Our Place in Space: The Moon Village

April 15, 2022April 14, 2022 ~ J.S. Pailly ~ 11 Comments

Hello, friends! Welcome to Our Place in Space: A to Z! For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space. If you don’t know what the A to Z Challenge is, click here to learn more. In today’s post, M is for…

THE MOON VILLAGE

The last time humans went to the Moon, it was motivated in large part by the Cold War. Yes, there were scientific and humanistic reasons to go to the Moon as well, but the Cold War was a big part of it. There’s no denying that. Let’s hope that next time will be different. Let’s hope that next time, human beings will set foot on the Moon as a result of international cooperation, rather than as a result of quasi-militaristic competition.

A few years ago, the European Space Agency proposed building a “village” on the Moon. This International Moon Village would serve as the logical successor to the International Space Station. Anyone and everyone who wanted to participate would be welcome to participate in the Moon Village program. As the E.S.A.’s website explains it:

By “Moon Village” we do not mean a development planned around houses, some shops and a community centre. Rather, the term “village” in this context refers [to] this: a community created when groups join forces without first sorting out every detail, instead simply coming together with a view to sharing interests and capabilities.

It’s hard to say at this point what the Moon Village would look like. A lot depends on who decides to participate. A lot also depends on how the various participants want to use the Moon Village once it is built. The proposal is very open ended about this stuff. Government run space agencies could join the program. So could private companies. The Moon Village could be used for purely scientific and technological research. At the same time, it could also be used for economic interests, such as mining the Moon for resources. Even space tourism would be welcome.

When the Moon Village was first proposed a few years ago, my understanding was that the Russian space agency was going to be a key player in this project. That’s… ummm… I’m guessing that’s no longer the case. I’m also a little unclear about whether or not the United States is involved. It sometimes sounds like NASA’s Artemis Program and E.S.A.’s Moon Village Project are totally working together; other times, it sounds like Artemis and the Moon Village are two completely separate and unrelated projects.

Despite all that, and despite everything else happening in the world today, I get the sense that E.S.A. is still moving forward with their Moon Village plans. This is a project that really could happen, and I really hope that it does happen. Anyone who wants to participate in the Moon Village is welcome to participate in the Moon Village. No one will be excluded. No one will be left out. Those are the kind of values humanity needs right now, and in the future, those are the kind of values that will help us secure our rightful place in space.

Want to Learn More?

Check out this brief statement from Jan Woerner, the Director General of E.S.A., describing what the Moon Village would be like and how it might be used.

Our Place in Space: Lava Tube Habitats

April 14, 2022 ~ J.S. Pailly ~ 11 Comments

LAVA TUBE HABITATS

The surface of Mars is not a safe place for humans. Martian dust storms can be really scary. The temperature fluctuates wildly from a bit too cold to waaaaay too cold, and there’s basically no protection against all the deadly radiation raining down on the planet from space. Fortunately, humans in the distant future won’t need to live on the surface of Mars. Mars is offering us free housing in the form of underground lava tubes.

Mars was once a volcanically active world. In fact, the largest volcano in the entire Solar System is on Mars. Lower gravity means volcanoes can grow much larger on Mars than they ever could on Earth. But Mars hasn’t been volcanically active for a long, long time. The volcanos stopped erupting and the lava stopped flowing billions of years ago. Today, all those oversized Martian volcanoes are extinct, and all the lava tubes around them are now empty.

So what exactly is a lava tube? Well, have you ever seen rivers of lava (either in real life or in videos) flowing down the side of an active volcano? You know how the surface of these lava rivers starts to cool off, forming a blackened crust? Eventually, this crusty surface lava will become thick enough and solid enough to form a roof over the lava river, while the rest of the lava continues to flow freely underneath. This is how lava tubes form.

On Earth, lava tubes can get pretty large. They can be wide enough and tall enough for multiple people to walk through them comfortably. On Mars, lava tubes could (theoretically) be even larger—almost half a kilometer wide, perhaps! Once again, this is because of the reduced Martian gravity, which allows all sorts of natural structures to grow larger on Mars than they ever could on Earth.

