Destination: Mars

Mars will become a touristic destination in a matter of 20 years. At what price for a round trip would you consider buying a ticket? What safety concerns would have to be met to sway you over?
Ciro Villa (technologist, application developer, STEM communicator)

First and foremost, whether Mars will become a tourist destination in the next 20 years or not, it's still to be seen and subject to debate. There are still several critical hurdles to be overcome: financial, technical and societal just to name some of the main ones. As of today, these hurdles make just the prospect of humans traveling, let alone landing and settling on the red planet all but trivial and extremely challenging. Initially when human travel to the Red planet will begin, only trained astronauts will venture and embark in the journey that will no doubt be filled with difficulties and perils.

When and if we will finally be able to achieve tourism to Mars, prices will at the beginning undoubtedly be highly prohibitive and most likely out of reach for a large swat of the human population. I personally would most likely not be able to afford the journey in my lifetime. It is indeed hard to place a fair price tags with so many unknowns still in place.

If we let our fantasy go wild, then I would envision that in another 100 to 150-year technology will have advanced to the point to allow for “affordable” and safe commutes with round trips to Mars. I frankly still don’t know what exactly that price tag might or should be.

In terms of safety, it is also almost impossible to pinpoint what would be an acceptable threshold of risk metrics that would make me comfortable enough to embark in the journey with a relative degree of confidence that my trip would not be the last of my life. As mentioned in the beginning, obstacles to be overcome in terms of human planetary travel survivability still abound and only after several iterations, including discoveries, advancement in science and technology and lesson learned, would I believe that a journey to the Red Planet might be safe and enjoyable.

Fraser Cain (publisher at, co-host of Astronomy Cast)

I'm probably less adventurous than most people. I really love Earth, and I've barely explored this amazing planet and all it offers. I'd want to know that a trip to and from Mars is relatively safe and much much quicker before I was willing to make that journey. I'd do a few months on Mars to see some of the highlights and then I'd like to come home. I would like to experience lower gravity, but that would be even better on the Moon, which is only a few days away.

Paul Carr (Space Systems engineer at NASA, podcaster, blogger, investigator)

I've little doubt that the first tourist tickets to Mars will only be affordable by the wealthy or those able to obtain corporate sponsorship. The cheaper option is likely to be one way ticket, but still far beyond the means of all but a few of us. An optimistic price for a one way ticket in the early days is probably $5 million USD, but it's probably much more than that until Mars travel is far more efficient than it is now. Perhaps I could raise enough for a one way ticket, which I would have to consider if my health holds up long enough. A few million dollars, for the price of wearing corporate logos on my flight suit, might be possible for me.

I don't expect Mars travel to be as safe as getting on a cruise ship or an airliner for a long time to come. We can probably find efficient ways to address such threats as infectious diseases in a closed space, radiation exposure, or social meltdowns, so that the biggest risks are launch and landing. We shouldn't get into the same mentality we had in the early days of the Space Shuttle, with a delusional notion of how safe it is. After the Challenger tragedy in 1986, there was no shortage of astronaut candidates. Some people are willing to take risks if the reward is there. Many people have died leaping off of cliffs in a wingsuit, or climbing high peaks - not because they don't know what the risks are, but because they accept them and proceed nonetheless. We may never lose as many Mars tourists as the 290 people who have died climbing Everest, but it does seem that some will meet their destiny there. Those who fear the risks should stay on Earth, where they will also die when their time comes.

If I could choose, I'd choose to die on another planet.

Nancy Atkinson (Senior Editor for Universe Today, Host of the NASA Lunar Science Institute podcast & a NASA/JPL Solar System Ambassador)

Ah yes, this is what I jokingly call "The Mars Plan," where getting to Mars is a thing that is always 20 years off into the future, no matter when. Humans on Mars was touted as being 20 years away in the 1970's and it is still 20 years away today. Are we actually any closer now to accomplishing this great feat than we were in the 1970's? I'm not very confident that we are. There are still many technical hurdles to leap, like making the trip shorter than 7 months, being able to land large payloads on Mars, and developing habitats and life support systems that are truly foolproof. If someone dies on the first human mission to Mars, that will be the end of it. Also, this is going to cost a lot of money, and there will have to be a payoff in some fashion, whether it is mining, tourism or an Earth-catastrophe management endeavor.

As a journalist, I'm secretly hoping that someone will pay *me* to go to Mars so I can write about it! Otherwise, I don't think I'll ever have enough cash to do it on my own.

lt’s the size of Texas, Mr President.

At one point in the future we’ll be faced with a threat from an asteroid coming our way. Hopefully we’ll know about it long before it’s even close to Earth. What in your opinion is the best way to redirect an asteroid using current or future technology?
Andrew Rader (SpaceX engineer, MIT PhD, author)

I have a video about that:

The larger an object is and the faster is it moving, the more momentum and kinetic energy it has. Large objects moving in space are nearly impossible to stop, but if detected early enough, they can be deflected. Just a infinitesimal course correction can have a major effect on an object's trajectory months or years down the road. The key is to nudge the path of an asteroid early enough so that it grazes peacefully past our planet. Even simple things like painting an asteroid with absorbing or reflecting paint changes modifies the effect of solar rays, and could help steer the asteroid clear of disaster. Alternatively, you could attach a solar sail or small efficient engine. The key to any solution is early detection.

