Fraser Cain

One of the great accomplishments of the Apollo missions was to bring home hundreds of kilograms of lunar rock. Suddenly, geologists had a lifetime’s worth of lunar samples captured from several different spots across the Moon. These rocks and dust have been under continuous analysis since the Apollo 11 astronauts came home over 50 years ago.

And they’re still making discoveries.

Scientists have samples of the Sun’s solar wind, particles from a comet’s tail, a few grams from an asteroid, with more coming shortly.

But there’s one world, the focus of so much scientific study, which has never had a sample returned: Mars.

NASA and the European Space Agency have been making plans to bring a sample home from Mars for decades, and now, missions could fly in the next few years, finally bringing a chunk of the Red Planet home to Earth for us to study directly.

As I’ve mentioned in several episodes now, humanity is in a bit of a transition period, a time when it makes sense to launch material up and out of Earth’s gravity well into orbit, and beyond. But it’s really expensive, costing up to $10,000 per pound you want in orbit, and 10 times if you want it on the Moon.

But over the coming decades, more and more of our space-based infrastructure will be built in space, manufactured out of materials that were mined in space.

The only thing that’ll actually need to leave the Earth’s clingy gravity well will be us, the humans, the tourists, wanting to visit all that space infrastructure.

Of course, in order to achieve that space future, engineers and mission planners will need to design and construct the technology that will make this possible.

That means testing out new prototypes, technologies and methodologies for mining and space-based manufacturing.

In this week's questions show, I explain why all the planets astronomers have found are so bizarre. Couldn't we use laser highways to go faster? Is the lunar gateway really a lunar tollbooth?

Mars is the place that most of our spacecraft, landers and rovers are studying, searching for any evidence that life ever existed somewhere else in the Solar System.

But talk to planetary scientists, and they’re just as excited about the ocean worlds of the Solar System; the moons, asteroids, dwarf planets and Kuiper Belt objects where there could be vast oceans of liquid water under thick shells of ice.

The perfect environment for life to thrive.

We’ve only had tantalizing hints that these oceans are there, but NASA is building a spacecraft that will study one of these worlds in detail: the Europa Clipper. And they’re not the only ones. The European Space Agency is building their own mission, the Jupiter Icy Moons Explorer.

On Tuesday, July 30th, NASA announced 19 different partnerships with 13 different companies to use their expertise to help them develop space technologies, from advanced communications systems to new methods of entry, descent and landing.

Instead of contracting out specific projects, NASA will make its employees, facilities, hardware and software available to these companies, for free.

One of the most notable of these partnerships will be with SpaceX and NASA’s Glenn and Marshall Centers to help advance the technology of transferring propellant in orbit.

In other words, NASA is going to help SpaceX figure out how to refuel a spacecraft while it’s in space. And if they can figure this out, it could completely change the way missions are launched and flown.

In this week's questions show, I answer if techno optimism is blinding us to the challenges of spaceflight, why there aren't spacecraft at all the planets right now, could the Great Attractor be dark matter? And more...

It’s amazing to think there are telescopes up in space, right now, directing their gaze at distant objects for hours, days and even weeks. Providing a point of view so stable and accurate that we can learn details about galaxies, exoplanets and more.

And then, when the time is up, the spacecraft can shift its gaze in another direction. All without the use of fuel.

It’s all thanks to the technology of reaction wheels and gyroscopes. Let’s talk about how they work, how they’re different, and how their failure has ended missions in the past.

NASA’s Transiting Exoplanet Survey Telescope launched back in April, 2018. After a few months of testing, it was ready to begin mapping the southern sky, searching for planets orbiting stars relatively nearby.

We’re just over a year into the mission now, and on July 18th, TESS has shifted its attention to the Northern Hemisphere, continuing the hunt for planets in the northern skies.

As part of this shift, NASA has announced a handful of fascinating new planets turned up by TESS, including a couple of worlds in categories which have never been seen before.

In this week's questions show, I answer a question about solar sails, what geologists might learn from lunar rocks, if Earth could survive inside Jupiter, could gas giants be closer to the Sun, and more.

When we look outward into space, we’re looking backwards in time. That’s because light moves, at the speed of light. It takes time for the light to reach us.

But it gets even stranger than that. Light can be absorbed, reflected, and re-emitted by gas and dust, giving us a second look.

They’re called light echoes, and allow astronomers another way to understand the Universe around us.

There are few places in the Solar System which are as fascinating as Saturn’s moon Titan. It’s a world with a thicker atmosphere than Earth. Where it’s so cold that it rains ammonia, forming lakes, rivers and seas. Where water ice forms mountains.

Like Europa and Encleadus, Titan could have an interior ocean of liquid water too, a place where there might be life.

Titan’s got layers, and fortunately, there’s an awesome new mission in the works to explore it: the Titan Dragonfly mission.

In this week's questions show, I explain how long it'll take for space junk to burn up in the Earth's atmosphere, would it be possible to put advertising in space, and why panspermia is appealing as a hypothesis.

As NASA prepares to return to the Moon by 2024 as part of its Artemis program, the agency is focusing its efforts on exploring the Moon’s polar regions. These are areas of the Moon which seem to have a lot of water mixed in with the regolith.

Some of these craters are permanently in shadow, and might still have large quantities of water, that’s accessible to human and robotic explorers. This is a critical resource, and the Moon might be just the place to help humanity as it pushes out to explore the rest of the Solar System.

But it might also be an illusion. We really won’t know until we look up close.

Where you can travel in space depends on how much propellant you’ve got on board your rocket and how efficiently you can use it. But there’s a source of free propellant right here in the Solar System - the Sun - which is streaming out photons in all directions. You just need to catch them.

And right now, the Planetary Society’s new LightSail 2 spacecraft is testing out just how well it’ll work.

In this week's QA, I tackle constant acceleration. Do we have anything that can accelerate at 1G for long periods of time? Why are there different sized stars? And do the heavier elements come from supernovae or colliding neutron stars?

People are always worried that alien civilizations will detect the transmissions from our old radio shows and television broadcasts, and send in the invasion fleet. But the reality is that life itself has been broadcasting the existence of life on Earth for 500 million years.

Blame it on the plants.

In addition to filling the atmosphere with oxygen, plants give off a very specific wavelength visible in infrared radiation. It’s the kind of signal that other civilizations could search for as they’re scanning the galaxy.

It’s what we’ll be looking for too.

But don’t just blame the plants. Other forms of life have been giving off signals too, signals we can search for as we discover new exoplanets and wonder if they have life there.