By Benjamin Vermette
DNA sequenced in space for the first time!
Just as architects design buildings, DNA makes you.
Genes are made up of DNA (deoxyribonucleic acid), which contains the necessary genetic information for your cells to accomplish all their life-depending functions, such as reproducing, growing hair, digesting food, reading this sentence, etc. But just as architects are made of smaller entities themselves, so is DNA.
First, DNA is a molecule, so it’s of course made of smaller atoms. But let’s say it’s an organized molecule, so it contains a special set of atoms that repeat themselves over and over again. These sets of atoms are also molecules, so we can say DNA is a molecule made of smaller molecules (which we call nucleotides). Nucleotides are then made of even smaller molecules, which we call nitrogenous bases, which are the ’characterizing’ element of the DNA segment.
There are only four different nitrogenous bases for DNA, and they are represented by the letters A (adenine), C (cytosine), G (guanine) and T (thymine).
Let’s recap. Genes are made of DNA (a single molecule of DNA may contain hundreds of genes). But DNA itself is made of a series of nucleotides, which are in their turn made up of four different types of nitrogenous bases (A, C, G, T) that ‘characterizes’ the DNA, and thus the gene. In the end, atoms (mostly carbon, hydrogen, oxygen, nitrogen and phosphate) make up all of this.
But then, how can only four different types of nitrogenous bases account for the extreme diversity of life? Mind you, it’s not the number of different types that counts, but rather the sequence in which they are arranged. Just like the architect’s job was decided by the sequence of events he experienced earlier in his life, the gene’s ‘job’ is decided and made possible by the sequence of nitrogenous base it contains.
So a gene responsible for accomplishing a specific function, say, keeping your hair colour brown, has a different nitrogenous base sequence than another gene that is responsible for dealing with a specific type of virus.
I think you get it. Now, enough biology, let’s get to the cooler stuff, the space stuff!
On August 29, astronaut and molecular biologist Dr. Kate Rubins did just that: she sequenced DNA, meaning she, using a machine, determined the particular order of the nitrogenous bases in a DNA molecule. For the first time, the experience was done in space! In itself, it’s not a new thing as scientists have been sequencing DNA since the 1970s.
The experiment hardware flew on SpaceX’s cargo resupply mission on July 20, along with the International Docking Adapter. (For more on Kate Rubins’s mission check out the August 22/16 entry) The hardware included the sequencing device called MinION, which was developed by Oxford Nanopore Technologies.
“The MinION works by sending a positive current through pores embedded in membranes inside the device, called nanopores,” wrote Melissa Gaskill from NASA’s Johnson Space Center. “At the same time, fluid containing a DNA sample passes through the device. Individual DNA molecules partially block the nanopores and change the current in a way that is unique to that particular DNA sequence. By looking at these changes, researchers can identify the specific DNA sequence.”
To reduce the variables to only one, namely, microgravity, researchers did the same experiment on the ground while Dr. Rubins was doing it at an altitude of 400 km and at a speed of 27,000 km/h. Although testing pre-made samples, Rubins’ results matched the ones the teams had on the ground.
Sequencing DNA in microgravity engages a lot of unknowns, such as air bubbles. On earth, air bubbles rise to the top, but not in space. A concern that they might block the nanopores was investigated. To make sure microgravity hides the least amount of potential threats to the investigation as possible, NASA tested the whole experiment underwater, where gravity, pressure and humidity were less controllable variables.
What does this mean for space exploration?
Sequencing DNA in space means a lot, especially considering the long-duration spaceflights NASA is anticipating. Astronauts will be able to identify microbes in their spacecraft in real time! Knowing what’s in their environment at any time, the astronauts will be aware if a virus is around and, not only that, they’ll also be aware of what kind of virus there is so they can treat it more effectively.
Bad microbes-hunter and a science experiment tool, but what else can sequencing DNA in space be?
You guessed it. No need to extract a sample from Mars’ soil, bring it back to Earth and wait for the results of the analysis to know if the sample contained life. You can do just the same thing, but on Mars!
Therefore, sequencing DNA in space will allow humans to know the answer to “Is there life on Mars?” more rapidly.
Essential for crew safety and helpful for science experiments in space, the new milestone of sequencing DNA in space for the first time was achieved, making us even closer to Mars than before.
