The news from space this week gets our attention: There may be 40 billion Earth-like planets in our Milky Way galaxy. Planets like Earth “relatively common,” say the researchers. In the “Goldilocks” zone. Not too hot, not too cold. Forty billion chances for life to get started and evolve on Earth-like planets around Sun-like stars. Wow. Earth 2.0. And we thought we were special. Well, around here we are. The closest near-Earth – 12 light years away. And yet, just the idea of a single twin or sibling out there is amazing. Up next On Point: Maybe we are not alone. Contemplating Earth 2.0.
Tagged with “exoplanets” (9)
We now know, Schwartz began, that nearly all of the billions of stars in our galaxy have planets. If we can master interstellar travel, "there’s someplace to go." Our own solar system is pretty boring—-one planet is habitable, the rest are "like Antarctica without ice" or worse.
So this last year a number of researchers and visionaries have begun formal investigation into the practicalities of getting beyond our own solar system. It is an extremely hard problem, for two primary reasons—-the enormous energy required to drive far and fast, and the vast amount of time it takes to get anywhere even at high speed.
The energy required can be thought of in three ways. 1) Impossible—-what most scientists think. 2) Slow. 3) Faster than light (FTL). Chemical rockets won’t do at all. Nuclear fission rockets may suffice for visiting local planets, but it would take at least fusion to get to the planets of other stars. Schwartz showed Adam Crowl’s scheme for a Bussard Ramjet using interstellar ions for a fusion drive. James Benford (co-author of the book on all this, Starship Century) makes the case for sail ships powered by lasers based in our Solar System.
As for faster-than-light, that requires "reinventing physics." Physics does keep doing that (as with the recent discovery of "dark energy"). NASA has one researcher, Harold White, investigating the potential of microscopic wormholes for superluminal travel.
Standard-physics travel will require extremely long voyages, much longer than a human lifetime. Schwartz suggested four options. 1) Generational ships—-whole mini-societies commit to voyages that only their descendents will complete. 2) Sleep ships—-like in the movie "Avatar," travelers go into hibernation. 3) Relativistic ships—-at near the speed of light, time compresses, so that travelers may experience only 10 years while 100 years pass back on Earth. 4) Download ships—-"Suppose we learn how to copy human consciousness into some machine-like device. Such ‘iPersons’ would be able to control an avatar that could function in environments inhospitable to biological humans. They would not be limited to Earthlike planets."
Freeman Dyson has added an important idea, that interstellar space may be full of objects—-comets and planets and other things unattached to stars. They could be used for fuel, water, even food. "Some of the objects may be alive." Dyson notes that, thanks to island-hopping, Polynesians explored the Pacific long before Europeans crossed the Atlantic. We might get to the stars by steps.
Futurist Schwartz laid out four scenarios of the potential for star travel in the next 300 years, building on three population scenarios. By 2300 there could be 36 billion people, if religious faith drives large families. Or, vast wealth might make small families and long life so much the norm that there are only 2.3 billion people on Earth. One harsh scenario has 9 billion people using up the Earth.
Thus his four starship scenarios… 1) "Stuck in the Mud"—-we can’t or won’t muster the ability to travel far. 2) "God’s Galaxy"—-the faithful deploy their discipline to mount interstellar missions to carry the Word to the stars; they could handle generational ships. 3) "Escape from a Dying Planet"—-to get lots of people to new worlds and new hope would probably require sleep ships. 4) "Trillionaires in Space"—-the future likes of Elon Musk, Jeff Bezos, and Richard Branson will have the means and desire to push the envelope all the way, employing relativistic and download ships or even faster-than-light travel.
Schwartz concluded that there are apparently many paths that can get us to the stars. In other words, "Galactic civilization is almost inevitable."
Astronomer Dimitar Sasselov, director of Harvard’s Origins of Life Initiative, joins us to discuss his new book "The Life of Super-Earths" and to explain why he thinks planets larger than Earth offer the best prospects for finding life as we know it.
Astronomer Dimitar Sasselov and his colleagues search for Earth-like planets that may, someday, help us answer centuries-old questions about the origin and existence of biological life elsewhere (and on Earth). Preliminary results show that they have found 706 "candidates" — some of which further research may prove to be planets with Earth-like geochemical characteristics.
Seth is the Senior Astronomer at the SETI Institute, in Mountain View, California. He has an undergraduate degree in physics from Princeton University, and a doctorate in astronomy from the California Institute of Technology. For much of his career, Seth conducted radio astronomy research on galaxies, and has published approximately sixty papers in professional journals.
He has written several hundred popular magazine and Web articles on various topics in astronomy, technology, film and television. He lectures on astronomy and other subjects at Stanford and other venues in the Bay Area, and for the last six years, has been a Distinquished Speaker for the American Institute of Aeronautics and Astronautics. He is also Chair of the International Academy of Astronautics’ SETI Permanent Study Group. Every week he hosts the SETI Institute’s science radio show, “Are We Alone?”
Seth has edited and contributed to a half dozen books. His most recent tome is Confessions of an Alien Hunter: A Scientist’s Search for Extraterrestrial Intelligence.
Phil Bowermaster and Stephen Gordon discuss the implications of the discovery of the first potentially habitable planet outside the solar system. What does the existence of Gliese 581g imply about the existence of more such worlds? What does it tell us about the potential for life elsewhere in the galaxy.
If we’re ever to travel to a planet such as 581g, how will we get there? And what will motivate us to go?
It’s famously called the Final Frontier, and thanks to rapidly developing technology we now know more about the outer reaches of our galaxy than ever. But that leaves unknowns.
Does the universe have any limits? Are there any other earth-like planets out there? And the big one, are we alone?
Addressing the University of Melbourne recently, Britain’s Astronomer Royal, Lord Martin Rees, reports on the latest research.
Rupinder Brar from the Science and Physics Department at the University of Ontario Institute of Technology presents his competition winning lecture entitled Exoplanets: The Search for Other Earths.
Host: Commonwealth Club Location: San Francisco, CA Event Date: 03.13.09 Considered a leader in the search for planets outside our solar system, Alan Boss says we are at a turning point in our search for extraterrestrial life.
He expects we are on the verge of finding many different Earth-like planets across the universe, and he expects it will be common to find life on those planets. He shares his ideas for how the United States can be on the forefront of the next great discovery: life on another planet.