Tag Archive | "space"

Lab Letters Issue #12: Soft Robots, Super Rice, and a Wet Towel in Space

It’s that time again – the time for your weekly science updates. This is Lab Letters. Let’s go!


Hello doggie! An example of an evolved soft robot, showing natural-looking body structure and gait. The red and green blocks represent muscle-like materials. (Not shown: dark blue blocks represent bone, light blue blocks represent soft support/tissue) (source: Cheney, MacCurdy, Clune, & Lipson, Cornell/University of Wyoming)

Robot Evolution

Studying the evolution of a species can get tricky. There’s a lot of observing, measuring, cataloguing, sample collecting, testing, and waiting – especially for organisms that take a long time to mature. So a team of engineers at Cornell University in New York presumably just said, “Y’know what, evolutionary biology? We’ll just build our own organisms! With cubes and stuff!” That’s exactly what they did. Using a compositional pattern-producing network (CPPN), they built up block shaped robots consisting of 4 types of materials: bone, tissue, and two types of muscles. Then they laid down one rule: faster robots have more offspring. Then they let the simulation run. Here’s what happened:

So far, I’ve been able to make out a galloping sofa and a drunk goat. What do you see?



It’s alive! (1) Orysza sativa variety IR56 grown on normal soil (2) IR56 grown on salty soil (3) Oryza coarctata grown on salty soil (4) IR56 and O. coarctata’s first and second generation offspring, grown on salty soil. IRRI scientists hope to make this supercrop available to farmers in 4 to 5 years. (source: Jena/irri.org)

IRRI breeds super crop

Don’t you just hate it when the Assyrian army marches into your city, burns your houses, kills your babies, enslaves you and your buddies, and then, just to make sure you’re completely screwed over, salts your land so that nothing can ever grow again? Well! Those Assyrians shouldn’t be so smug! The International Rice Research Institute in Los Baños has announced the successful production of a rice strain that can tolerate high amounts of salt in the soil. This new strain capable of tolerating twice as much salt as its predecessor was made by crossing two very genetically different rice species. The exotic wild rice O. coarctata can tolerate salt levels comparable to seawater, but isn’t edible. Meanwhile, O. sativa variety IR56 is a cultivated and edible species. Sounds easy? Out of 34,000 crosses, only three embryos were rescued, and only one embryo actually started growing.


The most massively useful thing an astronaut can have

Commander Chris Hadfield of the International Space Station has been busy showing us Earth-bound humans how astronauts live (eat, exercise, sleep, cry, pee) in space. In this video, he performs a simple experiment: what happens when you wring a wet towel in space?

Magic happens.

The experiment was actually conceptualized by two grade 10 students in Nova Scotia, Canada, using items that are readily available in the ship.


And finally…

Happy Earth Day! Here’s a picture showing the Earth, as seen from outer space. That there is the reusable Dragon spacecraft docked to the International Space Station.


Tweeted by SpaceX


That’s it for today, see you next time here on FF Lab Letters!


Posted in ScienceComments (0)

Curiosity Speaks

Now that the hoopla over Curiosity’s landing has died down, let us stand back and examine what has been achieved to see if it was really worth all that hype.

Below is a picture of Mars as seen from Earth. That reddish dot in the sky is an alien world hurtling and spinning through the unimaginable vastness of space at astounding velocities, billions of kilometers away from Earth. The smartest members of our species have just sent a laboratory on wheels to that dot. But they did not just aim for that dot, they aimed for a tiny pixel within a pixel within that dot. And they hit the mark. Soon, that lab on wheels will rove its way around a very tiny portion of that little bright spot in the night sky. If that does not make the hairs on the back of your neck stand on their end, then I do not know what will.

Mars as seen from Earth. [Photo credit: stars.astro.illinois.edu]

A pixel in a pixel in a dot in space. [Screenshots from Google Earth.]

And now that we have placed things in perspective, I believe it’s time for Curiosity itself to tell us the rest of its story.


Curiosity Speaks

Hello, my name is Curiosity. I am the rover of NASA’s Mars Science Laboratory (MSL) program. I know I am animate only in the broadest sense and that my artificial intelligence is comparable to that of a fly, but allow me this conceit of having conscious thought, if only to tell the story of my mission in Mars. It is, after all, also the story of my cousins, Spirit and Opportunity. It is also the story of Mars. Ultimately, it is also the story of life on Earth. My story is your story, too.

