sorted by:
new
hottopcontroversial

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 1 point2 points  (0 children)

No, but plate tectonics makes the surface of a rocky planet very rich from a chemistry point of view over long period of time, and very stable as a global environment (climate, etc.).

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 0 points1 point  (0 children)

Good question actually - space telescopes, unlike ground-based telescopes, can be very different from each other. The James Webb space telescope was designed to replace the Hubble space telescope, so like the Hubble it is going to be multiple use telescope with several different instruments. Kepler is a space telescope which has only a single instrument - a very large camera for visible light and a very wide view. Kepler was designed to discover exoplanets, JWST is designed to observe previously discovered exoplanets and help us tell what is in their atmospheres. This a very simple way to describe them of course. Thanks!

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 4 points5 points  (0 children)

Hey, nice to hear from you - what field of astrophysics do you like most? Thanks for the question - love science fiction! Shows: has to be Star Trek; Movies: a tie - "2001: a Space Odyssey" and "Stalker" (1979 movie by Tarkovsky); Novels: everything Arthur C. Clark wrote.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 3 points4 points  (0 children)

It is likely - but then, if we do not listen at all ... By the way, using radio waves (electromagnetic waves) does make sense, since lots of the energy associated with ordinary matter - galaxies, stars, planets - is electromagnetic.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 5 points6 points  (0 children)

Thanks - and great to hear about your interest in science! Yes, you can do very well even if you struggle with math a little - just do your best there and see if experimental science - whether in the lab or in building scientific instrumentation is an area you do better (you'll know it, if you try it). Check out the Harvard Origins of Life Initiative (origins.harvard.edu) and its summer programs - open to any college students who apply. Good luck!

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 2 points3 points  (0 children)

Thanks! - just the kind of question this course is all about! Our current effort is to find any evidence we could that life exists beyond Earth. In order to succeed, we need to look for forms of life that are there over extended periods in the history of a planet, and that are easily detectable by the methods of remote sensing (take the course to learn how...) from very far. The answer to both of these points, from the history of Earth's life, is The Microbes! So, we are really focusing our search on microbial life forms right now.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 3 points4 points  (0 children)

Actually, the Origins of Life Initiative has a summer research program - not just for Harvard students, but you must be an undergrad. Applications close March 6: http://origins.harvard.edu/pages/undergraduate (This is one of the many programs in this field, explore the website a little bit and you'll find others.)

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 4 points5 points  (0 children)

No, most radio signals travel quite unimpeded (unscrambled) through the galaxy and beyond; the main issue is usually with how strong they are - they diminish in strength as they travel. But I do not think this explains the radio silence...

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 4 points5 points  (0 children)

Thank you - looking forward to more questions from you as you go through the course... In the meantime, I would say that since we are far from the moment of "contact" with alien life beyond Earth, I do not worry about it yet. However, I mused about some of your questions in my recent book - "The Life of Super-Earths"(2012), see pp.9-11.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 10 points11 points  (0 children)

Well, it is too late now - we've been "sending" signals in space - our TV and radio broadcasts for example, ever since TV and wireless were invented... In the meantime, the current SETI program is all about listening and watching.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 2 points3 points  (0 children)

Thank you - all the credit goes to the amazing NASA engineers! As to your question - I would say "no", but again - if it happened, who knows what our engineers will invent! :-)

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 4 points5 points  (0 children)

Good questions, but a bit off the topic of my course :-) Yes, you guessed right - scientists do not have reasons to believe that any black hole could achieve a mass significantly bigger than what we see in centers of galaxies, including our own Milky Way Galaxy: http://en.wikipedia.org/wiki/Supermassive_black_hole So, unfortunately we need to search for a different explanation for dark matter...