In the future, sections of these lava tubes could be sealed off and pressurized with air. Dust storms could rage on the Martian surface while human colonists remain safely underground. All that natural rock would insulate us against the extreme temperature variations on the surface, and the rock would also serve as a natural barrier against all that radiation raining down from space. With relatively little effort, we could convert the smaller lava tubes into comfortable and cozy human habitats. Or, using those half kilometer-wide tubes, we could build much larger and more robust human communities.

At the moment, though, finding lava tubes that would be suitable for human habitation is tricky. Lava tubes are underground. Therefore, fully intact lava tubes are not visible in photos taken by our orbiting space probes. The only Martian lava tubes we currently know about are the ones where the roof has either partially or fully collapsed. This leaves us with a bit of a Catch-22 scenario: any lava tube we can currently find is structurally compromised and, therefore, might not be suitable for human habitation.

But that seems to me like a limitation of our current Mars exploration program. As NASA, the E.S.A., and other human space agencies send more and more orbiters, landers, and rovers to Mars, I’m sure new techniques (seismography, gravity mapping, etc.) can be used to find all the lava tubes hidden beneath the Martian surface.

Want to Learn More?

Here’s a short paper advocating for more research about lava tubes on Mars and also on the Moon.

And here’s a ten minute video from Fraser Cain describing what we currently know about Martian and Lunar lava tubes in more detail.

Our Place in Space: Kraken Mare

April 13, 2022April 12, 2022 ~ J.S. Pailly ~ 14 Comments

KRAKEN MARE

Earth is a pretty special place, what with all this liquid water covering our planet’s surface. You won’t find that much liquid water on the surface of any other planet or moon in the Solar System (underground, maybe, but not on the surface). In a similar way, Titan is a special place. Titan, the largest moon of Saturn, is covered with lakes and rivers of liquid hydrocarbons, a mix of mostly liquid methane and liquid ethane. You won’t find that much liquid methane/ethane on the surface of any other world in the Solar System.

Kraken Mare is the largest body of… I wanted to say the largest body of water, but that wouldn’t be right, would it? Kraken Mare is the largest body of liquid hydrocarbons on Titan. Take all five of North America’s Great Lakes, combine them together—that’s how large Kraken Mare is. Titan is much smaller than Earth, so Kraken Mare ends up being an enormous surface feature, sprawling across part of Titan’s northern hemisphere.

And nobody knows how deep Kraken Mare is. Scientists were able to measure the depth of every other lake on Titan using RADAR data collected by the Cassini space probe, but the data for Kraken Mare was inconclusive. This means either that Kraken Mare is too deep for Cassini’s RADAR equipment to measure, or some unknown substance at the bottom of Kraken Mare absorbed Cassini’s RADAR pings, limiting the data Cassini was able to collect. Either way, wouldn’t it be fascinating to know what’s down there?

NASA seems to think so, and there are proposals on the table to send some sort of robotic submarine to Titan, to explore Kraken Mare further. This is another of those space missions that is not actually happening yet. It has not been approved by NASA. It does not have the funding to go forward. But still, it’s an idea that scientists are working on, trying to figure out if it’s feasible, with the hope that someday they can make it happen.

Could there be life on Titan? Maybe. Some astrobiologists clearly think it’s possible, though they probably aren’t expecting to find an actual kraken at the bottom of Kraken Mare. Just some single-celled organisms doing some strange, alternative form of organic chemistry. Still, that possibility is there, and it’s another reason why diving to the bottom of Kraken Mare seems like a good idea.

Fortunately, NASA has approved a new mission to explore Titan. Unfortunately, this new mission does not include a submarine, and it won’t be going anywhere near Kraken Mare. Instead, the Dragonfly rotorcraft (a robotic mini-helicopter) will explore Titan’s Shangri-La region, a mysteriously dark colored region near Titan’s equator.

