It was an incredible year for space exploration.

In 2015, we saw the world's first orbital rocket touch back down on the ground. We saw the beloved dwarf planet Pluto in exquisite detail. And an astronaut broke the record for the longest time spent in space. 

We learned a lot about our own solar system this year, too, as NASA outlined in a recent blog post. 

Here's a look at nine of the biggest discoveries we made in our celestial neighborhood in 2015.

We reached Pluto, and the world fell in love from 3 billion miles away. From mountains that rival the Rockies to frozen water on its surface, the tiny planet seems to have no shortage of surprises.

And for the first time, we landed a probe on a rubber ducky-shaped comet called 67P/Churyumov-Gerasimenko. Scientists discovered a shocking amount of oxygen, a surface covered in sinkholes, and more.

A spacecraft sampled a geyser spouting from a tiny moon called Enceladus and confirmed that it holds a vast subsurface ocean. Like Earth's oceans, it appears to have hydrothermal vents that may support life.

HILO, Hawaii — Atop the giant Mauna Loa volcano, the landscape looks eerily similar to the surface of Mars.

Nothing green grows, and all you can see for miles are chunks of red rock and endless fields of lava tubes. It's easy to imagine you're on another world.

But it's even easier when you spot the 1,200-square-foot dome that sits near the summit, which looks exactly like the kind of space habitat that astronauts would use as a base camp on the red planet.

Researchers created this dome to lock volunteers inside and study the least-understood challenge that people will face on a real Mars mission, whether or not SpaceX or NASA sends them: Total isolation.

Volunteers are cooped up together for the better part of a year. Back in civilization, scientists monitor and measure their performance and see how well they work together as a team.

This ongoing series of studies is called the Hawaii Space Exploration Analog and Simulation (HI-SEAS), and the researchers conducting this research chose Martha Lenio as the commander for the last simulated mission. She and five other crew members finished an eight-month stay inside the dome in 2015.

During that time, their only contact with the outside world was an email account that linked them to the experiment's mission control. They could only leave the dome wearing a full spacesuit.

Tech Insider recently traveled to Mauna Loa to meet Lenio and spend a night on "Mars," and we chatted with her about her eight-month stay.

We sat outside on the lava tubes to chat — Lenio had already spent enough time inside.

TECH INSIDER: Why did you sign up for this?

MARTHA LENIO: I've been interested in space since high school, and I always wanted to be an astronaut. So I've kind of always been working towards that. I did a lot of aerospace stuff in undergrad and mechanical engineering.

But the chances of becoming an astronaut are slim. So what's something I could do that still gets me on the path to being an astronaut?

I did a PhD in photovoltaics in Australia, and I worked in the solar industry for four years. Then a friend from undergrad told me about [HI-SEAS] and I thought maybe now is the time to get back into space and take a few chances again.

TI: How did they select you and other "astronauts"?

ML: You had to come up with a research proposal. If you made the first cut, they sent you an online aptitude and personality test did a Skype interview. Then they started selection for a four-month crew. I put down in my application that I was interested in something longer, so they said "We're not picking you for the first mission, but we'll keep you in mind."

Then I didn't hear back for a while — it took almost a year. At the end of the four-month mission, they started contacting people for the eight-month. They picked nine final candidates — I was one — and we did this six-day backpacking trip in the Rocky Mountains.

That's what NASA does for their astronaut candidates as well, so there were astronaut candidates there at the same time. It was really cool. I've done a lot of camping and backpacking, so for me it was a really easy trip. We'd only do like 3 or 4 miles a day so we'd finish early and then we would do these lectures or courses on leadership, personality, and how to deal with conflict.

TI: What went through your mind when you made the cut?

ML: Well, that nervousness started on the backpacking trip. I was thinking "I don't know if I want to do this." What crazy people would want to get locked up in a dome for eight months? I know I'm normal, but these other people must be crazy!"

I think everyone else had been thinking that too. But then we all met each other and we were like, "Oh you guys are also normal, I could totally live with you for eight months."

Then coming up here and getting locked in — it was weird. It was like "OK we're going to Mars," and when the doors closed we all cheered and did a dance.

It's not the fastest or the sleekest, but NASA's Space Exploration Vehicle (SEV) is definitely the coolest car on the planet — and hopefully, before too long, something like it will be the coolest car on other worlds as well.

The SEV is one of NASA’s concepts for a new generation of flexible vehicles that can transport astronauts across near-earth asteroids and Mars. To see what this might be like, we got inside this 6,600-pound behemoth of a machine for a test run.

As you might expect, driving something that’s designed for traipsing across another planet is an out-of-this-world experience.

Join us on the journey:

We begin in the Mars Yard at NASA’s Johnson Kennedy Space Center in Texas, where the SEV currently lives.

It’s called the Mars Yard because NASA has decorated it with hills, small craters, and moderate-sized boulders to simulate some of the rugged terrain astronauts might experience on the Red Planet.

The SEV has a number of advanced features compared to the last manned space car, the lunar rover. For starters, it has an enclosed, pressurized cabin complete with sleeping and sanitary facilities, which can accommodate two astronauts for up to 14 consecutive days — that’s a lot of time to explore!

SpaceX pulled off the world's first orbital rocket landing just before the New Year, but there's one promise the company made in 2015 but didn't deliver.

One year ago, SpaceX CEO Elon Musk teased the plans for a monstrous rocket-and-spacecraft system that might fly 100 people to Mars at a time.

