When NASA selected the first civilian to travel into space, it wasn't a rock star or a journalist--it was a teacher. Today is the 25th anniversary of the Space Shuttle Challenger disaster, when seven explorers lost their lives doing something that they believed in. On January 28, 1986, I was a sixth-grade student, and I'll never forget the immediate silence that fell over my middle school cafeteria when the principal announced the event over the PA system during lunch. We all filed back to our classrooms to watch the television coverage for the rest of the school day.

That event solidified in me what had been a growing desire that began when I was four years old and watched Carl Sagan champion the need to explore the stars in his "Cosmos" series. Ten years after Challenger, I graduated from college with a degree in physics and astronomy and took my first job teaching high school in the Bronx. I learned more science that first year of teaching, and found more inspiration trying to help my students explore their own questions, than I had ever considered possible.

In the wake of September 11, 2001, NASA reached out to New York City students and offered 52 student experiment modules that would travel on a space shuttle mission. I found myself working with a group of NYC middle school students to help them develop their own collection of experiments that we would pack and send off to be launched into space. The space shuttle became our classroom. As we watched the space shuttle carry our experiments into orbit on January 16, 2003, I finally felt like I was playing a small role in space exploration. This was mission STS-107, and it tragically would be the last flight of the Space Shuttle Columbia, which disintegrated on reentry into the atmosphere, killing all seven crew members.

As I faced the loss of another space shuttle, I found myself on the other side of sixth grade. Now responsible for helping a large group of sixth-graders try to understand the enormity of what had happened, I reconnected with my Challenger experience. I found new inspiration in the words of Christa McAuliffe, a teacher from Concord, New Hampshire who was one of the seven crew members lost on Challenger--"I touch the future. I teach."

Why are these engineers dropping their new Mars rover from the ceiling? In my last post on Vandi Verma and the state of the "old" Mars rovers, Spirit and Opportunity, I mentioned some of the upgrades that are being installed on the next-generation rover, Curiosity. But I didn't mention one of Curiosity's wildest new features: its landing system. Check it out.

Spirit and Opportunity bounced onto the Martian surface encased in cushioning airbags. Curiosity, however, will be lowered wheels-down from a tether hooked to the upper stage of its spacecraft. The NASA folks call this system a sky crane, which makes it sound like something you might see on your average construction site--if that construction site was, you know, hurtling through an alien sky while urgently firing rockets to slow itself down. But if everything goes smoothly, right before the rover touches down, it will be falling at a gentle rate of about 0.75 meters per second, just like an enormous, 2,000 pound leaf fluttering softly to the surface. (Well, maybe not exactly like that.)

Before trying such a scheme on Mars, engineers at the Jet Propulsion Laboratory have to test it here on Earth--and, of course, post the test to YouTube. Based on the engineers' reactions, I guess it worked. What will this all look like when it happen on Mars? That's on YouTube, too.

Drive safely!

As soon as I turned 16 and got my driver's license, my parents greeted my every move with these two magical words. I couldn't set my hand on the doorknob without hearing them. Heading to school? "Drive safely!" Going out for coffee? "Drive safely!" Tossing the empty peanut butter jar into the recycling bin in the garage? "Drive safely!" It's entirely possible that my parents wired the door to chime "Drive safely!" every time I turned the handle, like some kind of teenager-sensing reverse-doorbell.

Vandi Verma would get along really well with my parents. As a Mars rover driver at NASA's Jet Propulsion Laboratory, Verma helps plan the Opportunity rover's route across the Martian surface. Opportunity is currently exploring a 90-meter-wide crater called Santa Maria, and on January 25, Opportunity will celebrate seven (Earth) years on Mars--pretty good for a mission that was only supposed to last three months. One of the big factors in Opportunity's long-term survival: The safe driving of Verma and her colleagues.

The view from here: Opportunity's navigation camera looks out at the edge of the Santa Maria crater on January 10, 2001. Image credit: NASA/JPL-Caltech

On NOVA scienceNOW's Can We Make It To Mars?, Verma explains how rover drivers manage to get the rovers to interesting places--boulder fields, steep-walled craters--while keeping them safe. As Verma told our producers (and as 16-year-old-me fruitlessly told my parents), "Safety's the biggest concern, but you can't be so risk averse that you don't go anywhere."

