Meet Mars’s Moons

Jn13 Mars's MoonsThis month, as part of the 2015 Mission to the Solar System, we’ve been visiting the planet Mars. How could we not spend at least one post talking about Mars’s two moons, Phobos and Deimos?

Someday, humanity will colonize Mars. When we do, these two moons should provide some interesting stargazing opportunities.

Phobos, as observed from the surface of Mars, may not be quite as large as Earth’s Moon as observed from the surface of Earth, but it’s still a large, easy to spot object. Now imagine watching this large object racing through the sky, rising and setting two or sometimes three times per day (I mean per sol). That’s what Martian colonists will get to see.

Meanwhile, Deimos only rises and sets once per day. That seems a bit more normal, expect for Martian stargazers, Phobos and Deimos will seem to be moving in opposite directions. This is because Deimos lags slightly behind Mars’s rotation, making it appear to be moving backwards compared to Phobos.

Deimos is also slowly drifting away from Mars.

Jn13 Deimos Sneaks Off

Eventually, Deimos will break free of Mars’s gravity and escape into a new orbit around the Sun.

Phobos, on the other hand, is getting gradually closer to Mars. At some point, tens of millions of years from now, it’s expected to crash into the planet’s surface.

Jn13 Phobos Falling

Lastly, both Phobos and Deimos look suspiciously like asteroids. On that note, our month-long tour of Mars comes to an end. The 2015 Mission to the Solar System will continue in July as we enter the asteroid belt (a region that went into an uproar after two of its asteroids mysteriously went missing).

P.S.: There’s another possible fate for Phobos: rather than crashing to the surface of Mars, it might be shredded by tidal forces. If so, the fragments could end up forming a faint planetary ring around Mars, which would be pretty cool.

Sciency Words: Entomophagy

Sciency Words BIO copy

Sciency Words is a special series here on Planet Pailly celebrating the rich and colorful world of science and science-related terminology. Today, we’re looking at the term:


If you want to live on Mars, you may have to get used to this term. It combines the Greek words for insect and eating. Yes, my friends, we’re talking about eating bugs.

Why Can’t We Eat Beef on Mars?

Keeping humans well fed will be one of the biggest challenges for Mars colonization (or frankly any long-term settlement off Earth). First off, you won’t have access to beef. Cattle require way too much grazing land.

The initial colony on Mars will likely only have a few small greenhouses to provide all their food. There simply won’t be room to spare for cows, pigs, or chickens. That also precludes having things like milk, cheese, and eggs.

It may be possible to raise fish on Mars. Loach and tilapia are sometimes included on the Mars diet menu. As a seafood fan, I’m all for that, but finding enough water for the required fish tanks could prove problematic.

Do We Really Need to Eat Insects?

Compared to more traditional barnyard animals, insects look like a much better option for feeding hungry colonists. Many insect species have already visited the International Space Station, so we know they’re okay with low or no gravity environments.

Insects don’t require much room. They can live in our tiny greenhouses and even help decompose plant waste like dead leaves, stems, and other inedible vegetable matter. In fact, we may have to bring insects with us anyway to help keep our plants healthy.

Best of all, insects convert almost everything they eat into insect protein. Very little nutrition is lost as it moves along the food chain.

So who else is ready to go to Mars and eat a handful of crickets?

Couldn’t We Just Be Vegans?

Plenty of people here on Earth survive without any animal protein whatsoever. No beef, chicken, dairy, tilapia, or even crickets. Some of these people assure me that they feel healthier on a vegan diet, and I have no reason to doubt them.

Maybe veganism would work on Mars, but the idea raises some concerns. With only a small number of greenhouses, the first colonies on Mars might not be able to supply a sufficiently diverse range of vegetables. Mission planners have therefore struggled to prepare a menu that doesn’t include at least some form of animal protein.

So entomophagy is something that both mission planners and science fiction writers alike might want to think about when designing future colonies on Mars or elsewhere.


Entomophagy as Part of a Space Diet for Habitation on Mars from the Japanese Rocket Society.

Space Diet: Daily Mealworm (Tenebrio molitor) Harvest on a Multigenerational Spaceship from the Journal of Interdisciplinary Science Topics.

Predicting Mars Cuisine: Grasshoppers with a Side of Fungi from

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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here for more about this series.