Called the Mars Colonial Transporter (MCT), Musk said he would release the preliminary designs by the end of 2015.

Now he says we'll have to wait for the designs to come out sometime in 2016.

However, Musk's silence hasn't stopped a dedicated community of SpaceX fans, including engineers, from speculating on how this potentially revolutionary space rig might look and function.

Getting 100 people and 100 tons to Mars

Details were sparse in January 2015, when Musk first teased the idea of the MCT in a Reddit Ask Me Anything (AMA) chat.

We know it'll be some kind of massive spaceship propelled by a massive rocket. And with 100 people on board and enough rocket fuel to get to Mars, the MCT is going to be big and it's going to be heavy.

"Goal is 100 metric tons of useful payload to the surface of Mars," Musk wrote.

One metric ton is roughly 2,205 pounds (or about the weight of an elephant). That means the rocket that powers the MCT will have to be able to carry at least 220,500 pounds — 100 elephant's worth of mass (or, if you prefer, about nine Hubble Space Telescopes). And that's not including the fuel required to leave Earth's grasp.

We know that's already possible, though. NASA's giant Saturn V rocket lifted about 260,000 pounds of payload back during the Apollo missions.

However, there's an important difference between the two rockets. The Saturn V moon rocket only had to get its payload 239,000 milesto the moon. The MCT has to get everything 140 million miles to Mars.

"This obviously requires a very big spaceship and booster system," Musk wrote.

Musk nicknamed the booster the "BFR," short for "Big F***ing Rocket," and it's rumored that SpaceX is working on a completely new type of methane-fueled engine to power it.

Rocket speculation

The delay in any concrete plans has inspired deep speculation on Reddit.

Self-described engineer John Gardi even crunched all of the numbers to make a conceptual sketch of the MCT, which he estimates is 200 feet tall and 50 feet wide, and what its various sections might look like.

The passengers would sit in a section near the top. The capsule is structured into several levels, a lander, and escape systems. Below that is a crew and cargo section.

Then, below the crewed section is the upper stage of the BFR itself (the first stage isn't shown). This part of the sketch depicts a fuel tank (for methane), an oxygen tank (to burn the fuel), and a mount for the engines (which aren't depicted):

"I put that out there on a whim, but did take a week to work out the rough design with a bit of help," Gardi told Tech Insider via Twitter. "My primary focus was on passenger safety and modularity, being able to repurpose the various components of MCT at Mars."

Gardi also sent us this rough image, which shows how all of the sections of the lander look when separated into pieces:

While Gardi and others imagine what MCT might look like, based on the few limited details and rumors out there, there are still no specifics on how Musk will safely land 100 metric tons and 100 passengers on Mars.

The biggest problem is Mars' thin atmosphere.

There's so little air on Mars — the planet has about 1% of Earth's atmopsheric pressure on the surface — that landing even half of a ton is a years-long engineering challenge. (Without air to slow down a spacecraft, rockets or some other technology has to get the job done.) Landing 200 times as much mass will be that much trickier of a feat.

So as much as we enjoy imagining SpaceX's next engineering marvel, we're really looking forward to seeing the official preliminary designs for the MCT. We can only hope Musk or others at SpaceX will unveil them later this year.

Join the conversation about this story »

NOW WATCH: SpaceX just released epic footage of its SuperDraco engines that can take a rocket from 0 to 100 mph in 1.2 seconds

After more than three years on the Martian surface, the car-sized Curiosity Mars rover is giving us a close-up glimpse of terrain unlike anything we've seen before: tall, ripple-ridden sand dunes like this one:

Satellites orbiting Mars have snapped photos of these sand dunes before, but never up close like this:

And NASA scientists are incredibly excited because it's the first time anyone has had the chance to study active sand dunes beyond Earth.

One of the first things they want to explore is the "grain size and morphology of different parts of the slipface," Lauren Edgar, a member of the Curiosity team and a USGS Astrogeology Science Center research geologist, wrote in a mission update.

The ripples on these dunes change over time due to Martian winds and mini avalanches. Notice in the picture below the breaks in the ripple pattern near the top:

These breaks happen after Martian winds deposit sand on the slope, where it gradually accumulates. Eventually, so much sand builds up that the sand underneath can't sustain the weight of the sand on top, and a mini avalanche occurs.

On Earth, this sort of thing usually happens on wind-protected slopes, leading NASA scientists to conclude the side of this dune, called Namib Dune, is also shielded from the wind.

For comparison, the wind-facing side of another nearby dune reveals a very different sand pattern:

Namib Dune is between 13 to 17 feet tall and is just one of many sand dunes located in the Bagnold Dunes field situated along the northwestern flank of the base of Mount Sharp, which forms Gale Crater's central peak.

Gale Crater is initially where Curiosity first touched down back in 2012. Here's a map of where Curiosity landed in the upper right, and where it has gone over the last 1196 sols, or Martian days:

And here's a better view of the environment, with Namib Dune on the right:

Mount Sharp is a 3.4-mile-high mountain that NASA's Curiosity team has been dreaming of exploring for a long time. They first snapped a photo of Mt. Sharp with Curiosity's Hazard-Avoidance camera in 2012 — that's Mt. Sharp in the distance:

Though NASA scientists haven't seen sand avalanches or ripple movement, yet, Edgar is hopeful:

"We’ll be in the same location for a little while, so hopefully we’ll have the chance to observe some sand movement!"