Last week, I checked in with Verma to find out where the rovers have been roving. The bad news: Spirit, Opportunity's near-twin, is stuck in the soft sand of a Martian plateau, and engineers on Earth haven't been able to communicate with it since March 2010. Why isn't Spirit answering our calls? Its dusty solar panels may not be gathering enough energy to keep it awake; if that's the case, engineers are hopeful that when the brightest days of the Martian year come around this March, Spirit might power back up. Power loss or cold-temperature damage may also have caused Spirit to "lose track of time," meaning that the rover won't know when to expect its scheduled calls from Earth.

Last summer, when Spirit was stuck in the Martian sand but still phoning home regularly, Verma helped build an Earthbound testbed in which engineers could test out rescue scenarios using a robotic Spirit body-double. (Check out this JPL video documenting how engineers plotted Spirit's escape.) With Martian winter on its way, the rover team was racing against time. They finally found an escape strategy that worked--on Earth, at least--but not soon enough. Before they could free Spirit, winter set in and the solar-powered rover's energy reserves dipped too low for it to continue to talk to Earth. Now that spring has sprung on Mars, the team has renewed attempts to talk to the rover.

I am standing in the middle of a TV studio at IBM's research center in Yorktown Heights, New York. This is not the kind of bare-bones TV studio where they have a velvet backdrop in a small multi-purpose room so the executives can come down from their offices and talk about the latest quarterly forecasts to the business channel. No, this is an elaborate game show set, with banks of lights, dozens of cameras and a small army of hair and makeup folks. Craziest of all: They are preparing for a science experiment, one that has the potential to revolutionize how we think about computers.

Here, an IBM computer named Watson is going to play on the quiz show Jeopardy!. For the team of IBM scientists watching, it's the culmination of four years of work, and a very public test of their efforts. The matches they tape today will air February 14, 15, and 16, with Alex Trebek as host. Watson's competition will be Ken Jennings and Brad Rutter, the world's two best players.

Watson's competition-ready poker face. Image courtesy of IBM.

The biggest challenge for Watson will be to understand human language, with all its subtleties and ambiguities. It is something that we take for granted but for computers it is devilishly tricky. For all the advances in computer science, there is no computer today that can astutely answer a broad range of questions posed in human language.

Why? Well consider the following example: "I shot an elephant in my pajamas." Now you probably imagine that the hunter walked out of his tent, dressed in night clothes, and pulled the trigger. But how do you know?

Maybe it was the elephant that was wearing pajamas. Maybe you were shooting with a camera. How do you teach a computer to understand?

And Jeopardy! questions are even trickier. Try answering this one. The category is Rhyme Time, and the clue is "a politician's rant and a froth desert." Stumped?

The answer is "meringue harangue." Amazingly, Watson was able to correctly answer this one.

Through a combination of incredible computing speed and very sophisticated programming, the IBM team has gotten Watson to the stage where it can now understand Jeopardy! questions and answer them in less than three seconds. At the moment it is playing at the level of a very good player. The question now is: Will it be able to beat the best?

Publicist's note: Michael Bicks is the producer of NOVA's Smartest Machine on Earth, premiering Wednesday, February 9 at 10pm on most PBS stations. Please check your local listings to confirm when it will air near you. Oh, and don't worry: We'll give you the inside science scoop, but we won't give away the ending. You'll have to tune in to Jeopardy! to see who--or what--wins the game.

Not very. In the movie, geneticists extract dinosaur blood from mosquitoes preserved in fossilized amber, but it is extremely unlikely that DNA would be able to survive for 65 million years, even in the best conditions. If the scientists somehow found a large enough workable sample, they still wouldn't have a complete genome, as it deteriorates over time. They would also need a surrogate mom from a closely related species to provide an egg and carry the embryo. These are just a few of the major advancements which would be necessary to make dinosaur cloning a reality.