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)

Every year, astronomers discover new asteroids in the Solar System. Current and past Near Earth Objects (NEO) programs, such as the Catalina Sky Survey (CSS) and The Minor Planet Center (MPC), currently use optical telescopes at high altitude with thermo-electrically cooled cameras. These methods require dark skies with a high transparency, extended camera exposure times, and image data processing. Although the entire process is cumbersome, these surveys have been responsible for detecting and discovering hundreds of asteroids in our Solar system. Recently, Congress signed the NASA Transition Authorization Act of 2017, which directed NASA to expand the NASA Near Earth Object program to detect, track, catalog, and characterize potentially hazardous NEOs less than 140 meters. The act, moreover, leverages the capabilities of the private sector and philanthropic organizations to the maximum extent practicable in carrying out the NEO Survey Program. Asteroid impact events, specifically on Earth, have played a major role in the evolution of the Solar System. These events have shaped the history of our planet and numerous theories suggest that an impact from an asteroid formed the Moon, shaped life on Earth, and caused at least 5 mass extinction events on Earth. These private and public asteroid detection programs, however, are not responsible for redirecting an asteroid that could impact Earth nor do we have the current capability to do so.

NASA’s Planetary Defense provides several mitigation strategies to prevent an asteroid impact – but none of the proposed strategies have not materialized into anything other than blueprints. Nonetheless, there is a noteworthy piece of information that, according to NASA, is required prior to attempting an asteroid redirect mission: “changing the velocity or trajectory of the object by less than an inch per second years in advance of the predicted impact”. In the past 50 years, a variety of proposals have recommended several approaches to stopping or redirecting an asteroid from impacting Earth. Some of these include the use of nuclear weapons to destroy the asteroid, towing the asteroid away by using gravity or a cable, or landing a robot on the asteroid, which would them use propulsion to slightly move the asteroid into a different trajectory. Unfortunately, we currently do not have the technology to advance any of these proposals or motivation from Congress to spend billions or trillions of dollars to develop them.

The possibility that one day another asteroid will impact Earth is mathematically probable. The best-case scenario is that we would detect the asteroid well in advance for NASA or the private space industry to develop one of these programs to stop it. Personally, of all the proposals, my choice to stop the asteroid would be the gravity tractor, as proposed by NASA. If we could detect the asteroid years in advance, the asteroid’s path could be changed by using the gravitational pull of a spacecraft. The spacecraft, which could be launched from the Moon, would travel alongside the impactor for several years and gently pull it out of Earth’s path. The spacecraft, moreover, could be controlled remotely from Earth or the Moon and thus provide the best solution against Earth impact event.

Fraser Cain (publisher at, co-host of Astronomy Cast)

The bottom line is that we just don't know. Maybe it'll be by shooting a laser at it? Or maybe by detonating a nuke near it? Or putting a railgun on it and blasting out material. Until we have the commitment and courage to send a mission to an asteroid and practice some of these different techniques we won't truly know the best way to redirect them.


It’s this time of year when we make predictions for the upcoming year. What should we look for in the year 2018? What event or mission will be on everyone’s lips next year?
Fraser Cain (publisher at, co-host of Astronomy Cast)

There are a couple of big missions coming from SpaceX that I think will keep people on their toes. The first, of course is the launch of SpaceX's Falcon Heavy Rocket, which has been delayed for several years now. This will bring serious heavy lift capability to SpaceX, which has only been possible from the traditional launch providers. In addition, SpaceX is expected to launch a couple of space tourists on circumlunar trajectory on board a Dragon capsule This will be the first time humans have gone beyond low Earth orbit since the Apollo era. Of course, SpaceX timelines will likely slip, so it's entirely possible that these predictions will be totally wrong.

In terms of astronomy, I think the result I'm most excited about will be the first pictures from the Event Horizon Telescope, which gathered data back in April 2017. To think that we'll see an image of the region around a black hole is mind boggling.

Of course, the biggest things will be the unexpected. 2017 surprised us, and I'm sure 2018 will surprise us too.

Nancy Atkinson (Senior Editor for Universe Today, Host of the NASA Lunar Science Institute podcast & a NASA/JPL Solar System Ambassador)

Although I’m a big fan of every “branch” of space exploration, I’m especially interested in planetary exploration (and that’s why I wrote a book about it!) There are several big planetary events coming up in 2018 and I’m looking forward to all of them. The InSight seismology probe is scheduled to launch to Mars in May, and land later this year. There are two asteroid sample missions that will arrive at their destinations this year: OSIRIS-REx will reach Bennu in August, and Hayabusa 2 is scheduled to reach Ryugu in July. Also, ESA and JAXA are teaming up to launch BepiColombo to Mercury in October (arriving in 2025). China is expected to launch the Chang'e 4 lander/rover sometime this year to land on the moon’s far side.