Martian Sandstorms: Just How Worried Should You Be?

Before you plan your next trip to Mars, be sure to check the weather forecast. Martian sandstorms can be rather extreme, in some cases spreading over the whole planet, reducing visibility to almost zero.

Totally legit Hubble images of Mars before and during a global sandstorm.
Totally legit Hubble images of Mars before and during a global sandstorm.

However, the dangers associated with these sandstorms are sometimes exaggerated.

Attempting to land during a Martian dust storm can be hazardous. In 1971, a global storm happened to occur just as a pair of Soviet landers arrived. Let’s just say things didn’t go well.

But if you’re already on the surface of Mars when a dust storm begins, as quite a number of NASA landers and rovers have been, you really don’t have much to worry about. Yes, there are 60 mile per hour winds, but atmospheric pressure on Mars is less than 1% that on Earth. So while these storms have wind speeds comparable to Earth hurricanes, they are nowhere near hurricane force.

Dust storm season takes place during summer in the planet’s southern hemisphere. Martian southern summer happens to coincide with Mars’s closest approach to the Sun, making it warmer than northern summer. This extra heat releases extra volatiles (mostly CO2 gas) from the south polar ice cap. This agitates the atmosphere, which in turn whips up some spectacular sandstorms.

So if you’re planning a vacation on Mars, try to avoid landing during southern summer. Since you can only schedule your trip for times when Earth and Mars line up properly, this greatly reduces the number of possible launch windows. But trust me: crash landing on Mars during a sandstorm could really spoil your trip.


What are the Risks of Dust and Sand on Mars? from Mars One.

Spacecraft Monitoring Martian Dust Storm from NASA.

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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here to learn more about this series.

Molecular Monday: Mars’s Hydrogen Peroxide

Welcome to Molecular Mondays! Every other Monday, we examine the atoms and molecules that serve as the building blocks of our universe, both in reality and in science fiction. Today, we turn our attention to:

Hydrogen Peroxide on Mars

The surface of Mars is covered with hydrogen peroxide, a strong oxidizing agent. Here on Earth, we use hydrogen peroxide (chemical formula H2O2) as a disinfectant, among other things.

Jn10 H2O2

So I guess that’s it. My hope that one day we’ll discover native Martian organisms is crushed. How could life survive on a planet covered in disinfectant?

The Office of Planetary Protection must be happy.

This could be good news for the Office of Planetary Protection (real thing, not kidding). The O.P.P.’s job is to ensure that NASA doesn’t accidentally contaminate other worlds with microorganisms from Earth.

They don’t worry about contaminating Venus because Venus is self-sterilizing (in many more ways than one). So with all that H2O2 lying around, is Mars a self-sterilizing planet too?

Turns out it isn’t. Researchers found that while microbes from Earth would probably struggle on Mars, enough could survive to cause problems. Despite all that H2O2, we could still contaminate Mars if we’re not careful.

And if Earthly microorganisms can survive, surely native Martians—which would have evolved in this peroxide-rich environment—would be okay as well.

Wait, did you say oxidizing agent?

Long ago, life on Earth was nearly wiped out by a certain oxidizing agent called oxygen. This event is known as the oxygen catastrophe.

Free oxygen can rip chemical bonds apart, to the detriment of most early organisms on Earth. And yet, life adapted. Not only that: life figured out how to take advantage of an otherwise bad situation.

Perhaps a similar story could have occurred on Mars. If Martian life forms exist, maybe they “breathe” hydrogen peroxide as we breathe oxygen, using it to power their bizarre, alien biochemistries.

Some experts would argue that Mars’s hydrogen peroxide is the final proof that life cannot exist anywhere near the planet’s surface. But perhaps, quite to the contrary, hydrogen peroxide might be the very thing that makes Martian life possible.

At the very least, it’s enough to give science fiction writers something to think about.

P.S.: Regular readers of this blog already know that Martians are convinced life cannot exist on Earth. After all, oxygen can be used as a disinfectant. How could life survive on a planet with an atmosphere full of disinfectant?

Sciency Words: Yestersol

Sciency Words MATH

Sciency Words is a special series here on Planet Pailly celebrating the rich and colorful world of science and science-related terminology. Today, we’re looking at the term:


In the course of my research, I sometimes stumble upon new words that just make me smile. Sol is the technical term for a Martian day, a period of roughly 24.6 hours. Knowing that, I’m sure you can guess what yestersol means.

