Universe Today Podcast

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.

On October 19th, 2017 astronomers detected the first interstellar asteroid (or maybe comet) passing through the Solar System: Oumuamua. It had a brief encounter with the inner Solar System and then hurtled back out into interstellar space.

Once astronomers noticed it, they directed the world’s telescopes on the object, but it was too far away to reveal anything more than a faint dot.

Until now, we’ve only been able to study objects in our own Solar System. We have no idea what the rest of the Milky Way is like.

But we were too late to catch it, no spacecraft was ready to make a quick intercept.

Well, scientists aren’t going to make that mistake again. The European Space Agency announced their plans to build a comet interceptor. A spacecraft that will lurk out at the Earth-Sun L2 Lagrange point, waiting for a long-period comet or interstellar object to pounce on, and give us the first close up view ever.

In this week's QA, I answer why space telescopes aren't a waste of taxpayer resources, if ground-based space telescopes will become obsolete, and whether it makes sense to crash phobos into Mars.

This past weekend Skylias moderated a debated between John Michael Godier and Fraser Cain over their Fermi paradox theories. If there are aliens where are they? The Fermi paradox theory asks where are the alien civilizations in the galaxy? And in the universe. If they exist. Where are the extraterrestrials?

In this week's questions show, I explain how astronomers know what the Milky Way looks like, what would happen in a catastrophic impact on the International Space Station, and who is the team who works with me on Universe Today?

The Solar System is a really big place, and it takes forever to travel from world to world with traditional chemical rockets. But one technique, developed back in the 1960s might provide a way to dramatically shorten our travel times: nuclear rockets.

Of course, launching a rocket powered by radioactive material has its own risks as well. Should we attempt it?

In this week's questions show, I explain why NASA decided to build James Webb and not more Hubble Space Telescopes, what would happen if you opened up a jar in space, and do we know of any stars without planets?

Explorers have always brought stowaways with them on board. Thanks to our travels around the world, hardy creatures like rats, goats, pigs and starlings and more have found their way to every corner of the globe. Not to mention our plants, microbes and viruses.

Wherever we go, life goes with us, whether we want it to or not. And when we travel to other worlds, it looks like the most extreme life Earth has ever cooked up is ready and willing to make the journey with us.

Now that the big flybys are over, it’s time to dig into the regolith, search for life in underground lakes and oceans, return samples back to Earth. We’re going to give life every opportunity to contaminate other worlds.

What can we do to prevent it?

In this week's penultimate episode of Open Space before our summer hiatus, I give tips and tricks on seeing Jupiter, what's a good starting telescope, updates on LIGO, why rockets launch straight up, and more...

In this week's live QA episode, I tackled questions about the reality of returning astronauts to the Moon by 2024, the loss of dark skies, will we ever be able to shop for our own personal spacecraft, and more.

In this QA, I explain why only gas giants have rings, if it would be possible to cool down Venus, what would it take to build a generational ships and more...

Every time we send a spacecraft to another world, our Earth-based lifeforms are going with us. No matter how well we try to keep them clean, a few stowaways will always come along for the ride.

You’d think that years in the cold hard vacuum of space, suffering extreme temperature changes, and receiving brutal doses of radiation would be all it takes to sterilize any life caught on the outside of a lander or rover headed to Mars or Europa.

Well, think again. Life just demonstrated that it’s surprisingly ready to make the journey, and happy to get back to work the moment conditions improve.

In this week's questions show, I give my personal experience of how bright the Starlinks are, and I wonder if companies like SpaceX have the right to provide internet to the planet. Who asked them? Why do people think black holes are so cool? They're scary!

On Thursday, May 23rd, 2019, SpaceX launched one of its most important payloads in the history of the company - 60 satellites that will begin the constellation of their Starlink internet satellite system.