When I landed safely on the surface of Mars on the 6th of August, 2012, my parents at the Jet Propulsion Laboratory (JPL) were ecstatic. Their ecstasy is understandable not only because they have high hopes for me, but also because my landing was daring. In fact, it was so risky I wouldn’t blame you if you think they were a bit nutty when they planned my entry, descent and landing. To provide a comparison, my cousins Spirit and Opportunity touched down on the surface of the red planet surrounded by giant airbags while I was dropped naked. (In this way, I am more human-like than my predecessors.) The slogan “Dare mighty things” was well chosen for my landing.

I may be beautiful and sophisticated, but I am also hardy. To appreciate this, imagine what I had to survive during my “7 minutes of terror”. Upon my entry to Mars’ thin atmosphere, I was travelling at a speed of 21,000 kilometers per hour. That’s more than 60 times the speed of sound. At that speed I would be able to circle the world in less than two hours. From such unimaginable velocity, I had to decelerate to zero in a mere 7 minutes. At one point during my descent, I survived a deceleration of 9g. Imagine stopping from 120 kph in less than half a second – basically the definition of a fatal car accident – that’s 9g.

My landing was tough, but I was able to pull it off. Sometimes, I had to pull it off literally, as with the sky crane. [Photo credit: universetoday.com]

While the whole world celebrates my safe landing, the challenges I am to face have only begun. Although it is my home from now on, Mars will also be my constant enemy. Unlike Edgar Rice Burroughs’s Barsoom, the real Mars is a world very different from Earth. With temperatures ranging from –15°C in the summer to –100°C in the winter, it forbidding even to most robots and extremophiles. But cold as it is on the Martian surface, the pressure here is so low that if you were to stand next to me without wearing a space suite, your blood will boil away into the sparse atmosphere. (That scene from Watchmen when Dr. Manhattan brought Silk Spectre to the surface of Mars is a reminder of how difficult it is for human intuition to understand the environment of another planet.) If any creature evolved to survive on Mars’s surface, it would find the pressure on the summit of Mt. Everest crushingly high.

The hypothetical Martian would also find the Earth’s oxygen-rich atmosphere exceedingly poisonous. For you earthbound animals who have evolved to handle oxygen so well, it is forgivable that you forget how potent an oxidizing agent it actually is. Here on the fourth planet, the oxygen is locked in the rusty soil and rock that gives the planet its characteristic color. Since Mars’ thin atmosphere is composed largely of carbon dioxide, it will not only suffocate any human foolish enough to breathe it in, it will suffocate even fire. No campfire or candle will burn on the surface of the my new home planet.

The Martian surface is also buffeted by nearly direct solar radiation. Mars does not have an ozone layer. It does not even have a magnetosphere, which means the fierce “solar wind” batters its atmosphere like crazy. And because Mars lacks a significant magnetic field, no auroras streak its pinkish sky. Using a magnetic compass for navigation is not an option here.

Snapshot taken by my cousin, Opportunity. [Photo credit: news.discover.com]

Finally, there are the notorious dust storms of Mars. Because of a combination of low pressure and low gravity, the dust particles on the Martian surface are eager to be airborne. My predecessors have warned me that such storms can rage for months on end. Luckily, my parents at NASA designed me so that I do not depend on the Sun for my energy. Instead of having solar panels like Spirit and Opportunity, I am, like Vikings 1 and 2, powered by the heat generated by a radioactive isotope I carry around with me.

And speaking of power, I need lots of it. After all, I am a not just an explorer, I am a science laboratory on wheels. I carry with me tools as simple as cameras and light microscopes to equipment as complex as a gas chromatograph coupled to a mass spectrometer. (I have at least 4 kinds of spectrometers. You cannot have too many spectrometers.) I use my equipment to analyze the composition of interesting rocks I happen to pass by. However, I do not limit myself to the rocks on the surface. I am armed with a laser gun that blasts off surface rocks,  allowing me to analyze the chemistry of the underlying rocks. I am a mean machine. If intelligent Martians see me walking around their planet, they would think earthlings are waging war against them. It’s like War of  the Worlds, only it’s the other way around.

My parents at NASA call me a robot scientist. In that case, I am a robot meteorologist, geologist, and chemist. Using my powerful instruments, more numerous and sophisticated than the ones aboard Spirit and Opportunity, my mission here is to study the climate of Mars, examine its rocks, and peer into its history. For these purposes my landing site, Gale Crater, was carefully and well chosen. Gale Crater houses kilometers upon kilometers of exposed rock layers. For a terrestrial analogy, think Grand Canyon. Because of its exposed rock strata, Gale Crater is like an open book into parts of Mars’ history. Studying the rock layers at Gale Crater might provide clues to the following questions: Why is Mars so different from Earth? Was there ever plate tectonics on Mars? And did water play an important role in Mars’ history?

