Chris Hadfield, the Canadian astronaut who’s become a YouTube sensation aboard the International Space Station, has showed us why tears won’t fall in space and the dangers of clipping one’s fingernails in zero gravity. But he has truly outdone himself with his latest video. Scheduled to leave the space station tonight at 7pm – and to touch down in Kazakhstan hours later — Hadfield has remade David Bowie’s “Space Oddity.” (For those not up on their Bowie song titles, this is the song that starts: “Ground control to Major Tom.”) Watch it — it’s truly awe-inspiring.

At TED, we’ve had talks from explorers of the mind, charterers of the polar regions and investigators of insects. Today, we’re taking a look at talks from those who’ve seen the earth from outside its atmosphere. All of these TED, TEDx, and TED-Ed speakers are astronauts, yes, but they also have something else in common: a desire to never stop exploring. We’ll start, of course, with Hadfield welcoming TED to Canada, upon hearing that TED2014 would be held in Vancouver.

1. Commander Hadfield welcomes TED to Canada
2. Mae Jemison: On teaching arts and sciences together
3. Cady Coleman greets TED2011 from the International Space Station
4. Roberta Bondar: The challenge of change
5. Lodewijk van den Berg: How a crystal growth scientist became an astronaut
6. Joseph Allen: A sense of place in space
7. Yvonne Cagle: The human microscopic
8. Jerry Carr: Life of an astronaut
9. Ed Lu: The biggest conversation project imaginable (See also: Changing the course of the solar system and Oceans of robots)
10. Michael Massimino: Spaceflight
11. Nicole Stott: The glass floor: Reaching for the stars
12. Stephanie D. Wilson: My journey to space
13. Michael E. Lopez-Alegria: Human exploration of space
14. Ron Garan: The orbital perspective of our fragile oasis (See also: Connecting humanity’s changemakers and his greeting to TED2011 from ISS)

An artist’s rendering of the Planck satellite. Courtesy of: ESA

Today—March 21, 2013—the much-anticipated cosmological results from the Planck satellite have been released. In a recent blog post on her own website, TED Fellow and cosmologist Renée Hlozek describes why this is a big day for astrophysics and cosmology. We asked her to explain what the excitement is all about.

“Planck is the ‘next generation’ satellite that measures the tiny fluctuations in the temperature and polarisation of the Cosmic Microwave Background (CMB) – which is light that comes from shortly after the Big Bang, and has been travelling towards us for over 13 billion years,” she says.

“Planck has been operating in space since 2009, and will dramatically increase the precision with which we can measure this radiation, which tells us about the physical conditions of the universe at very early times. We use this data to fit a cosmological model, to figure out what the universe is made of, its properties and how it is changing with time. So today is a big day because it further refines our picture of where we came from and where we are going on the grandest scales imaginable!”

Planck results are now available at the Planck Legacy Archive »

TED Fellow Renée Hlozek speaks at TED2013. Photo: Ryan Lash

Mock-up of a proposed installation in which live chanting triggers the sounds of the stars. The orange squares are meditation cushions arranged in the shape of the Kepler telescope’s detectors, and the projection is of the star field from which the data originate – near the constellations of Cygnus (the swan) and Lyra (the harp). Image: Lucianne Walkowicz

Ever wondered what the music of the cosmos sounds like? You’re about to find out. Astrophysicist and TED Senior Fellow Lucianne Walkowicz works on the Kepler mission, looking at a patch of our galaxy to learn about stars and their planets. During an interview at TED2013, she mentioned that she is also an artist and has begun composing music woven from star data, after feeling inspired by the work of Fellows like data artist Julie Freeman. Here, she tells us how this is done:

“One of the things I like about science is that I can entertain myself by looking at the world and thinking about what’s happening at a microscopic or macroscopic level. It makes me feel like I have access to an additional dimension of information that’s around me all the time.

Recently I’ve started doing sound installations based on the data that I use for my own work. The Kepler mission finds planets and studies stars by measuring how stars get brighter and dimmer with time. Planets block some of the starlight as they pass in front of the star, making little dips in the stars’ brightness that tell us the planet is there.

However, stars periodically appear brighter and darker on their own because they have bright and dark patches on their surfaces caused by the star’s magnetic field. As it spins, we see light fluctuate as the patches rotate into and out of view – and the frequency of the fluctuation tells us how fast it’s spinning. To make things a bit more complicated, stars don’t rotate exactly like tops, in that different latitudes on the star spin at different rates – so usually there are several frequencies in the star’s light, and they can change and drift in time.

I take the data and search for which frequencies are present at different times, then scale them to frequencies the human ear can hear, using a sine-wave generator. Then I create tones that change with time to represent how the frequencies in the star are changing. A first pass sounds like this: in each second of playback, you hear the three strongest frequencies in the star for a day of real time. As you listen, the sounds change as the frequencies change.

Then I do some additional processing to get the effect I want. Usually I want to capture some echo to convey a sense of vast space, and some blending between notes to convey the dynamic nature of the features on the star’s surface that are creating the changes in the star’s light. It sounds like this:

I do this for multiple stars, and can then weave them into compositions along with other samples. It sounds like this:

In the following piece, Powerful Protectors, I’ve woven the sounds of two stars in with samples of Buddhist chanting around the world. The composition is about how people try to access deeper knowledge about our universe.

As a scientist, communicator and educator, I am driven by wanting to share with others how science offers access to a deeper dimension of information. But sometimes you end up at odds with people who have looked for other ways to explain or address mysteries in their lives, and in fact some people feel alienated from science.

Many people seek deeper meaning through religion, which is often (though not always) at odds with science. I chose these chants for their rhythmic qualities, similar in nature to the periodic frequencies of the stars I study. As the piece evolves, the sounds weave together – sometimes blending and complementing one another, but sometimes battling and drowning one another out.”

Gazing up at the night sky is always both humbling and thrilling. In this episode of TED Radio Hour, you’ll hear from speakers who share a sense of wonder and curiosity about our place in the universe. Phil Plait breaks down how we can defend Earth from an asteroid. Jill Tarter of the SETI Institute explains why it’s crucial for humans here on earth to continue searching for sentient beings in the cosmos. And Cosmologist Brian Greene unravels the strange tale of dark matter and why our universe may be one of the many in the “multiverse.”

Check your local NPR schedule to find out when the show airs today, or listen via NPR’s website »

Or head to iTunes where the podcast is available now »

Ancient clues
Five fascinating talks by archaeologists and evolutionary biologists about humanity’s beginnings and journey.

Planes, trains and automobiles
Drive a plane? Race a car with your eyes closed? Fly? 11 innovators in transportation show that getting from point A to point B doesn’t have to be boring.

Are we alone in the universe?
Can it really be possible that Earth is only life-sustaining planet in existence? These 5 speakers think there might just be something or someone else out there, and urge us not to stop the search.

It’s a humbling day to be an Earthling. Just sixteen hours before the highly-anticipated flyby of the asteroid 2012 DA14, the skies above the Chelyabinsk region of Russia were shattered by the explosion of an incoming meteor. Although fortunately nobody appears to have been killed by the blast, more than 1,000 people reported injuries, mostly from flying glass and debris.

We know that these objects are out there, but what are scientists doing to locate them? And how would we respond if one were found to be on a collision course with our planet?

At TEDxMarin, Dr. Ed Lu gave a fascinating talk highlighting the efforts that scientists like himself are making to detect and deflect near-Earth objects.

“You don’t need oil miners and Bruce Willis” to push an asteroid off course, says Dr. Lu. “Deflecting asteroids is not that hard. We have the technology to do something like this.”

Phil Plait: How to defend Earth from asteroidsThe bad news? We can’t deflect an asteroid we don’t know is coming. And there are a lot of asteroids out there (check out the jaw-dropping graphics at about 6:00). That’s why Dr. Lu and his team are working on satellites to detect them from space — before it’s too late.

Also of interest today: Phil Plait’s “How to defend the earth from asteroids.”

This post originally appeared on the TEDx blog. Check out more »

• In TIME’s end-of-the-year “New Space Discoveries” special, the magazine picked “The 25 Most Influential People in Space” — from telescope innovators to planet hunters. Of those included in the list, we couldn’t help but notice that five had given TED Talks. Below, check out what each had to say on the TED stage.

1. Andrea Ghez on “the hunt for a supermassive black hole”

2. Jill Tarter sounds a “call to join the SETI search”

3. Brian Greene “makes sense of string theory” and says that “maybe this universe isn’t our only universe”

4. Martin Rees asks if “this is our final century”

5. Carolyn Porco says “Saturn could harbor moon life” and takes us there in “This is Saturn”

Read TIME’s full slate of space innovators >>

Teen reporters Sadie Cruz and Nia Ashley conducted lots of interviews with speakers at the TEDYouth conference on November 17. Their Q&As will run on the TED Blog over the next few weeks. Below, an interview conducted by Nia.

The Flight Director of the Mars Curiosity Mission, Bobak Ferdowsi, is best known for landing a two-ton rover on Mars. But “Mohawk Guy,” as he’s called by his thousands of Internet followers, is also famed for representing the uniqueness of NASA.

He sat down with me the night before his TEDYouth talk to discuss Mars, his unexpected celebrity and how soon I can hope to report to the USS Enterprise.

Nia Ashley: So, you led a mission on Mars. That’s kind of awesome. Can you talk about that for a second?

Bobak Ferdowsi: I worked on the Mars Science Lab Curiosity Mission. It’s been about nine years for me. I ended up as Flight Director for crews and landing operations. I don’t know, it’s kind of the coolest thing I’ve ever done.

NA: What does a flight director do?

BF: Basically, we have this responsibility to make sure that the activities that we’re executing are safe for the spacecraft, to make sure we understand the consequences if something goes wrong. What are our outs? What are we going to do? And then I work with the team, both when they design the activity and when they execute the activity, to make sure that we have all those bases covered.

NA: What if you had dropped [the rover] and it had just bounced and flipped over on its back like a turtle?

BF: That would have been the end of the game, I guess. There’s no way to turn it back right side up once it’s on Mars.

NA: So, what is your typical day, now that the flight happened?

BF: Basically, activities fall into two categories. We have activities based on what happened the day before — like, we discovered a rock and we want to go investigate the rock. But we also have activities that we know we want to do in a month or so — like, we want to try drilling on Mars. So we want to understand: what are all the interactions that have to happen there? Part of what I’m working on right now is making sure those activities are all ready to go when the time comes.

NA: Why do you think that we on Earth are so obsessed with finding life on other planets?

BF: I think it’s such a natural human endeavor to understand: what is our place in the universe? We have this amazing planet, and all this amazing stuff going on around us, but where does that fit into the scheme of things? Other planets, they’re not so different from us, and you think, “What if there’s life? What if it’s like us? What might be different?”

It’s hard because we have one data point: I live on the Earth. Arguably, we have a lot of data about that one point, but then you’re trying to understand: Would life [on other planets] be more intelligent than us? Does it ever really get past bacteria? What is it going to look like? It’s a slow process of scientific understanding.

NA: You are an Internet sensation. Do you appreciate the fact that you’ve made science cool? Or is it, “I have a job to do?”

BF: I love my job, so I focus on that, but I am excited about bringing attention to what I think is a really cool job. I love that people see me as looking different — which I actually don’t! This is what most engineers and scientists look like nowadays. The perception is dated, so it’s cool for kids to see that and to realize, you can be your own person. It takes all sorts of types and looks and everything else to get these missions to happen. We had 3,000 people on this project — a variety of backgrounds, both educationally and culturally and everything. And it’s cool that that’s been shown in a new light.

NA: What do you think is more likely: Martians or life on one of the Galilean moons, like Europa or Titan?

BF: Tough question. I’m a big fan of Europa. I love Mars, I think it’s really amazing, but we’ve been there and it doesn’t look like there’s life there.  Europa is kind of shrouded in mystery, like Mars was in the early days. Ice moon, very likely ocean in the center, it’s warmer, volcanic – and we know that life exists on the Earth at the very bottom of the ocean near these volcanic vents. So it seems like the possibility is there for life to exist.

NA: How close are we to Star Trek? Because that’s what I want.

BF: I think we’re a ways away from Star Trek. But one of the cool things about Star Trek that I loved, and I think it’s still true, is that we are increasingly moving towards international cooperation in all that we do. We’re not going to have warp drive, probably, or transporters anytime soon, but the idea that all these countries are coming together, it’s a planetary endeavor to explore space, I think we’re getting there pretty fast.

NA: If you could meet your teenage self today, what’s something that you would tell them?

BF: It gets better? No, you know, it’s so funny, but as a sort of nerdy person, you feel a little ostracized as a kid, and yet we’re living in this era now where it’s okay to be nerdy. In fact, it’s kind of more relevant and cool. It gives me hope. I would have told my teenage self that. Like, “Listen, in 10 years you’re going to love that you read all this sci-fi. In your room. Without any friends.”