Of course, all the current planetary missions will continue to awe and amaze us: Juno is telling us more about Jupiter while sending back incredible images; the two Mars rovers carry on with their journeys across the surface of the Red Planet, Dawn is still orbiting Ceres, and at the end of the year, New Horizons will be approaching its next target, an intruging Kuiper Belt Object. So, there will be no shortage of exciting planetary science news to cover in 2018!

Seth Shostak (Senior Astronomer and Director of the Center for SETI Research at SETI Institute)

Discovery of a new, big planet in the outer solar system.

Paul Carr (Space Systems engineer at NASA, podcaster, blogger, investigator)

The first thing should be the launch of the Falcon Heavy. We don’t yet know how important a launch vehicle the Heavy will be, but stay tuned for a wonderful spectacle as multiple boosters return to the launch site at once.

The planned launch of TESS is probably the biggest item on my list. It will take a few months to settle into the science, but towards the end of 2018 TESS should start delivering a much better census of planets, especially Earths and Super Earths that are relatively near to us compared to Kepler’s discoveries. We might even find some Earth-like planets quite close by. Along with follow-up ground observations, this should push us truly into the golden age of exoplanet discoveries.

Another big event at about the same time as the TESS launch is the Gaia DR2 data release. I am especially hoping for much smaller error bars on the distance to Boyajian’s Star, which would help to constrain theories about what causes the slow dimming ad brightening episodes we observe.

Prepare for warp speed

Science fiction has shown us spaceships travelling at enormous speeds, some of them had faster-then-light capabilities (and some have done the Kessel run in 12 parsecs). Which metods of transportation that are being developed or thought about in the near/far future you think are the most promising?
Paul Carr (Space Systems engineer at NASA, podcaster, blogger, investigator)

I'm not optimistic about faster than light travel at any time in the future, although I would love to be proved wrong. Not only do we not have the technology to travel faster than the speed of light, we don't know what technology we need, or even if it's possible.

For the near future, something we could make happen would be nuclear space propulsion - first fission reactors, and then fusion reactors. My dream reactor would be a Helium 3 fusion reactor. Helium 3 is stable, and the Helium 3 fusion reaction produces Helium 4 (also stable), a proton (or two) (that can be used to generate electric power), and energy, but no neutrons. Neutrons are a problem that make most fusion reactors unusable for space applications. Such a reaction is far more mass efficient than chemical rockets, and with some work, could open up the entire solar system to us.

Fraser Cain (publisher at, co-host of Astronomy Cast)

In the near term, I'm mostly excited about the potential for light sails, like the Breakthrough Starshot. If this technology can be developed, we could see spacecraft traveling out to Pluto within a few weeks or even days. Once we've mastered this tech, we can start sending spacecraft out to other stars.

Ciro Villa (technologist, application developer, STEM communicator)

Ever since human have been able to use their imagination they have been dreaming of traveling far away in space to explore and discover new worlds. Unfortunately, as much as our brains can dream it, we are limited by our physical and technological capabilities to only be able to travel very nearby.

So far in the history of space travel, chemical rockets have been the main mean of propulsion and other new propulsion technologies are only at their infancy. Many studies are underway and much literature has been created to envision the design of new ways to propel human made spaceships further in space and in shortest amount of times. In the shortest term, more efficient forms of propulsion are being developed such as electric variants like Ion, Plasma and Hall-effect thrusters some of which are already operational on some space crafts ( Also, Solar sails which are still somewhat experimental in nature with their size challenges and limitations, are being investigated as another promising mean to accelerate spaceships beyond the confines of our Solar System.

More futuristic forms of propulsion are unfortunately still only on paper at this time and it will take willpower, new discoveries, money, time or most likely all the above to be further developed. The hope is that with the accelerating pace of technological advancements, some of these new, exotic propulsion technologies will materialize at some point in our future make human exploration of deep space a reality.

Andrew Rader (SpaceX engineer, MIT PhD, author)

For faster than light travel, it's always possible that there will be some breakthrough that we can't anticipate. Apart from that, I think we're going to end up taking a long time to get to other stars, possibly in some kind of suspension or by just sending robots or human embryos. In terms of advanced propulsion in general, anti-matter offers the best mass to energy ratio we know of, but that's a long way off (hundreds of years?). Fusion rockets might be possible before the end of the century. These would be great for travel in the solar system, but probably not to another star.

Robert Novella (co-founder and vice-president of New England Skeptical Society, co-host of Skeptics’ Guide to the Universe)

Chemical rockets have served humanity very well for many decades. They have launched satellites into orbit and blasted our probes and landers into the nooks and crannies of our solar system. They have lifted humans to low earth orbit and our moon. All of this has given us a priceless cornucopia of images and data and mind-boggling discoveries.