In the mean time, we can sit back and enjoy some amazing photos, like this breath-taking panoramic view of Curiosity's rover deck, Namib Dune in the middle, and Mount Sharp's peak in the background:

UP NEXT: I drove the 6,600-lb 'car' that NASA designed for astronauts on Mars, and I'll never see space exploration the same way again

DON'T MISS: Neil DeGrasse Tyson's best quotes may make you fall in love with science all over again

Join the conversation about this story »

NOW WATCH: NASA is revolutionizing our understanding of Mars — here's how

Using the Age of Exploration as a basis, Neil deGrasse Tyson takes a close look at what life on Earth could look like in another 500 years. Spoiler Alert: It's going to get crowded. But he's got some solutions if we take action today.

Produced by Rob Ludacer, Darren Weaver and Kamelia Angelova. Additional production by Kevin Reilly.

Follow TI: On Facebook

StarTalk Radio is a podcast and radio program hosted by astrophysicist Neil deGrasse Tyson, where comic co-hosts, guest celebrities, and scientists discuss astronomy, physics, and everything else about life in the universe. Follow StarTalk Radio on Twitter, and watch StarTalk Radio "Behind the Scenes" on YouTube.

Join the conversation about this story »

This is what the first human explorers might see when they step outside their spacecraft and take their first steps on Mars:

The Mars Curiosity rover took this image of the Namib dune in the Gale Crater on Mars. (Click here to download the high-resolution image.)

NASA did a color adjustment on the image to make the rocks and sand appear as they would on Earth in broad daylight.

The distorted-looking equipment is actually the rover itself, and the Namib dune appears as a darker-brown pile of sand in the foreground.

You can also see part of Mount Sharp rising in the background:

Right now Curiosity is getting closer and closer to Mount Sharp — part of a mountain range that sits in the middle of the crater.

Curiousity took this panorama on December 18, 2015 on its 1,197th sol on Mars. Martian days are called "sols" because they're slightly longer than Earth days.

The rover is gathering data and surface samples that will better prepare the first astronauts who travel to Mars. While humans might not land in the same spot as Curiosity, it's exciting to get an idea of what their first glimpse of the rocky, desert-like horizon will look like.

You can scope out more panoramic views of Mars here.

Join the conversation about this story »

NOW WATCH: Here's why Elon Musk wants to colonize Mars

SpaceX pulled off the world's first orbital rocket landing just before the New Year, but there's one promise the company made in 2015 but didn't deliver.

One year ago, SpaceX CEO Elon Musk teased the plans for a monstrous rocket-and-spacecraft system that might fly 100 people to Mars at a time.

Called the Mars Colonial Transporter (MCT), Musk said he would release the preliminary designs by the end of 2015.

Now he says we'll have to wait for the designs to come out sometime in 2016.

However, Musk's silence hasn't stopped a dedicated community of SpaceX fans, including engineers, from speculating on how this potentially revolutionary space rig might look and function.

Getting 100 people and 100 tons to Mars

Details were sparse in January 2015, when Musk first teased the idea of the MCT in a Reddit Ask Me Anything (AMA) chat.

We know it'll be some kind of massive spaceship propelled by a massive rocket. And with 100 people on board and enough rocket fuel to get to Mars, the MCT is going to be big and it's going to be heavy.

"Goal is 100 metric tons of useful payload to the surface of Mars," Musk wrote.

One metric ton is roughly 2,205 pounds (or about the weight of an elephant). That means the rocket that powers the MCT will have to be able to carry at least 220,500 pounds — 100 elephant's worth of mass (or, if you prefer, about nine Hubble Space Telescopes). And that's not including the fuel required to leave Earth's grasp.

We know that's already possible, though. NASA's giant Saturn V rocket lifted about 260,000 pounds of payload back during the Apollo missions.

However, there's an important difference between the two rockets. The Saturn V moon rocket only had to get its payload 239,000 milesto the moon. The MCT has to get everything 140 million miles to Mars.

"This obviously requires a very big spaceship and booster system," Musk wrote.

Musk nicknamed the booster the "BFR," short for "Big F***ing Rocket," and it's rumored that SpaceX is working on a completely new type of methane-fueled engine to power it.

Rocket speculation

The delay in any concrete plans has inspired deep speculation on Reddit.

Self-described engineer John Gardi even crunched all of the numbers to make a conceptual sketch of the MCT, which he estimates is 200 feet tall and 50 feet wide, and what its various sections might look like.

The passengers would sit in a section near the top. The capsule is structured into several levels, a lander, and escape systems. Below that is a crew and cargo section.

Then, below the crewed section is the upper stage of the BFR itself (the first stage isn't shown). This part of the sketch depicts a fuel tank (for methane), an oxygen tank (to burn the fuel), and a mount for the engines (which aren't depicted):

"I put that out there on a whim, but did take a week to work out the rough design with a bit of help," Gardi told Tech Insider via Twitter. "My primary focus was on passenger safety and modularity, being able to repurpose the various components of MCT at Mars."

Gardi also sent us this rough image, which shows how all of the sections of the lander look when separated into pieces:

While Gardi and others imagine what MCT might look like, based on the few limited details and rumors out there, there are still no specifics on how Musk will safely land 100 metric tons and 100 passengers on Mars.

The biggest problem is Mars' thin atmosphere.

There's so little air on Mars — the planet has about 1% of Earth's atmospheric pressure on the surface — that landing even half of a ton is a years-long engineering challenge. (Without air to slow down a spacecraft, rockets or some other technology has to get the job done.) Landing 200 times as much mass will be that much trickier of a feat.