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Curious about Bobak Ferdowsi’s favorite TED Talks? Check out his playlist, “On our home in the universe” >>

Last Sunday, Austrian skydiver Felix Baumgartner jumped out of a helium balloon from over 24 miles in the sky, and shattered world records by freefalling from an altitude of 128,100 feet to Earth. With the jump, Baumgartner became the first human to break the sound barrier, reaching an astonishing peak speed of 833 mph and creating a new answer for children everywhere to the question “What do you want to be when you grow up?”

So what does you wear for a freefall of this magnitude? The answer comes in this talk from Dr. Jon Clark, a six-time space shuttle crew surgeon who helped create the suit that allowed Felix the Fearless to make this monumental leap.

A 26-year Navy veteran and former Special Forces parachutist, Clark has served in top roles at Johnson Space Center and specializes in crew survival, both in space and during re-entry to the earth’s atmosphere. It’s a topic very personal to him, as his wife — Laurel B. Clark — was killed when the space shuttle Columbia disintegrated in the earth’s atmosphere in 2003. Clark serves as the space medicine advisor for the National Space Biomedical Research Institute (NSBRI) at Baylor College of Medicine and is the chief medical officer for orbital commercial space company, Excalibur Almaz.

Since 2009, Clark has been a volunteer for the “Stratos” team, tasked with keeping Baumgartner safe through three stratosphere jumps. In this talk from TEDxUSC, Clark lays out the risks of the stratosphere, and the challenges that his team had to surmount to protect Baumgartner during his freefalls. Clark explains that the new age of space exploration will be underwritten by private entrepreneurs rather than that government (Baumgartner’s jump was sponsored by Red Bull) and that, within our lifetimes, the average citizen may be able to experience the stunning view from the stratosphere. Safely.

In today’s thrilling TED-Ed lesson, Bill Nye the Science Guy admits that he has S.O.D., otherwise known as Sundial Obsessive Disorder. But there is a good reason for it — a sundial helped Nye’s father escape from a prison camp in China during World War II, launching a lifelong obsession that Nye eventually picked up himself.

At an event several years ago, Nye caught a glimpse of a device — called a “photometric calibration target” — that would soon be on its way to Mars on the outside of the Spirit and Opportunity rovers. The device was essentially a test pattern for cameras — a metal post with gray rings around it — that would allow them to gauge the color of the Martian sky. Nye had an “aha” moment. These devices could easily be turned into sundials, charting the progression of time on the red planet.

Because of Nye’s suggestion, a sundial has now been on Mars.

To hear the amazing story of how Nye’s father escaped from prison camp, and how exactly this Martian sundial works, watch Nye’s wonderful talk. And after the jump, watch seven more talks about Mars.

Joel Levine: Why we need to go back to Mars
The surface of Mars was not what was expected, says atmospheric scientist Joel Levine in this talk from TEDxNasa. Levine explains the tantalizing hints of past life — including craters of ice and evidence of ancient oceans — and why we need more research on the planet.

Penelope Boston says there might be life on Mars
Cave scientist Penelope Boston believes that there is a 25 to 50 percent chance that the Mars Rovers didn’t find life on Mars because said life is inhabiting deep caves.  At TED2006, she gives ideas on where — and how — we should continue the search.

Cynthia Breazeal: The rise of personal robots
The first robot landed on Mars in 1997. So how is it possible that we don’t have them in our homes and offices yet? In this talk from TEDWomen, Cynthia Breazeal explains her work in teaching robots to interact with human beings.

Charles Elachi on the Mars Rovers
NASA’s Jet Propulsion Lab has become the stuff of legends. At Serious Play 2008, director Charles Elachi tells behind-the-scenes stories and shows rarely seen footage recorded by the Mars Rover project.

Stephen Petranek counts down to Armageddon
What will bring on the end of the world, and what is our best chance for surviving it? In this talk from TED2002, Stephen Petranek describes how we could go about “terraforming” Mars — a process that could take hundreds of years.

Jon Nguyen: Tour the solar system from home
Jon Nguyen is the Visualization Software Engineer at NASA’s Jet Propulsion Laboratory. In this talk from TEDxSanDiego, he demos a tool that allows anyone to explore the solar system in detail — even take a trip to Mars — using data provided by spacecrafts in orbit.

Burt Rutan sees the future of space
In this talk from TED2006, spacecraft designer Burt Rutan admits that Mars was not quite as interesting as space enthusiasts had hoped. But he believes that is in part because NASA used robots for the mission to the planet and explored only the deserts. A call for entrepreneurs to pick up the slack in government funding for space exploration.