Category: aliens

Ask Ethan: Would An Alien Civilization Classify Earth As An ‘Interesting’ Planet?

“I was thinking about the projection of light through space. My curtain was open and I saw the stars and something from a book popped into my head. It had said that the stars we see are basically reruns. The light is from so long ago, we don’t even know if the star still exists or not.

[…] Whatever signals we send out, or changes in our planet that might be observable to prove intelligent life lives here, would take billions of years to reach anything alive and capable of responding! What do you think?”

The cosmic distances separating the stars and galaxies are absolutely tremendous, and even though the speed of light is the fastest speed there is, it still takes an awfully long time to traverse the astronomical abyss of space. Humanity has only been a technologically advanced civilization for a few hundred years, and we’ve only entered the space age a few decades ago. Yet that doesn’t mean we’re off-limits to advanced aliens who might be looking for us at all. Even if they couldn’t discover our technosignatures, they could still tell, even from billions of light-years away, that Earth was an interesting, inhabited planet, using nothing more than more advanced versions of the technologies we’re using today and in the near-future to look for life on exoplanets in our cosmic backyard.

An alien civilization with more advanced technology could detect cosmically interesting things about Earth from extremely far away. Here’s where your hopes and fears meet with reality: on this week’s Ask Ethan!

Why Does Mars Appear To Have Smoke Plumes In Its Atmosphere?

“On Earth, such plumes typically indicate one of two things: fires or volcanic eruptions. Without carbon-based material or copious amounts of available oxygen, we can rule out fire. Mars possesses the Solar System’s largest volcano in Olympus Mons, but it appears to be extinct. Although there is some circumstantial evidence that Mars may be volcanically active, we’ve never witnessed an eruption. Instead, these plumes are a simple atmospheric phenomenon: clouds.”

Have you ever seen a picture of Mars that displayed a feature that appeared to be an enormous smoke plume rising up from its surface? It isn’t a dust devil, as even though Mars has those, they don’t look like this. It isn’t a volcanic eruption, as even though Mars has multiple enormous volcanoes, they’re not active at this time. And it definitely isn’t fire from a Martian civilization, as Mars doesn’t even have the right atmospheric constituents to make a fire like we can on Earth.

Instead, it’s simply a cloud, albeit a type of cloud that can extend for many hundreds of kilometers around the Martian globe. Come find out how it forms today!

Is Alien Life Hiding Beyond Earth 2.0?

“It may be the case that life is rare in the Universe, in which case it will require us to look at a lot of candidate planets — possibly with very high precision — in order to reveal a successful detection. But if we search exclusively for planets that have similar properties to Earth, and we restrict ourselves to looking at parent stars and solar systems that are similar to our own, we are doomed to get a biased representation of what’s out there.

You might think, in the search for extraterrestrial life, that more is more, and that the best way to find life beyond Earth is to look at greater numbers of candidate planets that might be the Earth 2.0 we’ve been dreaming of for so long. But non-Earth-like planets could be home to life that we’ve never considered, and we won’t know unless we look. More is more, but “different” is also more. We must be careful, as scientists, not to bias our findings before we’ve even truly started looking.”

If we want to find life elsewhere in the Universe, it only makes sense to look at our own world, where we know it was successful, and to try and find other worlds similar to our own. But that absolutely cannot be the only thing we do, or the only inhabited worlds we’ll even have a chance at finding are the ones similar to our own.

We have many good reasons to favor or disfavor the probability of finding life on a variety of planets and moons out there in our galaxy, but the real truth of the matter is we don’t know how common or rare life is. We don’t know how common or rare a huge variety of processes are, or even whether life is more likely to arise under conditions very different from those we find on our own planet.

It’s possible that Earth-like worlds are the best bet for life in the Universe, but don’t count out the non-Earth-like worlds without looking. Here’s what everyone hopeful for discovering alien life should keep in mind as we search the galaxy.

What If It’s Just Us?

“Our scientific discoveries have led us to a remarkable point in the quest for knowledge about our Universe. We know how big the Universe is, how many stars and galaxies are in it, and what fraction of stars are Sun-like, possess Earth-sized planets, and have planets in orbits which are potentially habitable. We know the ingredients for life are everywhere, and we know how life evolved, thrived, and gave rise to us here on Earth.