Meanwhile, the proposal to put a robotic submarine in Kraken Mare is still on the table. Sooner or later, that mission is going to happen. I’m sure of it. Kraken Mare is simply too big and too mysterious for us humans to leave it unexplored.

Want to Learn More?

Here’s a short article from NASA, which includes a short video, on the Titan Submarine proposal.

And here’s a longer piece from EarthSky.org with more details about Kraken Mare and how we might one day explore its depths.

Our Place in Space: Jezero Crater

April 12, 2022April 11, 2022 ~ J.S. Pailly ~ 8 Comments

JEZERO CRATER

Someday, I’d like to help dig up dinosaur fossils. That’s apparently a thing pretty much anybody can volunteer to do. Someday, I’d also like to live on Mars. In the distant future, it may be possible to do both of those things. Places like Jezero Crater on Mars may be full of ancient Martian fossils!

If you look at satellite images of Jezero Crater, it’s pretty obvious it used to be full of water. You can see what appears to be a dried-up river bed snaking its way across the Martian landscape. Where that river meets the crater, there’s a breach in the crater wall and a large river delta where the river would have spilled into the crater basin.

Right now, NASA’s Perseverance Rover is driving around that river delta, scoping the place out, examining the sediments and clays found in the region.

Okay, I may have taken some creative liberties with the cartoon above. If life ever did evolve on Mars, it would have been short-lived. All of Mars’s lakes, rivers, and oceans would have dried up fairly early in the planet’s history. It is highly unlikely that anything as complex as fish or seaweed could have developed, and there certainly wouldn’t have been anything as awesome as a Martian dinosaur.

But in places like Jezero Crater, simple microorganisms could have been plentiful. These microbes may even have joined together, creating larger structures like the bacterial mats we sometimes find here on Earth. That’s kind of icky, I know, but it could have happened, and those bacterial mats may still be there, preserved as fossils beneath all that red dust.

I don’t expect questions about life on Mars (past or present) to be answered any time soon. Even if one of our Mars rovers did stumble upon something that looked like a fossilized bacterial mat, there would be scientific debates for years—decades, even—over what that fossil-looking-thing really is and what it’s presence on Mars really means. We’ve been through this before, when scientists found “bacteria shaped objects” inside a Martian meteorite. Something can look like a fossilized bacterium, and yet not be a fossilized bacterium.

But someday in the distant future, we will know, one way or the other, if life ever existed on the Red Planet. And perhaps in that distant future, humans living on Mars will volunteer to help dig up fossils in Jezero Crater, or other places very much like it.

Want to Learn More?

Here’s an interactive map from NASA showing the Perseverance Rover’s current location. You’ll have to zoom out a little to see all of Jezero Crater. If you do, you’ll see that the dried-up river (marked Neretva Vallis) and river delta I mentioned are pretty obvious.

And here is a NASA press release from a few years back, announcing Jezero Crater as the Perseverance Rover’s landing site and explaining why the crater was selected.

Also, here’s an article from Space.com about that Martian meteorite I mentioned, the one with those “bacteria shaped objects” inside.

Our Place in Space: An Immature Technosphere

April 11, 2022April 10, 2022 ~ J.S. Pailly ~ 14 Comments

AN IMMATURE TECHNOSPHERE

In a previous post, I told you about the DART Mission, our first real experiment to see if we can defend our planet from incoming asteroids. I believe humanity has a tremendous responsibility to protect our planet, not only for our own benefit but for the benefit of the entire Earthly biosphere. Incoming asteroids can do serious harm to Earth’s biosphere (just ask the dinosaurs). But, of course, there are other threats to the biosphere that should concern us—more immediate and urgent threats, too.

The term “immature technosphere” is mainly associated with SETI research. Imagine, if you will, a planet that is home to alien life. Over cosmic timescales, we might expect this hypothetical alien planet to go through several phases of development.