So as much as we enjoy imagining SpaceX's next engineering marvel, we're really looking forward to seeing the official preliminary designs for the MCT. We can only hope Musk or others at SpaceX will unveil them later this year.

Join the conversation about this story »

NOW WATCH: SpaceX just released epic footage of its SuperDraco engines that can take a rocket from 0 to 100 mph in 1.2 seconds

Ridley Scott's "The Martian" just won a Golden Globe for Best Comedy.

While the movie certainly has its funny moments — lots of disco music, quippy one-liners, and that whole "space pirate" scene— the humor isn't what makes this movie great.

I think "The Martian" is the best space sci-fi movie made in my time. Here's why. (Spoiler alert: it doesn't have anything to do with comedy.)

If you haven't seen it, "The Martian" is a gritty survivalist tale that follows the story of astronaut Mark Watney (played by Matt Damon). Watney gets stranded on Mars when his crew is forced to leave him for dead during a major dust storm. When he wakes up, all he has is a space habitat designed to last for only 30 days and no way to contact anyone on Earth.

The next crew isn't coming to Mars for another four years, but Watney is determined to survive until they arrive.

On the surface, "The Martian" may sound a little like "Interstellar" 2.0: a big budget sci-fi movie where Matt Damon gets stranded in space. We're all aware of the symmetry.

"Why yes, Matt Damon did play a stranded astronaut in Interstellar," author of "The Martian" Andy Weir tweeted in June. "Thank you, thousands of people, for pointing that out over and over."

But the similarities start and end there. What makes "The Martian" such a brilliant, captivating film is that it has more science fact than science fiction. This may sound counter-intuitive — a nerdy, science-heavy plot is a turnoff for a lot of moviegoers.

Luckily, all the science in the "The Martian" is executed by a charming, hilarious character who makes it feel real and accessible. That also means no one will feel so intimidated that they miss the point of the story: a celebration of human perseverance and ingenuity.

Since everything that happens is so realistic, and (mostly) backed up by real science, the movie flows like a highlight reel of some of the most incredible feats the human race is capable of — we really can send humans through 140 million miles of space to Mars, and we really can survive there. Some day.

In short, it's inspiring. And not in a "gee, wouldn't it be cool if we had warp drives or teleportation" kind of way. All of the spacecraft, spacesuits, and rovers in the movie are based on real technologies we already have or that are within reach. So even though we haven't sent humans to Mars yet, this movie is a picture of how we could do it — and how we could do it soon.

Science fact vs. science fiction

Director Ridley Scott had wonderful reference material to achieve the movie's potent realism: Weir's book. The author spent an ungodly amount of time researching everything from astronomy to chemistry to orbital physics while writing "The Martian."

He even wrote his own software to calculate the orbital paths he uses for spacecraft in the story.

"To a nerd like me, working out all the math and physics for Mark's problems and solutions was fun," Weir wrote in a Q&A at the end of the book. "The more I worked on it, the more I realized I had accidentally spent my life researching for this story."

And the film adaptation keeps most of that intact.

There's a moment in the movie when Mark Watney realizes the gravity of his situation and says "I'm going to have to science the shit out of this." And boy, does he.

Almost every scene sticks to hard science. Like what can happen when you mess with rocket fuel:

And when your habitat airlock breaks due to a completely plausible design flaw:

NASA even got in on the film. While the government agency can't support a private enterprise, NASA experts consulted on the movie, and production has worked very closely with NASA's Jet Propulsion Lab officials, Weir said.

NASA also gave permission for the film to use the copyrighted — and coveted — NASA logo on its costumes, as you can see in these screenshots from the trailer:

Why the science won't scare you

It's easy to dive in too deep when it comes to the science of space travel. A lot of it is, after all, rocket science.

But the movie found a way to dip its toes in without drowning anyone. It describes how you can make water out of hydrazine rocket fuel without getting into the nitty-gritty chemistry. It references complicated rocket maneuvers, but smartly relies on visuals to explain the crux of them.

And while it's devoted to scientific realism, the movie does exercise its fiction liberty where it should. For example, communication between Earth and Mars in reality would be on a 20-minute time lag. "The Martian" largely — and wisely — ignores this fact to avoid seemingly choppy editing and a movie that'd last as long as a Mars mission itself.

Somehow, "The Martian" strikes a perfect balance between fact and fantasy. 

Humor and comedy play a very small role in a much bigger message.

You can watch the first trailer here:

And the second trailer here:

SEE ALSO: 9 tripped-out sci-fi technologies in 'The Martian' that NASA really uses

CHECK OUT: We spoke with the costume designer for 'The Martian' to see just how realistic those fashionable spacesuits really are

Join the conversation about this story »

NOW WATCH: This 'Mission Impossible' behind-the-scenes footage of a 53-year-old Tom Cruise hanging off a plane is terrifying

As far as we know, no one has ever had sex in space. 

NASA and the Russian Federal Space Agency have consistently and aggressively denied that any astronaut has had sex in space on the International Space Station (ISS).

So it seems that no one, yet, is part of the "250-mile-high club."

PornHub, the internet's largest pornography website, wants to change that.

PornHub made headlines in June 2015 when it announced its plans to be the first company to shoot a sex tape in space. It even launched an Indiegogo campaign to raise the $3.4 million it estimates the film will cost to produce.