This video, from the Howard Hughes Medical Institute, shows the first step in the reproductive cloning process, known as somatic cell nuclear transfer. Cloning existing animals, especially mammals, is challenging enough for scientists. Clones often die soon after birth if they survive at all. And there are always concerns over maintaining a diverse gene pool.

Yet some scientists have already attempted to replicate animals in danger of extinction or which recently went extinct, all of them far less daunting than dinosaurs. Advanced Cell Technology cloned a gaur, a threatened species of Asian ox, in January of 2001. This was the first attempt to clone an endangered species. The gaur was carried to term in a cow, but died of a common infection two days after its birth. In late 2001, scientists in Italy reported the successful cloning of a baby mouflon, an endangered wild sheep, which lived out its adult life at a wildlife center in Sardinia. In 2003, scientists cloned a banteg, an endangered species of wild cattle.

Not far from the Cannon Beach City Hall shown in "Deadliest Earthquakes," on quiet Beaver Street just steps from Ecola Creek, is Cannon Beach Elementary, a grade school with 110 students. I often think about the children who attend that school as I work to reduce tsunami hazards on the Pacific Northwest coast.

Cannon Beach Elementary, like three other schools in the Seaside school district, lies smack in the tsunami inundation zone. No one recognized the danger when the school was built. If the Cascadia Fault ruptures during school hours, nine teachers will have to get those 110 children to duck under their desks, cover their heads, and hold on to table legs until the shaking stops. Hopefully the school itself will stand up through the shaking; one of its two wood-framed buildings is highly collapse-prone.

After the shaking, frightened children and stressed teachers may not be able to reach the nearest high ground for safety, because the bridge they would normally use to cross the nearby creek is considered likely to collapse. Instead, the teachers may have to lead their students across Ecola Creek on foot or else walk a half-mile through the shaken town to the Tsunami Evacuation Building (if it is built) or even farther to a designated evacuation site in the hills. If everything goes just right, teachers and children will reach safety just minutes before the tsunami strikes.

I think of those students (and their families) to remind myself what it means to live along the Cascadia fault. Cannon Beach Elementary is typical of many coastal schools in the tsunami zone, built long before scientists had deciphered the risk from Cascadia earthquakes.

In "Back to the Future II," director Robert Zemeckis envisioned a future--now a mere five years away--in which every home comes equipped with a Mr. Fusion Home Energy Reactor. Mr. Fusion can power just about anything, even the flux capacitor of our favorite time-traveling DeLorean, using everything from banana peels to beer cans. Zemeckis may have overestimated the ubiquity of mini fusion reactors--not to mention flying cars--but we have made some progress in transforming waste into power since 1985. Manure and some forms of garbage have been used to produce methane gas, hydrogen gas, and to directly generate electricity. But one of the most surprising of these renewable biomass energy sources is urine.

Urine may not be a particularly powerful energy source, but its abundance and inherent renewability could make up for what it lacks in energy density. Using a technique called urea electrolysis, says Dr. Geraldine Botte of the Center for Electrochemical Engineering Research (CEER) at Ohio University, farms and office buildings could become self-sustaining pee powerhouses.

Urea is one of the main components of urine. If left untreated, urea will react with water and turn into ammonia and other pollutants. To turn this would-be pollutant into power, Botte and her colleagues extract urea from the wastewater and pass an electrical current through it, releasing hydrogen gas. The hydrogen can then be used to power generators or create fuels, and the urea-free wastewater can safely be used for irrigation.

Traditionally, hydrogen has been produced using water electrolysis, but that process is far more expensive and inefficient. Dr. Botte says one cow could provide enough hydrogen to heat water for 19 homes and an electrolyzer could easily fulfill all the electricity needs of a small farm. Some researchers speculate that an office building could be fully powered by the liquid waste of its office workers. And Botte's lab has even used hydrogen made from pee to create a pee-powered car.

In this video Purusha Bonnin, a graduate student working with Dr. Botte, demonstrates how CEER's hydrogen-powered car would work using a small model. But what about the DeLorean? Dr. Botte, like most researchers, thinks that this technology is better suited to stationary purposes for electricity production or perhaps for powering the electrical systems of the car. It is not powerful enough to keep a car engine running efficiently. We are decades away from surmounting the technical and economic hurdles to widespread use of hydrogen cars--and they may never become widely available.