Phase One: The Immature Biosphere
Life has begun! The first microorganisms are swimming around in the planet’s water (or whatever liquid this planet has instead of water). But biological activity produces biological waste, in one form or another, so as these early organisms multiply and spread, they may end up poisoning their own environment with their own waste products.

Phase Two: The Mature Biosphere
Life has found a way. A variety of organism have now evolved, and the waste produced by one organism serves as fertilizer, food, or fuel for others. A natural balance has been achieved. Natural cycles have emerged. Life not only survives but thrives!

Phase Three: The Immature Technosphere
Intelligent life has emerged, by which I mean life capable of creating and using technology. But as these intelligent life forms begin using technology on a grander and grander scale, they may inadvertently disrupt the natural cycles and the natural balance of their world. Life is threatened once again, this time by technological waste.

Phase Four: The Mature Technosphere
If intelligent life is truly intelligent, it will recognize the harm it is doing to its own environment and start inventing ways to undo that damage, or at least to keep the damage in check. In time, perhaps a new balance will be achieved, with nature and technology working together in harmony.

Turning our attention back to Earth, I think it’s fair to say our planet is in the “immature technosphere” phase of development. But an immature technosphere today implies that a mature technosphere may develop later on, and that gives me hope.

I keep saying that this “Our Place in Space” series is a highly optimistic view of humanity’s future. Part of what I mean by that is that we will not leave Earth behind. We will not make a new home for ourselves on the Moon or Mars or elsewhere after destroying our first home here on Earth. I doubt that that would work anyway; any off-world colony we might establish would still be dependent on Earth for a long, long time to come.

I know a lot of people who see the state of the world and despair. Things are bad right now, and some of the damage we are doing to our planet and to each other cannot be undone. But a better future is still possible. Humanity just needs a bit more time to mature.

Want to Learn More?

Earth in Human Hands by David Grinspoon is one of my all time favorite books. It’s certainly my #1 favorite non-fiction book. As an astrobiologist, Grinspoon has more knowledge and authority on scientific matters than I do, but his view of the future is much like the view I’ve been presenting in these A to Z Challenge posts.

So if you’re worried about the state of the world and you want to believe that a better and brighter future is still possible, I highly recommend picking up Grinspoon’s book.

Our Place in Space: HAVOC

April 9, 2022April 8, 2022 ~ J.S. Pailly ~ 16 Comments

HAVOC

Venus is my favorite planet. If you’ve been reading this blog for a while, you probably already know this about me. The Venusian atmosphere is weird and chemically complex. The surface is mysteriously smooth, hinting at some pretty extreme geological activity. And did you know Venus is spinning the wrong way? She rotates clockwise where every other planet in our Solar System has counterclockwise rotation. In many ways, I feel like Venus is the planet with the most personality (aside from Earth, of course). So if there’s a realistic possibility of humans colonizing Venus one day, nothing would please me more!

HAVOC stands for High Altitude Venus Operational Concept. It’s NASA’s very preliminary plan for exploring Venus, first with robots, then with astronauts, with the eventual goal of establishing a permanent human presence. Most people scoff at the idea of sending humans to Venus. Surface conditions are hellish. The surface temperature is 475 degrees Celsius (900 degrees Fahrenheit). Atmospheric pressure is 90 times greater than what we experience here on Earth. Sulfuric acid falls from the sky as rain, and don’t forget about that extreme geological activity I mentioned. Nobody’s sure what’s happening, but the ground is too smooth, as if it gets regularly “repaved” with fresh lava.

But HAVOC would not involve putting boots on the ground. Instead, astronauts would explore Venus from the safety of blimps and other airborne habitats. At an altitude of 55 kilometers above the surface, Venus is quite nice. You might even call it heavenly. The temperature and pressure are roughly Earth-normal. We’d experience Earth-like gravity, too, and Venus would provide almost Earth-like protection from solar and cosmic radiation (a service that the Moon and Mars do not offer). Also, 55 kilometers up, we wouldn’t have to worry about the sulfuric acid rain; we’d be above the layer of sulfuric acid clouds!