But how did life arise to begin with, and how likely is a planet to develop life from non-life? If life does arise, how likely is it to become complex, differentiated, and intelligent? And if life achieves all of those milestones, how likely is it that it becomes spacefaring or otherwise technologically advanced, and how long does such life survive if it arises? The answers may be out there, but we must remember the most conservative possibility of all. In all the Universe, until we have evidence to the contrary, the only example of life might be us.”

When it comes to the big questions, there’s perhaps none more profound than asking about life in the Universe beyond planet Earth. Are there other intelligent alien species out there, flying through the galaxy, modifying their planets, generating enormous signals, colonizing other worlds, and so on? Or, perhaps, in all the Universe, is life like us, and perhaps life at all, a great cosmic rarity? While most of the stories you’re likely to read on the topic are extraordinarily optimistic about the existence of intelligent aliens, we must let the science, rather than our hopes or emotions, guide us.

In all the Universe, we still might stand out as the only example of intelligent life. Here’s the scientific story of why it may just be us.

What If It’s Just Us?

“Our scientific discoveries have led us to a remarkable point in the quest for knowledge about our Universe. We know how big the Universe is, how many stars and galaxies are in it, and what fraction of stars are Sun-like, possess Earth-sized planets, and have planets in orbits which are potentially habitable. We know the ingredients for life are everywhere, and we know how life evolved, thrived, and gave rise to us here on Earth.

But how did life arise to begin with, and how likely is a planet to develop life from non-life? If life does arise, how likely is it to become complex, differentiated, and intelligent? And if life achieves all of those milestones, how likely is it that it becomes spacefaring or otherwise technologically advanced, and how long does such life survive if it arises? The answers may be out there, but we must remember the most conservative possibility of all. In all the Universe, until we have evidence to the contrary, the only example of life might be us.”

When it comes to the big questions, there’s perhaps none more profound than asking about life in the Universe beyond planet Earth. Are there other intelligent alien species out there, flying through the galaxy, modifying their planets, generating enormous signals, colonizing other worlds, and so on? Or, perhaps, in all the Universe, is life like us, and perhaps life at all, a great cosmic rarity? While most of the stories you’re likely to read on the topic are extraordinarily optimistic about the existence of intelligent aliens, we must let the science, rather than our hopes or emotions, guide us.

In all the Universe, we still might stand out as the only example of intelligent life. Here’s the scientific story of why it may just be us.

Aliens? Or Alien Impostors? Finding Oxygen Might Not Mean Life, After All

“This doesn’t mean that finding an Earth-like world with an oxygen-rich atmosphere won’t be incredibly interesting; it absolutely will be. It doesn’t mean that finding organic molecules coincident with the oxygen won’t be compelling; it will be a finding worth getting excited over. It doesn’t even mean that it won’t be indicative of life; a world with oxygen and organic molecules may well be overflowing with living organisms. But it does mean that we have to be careful.

Historically, when we’ve looked to the skies for evidence of life beyond Earth, we’ve been biased by hope and what we know on Earth. Theories of dinosaurs on Venus or canals on Mars still linger in our memories, and we must be careful that extraterrestial oxygen signatures don’t lead us to falsely optimistic conclusions. We now know that both abiotic processes and life-dependent ones can create an oxygen-rich atmosphere.

The hard problem, then, will be disentangling the potential causes when we actually find our first oxygen-rich, Earth-like exoplanet. Our reward, if we’re successful, will be the knowledge of whether or not we’ve actually found life around another star.”

If you were looking for life around a planet orbiting another star, how would you do it? Your first inclination might be to look for something just like Earth: an Earth-mass planet with Earth’s size and Earth’s orbital parameters around a Sun-like star. You might then go a step further and try to examine its atmospheric contents. If you found a large amount of oxygen and organic molecules in the same atmosphere, you might conclude that you’d found it: a world beyond our Solar System that was inhabited. But that’s not necessarily the case! 

Out of Dr. Sarah Hörst’s lab comes a new finding: oxygen and organics can arise through abiotic processes on exoplanets. Oxygen may not mean life, after all.

Starts With A Bang #38 — Interstellar Interloper `Oumuamua

The first identified visitor from another solar system gets its own Starts With A Bang podcast!