The company wants to film its stars having sex during the few minutes that the spaceship will be in zero gravity as it reaches its maximum height over Earth. (No word yet on what spaceship they'll be using for the film yet). 

There's one glaring problem here: We know almost nothing about the science of sex in space and the potential risks and problems that could arise.

There are some biologists, astronomers, and anthropologists who have spent time speculating about what sex in space will be like. We can't be 100% sure of anything since we have little research and zero data, but it's clear sex in space won't be anything like sex on Earth. 

The zero gravity problem

It's not something most of us spend any time thinking about, but gravity is pretty critical for sex.

Getting it on in a zero g environment might sound kind of hot (PornHub certainly seems to think so), but most experts who have spent time thinking through the logistics have a different opinion.

"One of the things that gravity helps us do is stay together, so sex in microgravity might actually be more difficult because you’re going to have to make sure that you’re always holding each other so you don’t drift apart," Paul Wolpe, a senior bioethicist at NASA, told VICE. "It might be a lot more challenging and a lot less fulfilling than most people think."

Chris Impey, an astronomy professor at the University of Arizona, takes this idea even further.

"But there'd also be ways in which Newton's third law — of action and reaction — interfere with the normal methods of sex that you might use on Earth," Impey said during an interview with NPR's Fresh Air host Terry Gross.

Then we have to consider how zero gravity affects the actual human body, not just its motion. 

The human body — blood vessels, muscles, everything — is designed to deal with the pull of gravity. Blood doesn't flow through the body very well in zero-g. That means men could have a difficult time getting and keeping an erection.

Another natural turn off is that people sweat way more in space. It builds up in layers and clings to the body because there's no gravity to make it drip off. That could make intimacy a lot less pleasant, Impey points out.

If we work out all the logistics here, there are still more questions to answer. There's a fantastic Reddit discussion about the intricacies of sex in space, and Reddit user myprocessor posed an interesting question:

"I can't imagine going through pregnancy in zero gravity. I also wonder how this would effect the development."

 The bottom line is that we have no idea. Some studies on mice suggest that radiation (in addition to lowering a male's sperm count) could create pregnancy complications and even birth defects.

There have only been a handful of these kinds of studies though. Clearly we need a lot more research.

Psychological complications

When a small group of people are confined to a small space for months, as they would be on a journey to Mars or beyond, it's hard to keep the peace. If two of those people were having sex, there's no telling how it might affect the group dynamic. 

"Now that brings other problems: not all relationships last," astronaut Ron Garan told VICE. "Imagine a breakup on a three-year mission to Mars."

NASA has a strict policy that no couples can be on board the ISS at the same time. (Even though it happened by mistake one time). 

Sex on Mars

Gravity on Mars is about 40% of Earth's, so sex on Mars will be less complicated than sex in zero g.  

Physically having sex may be easier but there are other complications with intimacy and procreation on an alien world. Impey has a great summary of the some of the biggest problems in his book "Beyond: Our Future in Space:"

The 40% gravity would require minor adjustments. To finesse the issue of procreation, if not coupling, all-male or all-female crews have been proposed. More controversially, voluntary sterilization has been suggested for the first colonists. Mars One plans to arm its colonists with contraceptives, but it’s not known how well they would work on Mars. Norbert Kraft, the medical director of the project, isn’t entirely reassuring when he says they will "make colonists aware of the risks associated with having sex." The first waves of Mars colonists will die there, and they know that the medical facilities will be rudimentary; they’re unlikely to want babies. But as colonies get established, the dictates of biology and human culture will prevail. 

We'd also need to have a huge number of colonizers to ensure there's a healthy amount of genetic variability. If Elon Musk gets his way then we'll have a million people on Mars, which should do the trick. 

While we're still a long way away from seeing births on Mars, space travel and exploration is progressing, and eventually these are problems that we'll have to solve if we want to become a multi-planetary species.

So how do we move forward? NASA seems a little prudish about the subject — it's published very little information about sex in space and most of its communication effort on the topic has gone toward squashing all rumors that any astronauts have done it.

In some ways that makes sense — there are still tons of other, more pressing health issues we need to figure out about living in space. So sex research is not a priority for any space agency right now. But it's a subject that needs a lot more attention and open conversation. 

"I'd just assume [sex in space] is going to be an adventure, and people will be creative and they'll find new ways to enjoy themselves," Impey said.

Join the conversation about this story »

NOW WATCH: Couples therapist reveals the key to having a good sex life

Produced by Jenner Deal. Original Reporting and Camera by Jessica Orwig.

Follow BI Video: On Facebook

Join the conversation about this story »

Ridley Scott's blockbuster film "The Martian" has been nominated for six oscars, including Best Actor (Matt Damon), Best Picture, and Best Adapted Screenplay.

In the film, based on the novel by Andy Weir, Damon plays NASA astronaut Mark Watney, a botanist on a fictional mission to Mars.

Watney gets stranded on the Red Planet when a massive dust storm gravely injures him and forces his crewmates to escape, leaving him for dead. But Watney survives, and faces the daunting task of figuring out how to stay alive on an alien wasteland until he can be rescued.

Watney's technical prowess enables him to tackle the practical problems of getting enough water, oxygen, and food.

But perhaps the greatest hurdle he faces is psychological.

We talked to a NASA psychologist to find out if someone stranded on Mars could really make it without losing his or her mind.

"People have been able to keep it together mentally before" under extreme circumstances, such as being prisoners of war, Al Holland, a senior operational psychologist at NASA, told Business Insider. "We know that humans can be very resilient. One thing humans do very well is adapt."