The term yestersol was apparently coined during NASA’s Spirit and Opportunity rover missions. Scientists and engineers assigned to those missions had to sync their work schedules to Martian time, screwing up their sleep cycles, eating habits, and no doubt many other aspects of their personal lives. This was necessary because the rovers could only operate during Martian daylight hours.

Additional new terms include “tosol” for today and several versions of tomorrow, such as “nextersol” and “solmorrow.”

In the distant future, Earth time may well be retained as an interplanetary standard, but each colonized world will probably develop its own version of local time, along with playful local terminology like yestersol.

Another timekeeping idea that made me smile appeared in Robert Zubrin’s book The Case for Mars. Zubrin suggests dividing Mars’s 687 day-long (or 669 sol-long) year into twelve months based on the twelve Zodiac constellations. So Martian months may end up having names like Sagittebruary, Leotober, or Cancricember.

These months would be significantly longer than Earth’s, but they could be made to correspond with Martian seasons in a manner similar to Earth’s calendar. Martian colonists may find that convenient. Also, who wouldn’t want their birthday (I mean birthsol) to be something like Sagittebruary the 49th?

When world building in science fiction, it can be tempting to either adhere to the familiar Earth calendar or try to impose some sort of intergalactic standard time on everyone. But it might be more fun (and perhaps more true to life) to think about how different communities spread across space might track time in their own unique ways, using their own colloquialisms like yestersol.


Yestersol from Word Spy.

Martian Language: Where Curiosity Can Take You from A Way with Words.

Workdays Fit for a Martian from the Los Angeles Times.

Long Day at the Office as Scientists Get in Sync with Mars from the Sydney Morning Herald.

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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here for more about this series.


Martian Vacation, Part Two (Conjunction-class Missions)

So you’re planning a vacation on Mars and want to know when is the best time to go. This may seem counterintuitive, but you might want to schedule your launch for when Earth and Mars are on opposite sides of the Sun. This is known as a conjunction-class mission.

Keep in mind that any journey to Mars will take months. During that time, the planets will move around in their orbits, with Earth moving slightly faster than Mars (66,000 m.p.h. versus 54,000 m.p.h.). Earth’s orbit is also smaller than Mars’s, so if the two planets were racing, Earth would be lapping Mars on the racetrack quite frequently.

Jn08 Solar Racetrack

In conjunction-class missions, Mars may be on the far side of the Sun at launch, but your spacecraft takes full advantage of Earth’s greater momentum and soon catches up. This gives conjunction-class missions certain benefits over the alternative opposition-class missions (which we covered on Monday):

  • You need a lot less fuel.
  • You get to spend a lot more time on Mars—almost two years! For this reason, conjunction-class missions are also known as long-stay missions.
  • Unlike in opposition-class missions, you don’t have to cut through the Inner Solar System on your way home to Earth. This makes conjunction-class missions far less complicated and, at least on the return leg of your voyage, safer.

The only real downside is that your journey to and from Mars will take longer. Although spending more time in space does raise a few health and safety concerns, almost every serious plan for the long-term exploration and colonization of Mars seems to favor conjunction-class missions.

Personally, if I were going on a Martian vacation, I’d choose a conjunction-class flight. The lower fuel requirements mean lower ticket prices. Having more time to go sightseeing on Mars is an added bonus. I just have to convince my day job to let me take a two-year vacation.

So how would travel to Mars? Would you prefer the faster, marginally safer opposition-class flight or the longer, less expensive conjunction-class?

P.S.: If you want to learn more about opposition- and conjunction-class missions to Mars or about humanity’s future on Mars in general, I highly recommend The Case for Mars by Robert Zubrin. The book lays out the most believable and compelling plan for the exploration and eventual colonization of Mars I’ve ever seen.

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Today’s post is part of Mars month for the 2015 Mission to the Solar System.

Martian Vacation, Part One (Opposition-class Missions)

Planning a vacation to Mars? Wondering when is the best time to go? Here’s one option:

Once every 26 months, while Earth and Mars are on the same side of the Sun, the two planets line up just right for a launch. Although Mars is not necessarily in opposition at this time, it’s close to it, so your flight is known as an opposition-class mission.