“Welcome to systems biology in space,” said Kate Rubins, space milestone-achiever.
Have we found intelligent extra-terrestrial life?
Maybe you’ve seen articles on the Internet congratulating humankind for its discovery of an intelligent civilization not so long ago. Yes, a mysterious signal coming from space was measured by a group of Russian astronomers, but going from this to saying we found life is skipping steps.
Ninety-four light-years away from Earth, a solar system dubbed HD 164595 is believed to be the source of a mysterious radio signal. The solar system in question contains a star of comparable size and brightness to our Sun, and is thought of as a 6-billion-year-old system (slightly older than ours, the Sun being about 4.5 billion years old).
It seems to be the home of a planet about the size of Neptune, which revolves around its sun in a very tight orbit (taking 40 Earth-days to complete one revolution), thus “making it unattractive for life,” said Seth Shostak, astronomer at the SETI (Search for Extra-Terrestrial Intelligence) Institute.
But this isn’t enough to suggest the signal can’t come from aliens, because the quote needs to be taken as “making it unattractive for life [as we know it]”. So let’s dig deeper to see why the signal was probably not emitted by an intelligent civilization.
First off, the signal was detected using the RATAN-600 telescope in southern Russia. The RATAN-600 is sensitive to a relatively large part of the sky, so many stars are located where the sound seemed to come from, meaning astronomers are just assuming, based on estimations, that it originated from HD 164595. We’re not sure the signal came from where they say it came from, thereupon we can’t be sure of the identity of its sender either.
Second, the beep was measured by a Russian group of astronomers in May 2015. Protocol in the SETI business requires that if a received signal is thought to be emitted by extra-terrestrial intelligence, then the first to receive it needs to warn everyone else so they can turn on their telescopes as well, just to make sure they hear what the first one hears. For some reason, the Russian group didn’t go public after their discovery, so the signal was heard only once. In fact, the group said they were able to detect the sound only once (in 39 attempts), and SETI telescopes turned on as you read this still can’t hear the beep. Isn’t that a strange behaviour for aliens?
Third, the answer to our question — Did the signal came from E.T.? — may lie in the signal itself. With a strength of 0.75 Janskys, it was relatively weak. But if it did come from the star, which is, I recall, 94 light-years away, then it needed to be so darn powerful to reach us with this impact! Astronomer Seth Shostak from the SETI Institute did the math, and found that the energy required to emit the beacon was at best the total energy consumption of humankind, and, at worst, 1013 gigawatts. If you remember correctly, in Back to The Future Emmett ‘Doc’ Brown is terrified when he learns he needs 1.21 gigawatts to send Marty back – to the future!
So imagine how powerful 10,000,000,000,000 gigawatts is!
Okay. Now that we have reasonable arguments to think the signal didn’t come from aliens, we must then ask ourselves, where did it come from?
Maybe it had natural causes, like a radio burst from a star or a galaxy. Or maybe it indeed came from an intelligent civilization: “The signal is real, and may very well be from an intelligent civilization. That civilization, however, is us,” wrote Phil Plait, American astronomer. In fact, the origin of the mysterious signal may be any military satellite, because the wavelength they emit strangely matches the one measured by the Russian astronomers (2.7 cm).
I get it, we’re all (or most of us are) very excited when we look for extra-terrestrial intelligence. But sometimes, especially in science, we need to put our emotions aside in order to have a clear vision of what is really happening.
SpaceX’s Falcon 9 explodes on launch pad
On September 1, SpaceX was supposed to perform a static fire test. Indeed, they conducted a fire test, but let’s say it was not very static, unfortunately.
The first stage of SpaceX’s Falcon 9 rocket was powered by nine Merlin engines, which can be very powerful if fired correctly. However, one thing than can be even more powerful is when there’s an anomaly concerning the rocket’s kerosene and liquid oxygen tanks.
So, on September 3, SpaceX had a contract to launch an Israeli communications satellite to space; not a big deal, they do things like this all the time. But as you might have guessed, something explosively bad happened two days before during a maintenance test at Cape Canaveral.
A fire static test consists of igniting the rocket’s nine Merlin engines for a brief moment, thus giving teams on the ground time to see if everything is fine and good to go for launch. This time, however, it was obvious to anyone that something was undoubtedly wrong.