One thing that's important for staying sane on journeys to space is real-time communication, which helps astronauts feel connected to friends and family. Thankfully for most of today's astronauts — including NASA astronaut Scott Kelly, who's spending a year on the International Space Station — communication is delayed by only a fraction of a second.

But on Mars, there would be a lag of about 20 minutes each way, which means a single exchange would take 40 minutes. In "The Martian," Watney faces the added difficulty of having to communicate with NASA using the camera on an old rover, which NASA can only use by pointing at letters and spelling out words. Talk about frustrating.

In the movie and book, Watney copes with the prospect of almost certain death using humor. At one point in the film when he's figuring out how he's going to survive, he says, "I'm gonna have to science the shit out of this."

A sense of humor is a huge asset for anyone, particularly for an astronaut, because it allows him or her to remain positive. Studies have shown that people use humor to cope with everything from losing their vision to having cancer.

Holland says it's also completely healthy for someone who is completely isolated to start having relationships with inanimate objects (think Wilson the volleyball in the film "Cast Away"). As for Watney, he develops a kind of relationship with the camera he uses to log his captivity on Mars.

Keeping focused on actively doing things is also important for avoiding depression like the kind that Mark Watney might have experienced (psychologists call this behavioral activation). For example, people who are kept in solitary confinement will do things like construct a house in their mind, brick by brick, Holland says. In Watney's case, he throws himself into solving each problem that presents itself on Mars, MacGuiver-style.

But when it comes to training astronauts in the real world, NASA prepares them to work in teams, not on their own. "It would be a very rare situation to have somebody left by themselves," says Holland, but "we also plan for the worst-case scenarios."

Although NASA trains its astronauts to deal with solitude, American astronauts still felt isolated when they flew to the Russian space station Mir in the 1990s, according to Holland. The predominant language was Russian, and communication with family on Earth wasn't reliable.

Astronauts have different strategies for keeping busy in space. Some read, some make things, and others focus more on their work. But astronauts going to Mars will likely have to be even more independent, more focused, and more resilient than those of today are.

SEE ALSO: Here's how the first humans will live on Mars — and why traveling the 140 million miles to get there will be the easy part

CHECK OUT: Stunning images reveal SpaceX's revolutionary approach to landing on Mars

Join the conversation about this story »

NOW WATCH: Matt Damon is left to die on Mars in first trailer for ‘The Martian’

"The Martian"— last year's must-see film based on the best-selling novel by Andy Weir — has been nominated for a bunch of oscars, including Best Picture and Best Actor. 

Back when the film came out last October, we chatted with NASA Head of Planetary Science Jim Green, who was a consultant on the film, about just how much science the movie gets right.

"What Andy did is kind of unique in science fiction," Green told Business Insider, referring to Andy Weir, the author of the book. While a lot of sci-fi centers around things that are not possible in our current understanding of science, "Andy decided to write science fiction about a future which would be bounded by the laws we know."

Here's the inside scoop from Green about what was scientifically accurate in the movie:

Mars' biggest challenges

1. It's extremely cold.

The first problem anyone visiting the Red Planet would face is the fact that it is an extremely cold, harsh environment. The temperature swings dramatically, for example, sometimes between as many as 120 and 140 degrees Fahrenheit in a day, said Green.

In the book and film, the main character, astronaut Mark Watney (played by Matt Damon) travels long distances in a solar-powered rover. But he doesn't have enough power to drive the rover and keep it heated, so to keep himself warm, he uses a generator which produces heat from radioactive decay.

Turns out, NASA has a similar generator, only they use theirs to power the real Curiosity rover. The agency also plans to install one of these on the rover it plans to send to Mars in 2020. The excess heat will be used to keep the rover's instruments functioning (but it's risky to use around humans because of the risk of radiation exposure).

2. You can't breathe the air

Next there's the problem of oxygen, the life-giving gas we take for granted on Earth. The atmosphere of Mars is very thin, contains mostly carbon dioxide, and has less than 0.15% oxygen, compared with that of Earth, which has more than 20% oxygen.

In the film, Watney's habitat or "hab" has an oxygenator, a device that sucks in carbon dioxide, zaps it with electricity, and spits out oxygen (for breathing) and carbon monoxide (as waste).

This technology is pretty realistic as well. The International Space Station has an oxygenator that splits water to produce air for the astronauts to breathe. Green said NASA plans to send such an oxygenator to Mars on its 2020 rover as a proof-of-concept that they can convert carbon dioxide into breathable air.

3. There's no food.

Then there's the issue of food, and the fact that Mars doesn't have any crops or livestock.

In the book and film, Watney's mission was only supposed to last 30 days, but because of a rogue dust storm that causes him to be left behind by his crewmates, he must find a way to survive for more than a year. Being a botanist, he figures out he can grow potatoes in the hab by fertilizing Martian soil with his own feces and moistening the soil with water generated by burning hydrazine, a flammable liquid from rocket fuel.

This part differs a bit from reality. As it turns out, Green said, NASA is finding that the soil on Mars is much more moist beneath the surface than once imagined, and contains nitrates and other minerals that nourish plants. So Watney may not have needed to go to those lengths to make water and fertilize the soil — he could simply dig up some Martian soil and thaw it out to grow his food.

4. You might get lonely or go crazy

As if the other problems weren't enough, Watney faces the psychological burden of being stranded on a planet millions of miles from home with virtually no human contact. In the film and book, Watney gets by using his sense of humor, by throwing himself into the work of survival, and by focusing intently on problems as they surface, taking things one step at a time.