Your journey will take several months (exact time estimates vary depending on spaceship design and other mission parameters). Keep in mind that during your voyage, both Earth and Mars continue moving through their orbits. In fact, Earth will rapidly move ahead of you, so you’ll only be able to stay on the surface of Mars for a short time before you have to come home. For this reason, opposition-class missions are also known as short-stay missions.

On your return flight, Earth is still moving away from you, so to catch up, your spacecraft will have to cut through the inner Solar System, swinging in a wide arc around the Sun, possibly utilizing a difficult and dangerous gravity assist maneuver at Venus.

Opposition-class missions aren’t the only way to get to Mars, but they do offer some advantages:

  • You get to Mars faster.
  • You get home faster.
  • Some argue the trip is safer. Since you spend less time in space, you should suffer less radiation exposure and less bone-loss due to zero-gravity.

However, there are some noteworthy disadvantages too:

  • Opposition-class missions require a whole lot of fuel, significantly more than alternative conjunction-class missions.
  • You only get to spend a few weeks on Mars. Depending again on mission parameters, you might get a little over a month.
  • About that safety thing… some argue opposition-class missions aren’t so safe after all because more things can go wrong, especially during your return flight.

I’d guess that the first manned mission to Mars may well be opposition-class. I think humanity might prefer to dip its toe in the water, so to speak, with a short-stay mission.

Subsequent missions (and vacations) will probably be conjunction-class, long-stay missions, for reasons that we’ll examine on Wednesday.

P.S.: It’s difficult to find reliable information about opposition- and conjunction-class missions online, so for further research, I recommend The Case for Mars by Robert Zubrin. Zubrin, a former aerospace engineer for Lockheed Martin and founder of the Mars Society, lays out one of the most believable and compelling plans for Mars exploration and eventual colonization that I’ve ever seen. If you have any interest in going to Mars (or writing science fiction about Martian colonists), you should read Zubrin’s book.

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Today’s post is part of Mars month for the 2015 Mission to the Solar System.

Sciency Words: Opposition and Conjunction

Sciency Words PHYS copy

Sciency Words is a special series here on Planet Pailly celebrating the rich and colorful world of science and science-related terminology. Today, we’re looking at two related terms:


Admit it: you want to go to Mars. Despite all the radiation and sandstorms and saltwater, you still kind of want to do it. But which way is it to Mars? Bonus credit if you can point in the correct direction right now without checking a smartphone app.

Mars, like pretty much everything in space, is a moving target. Sometimes, it’s fairly close to Earth. Other times, it’s all the way on the far side of the Sun. To make life slightly easier, astronomers have special terms to describe the positions of other planets relative to Earth.

Jn06 OppositionOpposition: Earth and Mars, as pictured above, are on the same side of the Sun, almost perfectly lined up. In this situation, Mars is said to be “in opposition.”

Jn06 ConjunctionConjunction: Mars is now on the far side of the Sun, basically as far from Earth as it can get. Mars is now said to be “in conjunction.”

In my mind, these terms would make more sense the other way around. Mars should be in opposition when it’s on the opposite side of the Sun, don’t you think? But I’m guessing this all originates from a more geocentric view of the Solar System. Opposition, therefore, gets its name because the Sun and Mars are on opposite sides of the Earth.

What about Mercury and Venus? Since neither can be on the opposite side of Earth from the Sun, they’re never in opposition. Instead, astronomers use slightly different terms.

Jn06 Superior ConjunctionSuperior Conjunction: Venus, as pictured above, is on the opposite side of the Sun as viewed from Earth. This is called a “superior conjunction.”

Jn06 Inferior ConjunctionInferior Conjunction: Venus is now on the same side of the Sun as Earth. This is an “inferior conjunction.”

Of course, all this terminology can be shifted around if you want to take the perspective of a planet other than Earth. From a Venusian point of view, Earth could be in opposition or conjunction, and Martians could observe Earth to be in superior or inferior conjunction.

Knowing where planets are in relation to each other is critical for interplanetary voyages. Next week, we’ll start planning a Martian vacation, keeping an important question in mind: would you rather travel to Mars when Mars is in opposition or conjunction?

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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here for more about this series.

Do You Believe in Martians?

I believe in Martians. The planet Mars was once a wet, warm world like Earth, and it stayed that way for billions of years. That means Mars had ample opportunity to start growing its own organisms, even if things didn’t turn out quite as successfully as they did on Earth.

And while the evidence is not exactly conclusive, there’s plenty of reason to believe that life of some kind did exist and still exists on the Red Planet.

Surviving in Saltwater

On Monday, we looked at Martian water, which some claim is way, way too salty to support life. Meanwhile, here on Earth, scientists have been investigating a creepy, blood-red substance seeping out of Antarctic ice.

Turns out this red substance is produced by large communities of bacteria living beneath the ice. These bacteria have been virtually cut off from the rest of the world for over a million years, surviving in a frigid and super-salty environment almost identical to what hypothetical Martian microbes would have to endure.

Click here to learn more about these Antarctic bacteria.

Debating Over Meteorites

I’m sure we all remember meteorite ALH-84001. That’s the meteorite found in Antarctica that allegedly contained fossilized Martian microbes.

Although the origin of these “fossils” has been called into question, this piece of evidence has not been fully discredited. The scientific debate is ongoing, and additional Martian meteorites have been discovered bearing still more hints of possible biological activity on Mars.

The most recent meteorite, named Tissint, somehow got organic material wedged into cracks and fissures in its surface before traveling to Earth.

Click here for more information about Tissint.

Sniffing Martian Methane

And on the surface of Mars itself, the Curiosity rover has detected several sudden spikes in atmospheric methane, one in late 2013 and another in early 2014. This is mysterious for two reasons: where did all this methane come from, and where did it all go?

Although there are several possible explanations, scientists seem hard-pressed to account for these sudden, dramatic fluctuations of atmospheric methane without involving some sort of native Martian organisms.

Click here for more about methanogenesis on Mars.


Of course, this is all circumstantial evidence. The anomalous methane doesn’t have to come from biological sources, and some experts suspect that the rover itself, which apparently has pressurized methane stored inside it, might simply have sprung a leak. Evidence from Martian meteorites will always be controversial, and discovering bacteria sequestered beneath Antarctic ice is not the same as finding microbes on Mars.

Still, this circumstantial evidence is piling up. It’s enough to convince me that life probably exists on Mars, but what about you? Do you believe in Martians?

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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here for more about this series.

Molecular Monday: The Waters of Mars

Welcome to Molecular Mondays! Every other Monday, we examine the atoms and molecules that serve as the building blocks of our universe, both in reality and in science fiction. Today, we turn our attention to:

The Waters of Mars

If you ever find yourself on Mars, do not drink the water. And not just because of a certain episode of Doctor Who.

In real life, the waters of Mars probably won’t transform you into a space zombie, but they still might kill you or at least leave you severely dehydrated. That’s because Martian water is saltwater.

What’s So Dangerous About Saltwater?

Human beings need water. We also need salt. Given those two facts, you’d think drinking saltwater would be great! But introducing all that salt to your system all at once dramatically raises the salinity (salt content) of your blood. You don’t want that.

To lower your blood’s salinity, water molecules will start passing through your cell membranes in a valiant but futile effort to dilute the salt to more acceptable levels.

Jn04 Water Molecule

Ultimately, your body will flush all the excess salt AND excess water out through your urine. In the end, drinking saltwater causes you to lose more water than you gain.

What Do Saltwater Fish Do?

Most organisms here on Earth that live in saltwater environments do so by either actively pumping salt out of their bodies or constantly rehydrating (i.e.: drinking like a fish) to replenish all the water their cells are losing.

What About Life on Mars?

Some scientists here on Earth argue that life cannot exist on Mars because the water is just too salty, both now and in Mars’s past. As a counterpoint, Martian scientists have been quoted saying life couldn’t exist on Earth because the water isn’t salty enough.

P.S.: As you’re probably aware, the freezing point of saltwater is lower than that of regular water. Given how cold Mars is, the high salinity of Martian water is a big part of why Mars has liquid water in the first place.


Mars Perhaps Too Salty for Life from

Salt of the Early Earth from Astrobiology Magazine.

Surviving in Salt Water from American Museum of Natural History.

Do Fish Drink Water? from SciShow.

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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here for more about this series.