NASA Habitable Alien Planet Live Stream Today

Just a "head's up" FYI:

NASA will host a live panel discussion today (Aug. 20) on the search for habitable alien planets, and how studies of ancient Earth can help scientists today.

The one-hour panel will include a discussion with "leading science experts describing what is known about our ancient Earth and how that information can guide the search for habitable planets orbiting other stars," according to a NASA announcement. Watch live at 5:30 p.m. ET (2130 GMT) at this link:

www.ustream.tv...

The scientists on the panel are:

Phoebe Cohen, Professor of Geosciences Williams College, Williamstown, Massachusetts.

Shawn Domagal-Goldman, research space scientist, NASA’s Goddard Space Flight Center, Greenbelt. Maryland.

Christopher House, Professor of Geosciences, Pennsylvania State University, University Park, Pennsylvania.

Timothy Lyons, Professor of Biogeochemistry, UC Riverside, Riverside, California.

Dawn Sumner, Professor of Geology, UC Davis, Davis, California.

David Grinspoon, senior scientist, Planetary Science Institute, Tucson, Ariz. and former Blumberg NASA-Library of Congress Chair in Astrobiology, Washington

WTF is an "alien" planet?

Cool. I think the US government has already found/visited such planets but don't hold that against me. I am wondering what you, as an astrobiology major, think of the supposed discovery of plankton living on the outside of the ISS. There is a big thread on it here at ATS. I am new on ATS so forgive me if this question is an inappropriate one to ask on your thread. I just thought with your background your opinion on the matter would hold more weight than most. Thanks

originally posted by: Psynic
WTF is an "alien" planet?

Exoplanets aka planets around other stars beyond our solar system.

originally posted by: Psynic
WTF is an "alien" planet?

look down .. see that dirt? that's an alien planet as with all things in the universe it's all perspective

Q

originally posted by: captainmjp
Cool. I think the US government has already found/visited such planets but don't hold that against me. I am wondering what you, as an astrobiology major, think of the supposed discovery of plankton living on the outside of the ISS.

It's almost certainly either a misunderstanding, bad translation or outright hoax/made up story.

It only appeared in a handful of British tabloids, no space science or astrobiology sites are running with it. It does not appear in places like Astrobiology Magazine, Universe Today, Space.com, Discovery News, The Planetary Society blog, Centauri Dreams nor is there a scientific paper on this supposed big discovery (which if it were real there certainly would be).

Remember the "faster than light" neutrinos which turned out to be a error in an experiment? That's what this is likely to be.

There is a big thread on it here at ATS. I am new on ATS so forgive me if this question is an inappropriate one to ask on your thread. I just thought with your background your opinion on the matter would hold more weight than most. Thanks

Its ok. If you read through that thread you'll see what I have had to say about it. There's something wrong with the story when people who are heavily involved with astrobiology and extremophile research aren't talking about it.

originally posted by: JadeStar

originally posted by: Psynic
WTF is an "alien" planet?

Exoplanets aka planets around other stars beyond our solar system.

So, Mars for instance, isn't an "Alien" planet.

Whew, that's a relief!

interesting !

thank you OP

originally posted by: Psynic

originally posted by: JadeStar

originally posted by: Psynic
WTF is an "alien" planet?

Exoplanets aka planets around other stars beyond our solar system.

So, Mars for instance, isn't an "Alien" planet.

Whew, that's a relief!

The phrase was "Habitable Alien Planets"

Is Mars an alien planet? Of course it is.

Is it habitable? Not now but in its past it was.

It's slightly less alien as we have actually sent things to Mars and are pretty familiar with our own Solar System. It's all a mater of degrees.

This is about what the study of our ancient Earth (which if we could go back in time would in many ways an alien planet to us) can help in the search for other habitable "alien Earths"

a reply to: JadeStar

Thanks. I agree.

I'm glad David Grinspoon is there. He (along with Chris McKay) is one of the leading NASA astrobiologist when it comes to what life elsewhere in the universe -- in different types of environments -- might be like.

I found the discussion on the importance on detecting free oxygen on an exoplanet to be very interesting. Should we use the presence of oxygen (possibly detectable using spectrography and the next generation of telescopes) as a major dtermining factor for searching for life?

On one hand, life could exist without oxygen -- in fact the ancient Earth had non-oxygen life (anaerobic life), and an alien looking at earth 3.5 to 4 billion years ago would not find oxygen, but life would still be here. The Earth did not really get it's abundance of oxygen until green plants proliferated. So a planet without oxygen could still have life.

On the other hand, considering that non-biological sources of oxygen are rare, so if there is an abundance of free oxygen detected in an exoplanet's atmosphere, that is a very string indication of biological processes.

BUT, because there are some non-biological sources for oxygen (albeit it is rare), finding free oxygen is NOT necessarily a "slam dunk" for life.

All in all, and interesting discussion.

Nice response in the end of the discussion to the tablod story about finding plankton on the ISS.

"When you hear a story like that the proper response is Hmmm, ok. We're skeptical but await further data."


I'll be waiting for that paper.

Someone else said it was likely diatoms in toothpaste.

At the end, they were talking about searching for life by searching for chemical dis-equilibriums in the atmosphere of exoplanets.

That's interesting even within our own solar system. I remember reading something by NASA's David Grinspoon (one of the panelists in the discussion that this tread is about) about 10 years ago where he was discussing chemical imbalances in the clouds of Venus that could (but not necessarily) indicate the presence of life processes in those clouds.