There are plenty of discoveries to be made in earthquake science. Predicting earthquakes and tsunamis, the Holy Grail of seismology, attracts top talent to that field. Stay tuned; breakthroughs are sure to come. Fortunately, designing and building safer structures to withstand the deadliest earthquakes is no mystery. Using what we know can save lives and protect property right now.

I was excited to be part of the team that developed the conceptual design for a Tsunami Evacuation Building that would replace the current City Hall in Cannon Beach, Oregon. That building will feature reinforced concrete columns with lots of open space to allow water to flow through, a deep robust foundation anchored extra-deep in the ground to handle scouring by waves, steel cables under tension to help the structure resist and recover from swaying, and wide stairs to a sturdy rooftop patio. These are methods common in the engineering of bridges, skyscrapers, and other structures designed to flex and move, but they are not commonly combined in structures close to sea level.

Architect Jay Raskin, former Mayor of Cannon Beach and co-leader of the TEB effort, says, "As we increasingly understand the risks of the Cascadia earthquake and tsunami, we must apply that knowledge to protect our residents and visitors. The new City Hall/TEB will provide a safe haven for those unable to reach high ground in time and will help the City lead relief and recovery efforts following the disaster."

In the movies, they go by many names: death ray, ray gun, laser beam, phaser, blaster and, of course, lightsaber. These weapons are science fiction icons. Remember Han Solo blasting Greedo the bounty hunter in "Star Wars"? The alien invaders annihilating the White House in "Independence Day"? Classic science fiction films like "War of the Worlds" feature equally fearsome aliens with death-ray-equipped UFOs. "Ghost Busters" taught us never to cross the streams of our super-cool, though equally fanciful, "proton packs."

In reality, they're collectively known as directed-energy weapons, and they channel lasers, heat, or particles into targeted beams. The military has made several attempts in recent years to create viable, field-ready directed-energy weapons, primarily for missile defense, but most of these projects have been abandoned. Starting in 2000, a joint U.S.-Israeli prototype called the Tactical High-Energy Laser (THEL) took down 25 Katyusha rockets during a demonstration program and a mobile version destroyed multiple mortar rounds. The project was discontinued in 2005.

The U.S. Air Force's Airborne Laser Test Bed successfully took out a ballistic test missile in February of 2010, but funding for the device was later suspended, as the test revealed that it was difficult to maintain the laser's precise alignment. The device also had a tendency to overheat and malfunction during adverse weather conditions.

While they may come up short in missile defense, directed-energy weapons like the ZEUS-HLONS system, commonly known as ZEUS, have been successfully deployed on Humvees on the battlefield to burn out land mines and unexploded munitions, preventing a larger explosion. The ZEUS heats up and defuses explosives up to 300 meters away using a laser beam.

As for targeting individual soldiers, it looks like we'll be setting our phasers to stun--at least for now--with devices that incapacitate people rather than eliminate them, like the military's Active Denial System (ADS). The ADS is essentially a ray gun, but it doesn't cause instant death or, like the "District 9" version, turn its targets into Jell-O. Instead, it uses a very precise frequency of microwaves to agitate fat molecules in the top layer of the skin. The skin heats up, causing a sensation which CBS News correspondent David Martin likened to scalding water.

It's also been described as similar to the blast of heat you feel upon opening a very hot oven. Most people find this unpleasant enough to send them running out of the beam's path within a few seconds--and once they do, the pain instantly subsides. These devices won't actually fit in your pocket, and you can't see or hear the beam. The beam projects from a large reflector plate usually mounted on top of a vehicle and controlled by an operator with a joystick. ADS could be used to repel a large group of people at a range of over 700 meters. The United States Marines and police are working on portable versions.

"Wait a minute, Doc. Ah... Are you telling me that you built a time machine... out of a DeLorean?" says an awestruck Marty McFly in the iconic film, "Back to the Future." While we probably won't be visiting our hormone-charged teenage parents in souped-up DeLoreans, there are a few natural phenomena which could transport us into the future and, maybe, even into the past.

Hollywood has long fantasized about time travel and its seemingly endless possibilities, from thrillers like "The Time Machine" and "12 Monkeys" to over-the-top comedies like "Bill and Ted's Excellent Adventure" and "Hot Tub Time Machine."

But how can time travel reach beyond the realm of science fiction? Technically, it already has, as astronauts travel a few nanoseconds into the future every time they travel into space. In fact, just by driving in your car, riding an airplane, or climbing a ladder, you change the rate at which time flows. Einstein's Theory of Relativity established that both motion and gravity could slow down the progression of time. The closer an object--let's say, a space shuttle--travels to the speed of light, the slower it travels through time and the slower the pilot ages.

There have been many fictional ideas for time travel devices--phone booths and hot tubs come to mind--but in reality time travel does not require a machine at all, except perhaps a space ship. According to Dr. Max Tegmark, professor of physics at MIT, the most plausible way to travel into the future is by orbiting a black hole. Flying just outside of the black hole's event horizon--the point at which nothing can escape its gravitational pull--would allow you to travel close to the speed of light. But Tegmark points out that we would need to find a suitable black hole close by, which is no easy feat. Theoretically, black holes from other galaxies consumed by our own could be orbiting nearby and these would be our best bet for traveling into the distant future.

So far, we've only been talking about going forward in time. Could a black hole also give us access to the past? In the newest "Star Trek" movie, Spock's vessel and the Romulan ship get caught in the event horizon of an artificial black hole and are transported 129 years into the past. In reality, Spock would be torn apart by the intense gravitational pull before he could reach the center of the black hole. However, some theorists postulate that a rotating black hole called a Kerr black hole could be traversable. So, Spock could theoretically travel to the past by exiting through a "reverse black hole" called a white hole on the other side, where he'd find himself at a different point in space and, perhaps, in time.

A hypothetical spacecraft warps space-time. Image courtesy of NASA/Les Bossinas.

Another possibility: Just build a wormhole. Wormholes are shortcuts in space-time that connect two distant points, like a train tunnel cutting through a mountain. But scientists aren't sure how to create a wormhole--or how to keep one open.

In NOVA's Deadliest Earthquakes, thanks to digital special effects, I stand on a beautiful Oregon beach as a tsunami looms and surges toward me. Of course I would not survive that encounter, and I hope never to experience it!

But tens of thousands of people (on a good summer day) could be on Pacific Northwest beaches at the moment the Cascadia Fault ruptures, unleashing a tsunami that could sweep ashore in as few as 15-20 minutes. If you are one of them, what should you do?

First, you should wait for the shaking to stop. An earthquake could last for as little as a few seconds to as long as several minutes. No matter the duration or apparent strength of the shaking, if you are on a beach or anywhere within the tsunami inundation zone you should get yourself and your loved ones to safe ground by moving inland and uphill.

So as soon as the shaking stops, get off the beach and move to safe ground as quickly and as directly as possible following any available designated evacuation routes. Bluffs and dunes don't count, and neither do beachside houses or motels. The only safe ground is outside the tsunami zone, until the risk has passed.

It's possible for tsunamis generated far from our shores to strike the Pacific Northwest. This risk is likely to be announced hours before impact by sirens and other warning systems. But any time water recedes from the shore in an unusual manner, even without earthquake shaking, leave the beach and seek safe ground.

More Pacific Northwest coast towns should consider Tsunami Evacuation Buildings like the one envisioned for Cannon Beach, Oregon. Such buildings could offer a safe refuge for many coastal residents and visitors. But until that day, no visitor to our spectacular coast should spend a day by the waves without taking note of high ground and the shortest way to get there.

Publicist's note: Yumei Wang is featured in NOVA's Deadliest Earthquakes, premiering Tuesday, January 11th at 8 PM ET/PT on most PBS stations. Please check your local listings.