The stress and isolation Watney faces are not unlike those faced by real spacefarers. NASA astronaut candidates go through a rigorous selection process, which involves thorough psychological evaluations. And outside of NASA, many people have endured extreme isolation (such as prisoners of war) and survived mentally intact.

So overall, how does the scientific accuracy of "The Martian" compare to other sci-fi films? It's the only film Green has worked on, but "it's certainly the most accurate one about Mars," he said.

NEXT UP: 9 tripped-out sci-fi technologies in 'The Martian' that NASA really uses

SEE ALSO: This would be the hardest part of being stranded like Matt Damon in 'The Martian'

Join the conversation about this story »

NOW WATCH: Matt Damon is left to die on Mars in first trailer for ‘The Martian’

When Russia launched the world's first satellite in 1957, it revealed a glaring hole in legal policy — how should we regulate outer space? Should Russia get in trouble for violating international law by flying a satellite over US airspace without permission? 

It was clear we'd need a new set of rules to govern airspace as humanity started climbing higher into the sky and eventually into outer space.

That, and the Cold War idea that the United States or Russia would try to colonize space and create a nuclear weapons base there helped inspire the United Nations Outer Space Treaty of 1967. 

The treaty was the founding body of space law and it's inspired several other international conventions and agreements. 

Here are some of the major laws that currently govern space, and what policies we'll need in the future:

One of the most important bodies of space law is the United Nations "Outer Space Treaty." It lays out several rules that dictate how countries must behave in space.

Source: The United Nations Outer Space Treaty.

1. Space is common ground and everyone is allowed to explore it.

"Outer space shall be free for exploration and use by all States," the Outer Space Treaty reads.

2. But anyone exploring space has to do it peacefully.

"The Moon and other celestial bodies shall be used exclusively for peaceful purposes," the treaty reads.

2015 marked 50 years of successful NASA missions to Mars which started with Mariner 4 in 1965. These are the NASA rovers and satellites currently exploring the planet.

Produced by Ruchika Agarwal

Follow BI Video: On Facebook

Join the conversation about this story »

Stephen Hawking has warned that humanity is in danger of destroying itself in the next 100 years as we rapidly progress in the realms of science and technology.

Speaking to the BBC, he said that while progress was good, it creates “new ways things can go wrong.” He highlighted nuclear war, global warming, and genetically engineered viruses as possible harbingers of doom of our own creation.

This is not the first time Hawking has warned that we face a self-made disaster. In 2014, he said that artificial intelligence could “spell the end of the human race.”

Hawking pointed out that he is ultimately an optimist, and he believes we can overcome the problems that could face humanity. But if the worst were to happen, one way we could ensure the survival of the human race is to have a colony on another planet, such as Mars.

This is unlikely to be a reality in at least the next century, though. Suggesting that a global disaster was a “near certainty” in the next thousand to ten thousand years, Hawking therefore said that the next 100 years are our most dangerous, as we become much more advanced but without a safe haven off this planet.

“Although the chance of a disaster to planet Earth in a given year may be quite low, it adds up over time, and becomes a near certainty in the next thousand or ten thousand years,” he said. “However, we will not establish self-sustaining colonies in space for at least the next hundred years, so we have to be very careful in this period.”

Nonetheless, Hawking said this was a “glorious time to be alive” for scientists, specifically theoretical physicists like himself, with countless new discoveries waiting to be made.

Hawking was speaking to the Radio Times ahead of his Reith Lecture on black holes, which will be aired on BBC Radio 4 in the U.K. at 9 a.m. GMT on January 26 and February 2. International audiences can listen in on the BBC World Service on the same days at 10:06 a.m. EST (3:06 p.m. GMT).

Hawking’s latest theory on black holes, published in a paper earlier this month, is that they could contain “hairs” at their event horizon — the boundary beyond which nothing, not even light, can escape. These hairs could contain information about the black hole, and help resolve the “information loss” paradox.

SEE ALSO: The first video footage of SpaceX's rocket-landing attempt reveals how incredibly close it came to success

DON'T MISS: The amazing perks of being a NASA astronaut

Join the conversation about this story »

NOW WATCH: Scientists just discovered a new way to get happy simply by listening to your voice

As humans continue exploring further out into space, through both government organizations like NASA and up and coming private space enterprises like SpaceX and Blue Origin, we're going to need a lot more laws to govern space.

The US just made it legal for Americans to mine resources from asteroids, but space, and especially business in space, is largely unregulated right now — which makes it surprisingly easy for someone to become a space pirate.

Space law basics

Could the first person who steps on Mars declare themselves supreme ruler of the planet? Would you have to obey a speed limit in your moon rover? If someone wanted to settle on Mars permanently and build a Martian castle (Elon Musk maybe?), would he be able to buy a plot of land?

Well, according to Article I of the United Nation's Outer Space Treaty, one of the most important parts of the laws that govern space, every celestial body in space, including Mars, falls under international law:

Outer space, including the moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.

And so, as of now, no state, person, or company can lay claim to any land that's not on Earth:

Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.

BUT! People, governments, and private corporations still own, say, their living quarters, spaceships and rovers that they send to another planet.

Space piracy

So essentially the universe beyond Earth counts as international waters. But crafts out in space still belong to their owners.

This is exactly what leaves ships in international waters open to piracy: when a crew commandeers a ship and steals its cargo.