Another intriguing chemical imbalance that may point to life is occurring on Titan. Geologists and other planetary scientists who are attempting to understand the chemistry of the geological systems on Titan are finding that there is less hydrogen and acetylene than they expect should be there.

The question then arises (asked by NASA's Chris McKay in the article below), "Is something alive on Titan 'eating' the hydrogen and acetylene?". It's premature to say that "dis-equilibrium = life", because there may be non-biological reasons for the dis-equilibrium, or maybe our measurements are lacking....

...However, it is an intriguing thought, and these dis-equilibriums may be a good method for looking for prime candidates among exoplanets for life-bearing planets.

Here is the NASA Article I mentioned above about the idea of life on Titan:

What is Consuming Hydrogen and Acetylene on Titan?

originally posted by: Soylent Green Is People
I found the discussion on the importance on detecting free oxygen on an exoplanet to be very interesting. Should we use the presence of oxygen (possibly detectable using spectrography and the next generation of telescopes) as a major dtermining factor for searching for life?

On one hand, life could exist without oxygen -- in fact the ancient Earth had non-oxygen life (anaerobic life), and an alien looking at earth 3.5 to 4 billion years ago would not find oxygen, but life would still be here. The Earth did not really get it's abundance of oxygen until green plants proliferated. So a planet without oxygen could still have life.

Absolutely. Anaerobic bacteria would be a good example. Oxygen would have been poison to the early life on early Earth. I found it fascinating that it seems that Earth's plant life (photosynthesis) would have been very detectable by an alien telescope as early as around 2 billion years ago.

That fact alone answers a question many have asked me on ATS: How long has the Earth been detectable as a life bearing world at interstellar distances.

It also has implications in our search for life on planets around other stars in that we have some idea how old a planet might have to be for photosynthesis to start if it is in a similar orbit as the Earth around a sunlike star.

What was also fascinating is that they are actually looking at ways to detect life on planets younger than 2.5 billion years old.

It's all going to come down (i think) to learning more about what would set a methane planet with life apart from a methane planet without life since there are plenty of abiotic sources of methane.

Methanogens (bacteria that produces methane) could be covering a planet but if we were not careful we might rule it out as abiotic methane (produced by volcanic eruptions for instance)unless we see a certain ratio of it vs other gasses or it changing over time.

[quote[On the other hand, considering that non-biological sources of oxygen are rare, so if there is an abundance of free oxygen detected in an exoplanet's atmosphere, that is a very string indication of biological processes.

Exactly. Follow the oxygen and you probably will find life since free oxygen will be extremely rare and low on planets where it is produced abiotically. So its simply a matter of measuring the amount. If a planet has a ton of free oxygen like the Earth then it will stick out like a sore thumb as having complex life. Like they said, it may be that planets like Earth with complex life will be easier to detect than the ancient version of life on Earth prior to photosynthesis.

Good news if you want to find aliens

BUT, because there are some non-biological sources for oxygen (albeit it is rare), finding free oxygen is NOT necessarily a "slam dunk" for life.

Not a slam dunk but a very good indicator of it.

Its probably going to be the case that we find an oxygen world or two nearby (within 100-200 light years of Earth) and there will be much debate over whether it is abiotic oxygen so a larger telescope or fleet of telescope will be put into service in space to actually take a detailed photo and map of it which could reveal things like forests. They spoke to this as being something perhaps done in the time frame past 30 years or more.

In reality the only thing holding all this back right now is funding. The technology and techniques to do this are fairly well understood but it would cost about as much as several aircraft carriers put together so for now we will just have the James Webb Space Telescope, the European Extremely Large Telescope and the 30 Meter Telescope for atmospheric studies of nearby Super Earths around things low mass stars.

Hopefully not long after James Webb is flying they will build a next-gen space telescope with a much larger primary mirror (say in the 8-20 meter range) which could reveal directly image oodles of nearby alien Earths around Sunlike stars

All in all, and interesting discussion.

Thanks. There are plenty of these discussions going, i try to weed out the ones which are too technical (which some might find boring) or the ones which don't take questions from the general public.

BTW for more on the subject this was a discussion on the same subject a year ago:

originally posted by: Soylent Green Is People

At the end, they were talking about searching for life by searching for chemical dis-equilibriums in the atmosphere of exoplanets.

That's interesting even within our own solar system. I remember reading something by NASA's David Grinspoon (one of the panelists in the discussion that this tread is about) about 10 years ago where he was discussing chemical imbalances in the clouds of Venus that could (but not necessarily) indicate the presence of life processes in those clouds.

Yes. It has been theorized that Venus's clouds may have a habitable zone where life could exist. It is an extreme longshot but worth looking for.

Another intriguing chemical imbalance that may point to life is occurring on Titan. Geologists and other planetary scientists who are attempting to understand the chemistry of the geological systems on Titan are finding that there is less hydrogen and acetylene than they expect should be there.

The problem with Titan is the extremely low temperatures. If that imbalance is due to life it would be remarkable that it could thrive at such low temperatures thats why they're trying to eliminate other more plausible solutions to that imbalance.

Titan is a fascinating place though. It's like having an exo-moon in our own solar system!

The question then arises (asked by NASA's Chris McKay in the article below), "Is something alive on Titan 'eating' the hydrogen and acetylene?". It's premature to say that "dis-equilibrium = life", because there may be non-biological reasons for the dis-equilibrium, or maybe our measurements are lacking....

...However, it is an intriguing thought, and these dis-equilibriums may be a good method for looking for prime candidates among exoplanets for life-bearing planets.

Agree totally.

Here is the video of the live stream from yesterday: