Universe Today Podcast

In this week's questions show, I talk about searching for life on Venus, trying to get to orbit with a jet, and why NASA probably shouldn't hire me. This episode features special guest SciManDan.

Welcome back to Season 2 of my weekly live QA. Your chance to ask me your questions about space and astronomy... live. Sometimes I'll have guests, and sometimes I won't. This week... I didn't.

You wanted to know about recent news about astronauts mixing concrete in space, the formation of craters on Titan, and what might be the difficulties of people going to the Moon or Mars?

We’ve reached the third part of our series on Lagrange Points, those stable spots in the Solar System, where you can sort of hover with the minimum amount of fuel.

This episode we’re going to look at the L4 and L5 points which share the orbit with a more massive object.

Lagrange Points. Stable spots in space that you just can’t stop thinking about. What spacecraft work best in which places? What are some amazing ideas that could utilize these regions across the Solar System?

In the last episode, I gave an overview of the Lagrange points, and then went into the details of spacecraft missions sent to L1, the perfect place to constantly observe the Sun, the Earth, or to block radiation coming from the Sun. The best place for a lunar elevator, or a spot to put a space station at the Moon.

This week, we’re going to talk about L2 and L3, the other meta-unstable spots that you can park a spacecraft at.

Thanks to gravity, there are places across the Solar System which are nicely balanced. They’re called Lagrange Points and they give us the perfect vantage points for a range of spacecraft missions, from observing the Sun to studying asteroids, and more.

Various spacecraft have already visited Lagrange Points, used them for some or all of their missions, and there are fascinating plans in the works that could put new missions and even space colonies into these balanced places in the Solar System.

Let’s explore the Lagrange Points.

In this week's questions show, I introduce Ona, by request. I explain why I don't think going to space is going to fix the big challenges that humanity faces, and how do astronomers figure out how big a planet is?

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.