NAI: Ask an Astrobiologist

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Origin and Evolution of Life

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Questions about Origin and Evolution of Life

Nucleosynthesis and our Solar System. Currently, I am working on a project related to habitability. My primary focus is related to the unique circumstances that support life on Earth. I've encountered in several places that our solar system is comprised of around 2% heavier than hydrogen and helium elements, and that it most likely took around three generations of stellar cycles to reach that level. However, in a review article for a book—this is the only place I have found this information—it mentioned that only 0.2% of the visible universe is made up of heavier than hydrogen and helium elements. Therefore, I wanted to know if the figure of 0.2% heavier elements for the visible universe is correct. If so, do higher concentrations only occur in isolated pockets, such as our solar system? If that is the case, than how often do these pockets of around 2% concentration occur? Also, do astrobiologists use these pockets as focal points in their quests for life beyond our solar system? Ultimately, I want to make the case in my project that they majority of the visible universe is very low in its concentration of heavier elements, and periodically, heavier elements collect in an area that would sustain the development of complexity. I just wanted to know if this is a realistic conclusion, or if I am pushing the evidence too far. Thank you for your time and consideration. Also, any suggestions on references to academic materials that would support these conclusions would be greatly appreciated.

Recent research into the possibility of the first life on earth forming near/in alkaline hydrothermal vents made me think...could scientists in a large lab recreate the conditions of those vents to see if they could recreate life? The lab would have to be extremely sterile so that any new molecules (RNA, etc) aren’t used by biological contaminants.

Is it possible that, when the core of Mars burned out, the water just sank to the center? This also raises the question to me, what's with the burning core of the earth, anyhow? Is Earth a star that is freezing over? As far as the necessity of extraterrestrial relocation for Earthen-life goes, I had always thought that the sun's expiration was our deadline, but won't our core expire before the sun does?

If something catastrophic may occur, wouldn't the governments and scientists deny it anyway to prevent mass hysteria?

Are there any technologies in existence or development that can absolutely identify the presence of life on other worlds using the electromagnetic spectrum? How does the earth appear when viewed this way and is there a way to use it as a baseline for discovering life elsewhere?

Do you think the earth will ever become "Non-livable" and we would have to go to that planet that is similar to earth?

I've noticed in many of the answers you state that the far more pressing threat to our planet is global warming. However, I'm wondering what specific threats humans will face if the carbon dioxide levels continue to increase, in the worst-case scenario. What can ordinary people be doing to address the problem of climate change?

I'm from Brazil and I have just one question. If all these stories are true would you (the government) tell the truth to people? People would go crazy, would no longer want to work or do any other activity that drive the economy. So, would the government tell people about an imminent destruction of the earth in order to avoid chaos and madness?

Why did the government make an announcement not to worry about 2012? How come nasa nor the government spoke about 2000 or 2003 like this but seem dedicated to make sure we believe 2012 are a hoax. is this a conspricy? AND If NASA is not worried about Dec 21, why did the head of NASA make a video warning NASA employees to prepare for disaster?

I just saw that you were featured on the news here in San Francisco. I don't have a question. I just wanted to say thank you for all of the time and energy you put into this. It is rare that there is even someone willing to answer questions (no matter how crazy they may seem) let alone not get so frustrated doing so. What touched me the most was when you described the children who are worried about Dec. 21, 2012 and wanted to know as much as they could because they were worried about their dogs. It makes me sick to my stomach to think that there are mothers out there who are planning on "saving" their children by killing them. I can only assume how reading those emails must feel, and I hope you know that you are now in my thoughts. There are no words that can express my heartbreak on hearing what some people have planned. I wish there was something I could do to help. I guess that's why I'm writing you. Just to say thank you on behalf of mankind. I wish you all the best in life. Thank you again.

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