Turns out if you tried the same move in space (by raiding a spacecraft instead of a ship) that would technically make you a "space pirate."

Currently, the International Space Station (ISS) belongs to Europe, the United States, Russia, Canada, and Japan, and the Mars rover Curiosity belongs to the US. So, if a crew ever boarded the ISS without permission from the countries that own it, it'd be space piracy.

While this has never happened in real life, there's an amazing list of fictional space pirates on Wikipedia.

And in "The Martian," Mars-stranded NASA astronaut Marc Watney gives a great (and hilarious) example of how international law would manifest on Mars. When he is inside a NASA-owned Mars habitat, US law applies. But as soon as he steps outside onto Martian soil, he's in international waters.

At one point, Watney needs to use a NASA spacecraft called Ares 4. NASA hasn't explicitly given him permission to climb aboard, and according to the UN Outer Space Treaty, you can't lay claim to anything in space — so he must "commandeer" Ares 4, an action that will technically make him a pirate under international law.

"After I board Ares 4, before talking to NASA, I will take control of a craft in international waters without permission," Watney says in the book. "That makes me a pirate! A space pirate!"

It's clear we'll need a real legal system if we set up a colony on Mars or some other distant world — especially if that colony is run by a private corporation. (SpaceX CEO Elon Musk dreams of setting up a whole civilization on Mars.)

Writing new laws is already a complicated process, but writing them for an inhospitable, alien world like Mars may be even harder. How much freedom can someone expect to have on a planet with no breathable air or protection from radiation?

Compliance with certain rules might deprive people of what we on Earth consider basic freedoms (think about having to stay indoors during a dust storm or only having a certain amount of oxygen per day to use to explore the planet), but it could mean the difference between life or death.

Some groups, like those at the annual International Extraterrestrial Liberty Conference, are already trying to figure out how we'll govern space if humans attempt to settle somewhere beyond Earth.

Join the conversation about this story »

NOW WATCH: The biggest science mistakes in 'The Martian'

On Monday, the space agencies of India and France signed a letter of intent stating that the two will collaborate on India's next mission to Mars, SpaceNews reported.

This mission, which is scheduled to launch in 2020 and would involve sending a satellite into orbit around the Red Planet, will mark India's second mission to Mars in history.

While the 2020 orbiter will not set a lander on Mars' surface, the president of French space agency National Centre for Space Studies (CNES) Jean-Yves Le Gall said a lander mission might not be far off for India.

"After India's Mars orbiter, the next step has to be a lander. A lander on Mars is not easy, but it will be interesting to undertake," Le Gall told NDTV.

When Le Gall says that sending a lander to Mars "is not easy," he's not kidding.

In the history of deep space exploration, only three space agencies have attempted a Mars lander: the Soviet Space Program, NASA, and the European Space Agency (ESA).

Of those three, NASA is the only agency who's had landers that functioned for longer than 15 seconds after touchdown. In fact, NASA's latest lander, the Opportunity rover, just celebrated 12 years of exploration on the surface.

Needless to say, sending a lander to Mars is a major undertaking. But with a partner like CNES, India might just pull it off.

Founded in 1961, CNES has helped design and build the technology for such groundbreaking missions as ESA's Rosetta mission to comet 67P/Churyumov-Gerasimenko and its Philae lander as well as the Cassini-Huygens mission, which included an atmospheric probe — Huygens — that landed on Saturn's moon, Titan.

READ MORE: This physicist tied himself to the side of a building then went plunging toward the earth — here's why he lived

SEE ALSO: Russia says a growing problem in space could be enough to spark a war

Join the conversation about this story »

NOW WATCH: Scientists can't explain these mysterious spots on one of Saturn's most remarkable moons

Landing humans on the surface of Mars will take technology that hasn't even been developed, yet. It will be unlike any space mission we've ever seen and by far the most difficult in history.

Produced by Jessica Orwig

Follow BI Video:On Facebook

Join the conversation about this story »

Aliens. They've captured the imagination and fear of humans for centuries.

And whether we're ready for it or not, there's a distinct chance that we may find some other life forms way out there in space — perhaps even within our own solar system.

"I think there has to be life out there," astronaut Mike Massimino, now a professor of mechanical engineering at Columbia University, told a crowd of theatergoers after opening night of "The Astronaut's Tale," an opera about a young man who dreams of becoming an astronaut.

With all of the planets we've found, Massimino said, the chances of finding alien life is high.

But aliens may not be the creepy, slimy, long-fingered creatures movies want us to believe they are. They could come in the form of teeny tiny microbes, or even fossilized life on Mars, astronaut Chris Hadfield said in a recent Tech Insider video.

We've made huge advances in our ability to see the enormous throngs of planets beyond our solar system. And more planets means more chances of finding life beyond ourselves.

"The rest of the universe is kind of unlimited potential," Hadfield said in the video. "We have a rough number for the number of planets in the universe, it's so big it's almost incomprehensible. It's like seven septillion, which basically is infinite."

We haven't found evidence of alien life yet, but there's so much more to explore and discover, including distant moons, asteroids, and objects floating beyond Pluto. Even this recent "alien megastructure" orbiting a distant start has potential.

But according to Massimino, even if we do find evidence of life beyond our rocky planet, ours will forever be the most special.

"With all the planets I don't think we'll ever find a place as beautiful as Earth."

Join the conversation about this story »

NOW WATCH: We asked an astronaut if aliens exist and his answer was spot on