I am also here to search for water. Such is a daunting task given how bone-dry Mars is. Compared to the red planet’s surface, the Sahara Desert is a lush, wet forest of life. Not even Frank Herbert’s Arrakis can match the dryness of the real Barsoom.

A view of my innards. [Photo credit: nssphoenix.wordpress.com]

However, there are tantalizing clues that liquid water once flowed in abundance on the ancient Martian surface. Orbiting space probes have taken pictures of what appears to be dried river channels, deltas, and flood plains. Spirit and Opportunity even discovered mineral formations that probably formed in the presence of neutral water. Even more intriguing are the suggestions that there’s more water on Mars today than was initially thought. Much of this is heavily debated by earthbound scientists. The results of my investigations here on Mars may end these debates. It may also start new ones.

You can also call me a robot biologist, although what that means no one clearly knows. In fact, one of my missions is to clarify what it really means to study life. When Viking 1, Viking 2, Spirit, and Opportunity tried to search for life on Mars, their tests were riddled with false positives and inconclusive results. The world even witnessed bedazzled NASA scientists excitedly, and some would say carelessly, announcing signs of “alien life” at every opportunity. Their failures remind you humans how ignorant you are of this thing called life. Because NASA has learned from the failures of my predecessors, I am not going to search for life directly. Instead, I am going to look for conditions that you think are “suitable for life”. For life “as you know it”, at least.

My cousins and I. [Photo credit: abc.net.au]

The success of my landing proves that you humans can achieve mighty things if only you work together. Wars and bigotry are a waste of your energy, resources, and lives. By successfully doing what has been deemed be crazy, my example has the power to encourage a generation of dreamers.

By now I think you understand why I am here on this desolate wilderness called Mars. By studying this world, I can give you humans more insights into your own. By examining this seemingly dead planet, I can help you understand the fragile balance of your living globe. By probing a planet possibly devoid of life, I can help you know more about what it means to be alive.

As for those dreamers my success will inspire, know that I will be here patiently awaiting the coming of your descendants to the surface of the red planet.

Wars vs. Mars.

Posted in ScienceComments (0)

Walking Through Our Solar System

Year of the Solar System

It's the Year of the Solar System!

Happy Year of the Solar System! The planets are so happy to greet you they decided to move too close to each other just so that they could fit in a family portrait to show you. Also, so as not to dwarf their smaller siblings, the giants of the family had to move a lot farther from the camera.

Shown below is a more candid family portrait. Here, the planets are shown in their correct size relationships.

All planets great and small. (I know, Pluto should not be there.)

But how far are the planets with respect to each other? When I taught high school astronomy two years ago, I tried to draw a Solar System that’s to scale on our classroom’s white board. Good luck to me! I ended up either trying hard to include Jupiter in my drawing or attempting to carefully draw the crammed orbits of the inner planets just so that they’re distinguishable from each other. In the end, I used a number of steps to illustrate the relative distances of the planets to each other. (“If the Sun were here, then Mercury would be so and so paces away.”)

Before we go to the relative distances involved in our cosmic neighborhood, let us first have a word about the units we use to measure the Solar System.


Measuring the Solar System

The average distance of the Earth from the Sun is about 150 million kilometers. If you could fly to the Sun in a spacecraft that travels at three times the speed of sound, it would still take you more than 5 years to get there! So that we don’t have to be inconvenienced by humongous numbers in describing distances within the Solar System, astronomers invented the astronomical unit (AU). 1 astronomical unit is equal to 150 million kilometers, the average distance of the Earth from the Sun.


How Many Steps from the Sun?

Using the astronomical units, the distances of the planets from the Sun can be written in convenient, sizable numbers. These numbers are shown in the table below.

 Planet Average orbital radius (AU)

















The second column is labeled average orbital radius because a planet’s average distance from the Sun is indeed the (average) radius of its orbit.

Now, let us make our mini Solar System. Imagine the Sun to be where you are right now. (Better yet, imagine you are the Sun.) If you take 4 steps from your current position, you’d get to where Mercury is. To get to Venus, you have to take 7 steps from where you are, while you need to take 10 steps to get to the Earth. Meanwhile, you need to take a good 15 steps to get to Mars’ obit. So far, so good.

