks in the Orion Nebula. But they are also common around other stars. Scientists are quite lucky if they can detect such disks because the matter immediately starts forming debris, that again form planets. Matter located too close at the central star is absorbed by it.
This process also describes why there are now rocky planets in the outer regions of the solar system. Actually, Mars is the last solid planet. Then come the gas giants. That’s the matter because the density of the matter in a protoplanetary disk is higher the closer it’s located to the star. Therefore it’s also hotter. According to the law of gravity, the more massive particles are pulled towards the star. In the end, this dust forms the solid planets. The dust located in the outer regions of the system, is less massive and forms the gas planets.
[Leon:] This dust is quite rare in the universe. The more it was a surprise when scientists using the Hubble Space Telescope found 56 circumstellar disks around 110 stars in the Orion Nebula, located about 1500 light years away form earth, in 1994. At this time, they called it “the strongest evidence yet that the process which may form planets is common in the Milky Way galaxy, of which Earth is a part, and the universe beyond. […] Hubble Space Telescope’s detailed images confirm more than a century of speculation, conjecture, and theory about the genesis of a solar system.”.
Due to the fact that it’s easier to detect the protoplanetary disk than the star, scientists think that there probably are much more such disks than previously thought. In earlier observations, the Hubble Space Telescope has also found newly formed stars, which are still contracting out of primordial gas.
That’s it for today. I hope, you enjoyed it. If you have any questions, comments or suggestions, write me an email to hidden-space (at) gmx (dot) at or visit me at my website at www.hidden-space.at.tf.
Thanks for listening and clear-skies!
[Leon:] Good bye for now!
The next stories of this series will go on air soon!
End of podcast:
365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.
Trackbacks/Pingbacks