In the blockbuster action flicks "Iron Man" and "Iron Man II," Tony Stark doesn't need a vat of toxic waste or the bite of a mutated spider to obtain his superpowers. He uses the powers of science and engineering to create a robotic exoskeleton, which gives him superhuman strength, increased endurance, and the ability to fly. Many other science fiction films have featured similar devices--who could forget Ripley's machine-clad fight-to-the-death with the vicious queen in "Aliens"? In "Avatar" and "The Matrix Revolutions" powered exoskeletons are used in combat and for moving cargo.

Surprisingly, these on-screen machines are more science than fiction with one key exception: the power source. Tony Stark uses the fictional "arc reactor"--a fusion reactor--to generate the vast amount of energy needed to power his suit's jet boots, plasma weapons, and on-board computer. But if you could condense a nuclear power plant into a softball-sized reactor, would you really want to put that in your chest? Tony Stark did and managed to not be cooked alive, but in the real world, the heat output of such a device would be problematic to say the least.

In reality, generating that much power for exoskeletons would be overkill. Companies like Raytheon and Lockheed Martin, which are developing real-life exoskeletons for the military, are wrestling with the power-supply problem, but they seem more concerned with reducing power consumption than with finding new energy sources. Running these machines for sustained periods of time in the field is one of the last major hurdles Raytheon's XOS 2, Lockheed Martin's HULC and similar models face before they can be distributed for military and industrial use.

In September, Raytheon revealed its XOS 2 to the public in a demonstration cross-promoting the "Iron Man 2" DVD and Blu-ray release.

In this video, Rex Jameson, Raytheon's test engineer, demonstrates the maneuverability of the suit by lifting weights, running, and punching a speed bag. He also kicked a soccer ball, climbed stairs, and walked on his heels while wearing the suit.

It's been referred to as the real Iron Man, as it's the first full-body exoskeleton. The XOS 2 makes lifting 200 lbs feel like 12 lbs and it allows its wearer to punch through three inches of wood with ease. An internal combustion engine powers the exoskeleton, but the suit must also be plugged into an electrical power source to function. Raytheon is currently developing a battery option, which would be worn in a backpack. Raytheon expects to have a tethered (plugged in) version employed in major military operations in about five years and an untethered version available three to five years after that.

When will science catch up with Hollywood? In our new Cinema Science series, running all this week, NOVA intern Samantha Johnson examines the real science of classic sci-fi tropes like time travel, super-suits, ray guns, and more. First up: Saving Earth from killer asteroids.

"It happened before. It will happen again. It's just a question of when," says an ominous voice in the opening sequence of the film "Armageddon," as we watch a deadly asteroid strike the earth, decimating the dinosaurs. But before you build an underground bunker and stock up on a lifetime supply of SpaghettiOs, let's take a minute to find out what films like "Armageddon" and "Deep Impact" get right-and wrong-about how to save the world from killer asteroids and comets.

Image courtesy of NASA/Don Davis. Artist's concept of a catastrophic asteroid impact with the early Earth.

Though they seem to slam into movie and TV screens every year, asteroids capable of exterminating entire species are exceedingly rare. There are many smaller Near-Earth Objects (NEOs), which, on average, hit the earth every 200 years and could potentially level a city. Earth's most recent brush with destruction came in 1908, when a 30- to 50-meter-wide object exploded over Siberia, destroying more than 800 square kilometers of forest, but, apparently, killing no one.

So, what can we do to save humanity from the Big One? Hollywood often opts for big explosions with the latest Aerosmith power ballad blaring in the background. The heroes blow up the killer rock at the last possible second and the camera pans across cheering crowds from New York to Mumbai watching the mass detonation. In "Deep Impact," astronauts destroy an incoming comet with nuclear weapons minutes before impact.

In "Armageddon," a crew of rugged oil drillers lands on the asteroid, digs 800 feet into the surface, and deploys nuclear weapons four hours before impact. This would supposedly break the asteroid into two pieces, which would somehow clear the Earth. While this method does give the filmmaker an excuse to put Bruce Willis in space, it doesn't bode well for humanity.

But in reality, most scientists agree that, even in the most desperate circumstances, blowing up a threatening asteroid would be a bad idea. If we try to blast the big scary rock, we'll most likely end up with many little scary rocks. They would rock our world with the same amount of kinetic energy, resulting in an equally devastating event.