(Advance to 1:05)
Both the Falcon 9 and the Israeli satellite, valued at more than CAD $250 million, were lost. Reassuringly, no one was injured on the day of the incident, and hopefully it might warn SpaceX — which is about to send NASA astronauts to the International Space Station (ISS) — that a destroyed satellite may eventually lead to dead astronauts if SpaceX’s engineers don’t do their jobs, which I’m sure they’re doing.
Comprehensively, many on the day of the incident doubted SpaceX’s reliability as NASA’s commercial partner to eventually ferry astronauts to and from the ISS. Imagine if, instead of the satellite, there were NASA astronauts in there — which, if I recall, is still not possible yet.
If you remember, SpaceX had a similar mishap back in June of 2015, when a Falcon 9 rocket exploded two minutes after liftoff over the Cape. It contained cargo for the astronauts on board the ISS at the time.
Since then, the Falcon 9 had logged nine successful launches in a row, before obviously failing again, this September.
However, NASA seems not to be of the same opinion. “We remain confident in our commercial partners and firmly stand behind the successful 21st century launch complex that NASA, other federal agencies, and U.S. commercial companies are building on Florida’s Space Coast,” the agency said in a statement, while acknowledging that its partners must learn from their mistakes.
You judge if the statement was honest, or only made diplomatically.
But one thing is sure: we’ll always hear from SpaceX, whether it’s good news or bad news. Let’s hope it’s good news, considering the task they’ll face in a couple of years.
Launch of NASA’s ambitious OSIRIS-REx mission
On September 8, a rocket launched to space. But it wasn’t any rocket; it was an Atlas V rocket containing the OSIRIS-REx spacecraft!
Note that the launch was a success. Even though this Atlas V was near SpaceX’s Falcon 9 when the latter exploded on September 1, no damage was found on the former, hence the on-time launch.
The OSIRIS-REx mission is NASA’s first asteroid-sampling mission. You heard it. They’re going to sample an asteroid. Indeed, that’s a big deal.
In two years, the spacecraft will enter asteroid Bennu’s orbit and prepare to extract samples.
“We’re very excited about what this mission can tell us about the origin of our solar system, and we celebrate the bigger picture of science that is helping us make discoveries and accomplish milestones that might have been science fiction yesterday, but are science facts today,” said NASA administrator Charlie Bolden.
In fact, the mission is playing a big part in our understanding of our solar system. As asteroids are thought to be sources of water and organic molecules, Bennu may have a rich environment from which to sample and consequently perform experiments on.
Canada is playing a major role in the OSIRIS-REx mission, having built the OSIRIS-REx Laser Altimeter (OLA), a major science instrument onboard the spacecraft.
Using its lasers, OLA will be able to create a three-dimensional map of the surface of Bennu. This will be very useful, as the spacecraft will analyze the soil before selecting a sample site.
In total, the Canadian Space Agency is investing $61 million over 15 years on the mission.
So let’s hope it’s a success! Let’s hope it brings back answers in its samples when it comes back to Earth on September 24, 2023!
Astronaut Terry Virts retires
With more than 213 days in space including three spacewalks, astronaut Terry Virts decided to leave NASA.
Virts is an accomplished astronaut: he was the pilot on STS-130, a space shuttle mission, and last flew in space from December 2014 to June 2015, where he commanded Expedition 43 on board the ISS.
He is a graduate of the Air Force Academy, Embry-Riddle Aeronautical University and of Harvard Business School. As a colonel in the U.S. Air Force, he logged more than 4,300 hours on 40 different aircraft, notably on the F-16, on which he served as experimental test pilot as well.
He was selected to be an astronaut in 2000, and since then he served in many functions, including lead astronaut for the T-38 jet training program, chief of the astronaut office’s robotic branch, and lead astronaut for the Space Launch System program.
After circling the Earth more than 3,600 times, Virts said he was ready to start a new chapter of his life. “After serving 16 wonderful years at NASA, it is time to close one chapter of life and open another. Ad Astra,” he tweeted.
Buzz Aldrin, second man on the Moon and also a test pilot, reassured his colleague: “Don't worry [Terry]. Life can be pretty exciting on Earth too. Your next adventure is just beginning.”