These types of rockets however are not nearly as adept at ferrying our fragile bodies much beyond the moon. To keep us healthy and happy requires vast ships that are prohibitively slow and expensive for trips to the closest practical planet, Mars.

Luckily, conventional rockets are only a tiny subset of all rocket types, yet I've been disappointed for literally decades that we have made so little progress on other types of rocket technology for transporting humans.

I'm still holding out hope for the widespread realization that rockets using nuclear fuel are the only real option we have in the near future for getting humans well past our moon. The energy density of nuclear is orders of magnitude that of chemical energy. Nuclear thermal rockets using fission for example could weigh half as much as similarly powerful chemical rockets. Directly comparing chemical vs nuclear rockets is complex but many have concluded that such nuclear rockets would be at least as twice as efficient as chemical rockets. This would allow trips to mars requiring half the time, or less, which is especially important considering the more time spent in space, the more time you're exposed to life-threatening solar radiation and cosmic rays. Fission rockets would also allow for some serious maneuvering during a flight which is too expensive for modern chemical engines. You're just not much of a spaceship in my book if you can't maneuver easily.

A little beyond these fission rockets (which we can build now), we will create fusion rockets which should quickly predominate since they are even more efficient and produce less radioactive waste. Remember, a significant limitation to any ship's maximum velocity is the amount of fuel required to reach that velocity. You could actually reach 10% of the speed of light with chemical engines but you'd need a gas tank the size of our sun to do that. Doable? Yes, theoretically. Practical? Ummm, no. Fission would require far less fuel to reach that speed and fusion even less. So what would require the least amount of fuel? Read on...

Long-term scenarios for Space Travel will certainly offer humanity many fascinating hi-tech options but some type of antimatter engines will probably be required if you want to move something space ship sized as close as possible to the speed of light. Sure, there may be some bizarre quirk of physics that allows for superluminal travel but...probably not, so don't get your hopes up.

We know for certain right now that as you approach appreciable fractions of the speed of light, your mass starts increasing alarmingly fast (kinetic energy). To continue accelerating, your ballooning mass requires an exponentially increasing amount of energy. Eventually, to reach the speed of light itself you'll need infinite energy to move your infinite mass. Unless you have infinite energy in your back pocket, you'll never hit that speed.

To get as close as possible however, you'll need an efficient method of energy conversion and that's exactly what matter/antimatter annihilation provides. The energy released from such interactions is truly huge even if the masses involved are tiny (that is, after all, a key take-away from E=mc^2). The primary problem though is that we can't practically convert all the byproducts of matter/antimatter collisions into the kinetic energy of our spaceship. The bottom line then is that we will probably not be able to ever get arbitrarily close to the speed of light. The estimates seem to be all over the place but somewhere between 40 and 70 percent of the speed of light could be attainable eventually.

I'm totally ok with a spaceship going 753 million km per hour.

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)

For generations, science fiction has attempted to shape our future. From cameras on a watch as depicted in Dick Tracy; to warp speed, a common mode of travel used extensively in the Star Trek franchise. However, traveling faster than the speed of light or at warp speed, from a practical purpose, is not possible according to the laws of physics. The energy required to achieve the speed the speed of light, for example, would be infinite – sort of a an impossibility.

Today, and for the foreseeable future, spacecraft are limited to local orbits and interplanetary missions. There are numerous factors that shape spacecraft design and capabilities, but predominantly they are due to budget constraints, its intended function, and policy requirements. Extraordinary specific power and the ratio of jet-power to total spacecraft mass are required to reach interstellar targets within sub-century time frames. Some heat transfer is unavoidable and a tremendous heating load must be effectively handled. Thus, for interstellar rocket concepts of all technologies, a key engineering setback is controlling the heat transfer from the exhaust stream back into the spacecraft.

Based on research in the late 1950s to the early 1960s, it is technically possible to build spacecraft with nuclear pulse propulsion engines (i.e. driven by a series of nuclear explosions). This propulsion system contains the prospect of very high specific impulse and high specific power. This type of spacecraft, in my opinion, is our best hope for achieving interstellar travel.

In 1968, Project Orion team members proposed an interstellar spacecraft using nuclear pulse propulsion, which used pure deuterium fusion detonations with a very high fuel burn-up fraction. They calculated an exhaust velocity of 15,000 km/s and a 100,000-ton spacecraft able to achieve 20,000 km/s allowing a flight-time to Alpha Centauri of roughly 130 years. Later studies suggested that the top cruise velocity that can theoretically be achieved by a Teller-Ulam thermonuclear unit powered Orion spacecraft, supposing no fuel is saved for slowing back down, is about 8% to 10% of the speed of light. An atomic Orion can reach perhaps 3%-5% of the speed of light. A nuclear pulse drive spacecraft powered by Fusion-antimatter catalyzed nuclear pulse propulsion units would be comparably in the 10% range and pure matter-antimatter annihilation rockets would be theoretically capable of achieving a velocity between 50% to 80% of the speed of light.

