Discovery of Earth-Sized Worlds - Google+ Hangout

This is a Google+ Hangout we did to discuss the announcement of Earth-sized planets discovered by NASA's Kepler mission. Moderated by Fraser Cain from Universe Today/Astronomy Cast, with Nancy Atkinson from Universe Today, Dr. Phil Plait from Bad Astronomy, Emily Lakdawalla from the Planetary Society and Alan Boyle from MSNBC's Cosmic Log.

We discussed the announcement and then answered questions from the audience.

• Category

  Science & Technology

[Ullrich Fischer]

Awesome! More pictures and artists' conceptions would be nice. When Fraser was showing stuff it only showed up in the lower left corner of things while the main screen showed Phil Plait. Not that he's particularly ugly or anything, but it would have been nice to have the content photos front and center.

[Fraser Cain]

This was the way the Hangout worked. We're going to figure out a workaround for next time.

[Samuel Yu]

I still think that this video is 'TMBOTB' or 'THEMAXIMUMBESTOFTHEBEST' for eternity/forever no matter what of no matter what for it is what I love.

[marlonbu2]

For telling the truth, i was blocked from posting comments on universe today website. this is how democratic you are people... for this reason, i am more inclined to posts comments whenever, wherever possible. Let us not believe that you are that truthful when it is on the contrary...

[JOHN OWENS]

- 93 billion wold seem more logical, if not still on the low side, I can live with 93 billion. The antiquated propulsion systems that are being used will never get us any where close to exploring outside of our own solar system and still live to tell about it. Anti-gravity wave propulsion and beyond will have to be employed to escape our tiny solar system. Thank you for your response.

[Michael500ca]

The light would be equal in all directions, 14 billion years coming from one direction and at the same time 14 billion in the opposite direction. However, I did forget to mention that space has been expanding all this time, so once that is factored in, this still gives the universe an age of 14 billion years old, but 93 billion light years across observable due to the time light takes to travel and the expansion of the universe. Wikipedia has a good article.

[JOHN OWENS]

- Then, if I am correct, that would mean the observable Universe, as we know it now, has to be at least twice as old, or 28 Billion years old, and if we could go out further, this extrapolation could go on infinitely. Until we have the technology to see further and further, we are always going to be limited by our technology, that is until we discover another way to measure the Universe, which I think we had in the past, but was lost.

[Michael500ca]

You would be right. From our point of view we see the observable Universe, up to 13+ billion light years away, in all directions. A world near that threshold of 13 billion light years away would be able to see another 13 billion light years away. There are galaxies and stars that we will never see because they are beyond our observable universe and we will never see them.

[JOHN OWENS]

Q: if light takes 14 billion years to reach us, wouldn't light from that same galazy/stars travel 14 billion light years in the opposite direction making the Universe much, much larger than just from our vantage point. Earth ~~~~14 Billion light years distant >>>>14 Billion light years in the other direction? Am I looking at this the wrong way?

[palmeridigital]

Great hangout session! Hope to see more space and astronomy sessions like this, direct from the experts,

[Rob Mitchell]

Hi guys, LOVE this! Thank you so much for sharing. May I ask what database is being used for the Kepler data?

[Michael500ca]

Right.