Obviously this is not happening any time soon. The people at NASA seem to have their hearts set on returning to the Moon in the near future, with a long term goal of getting to Mars. Still, the idea of exploring Venus with blimps makes sense. In some ways, Venus might end up being a better second home for humans than Mars—just so long as we stay at that 55 kilometer altitude.

So in the distant future, when humanity is spreading out across the Solar System, don’t be surprised if large numbers of people live in Cloud City-like habitats on Venus.

Want to Learn More?

Check out this paper from the American Institute of Aeronautics and Astronautics, detailing HAVOC as a five phase plan to explore and colonize Venus.

Also, here’s a video from NASA showing what a HAVOC mission might look like, from first arrival in Venusian orbit to safe return back on Earth.

Our Place in Space: The Great Red Spot

April 8, 2022April 7, 2022 ~ J.S. Pailly ~ 17 Comments

THE GREAT RED SPOT

Humanity is struggling right now. There’s war and bigotry. There’s disease and poverty and climate change. Despite these problems, I still have tremendous hope for the future. I still believe that we can work past our current problems and build a better future for ourselves and for our planet. But when I think of this better and brighter future, there’s still one thing I worry about. It’s a minor thing, but still… I worry: what’s going to happen to Jupiter’s Great Red Spot? Will it still be there in the future, or will it slowly fade away and disappear?

In the late 1800’s, the Great Red Spot was observed to be approximately 50,000 kilometers wide. For comparison, the entire Earth is only 13,000 kilometers in diameter. But by 1979, when NASA’s Voyager space probes arrived at Jupiter, the Great Red Spot had shrunk to a mere 23,000 kilometers in width. It was less than half the size it once was! And today, it’s only 16,000 kilometers wide. You see now why I’m worried.

I get a bit frustrated with news reports declaring that the Great Red Spot is certain to disappear. I also get annoyed with news reports saying it’s certain not to disappear. The popular press goes back and forth on this. It’s sort of like those news reports you’ll hear about whether or not eggs are good for you. First they’re good, then they’re bad, then they’re good if you cook them this way, then they’re still bad no matter how you cook them. In a similar way, first the Great Red Spot is disappearing, then it isn’t, then it is again, and so on.

I think the popular press just doesn’t understand what it means when scientific research gets published. Published research is best understood as part of an ongoing conversation. One group of astronomers says they believe the Great Red Spot is disappearing for reasons X, Y, and Z. Then another group of astronomers say they think it will endure for reasons A, B, and C. Then maybe another group will contribute reasons J, K, and L to the discussion. This back and forth discussion continues on and on in the pages of scientific journals, until some sort of scientific consensus is reached (or until the Great Red Spot actually disappears—that would also settle the debate).

But the popular press always seems to latch onto one published paper and present it to the general public as if it is the final word on the matter, as if it is a proclamation of scientifically proven fact. That is until they latch onto the next published paper and present that as the final word.

So what’s really going to happen to the Great Red Spot? Well, it’s undeniable that it has shrunk significantly over that last century or so. Maybe it will keep shrinking until it’s gone, or maybe it’ll pick up steam again and start to expand once more. Maybe the Great Red Spot goes through century-long phases of shrinking and expanding. Maybe we just haven’t been observing it long enough to know that. Scientists are still studying this issue, comparing and contrasting their findings, and debating what it all means. That’s often the way with science (and I hope you’ll keep that in mind the next time you see a news report that begins with the words “According to a new scientific study…”).

Even without the Great Red Spot, Jupiter would be an awe-inspiring sight. I do hope, though, that it will still be there for all those future colonists on Callisto to see and enjoy.

Want to Learn More?

I found a few relatively recent articles that talk about the Great Red Spot and why it might or might not disappear. These articles are, in my opinion, more responsible in how they present their information than other articles I’ve seen.