In closing, although there have been numerous proposals and design concepts, spacecraft propulsion for interstellar flight is not an easy endeavor or economical. At current pace, we are at least hundreds or perhaps thousands of years before capable of interstellar travel to even the closest stars. Nevertheless, there are no doubts we will become an interstellar species in the foreseeable future.

Next Giant Leap

It looks like we’re about to become a multiplanetary species in a matter of 10-15 years. Would you choose to risk and become a part of a history as one of the first settlers arriving on Mars or would you wait until it gets safer? What would you take with you to kill boredom on a months long trip?

andrewraderAndrew Rader (SpaceX engineer, MIT PhD, author)

The answer to that question depends on the specific circumstances, but I certainly wouldn’t rule out going myself if given the opportunity.

I’d play a lot of board games in computerized form (hopefully some turn-based ones with friends at home). I can do that for weeks on end and be perfectly happy.

sethshostakSeth Shostak (Senior Astronomer and Director of the Center for SETI Research at SETI Institute)

Of course I’d love to go into space, but who knows if they’d TAKE me!


imageNicole Guggliucci (“Noisy astronomer”, blogger, educator, post-doc)

You know, when I was younger than I am now, I’d say, “sign me up!” But I think today I’d pass since I like the cool stuff I’m doing here on Earth. When they start needing astronomy professors on Mars, then I’ll go, with the caveat that my dog has to come, too! As for boredom… I have a huge to-read list on my Kindle, so I’m all ready for that. 🙂

frasercain1Fraser Cain (publisher at, co-host of Astronomy Cast)

Although I’d love to take a safe vacation on Mars, I really love Planet Earth. Living on Mars will be a constant struggle, and that takes a special kind of person, willing to take the risks to push humanity forward. Anyone will to step forward, and is aware of the risks has my support. But personally, I haven’t even finished exploring Earth yet.

paulcarrPaul Carr (Space Systems engineer at NASA, podcaster, blogger, investigator)

In the unlikely event that I could qualify to go on an early Mars Mission, it is not the risk that would deter me, even though I regard the risks as considerable. The dangers, it seems to me, are roughly comparable to those faced by countless generations of humans before us when they struck out in search of new lands and new freedoms. There are risks of disease, deprivation, and exposure to harsh environments. I have little doubt that at least some of the early Mars pioneers will meet an untimely death. As Geoffrey Landis wrote in his novel Mars Crossing, Mars is for heroes. I believe it eventually will become much more repeatable and safer, but the wait might be too long. I think there will a surplus of volunteers, even after the first deaths. Even those who successfully establish colonies and begin to raise families on Mars will find it tough going with many challenges. I believe the early Mars generations will genetically engineer themselves to adapt better, as well as their plants, and perhaps even their animals.

To kill boredom on the long trip, of course the younger crew members will immerse themselves in VR environments and play games all day when not working out on the treadmill. However, we older folks who remember rotary dial phones and manual transmissions – we will immerse ourselves in VR environments and play games all day.

One question

You have the chance to meet in person Galileo Galilei, Isaac Newton, Albert Einstein, Carl Sagan and you can ask each of them one question. What question would it be?

Andrew Rader (SpaceX engineer, MIT PhD, author)


Galileo Galilei – What do you think about humans visiting the Moon? Isaac Newton – What do you consider your greatest achievement? Albert Einstein – What inspired you to start thinking about the great problems of physics? Carl Sagan – If you could ask Galileo one question, what would it be? (I think he’d have a better answer than I did)

Fraser Cain (publisher at, co-host of Astronomy Cast)


I really wish I could go back in time and talk to these scientists, especially Galileo. I’m not sure I’d have a lot of questions for them, but I’d love to be able to give them an update on the science they figured out. I could tell Galileo about the moons of Jupiter, and the amazing features we’ve found on them. I could let Newton know about all the discoveries we’ve made about gravity, and how his calculations still form the basis of so much of our science and mathematics. I’d love to let Einstein know that Relativity is still holding strong 100 years after he first described it, including the recent direct detection of gravitational waves. I’m sure Sagan would love an update on the state of Solar System exploration and to learn about what we saw with a flyby of Pluto, or the rovers on Mars.

Nicole Guggliucci (“Noisy astronomer”, blogger, educator, post-doc)


Can I trade in my answers with the others and just talk with Carl Sagan? I think I’d ask him a BUNCH about methods of science communication, searching for extraterrestrials, and how to bring us away from the brink of ecological disaster. Maybe that’s cheating, but I’d get a lot more out of a conversation with him than the others!

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)


If I could travel back in time, to where the father’s of modern astronomers lived, I would ask them a variety of questions. Each of these questions, however, would be shaped to fit the era. For Galileo, I would ask him how did you react when you first observed the moon’s of Jupiter? What was your initial reaction? For Newton, I would ask him did an apple actually fall toward your feet, which shaped your curiosity to tackled gravity. For Albert Einstein, I would ask him he he could stop the building of atomic weapons during WWII, would he do it. And, finally, I would ask Carl Sagan … do you believe in God, seriously.