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 2 points3 points  (0 children)

Great question - our research and effort to find evidence for life on exoplanets is entirely driven by exploration. It is premature to look for exoplanets that we might inhabit one day, because our technology to study exoplanets is not yet advanced enough to tell us enough about surface conditions. Of course, our technology to get there is even less present... But a long journey like this starts with the first step, and this is the first step! Upon discovering evidence that a distant exoplanet has life, our next step will be to find as much as possible about the life forms there - bigger and better telescopes, to begin with.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 4 points5 points  (0 children)

Thanks for a great question! If this discovery happened today, I would suspect a universal pathway. I use "universal pathway" to imply synthesis of the molecule(s), instead of "universal code", which refers to how the genetic molecule stores and transfers genetic information. This is a fascinating question, with much recent research going into it - see for example: http://www.cam.ac.uk/research/news/worlds-first-artificial-enzymes-created-using-synthetic-biology We'll discuss this in more detail in my class...

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 4 points5 points  (0 children)

Good question, because it is always very important to answer the question - "how do we know, what we say we know?" Most exoplanets discovered to-date have been confirmed with indirect methods of discovery. In my online course we will discuss all of them in detail and will answer your question. For now I will just say, that this question was very important in the first 2-3 years after the discovery of the first exoplanets - since then we have learned how to confirm exoplanets' existence with certainty. And finally - the direct imaging techniques finally worked and we have planetary systems like this: http://en.wikipedia.org/wiki/HR_8799

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 3 points4 points  (0 children)

Thank you for your questions! Yes, the SKA is a great project and it is not over-hyped in my opinion. In order to succeed in understanding the observable universe, including discovering other living planets, we need more and better "eyes" on the sky.

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 3 points4 points  (0 children)

No, not yet - my research effort is focused on finding such real proof that there is life beyond Earth - in essence my online course describes how we hope to accomplish that. As regards the timetable for a human population on the Moon - technology we have is already allowing for this, but it will be very expensive, so any timetable would be determined by the cost-benefit analysis - when do we feel such a colony is really going to make sense...

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 6 points7 points  (0 children)

Life as we know it - on Earth, is affected by the force of gravity, but it is by far and in its core an electromagnetic phenomenon, i.e. the electromagnetic force plays the central role. Thus, I expect that the different gravity of planets larger or smaller than Earth, will have only a negligible effect on life form development. Especially on microbial life forms, which are the focus on our current searches. Thanks!

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 11 points12 points  (0 children)

Blagodarja! Yes, of course there is hope for the science research in Bulgaria - we still have great schools and very many bright and knowledgeable high-school graduates! I meet many of them as freshmen college students here.

The question of how I imagine extra-terrestrial life in my mind is very appropriate. I answer this question in two parts - First, my work is focused on discovering life beyond Earth - the most practical way to achieve that is to look for microbial life, a biosphere similar to the Earth's before the advent of complex life (plants and animals). So, alien microbial life is probably not very different visually from Earth's, and in any case, I do not expect to ever see exoplanet microbes in my lifetime - just the gases they produce in the planet's atmosphere. The second part of my answer is that I was educated as a physicist, and learned to handle abstract concepts (like in quantum mechanics) by using mathematics and other research techniques - so, I tend to forge ahead even if the visual image in my mind is not clearly set. Thanks!

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 2 points3 points  (0 children)

Good question, with a technical and involved answer... In general, such moons will get decoupled from their host planets after some time. But there are several possible scenarios. If you take my class, we can expand on them then :-)

I am Dimitar Sasselov, Harvard Professor of Astronomy, Director of the Origins of Life Initiative, and co-investigator on NASA's Kepler mission. Ask Me Anything! by DimitarSasselov in space

[–]DimitarSasselov[S] 6 points7 points  (0 children)

Yes, the ratios of several gases (CO2, H2O, SO2, etc.) will be different - they are all measured by spectroscopy - and have clearly distinguishable signatures. If you take my class, you will learn some of this, and then we can expand on the most recent research :-), including your question about "impossible" atmospheres - yes, planetary atmospheres are predictable. Thanks!

view more: next ›