“Jupiter: Mission Unveils the Depth and Structure of Planet’s Shrinking Red Spot and Colorful Bands” from The Conversation.
“NASA’s Juno Spacecraft Finds Just How Deep Jupiter’s Great Red Spot Goes” from The Verge
“The Shape of Jupiter’s Great Red Spot is Changing, Here’s Why” from The Planetary Society.

Our Place in Space: The Far Side of the Moon

April 7, 2022 ~ J.S. Pailly ~ 6 Comments

THE FAR SIDE OF THE MOON

The James Webb Space Telescope has been getting a lot of press lately. It’s the biggest and best telescope we humans have ever put into space. But today, we’re going to imagine an even bigger and (potentially) an even better telescope. We’re not going to put this telescope in space, though. We’re going to build it on the surface of the Moon.

The far side of the Moon is the perfect location to build a radio telescope. We’ve certainly built radio telescopes here on Earth, but those Earth-based radio telescopes keep running into the same two problems. First, Earth’s atmosphere (especially the ionosphere) blocks certain cosmic radio wave frequencies from reaching us here on the ground. And second, there’s a whole lot of terrestrial radio chatter happening here on the ground. That chatter can interfere with any radio signals that do make it through from outer space.

But on the far side of the Moon, those problems don’t exist. There’s no atmosphere, and certainly no ionosphere. And since this is the far side of the Moon we’re talking about—i.e., the side of the Moon that always faces away from the Earth—all that terrestrial radio noise is gone. The Moon itself would block those signals from ever interfering with our radio telescope.

The telescope itself would be absolutely enormous. It would be built inside of a crater, with a dish approximately one kilometer wide. NASA has already approved funding to research this idea; please note, they have not approved funding to build it yet! Only to research the idea, to see if it’s actually feasible using current technology. If it turns out that it is feasible, though, building a radio telescope on the far side of the Moon might end up being part of NASA’s new Artemis Program.

What would we do with our new lunar telescope? Well for one thing, we could “look back in time” to see what the ancient universe was like. Specifically, we could study a period of time known as the “cosmic Dark Ages.” This would have been a time after the Big Bang but before the formation of the first stars—literally, the cosmic Dark Ages, like I said. The hydrogen gas permeating the universe in that era would have emitted some amount of electromagnetic radiation, which we can still detect today in certain radio wave frequencies (or we could detect it, if Earth’s stupid atmosphere would stop getting in the way!).

In addition to looking for these naturally-occurring radio signals, our lunar radio telescope could also watch for radio signals that do not appear to be natural in origin. Radio transmissions from aliens, in other words.

Searching for aliens would definitely not be the main reason to build a radio telescope on the Moon. The stuff I said about the cosmic Dark Ages—that’s the main reason to do this. The aliens thing would just be a side benefit.

For this “Our Place in Space” series, I’ve mostly focused on projects that I think could happen in the distant future. But this lunar radio telescope project is something that probably needs to happen sooner rather than later. The far side of the Moon is the perfect location for a radio telescope right now, but as humans start spreading out across the Solar System, things may change. The far side of the Moon may get a whole lot noisier, in terms of radio chatter.

So in the distant future, rather than building a radio telescope on the Moon, we might prefer to build our radio telescopes farther out. Places like Pluto, Orcus, Eris, or Quaoar—all those little dwarf planets beyond the orbit of Neptune—may end up being super useful for future radio astronomers.

Want to Learn More?

Check out this article from NASA’s Jet Propulsion Laboratory: “Lunar Crater Radio Telescope: Illuminating the Cosmic Dark Ages.”

Also, here’s an article from Universe Today: “The Moon is the Perfect Spot for SETI.”

Our Place in Space: An Elevator to Space

April 6, 2022April 5, 2022 ~ J.S. Pailly ~ 16 Comments

AN ELEVATOR TO SPACE

It takes a lot of fuel to get to space. We’ve talked about this before, and we’re going to talk about it again (and again and again). In order for the human race to take our rightful place in space, we’re going to have to dream up some clever and crafty ways to reduce the fuel costs of space travel. One idea—an idea so crazy it might work—would be to build an elevator to space.