To boldly go where no man has gone before

Many associate survival of our species with humanity becoming a interplanetary civilization. It’s important to prepare ourselves for an event that might one day force us to leave our home planet. In more distant future we might have to leave our solar system. Will we ever become an intergalactic civilization like we already are in science-fiction? What’s the hardest obstacle to overcome?

Fraser Cain (publisher at, co-host of Astronomy Cast)


The hardest obstacle to overcome is the weightless environment of space itself. Humans evolved in Earth’s gravity, and without it, our bones soften, our muscles atrophy, and our bodies suffer. Until we can develop some kind of artificial gravity environment, like a rotating space station, space travel will be lethal for any length of time. We need to first learn to just live and survive in space before we have any hope of reaching out to another star system.

Andrew Rader (SpaceX engineer, MIT PhD, author)


If we survive for the next 100 years, I think we will become an interstellar civilization (although maybe not for several hundred years – the first step is to expand into our solar system first). The greatest challenges are in rough order of difficulty starting with the most challenging: I) Surviving long enough to reach the stars (avoiding disaster on our planet, whether created by humans or something external); II) The will to expand beyond Earth (will we even choose to do so, or will we for example, transcend into AI); III) The vast distances involved and the technological challenges involved. These include the velocity you need to travel and/or time it would take to get to another star, and the energy you would need to be able to produce for an exceedingly long time at a great distance from any light or heat from the Sun (even our best nuclear technology can’t currently do this). It’s a problem of distance, time, and energy. Here’s a links to my videos about it.


Human colonization:

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)


Emigrating beyond Earth is not a difficult task from a technological perspective. The current challenges are more centered on budgets rather than technology or human will. The most difficult challenge of interplanetary travel, in my opinion, is the challenge of humanity. Humans, today, are in the brink of destroying ourselves and our planet as well. The human population is increasing at an exponential pace while Earthly resources are diminishing at equal speed. Humans, eventually, will nonetheless have to travel beyond earth to survive as a species. We must, however, overcome the most difficult obstacle we conveniently ignore: the will to get along with other humans.

Pamela Gay (assistant research professor at Southern Illinois University, writer, co-host of Astronomy Cast)


Our science fiction stories show humanity escaping out to the stars, but our more terrestrial reality seems determined to keep us grounded. Two major problems currently face us. The first, quite simply, is resources. Human space exploration is a rich nation’s possibility, and as our global economy flattens, it is becoming harder to imagine any government-driven effort to colonize other worlds and other solar systems. At the same time, it’s impossible to predict what commercial space will make possible, and the extreme wealth of an elite few may be able to fill in gaps left by governments. While money is a current problem that has the potential to go away, the second problem is more likely to stay. That problem is human frailty. We are a race that can die from environmental extremes and disease. We periodically wage war, and we release toxins into our environment through our accidents and ignorance. The real question is, will we stay alive long enough to overcome money?

Ciro Villa (technologist, application developer, STEM communicator)


Be it for natural or man-made causes, there are a variety of possible future scenarios that we earthlings could face that could bring about the end of humanity or even life in its entirety here on Earth. This is why it is important to give serious consideration to plans for us to become a space faring civilization. Although we have a long way to go to arrive at the necessary level of technology and for us to be able to overcome a number of practical obstacles to make this feasible, it is important to start working toward this goal, this way at least our future generations can hope for the continuation of our species by embarking on “space lifeboats” toward new galactic shores. This is not going to be easy and it is going to take time and effort. We are now just making our first “baby steps” toward understanding how the human body reacts to hostile space environments and the lack of gravity and questions about our ability to withstand space environments are just now attempted to be answered with the hard work of our astronauts on the International Space Station. Probably one of the hardest obstacle to overcome is going to be having the ability to take down the barrier of skepticism of large portions of the public as a whole and raise realistic and not alarmist awareness that we live on a very fragile planet and that it is important to build contingency plans to leave it if we want the continuation of our species. Of course we hope that we will be able to achieve this goal before it will be too late.

Paul Carr (Space Systems engineer at NASA, podcaster, blogger, investigator)


I tend to be skeptical of top-down views of the human future, and the more our species is spread out into the solar system, the more it will diverge, with separate populations each pursuing their own interests. From, this is an optimistic view. The kings and battles view of history has always been something of a delusion, and I think in the future it will become clear, with hopefully no kings and many fewer battles. So, I think the simple-minded notion of a colossal public works project sending great arks full of people in uniform to seed humanity among other worlds is not only unlikely, it is undesirable and likely to fail. Someone with the power to make that happen has too much power. However, I do believe that as mastery of space travel, energy and information compounds, our wealth will grow to the point that the project of embarking with one’s friends and families to the stars is a choice many will have. How this will be accomplished I don’t know, and neither does anyone else, just as the hunter gatherers just before the neolithic revolution could not possibly see what their world was about to become. It is only an approximate result, but Daniel Cartin estimated that the range needed from a starship in order to establish a network of colonies in the local solar neighborhood was about 10 light years. That’s a long distance from the human perspective, but is a cosmic stone’s throw, and when humans can live for hundreds of years and casually command petawatts of power, it will not be a daunting sea to cross. By then, we may not even need to send biological bodies – just beam our minds ahead at the speed of light after the ship arrives at a suitable destination. It would of course, take millions of years to colonize even part of the galaxy, and such a diaspora could easily lose steam after a while. Still there is the chance it will continue until we either collide the current residents or fill up the available resources. Of course, by “we” I mean descendants of humans, but they will be fragmented into at least as many many societies as solar systems they occupy. There will be no emperor. How we go from there to an intergalactic society I have no idea. Crossing ten, or even a hundred light years is nothing compared to crossing millions of light years. Each of is free to imagine their own scenario, but I have no idea how it could happen.

We’re here!

We find new exoplanets every day, we found more than 3000. We’re very close to finding a planet very similiar to Earth that harbors life. What do you think about possibility of some other civilization discovering our planet and thinking “Wow, this planet may harbor life, it’s “OurPlanet”‘s size and in it’s star habitable zone?” How would our planet look like to a life forms like us located light years away?

Andrew Rader (SpaceX engineer, MIT PhD, author)

The answer to the question depends on their detection technology. If they merely found an average G2V star with 8-10 planets around it with a couple (Earth and maybe Mars) in the habitable zone, they’d probably simply add it to their catalog. If they were able to measure the composition of Earth’s atmosphere, they might realize that life thrived here and wonder what kind of life. If they were able to monitor and track our atmospheric composition over time, they might realize that an advanced civilization existed, but also one causing precarious changes in atmospheric concentrations of gasses like C02. This might raise the question of how wise our civilization really is, and how long it might survive.

Fraser Cain (publisher at, co-host of Astronomy Cast)

Any alien civilization that turned a powerful telescope on Earth over the last 500 million years or so would have known there’s life here by the composition of our atmosphere. And if they were sophisticated enough, they’d know what stage of the industrial evolution we’re in because of the pollution in our atmosphere. The fact that there’s life on Earth is no secret to advanced civilizations. And this is the technique that we’re about to use to find aliens around us with the next generation telescopes like James Webb.

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)

There are potentially billions of planets in our Milky Way alone. Some of these planets could harbor intelligent life capable conducting a survey of planets as well. However, we do no have any information to suggest that an intelligent species elsewhere in the Universe can understand astronomy, or for that matter planetary science, like we do. Humans, for example, have a predisposed bias to look for planets similar to Earth because we concentrate on “comparative science”, meaning we search the cosmos for “Earth-like” planets. An intelligent species that has evolved in a planet completely different than earth, including an atmosphere not comparable with Earth, could perhaps discover Earth but categorize our planet as “non-inhabitable. It is a matter of perspective.

Nicole Guggliucci (“Noisy astronomer”, blogger, educator, post-doc)

I just finished up my “Life Beyond Earth” class for the semester, so this topic has been on my mind a bit. I imagine that a civilization light years away would be interested in the presence of oxygen in our atmosphere, which typically only exists in stable form when being put out by photosynthetic life forms. A nearby civilization would probably be able to pick up our radio transmissions, but that’s IF they had sensitive enough receivers and IF they were looking in the right place. But that’s only a small bubble around us, less than 100 light years or so. I think the oxygen in our atmosphere would give away signs of life far before any of our human-created signals reached another civilization. We’ll be doing the same, by the way, as we analyze exoplanet atmospheres with the present and next generation of telescopes.

Ciro Villa (technologist, application developer, STEM communicator)

It’s an exciting and somewhat scary thought at once to think of the possibility of an extraterrestrial civilization becoming aware of our presence in the Universe with a whole series of other emotions mixed right in between.  We as humans are at the dawn of a new, exciting era of exoplanetary science and discoveries brought about by the extraordinary and accelerating advancements in our technologies.  We can see further and deeper in the Universe and our space “eyes” are getting more and more accurate.  Of course an extraterrestrial civilization finding our planet (exoplanet to them) could be more or less advanced than we are, so depending on their level of technological sophistication, could just be wondering about us as we do today or have the capability of being able to do more in order to find out if indeed there’s life on Earth or learn of our presence.  They might have the technology to easily and quickly analyze Earth or, like us they might be left wondering.  There are those that speculate that indeed there might also be a species that already know of our presence; we don’t know.  That’s when wide range of possibilities might present themselves.  We don’t know how similar this hypothetical species really is to us, neither do we know their history, the history of their evolution, their feelings, emotions, desires.  So, the number of variable and possibilities are pretty numerous and complex and the room for speculation is vast.

Galileo Galilei

On February, 15th we celebrated 452nd anniversary of Galileo Galilei’s birthday. Is it fair to say that he’s the person that influenced modern astronomy the most? How much more would he accomplish if he wasn’t seen as a heretic by the Church?

Fraser Cain (publisher at, co-host of Astronomy Cast)

Galileo was one of the very first people to see the wonders of the night sky though a telescope, and identified many of the things we take for granted now in a small telescope: the moons of Jupiter, the rings of Saturn, craters on the Moon, phases of Venus and the stars in the Milky Way. Right place, right time, right direction to point the telescope. I don’t know if it would have been possible for Galileo to not have ended up in trouble with the church. Even though he had many opportunities to keep his mouth shut and follow the party line, he kept finding new ways to enrage the church. I think he saw it as a badge of honor.

Andrew Rader (SpaceX engineer, MIT PhD, author)

That’s a tough question to answer, but certainly Galileo’s contribution to astronomy was enormous. He provided evidence to support the Sun-centered solar system by demonstrating that not everything revolves around Earth – if the four large moons of Jupiter revolve around that planet, clearly there is no hard and fast Earth-centered (or Sun-centered) rule. In addition to other scientific contributions (especially going a long way towards Newton’s law of Universal Gravitation), Galileo mapped the features of the Moon and sketched the phases of the Moon and Venus. This demonstrated that these were not perfect celestial spheres but worlds in their own right, complete with detailed features. This was probably the biggest step in going from a concept of Earth as the entire Universe to a system of many worlds – which would later be expanded into many Suns and then ultimately many galaxies. It would be hard to argue that Galileo’s accomplishments wouldn’t at least give him a strong contention for most influential astronomer ever.

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)

I would argue that Galileo Galilei was one of many great scientists, whom collectively, shaped the scientific revolution. Through the use of a refracting telescope, Galileo was able to finally put the geocentric model to rest. His observations of the moon’s of Jupiter and the phases of Venus led to direct evidence for the heliocentric model. Thereafter, using his work, others such as Kepler, Newton, and as recent as Einstein, collectivley shaped modern astronomy. One can say, therefore, that Galileo started it all.

James Webb Space Telescope

If everything goes as planned, James Webb Space Telescope will go in space and become operational in the end of 2018. It’s sometimes regarded as a successor to Hubble Space Telescope. If you could decide, where would you point it’s “eye” for a first look?
Nicole Gugliucci (“Noisy astronomer”, blogger, educator, post-doc)

I’d point it at a protoplanetary disk to see what exoplanets look like in formation! I was blown away when astronomers using ALMA (Atacama Large Millimeter/Submillimeter Array) got this image of one (, so I can’t wait to see what JWST reveals in the infrared for systems like this.

Nancy Atkinson (Senior Editor for Universe Today, Host of the NASA Lunar Science Institute podcast & a NASA/JPL Solar System Ambassador)

I’m looking forward to seeing how far in space and time the Webb can look.  Will it see the very first star formation in the Universe? Will it provide a glimpse at what the earliest galaxies looked like? Will we be able to observe the formation of the first planetary systems? Will we see back even farther to moments after the Big Bang? Will JWST give us more information about the Cosmic Dark Ages?  It is expected to be able to see objects between 10 to 100 times fainter than Hubble can see, so I’m hoping its ‘first light’ will test the limits of how far JWST can see.

Andrew Rader (SpaceX engineer, MIT PhD, author)

James Webb is perfect for looking at planetary formation and early galaxies from the birth of the Universe. It’s the kind of science where it’s hard to predict exactly what we’ll find, but that’s the point! Whatever it is, it’s sure to be fascinating and improve our understanding of the cosmos and our place in it.  I hope it helps shed more light (infrared of course!) on planet formation and how typical our solar system is likely to be.

Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)

Why not use the James Webb Telescope to search for alien planets? It is alleged by conspiracy claptrap that the Grays, an alleged species of extraterrestrials, are from Zeta Reticuli, which is a wide binary star system in the southern constellation of Reticulum. From the southern hemisphere the pair can be observed as a naked eye double star in very dark skies. Based upon parallax measurements, Zeta Reticuli is located at a distance of about 39 light-years from the Earth. Both stars are solar analogs and share comparable characteristics with the Sun. Although the kinematics of these stars imply that they belong to a population of older stars, the properties of their stellar chromospheres indicate they are only about 2 billion years old. On September 20, 1996, astronomers reported a provisional discovery of a hot Jupiter around Zeta-2, but the discovery was briefly retracted as the signal was caused by pulsations of the star. In 2002, moreover, Zeta-1 was scanned at an infrared wavelength of 25 μm, but no extrasolar planets were found.  The James Webb could possibly detect extrasolar planets, if any, around Zeta Reticuli and perhaps close the books on the Grays for good.

Fraser Cain (publisher at, co-host of Astronomy Cast)

James Webb should be able to look right back the edge of the observable Universe and see some of the earliest structures forming. It’ll be amazing to finally get a picture of what the Universe looked like so long ago, when everything was much closer together. How did those early galaxies form so quickly? When did the first supermassive black holes form? I can’t wait to find out the answers.