In 2017, the incredible happened: for the first time in history, we were able to identify an object passing through our Solar System that originated from outside of it! Interstellar interloper ‘Oumuamua was originally designated as a comet, then as an asteroid, and then as a new class of object: one of interstellar origin. It’s a fascinating object that’s the first of its kind, and much has been said about its composition, properties, and possible nature.

But, unfortunately, the most famous of those “nature” discussions was from Schmuel Baily and Avi Loeb of Harvard, claiming that it could be due to aliens.

Is that plausible? Is that even science? My guest for this edition is astrophysicist Paul Matt Sutter, author of the new book Your Place In The Universe, and we have an almost-hour-long discussion that goes to some fantastic and unexpected places. You won’t want to miss it!


The Starts With A Bang Podcast is made possible through the donations of our Patreon supporters, who get it early, get shout-outs, and much more!

Find Paul online on Twitter twitter.com/PaulMattSutter,
Video: www.pmsutter.com/shows/askaspaceman/,
Book: Your Place In The Universe amzn.to/2DCysNj

‘Aliens’ Is Not A Scientific Explanation For Interstellar Asteroid ʻOumuamua

“We often say that extraordinary claims require extraordinary evidence, and in all of these cases the evidence is very, very ordinary indeed. It’s worth keeping our mind open to the possibility that there’s more out there in the Universe than we presently realize, but not to embrace those possibilities as likely in any way whatsoever. When you leap to explanations that are fantastic, it’s all too easy to forget about the most likely explanations, which often involve nothing more than the natural phenomena already present and well-understood in the Universe we know.

In the case of interstellar interloper ʻOumuamua, we should be looking at the natural explanations first and foremost, not speculating about something for which the only evidence is our own wishful thinking. After all, what can be asserted without evidence can — and should — be dismissed without evidence.”

When you find a new phenomenon in the Universe, one that you’ve never seen before, the opportunity to discover something new about your reality is unparalleled. Oftentimes, you’ll try to use what you know to infer what behavior you expect, but it’s usually just a first-order, naive approximation. Until you collect enough data, find enough objects that fall into the new category, and study them with the required precision and detail, you’ll merely be speculating about what’s going on.

Last year, our Solar System got a visit from an interstellar interloper, marking the first time that’s ever happened. It’s been an interesting ride, full of interesting science and fascinating findings. Which is why it’s maddening that the one time it makes news is when a couple of scientists from Harvard take off their scientist hat and run headlong into sci-fi speculations.

For what I’m sure won’t be the last time, invoking aliens as an explanation for what you don’t understand isn’t science. Don’t fall for it. Get the facts instead!

New Podcast: Humanity’s 3 Hopes For Alien Life

There are three very different ways humanity is searching for alien life beyond Earth. We can directly search the various planets and moons in our Solar System for past or present biological signatures simply by sending decontaminated probes, and looking for the evidence in situ. We can indirectly look at distant worlds around other stars, searching for the characteristic changes to the atmosphere and surface that life would bring. And, most optimistically, we can search for intelligent signatures created, perhaps willfully, by a technologically advanced alien species. These are our three hopes for finding alien life, and we’re actively pursuing all three.

Here’s how the different searches work, along with some speculation about what we’re likely to find, and what motivates us to look!

Aliens In The Multiverse? Here’s Why Dark Energy Doesn’t Tell You Anything

“It’s important to recognize that there are a wide variety of possible values that dark energy could have, including significantly larger values, that would still lead to a Universe very much like our own. Until we understand where these values come from, and what makes one set of values more likely than another, it’s grossly unfair to claim that we won the cosmic lottery in having a Universe with the values ours possesses. Unless you know the rules that govern the game you’re playing, you have no idea how likely or unlikely the one result you see actually was.”

There are a series of interesting results that have just emerged from the EAGLE collaboration, which has been simulating the Universe to learn what types of stars and galaxies form within it. They varied the value of dark energy in it tremendously, and found that even if you increased the amount by five, ten, or fifty times as much, you’d still form plenty of stars and galaxies: enough to give you chances at life like we have here. This surprised them, since they assumed the value of dark energy we have is finely-tuned to allow life. But it appears that things may not be as finely-tuned as we had thought! The simulation results are interesting, but this doesn’t really tell you anything about aliens in the Multiverse, since we have no idea what causes dark energy to have the values that it does.

Until we know the rules that govern this, we can’t really say what dark energy tells us about aliens in Universes other than our own. Here’s why.