But wait, notice that to get to Jupiter, you need to take no less than 52 steps! Jupiter, it turns out, is more than three times as far from the Sun (that’s you) as Mars is. Why is there so much empty space in between Mars and Jupiter?

Well, as most of us know, the space between Mars and Jupiter is far from empty. Rather, the space is populated by a swarm of rocks called the asteroid belt. Some of the asteroids are so large they are considered dwarf planets. Many scientists think that they are rock fragments that failed to coalesce into a planet during the Solar System’s formation because of the constant gravitational tug of neighboring Jupiter.

But don’t imagine the asteroid belt to be a densely clustered group of flying rocks. Although the asteroids number by the hundreds of thousands, there’s plenty of space for them to distribute themselves in.

Asteroid Belt

Now let’s go back to our walk through of the Solar System. We learned that if the Earth is 10 paces from the Sun, then Jupiter is 52. Meanwhile, Saturn would be 96 paces from the Sun. Saturn is nearly ten times as far from the Sun as the Earth is! About twice as far out, at 192 paces, is Uranus. (No, I will not make a Uranus joke). Neptune, the farthest planet (yes, get over it), is 301 steps from the Sun.

As I am writing this, I am in a room whose biggest dimension is around a hundred steps (that’s “how far” Saturn is from the Sun). When I place textbook on one corner of this room (the “Sun corner”), I can hardly see it from the opposite corner (the “Saturn corner”). However, from the Sun corner, the positions of Mercury (4 steps), Venus (7 steps), Earth (10 steps) and Mars (15 steps) are literally within spitting distance. I highly doubt it if I can spit as far as the orbit of Jupiter (52 steps).


The Ends of the Solar System

Don’t worry, I did not forget about Pluto. Just because astronomers do not consider it a major planet anymore doesn’t mean I stopped loving it.

Before we “walk to” Pluto, let me first get this out: nothing “happened” to Pluto. No, it did not become a moon of Neptune. It did not even shrink. Above all, it did not become a star!

If you’re wondering why I had to say this, good for you. Many people – and I mean many – believe that something happened to Pluto to deserve its “demotion” from being a major planet to being a dwarf planet. And yes, some people think it became a star. (Well, in a sense, it became a ‘star’. But you know what I mean.)

Pluto and its twin, Charon, from the surface of Nix. Pluto's third moon, Hydra, is also within view.

I think the misunderstanding surrounding Pluto’s planethood (or stardom) reveals the natural human tendency to be essentialists. In other words, most people still think that to be a planet, one must have the essence of a planet – one must possess planetness. That truth, however, is that ‘planet’ is just another word for ‘biggish object orbiting a star’. In this case, the star is our Sun. And we get to decide how big is big. The problem with Pluto is not just that it’s really small, it’s that we found at least one other object orbiting the Sun that’s bigger than Pluto. That object is Eris, named after the goddess of discord and strife. Along with Pluto, Eris is part of the Kuiper Belt, a second belt of rocks orbiting the Sun. Most of the Kuiper Belt lies beyond the orbit of Neptune. Other members of the Kuiper Belt have names like Sedna, Xena (the warrior princess), Makemake and Haumea.

Eris and its moon, Dysnomia.

Artist's impression of the Kuiper Belt (courtesy of Don Dixon)

Now, let’s go back to our walk through. Recall that in our mini Solar System, you are the Sun. 10 steps away is the Earth, 52 steps is Jupiter and 301 steps is Neptune. Pluto is, on average, 395 steps from you. The Kuiper Belt starts at around 300 paces. To get to where Eris is, you have to walk 1,000 steps from where you are. If you think the Solar System ends there, then you couldn’t be more wrong. The Oort Cloud, a hypothetical body of rocks and comets, is no less than two thousand times farther from the Sun as the Earth is. That means that if the Earth is 10 steps from you, then the Oort Cloud is 20,000 steps away! Some astronomers even think that the heliopause, which could be thought of as the outer boundary of the Solar System, is no less than 500,000 steps away. The inner planets are indeed in the innermost part of the Solar System.

Oort Cloud


That concludes our overview of the vast dimensions in our own cosmic neighborhood. I hope the “walk through” inspired you to make a mini Solar System in your own backyard. And I hope that the next time you look up to the heavens, you will see the grandeur that held thrall all the great minds throughout the ages.


Photo credits:

  • www.nasa.gov
  • www.solarsystem.nasa.gov
  • www.universetoday.com
  • www.wikipedia.org
  • www.cosmographica.com
  • www.theiamfamilyoflight.com

Posted in ScienceComments (2)