So how would we build a space elevator? Here’s one method: the first step would be to place a space station in geostationary orbit. Next, our space station would lower a cable all the way down to Earth’s surface. For the purposes of gravitational stability, the space station would also have to extend a second cable straight out into space, to serve as a counterweight to the weight of the first cable.

Once both cables are fully extended, an elevator carriage could be attached to the cable here on the ground. Then just press a button, and the elevator takes you to space!

This whole space elevator system would still require an enormous amount of energy. Also, a ride on the space elevator would take a really long time. Some sources I’ve looked at say reaching the “top floor” would take several days; others say it would be more like several weeks. And safety concerns should not be overlooked, because if that elevator cable ever broke, it could become a big problem all around the world (or at least all the way around Earth’s equator, if you catch my meaning).

Still, compared to launching rockets, this would be a far more cost effective and fuel efficient way to transport people and materials from the ground up into space. As for the safety concerns, we just have to be sure we make that cable out of some really, really, really, really, really, really, really strong material, to ensure that it never breaks! One problem: no such material is known to exist yet. Carbon nanotubes and other experimental nano-materials might be strong enough, or they might fall a bit short of being strong enough. It’s hard to say at this point.

So this is definitely not a thing we can build right now, but maybe someday in the distant future, going space will be as easy as riding an elevator. I just hope they come up with better elevator music by then.

Want to Learn More?

I’m going to recommend this short video from Kurzgesagt (In a Nutshell) on space elevators.

I’m also going to recommend this slightly longer and slightly more technical video from Real Engineering.

Our Place in Space: The DART Mission

April 5, 2022April 4, 2022 ~ J.S. Pailly ~ 13 Comments

THE DART MISSION

So far this month, I’ve been telling you about things that I think will happen (or plausibly could happen) at some point in the distant future. But today, I’m going to talk about something that’ll happen in the not-so-distant future. Something that will happen in the very near future, actually. Later this year, in fact! In late September or early October of 2022, a NASA space probe named DART will deliberately crash into an asteroid named Dimorphos.

Dimorphos is a relatively small asteroid orbiting a much larger asteroid named Didymos. Basically, Dimorphos is Didymos’s moon. These two asteroids will be passing fairly close to Earth later this year. Now I want to be 100% clear about this: neither Didymos nor Dimorphos are going to collide with our planet. We are in no danger. But these asteroids will be coming close enough that we could do a little experiment—an experiment to see just how well we could defend our planet from a dangerous, mass-extinction-causing asteroid, should such an asteroid ever come our way.

DART stands for Double Asteroid Redirection Test. As you can see in the highly technical diagram below, the plan is for the DART spacecraft to have a head-on collision with Dimorphos.

This head-on collision should cause Dimorphos to lose some orbital momentum, which should alter Dimorphos’s orbit around Didymos. How different will Dimorphos’s new orbit be? Hard to say. The exact angle of impact… the astroid’s mineral composition… the amount of debris produced by the collision… all of these things may factor into what Dimorphos’s new orbit looks like.

Astronomers can do all the computer simulations they like, but until we throw a real life projectile at a real life asteroid, we won’t really know what will happen. Not with any kind of precision. Ergo, we need to do this experiment.

Looking once more into the distant future, I believe that humanity is going to spread out across space. Large numbers of people will eventually be living on the Moon and Mars, as well as on other planets and moons of our Solar System. But I also believe these humans in the distant future will take good care of the Earth. Among other things, they will know how to defend Earth from incoming asteroids and comets, so that what happened to the dinosaurs never has to happen again. And that capability—the capability to keep Earth safe from killer asteroids and comets—begins with a little NASA experiment scheduled to occur later this year.

Want to Learn More?

Here are a few papers that I’ve been reading about the upcoming DART Mission. This is where I got most of the information for today’s post: