Canadian astronaut Chris Hadfield in the Cupola of the International Space Station. Credit: NASA/CSA
While the world was enchanted with Chris Hadfield’s social media posts last year, a new video has the retired astronaut talking about loftier things. Say, for example, how humanity landed a camera on the Saturn moon Titan back in 2005. Or to be more practical, the fact that smallpox was eradicated in its naturally occurring form.
In his talks and books, Hadfield describes himself as one who never focuses on complaining. He was almost yanked from his command of the International Space Station due to a medical issue, but he pressed on and convinced the doctors to let him fly. And in this new video, he focuses on what humans do generally to make the world better — imperfect as it is.
“There are problems with everything, and nothing’s perfect, but that shouldn’t be cause to moan. That should be cause to achieve. Our world is a better place than we often claim it to be,” Hadfield said. “We live the way we do,” he added, “because people chose to tackle their problems, head on.”
The video appears to have a heavy emphasis on the Bill & Melinda Gates Foundation, a gigantic philanthropic network that works to improve lives in the developing world and also for the disadvantaged in the United States. But there are many ways to give back to your community, even through gestures as simple as volunteering.
Here are some examples in the space world (note that these aren’t necessarily endorsements for the organizations, but just ideas for making contributions in space and astronomy):
Cosmoquest, which runs online astronomy courses and also allows citizens to map extraterrestrial bodies right alongside astronomers.
Astronomers Without Borders brings astronomy education across the world, particularly to developing countries.
Uwingu says that half of its donations goes to grants to support learning in astronomy.
Other examples of space-y charity could include volunteering or donating to a local school or university, joining one of the numerous volunteer organizations in astronomy, or getting involved in a space advocacy group.
This Chandra image of the Tycho supernova remnant contains new evidence for what triggered the original supernova explosion. Credit: NASA/CXC/Chinese Academy of Sciences/F. Lu et al.
At one time or another, all science enthusiasts have heard the late Carl Sagan’s infamous words: “We are made of star stuff.” But what does that mean exactly? How could colossal balls of plasma, greedily burning away their nuclear fuel in faraway time and space, play any part in spawning the vast complexity of our Earthly world? How is it that “the nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies” could have been forged so offhandedly deep in the hearts of these massive stellar giants?
Unsurprisingly, the story is both elegant and profoundly awe-inspiring.
All stars come from humble beginnings: namely, a gigantic, rotating clump of gas and dust. Gravity drives the cloud to condense as it spins, swirling into an ever more tightly packed sphere of material. Eventually, the star-to-be becomes so dense and hot that molecules of hydrogen in its core collide and fuse into new molecules of helium. These nuclear reactions release powerful bursts of energy in the form of light. The gas shines brightly; a star is born.
The ultimate fate of our fledgling star depends on its mass. Smaller, lightweight stars burn though the hydrogen in their core more slowly than heavier stars, shining somewhat more dimly but living far longer lives. Over time, however, falling hydrogen levels at the center of the star cause fewer hydrogen fusion reactions; fewer hydrogen fusion reactions mean less energy, and therefore less outward pressure.
At a certain point, the star can no longer maintain the tension its core had been sustaining against the mass of its outer layers. Gravity tips the scale, and the outer layers begin to tumble inward on the core. But their collapse heats things up, increasing the core pressure and reversing the process once again. A new hydrogen burning shell is created just outside the core, reestablishing a buffer against the gravity of the star’s surface layers.
While the core continues conducting lower-energy helium fusion reactions, the force of the new hydrogen burning shell pushes on the star’s exterior, causing the outer layers to swell more and more. The star expands and cools into a red giant. Its outer layers will ultimately escape the pull of gravity altogether, floating off into space and leaving behind a small, dead core – a white dwarf.
Lower-mass stars like our sun eventually enter a swollen, red giant phase. Ultimately, its outer layers will be thrown off altogether, leaving nothing but a small white dwarf star. Image Credit: ESO/S. Steinhofel
Heavier stars also occasionally falter in the fight between pressure and gravity, creating new shells of atoms to fuse in the process; however, unlike smaller stars, their excess mass allows them to keep forming these layers. The result is a series of concentric spheres, each shell containing heavier elements than the one surrounding it. Hydrogen in the core gives rise to helium. Helium atoms fuse together to form carbon. Carbon combines with helium to create oxygen, which fuses into neon, then magnesium, then silicon… all the way across the periodic table to iron, where the chain ends. Such massive stars act like a furnace, driving these reactions by way of sheer available energy.
But this energy is a finite resource. Once the star’s core becomes a solid ball of iron, it can no longer fuse elements to create energy. As was the case for smaller stars, fewer energetic reactions in the core of heavyweight stars mean less outward pressure against the force of gravity. The outer layers of the star will then begin to collapse, hastening the pace of heavy element fusion and further reducing the amount of energy available to hold up those outer layers. Density increases exponentially in the shrinking core, jamming together protons and electrons so tightly that it becomes an entirely new entity: a neutron star.
At this point, the core cannot get any denser. The star’s massive outer shells – still tumbling inward and still chock-full of volatile elements – no longer have anywhere to go. They slam into the core like a speeding oil rig crashing into a brick wall, and erupt into a monstrous explosion: a supernova. The extraordinary energies generated during this blast finally allow the fusion of elements even heavier than iron, from cobalt all the way to uranium.
Periodic Table of Elements. Massive stars can fuse elements up to Iron (Fe), atomic number 26. Elements with atomic numbers 27 through 92 are produced in the aftermath of a massive star’s core collapse.
The energetic shock wave produced by the supernova moves out into the cosmos, disbursing heavy elements in its wake. These atoms can later be incorporated into planetary systems like our own. Given the right conditions – for instance, an appropriately stable star and a position within its Habitable Zone – these elements provide the building blocks for complex life.
Today, our everyday lives are made possible by these very atoms, forged long ago in the life and death throes of massive stars. Our ability to do anything at all – wake up from a deep sleep, enjoy a delicious meal, drive a car, write a sentence, add and subtract, solve a problem, call a friend, laugh, cry, sing, dance, run, jump, and play – is governed mostly by the behavior of tiny chains of hydrogen combined with heavier elements like carbon, nitrogen, oxygen, and phosphorus.
Other heavy elements are present in smaller quantities in the body, but are nonetheless just as vital to proper functioning. For instance, calcium, fluorine, magnesium, and silicon work alongside phosphorus to strengthen and grow our bones and teeth; ionized sodium, potassium, and chlorine play a vital role in maintaining the body’s fluid balance and electrical activity; and iron comprises the key portion of hemoglobin, the protein that equips our red blood cells with the ability to deliver the oxygen we inhale to the rest of our body.
So, the next time you are having a bad day, try this: close your eyes, take a deep breath, and contemplate the chain of events that connects your body and mind to a place billions of lightyears away, deep in the distant reaches of space and time. Recall that massive stars, many times larger than our sun, spent millions of years turning energy into matter, creating the atoms that make up every part of you, the Earth, and everyone you have ever known and loved.
We human beings are so small; and yet, the delicate dance of molecules made from this star stuff gives rise to a biology that enables us to ponder our wider Universe and how we came to exist at all. Carl Sagan himself explained it best: “Some part of our being knows this is where we came from. We long to return; and we can, because the cosmos is also within us. We’re made of star stuff. We are a way for the cosmos to know itself.”
This (in blue) is where the Philae lander came to rest on Comet 67P/Churyumov-Gerasimenko. The graphic is based on topographic modelling of the comet's nucleus and Philae's picture of a nearby cliff (in white). Credit: ESA/Rosetta/Philae/CNES/FD/CIVA
In scientific style, researchers are slowly narrowing down where the Philae lander arrived on Comet 67P/Churyumov-Gerasimenko. Earlier today (Dec. 17) at the American Geophysical Union meeting, more pictures from the European spacecraft were released showing its landing site and also what the terrain looked like underneath Philae as it bounced to its destination. The pictures were also placed on NASA’s website.
The lander is sleeping in a shady spot on the comet’s surface after the dramatic touchdown — actually, three touchdowns — on Nov. 12, when it flew for more than two hours across the surface and bounced as high as two miles (3.2 kilometers). This was partly because harpoons expected to secure it to the surface failed to deploy, and also because the comet crust was icier than expected, according to Gizmodo.
You can see in the diagram above Philae’s predicament; it’s wedged in a spot that doesn’t get a lot of sunlight, at least for now. That could change as 67P draws closer to the Sun in the late winter or early spring, but nobody yet knows for sure. And yes, the search for the landing site still continues in earnest, but the challenge now is the orbiting Rosetta spacecraft only has so much bandwidth to send back images, according to Wired. As more high-resolution OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) pictures arrive, scientists hope to figure out where it went.
Two pictures from Philae highlighted in today’s release are below. Will the lander take more? Scientists certainly hope so, but even if that doesn’t happen, the lander was only expected to return 20% of the science results in any case. Rosetta is still active and will stick with the comet through mid-2015, when 67P gets closest to the Sun.
The Philae lander captured a picture of a nearby cliff, nicknamed “Perihelion Cliff”, on the nucleus of Comet 67P/Churyumov-Gerasimenko. Reports say this picture had been released before, but was processed to show more detail (such as the glare, believed to be reflection from the lander). Credit: ESA/Rosetta/Philae/CIVAPhilae’s blurred view of the surface during its first bounce from Comet 67P/Churyumov-Gerasimenko on Nov. 12, 2014. The lander sailed for about two hours in the first bounce, made contact briefly, then bounced again before coming to rest. The black squares represent areas where data was not collected. Credit: ESA/Rosetta/Philae/CIVA
Still from a video short previewing "Weightless", a virtual-reality experience showing how to play with objects in a microgravity environment. Credit: Martin Schubert/YouTube (screenshot)
If you don’t have a few thousand dollars to spend on a “Vomit Comet” ride, and especially if you can’t afford to buy a ticket for a future weightless joyride in a spacecraft, virtual reality remains the best option to “experience” weightlessness.
There’s a new game available for the virtual-reality headset Oculus Rift that lets people play with objects in microgravity to see what happens next.
Called “Weightless”, the game appears to have a person zooming around a sort of space station and playing with things including pill bottles and cubes, seeing how they spin and soar without gravity’s pull weighing them down. (Note that the author does not have an Oculus Rift and could not test the game out for this article.)
“I wanted the player to have an experience that’s only possible in VR [virtual reality],” wrote creator Martin Schubert on the game’s webpage. “That means taking advantage of the ability to look around in any direction and having good spatial awareness. This led to investigating a weightless environment that allowed freedom of movement in any direction.”
Schubert wrote that the game is available in prototype form for the Oculus Rift DK2, and is best used with a head-mounted Leap Motion finger-tracking sensor. Bear in mind that the Oculus is still very much a prototype gaming platform, but that being said, the experience looks like a lot of fun for those of us lucky to have one. You can learn more about the hardware requirements and download information here.
An xkcd comic from December 2014 showing spacecraft mass and launch vehicle capacity in terms of horses. The full comic is at http://xkcd.com/1461/large/. Credit: xkcd
The challenge with thinking about space is putting it into terms that we can understand. How far is a light-year? Just how powerful is NASA’s next-generation Space Launch System, which the agency hopes will bring astronauts out into the solar system?
Luckily for us, the comic xkcd is a regular contributor to making space understandable, and the latest comic from Randall Munroe is a gem — explaining launch vehicle capacity and spacecraft mass in terms of horses.
So now comparisons are fairly easy. At the left of the diagram, for example, you can see the Saturn V — that rocket that was the first stage of bringing astronauts to the moon in the 1960s — carried the equivalent of 262 horses. The SLS Block 2, if it is ever developed, will have a slightly larger capacity of 289 horses.
Blastoff of NASA’s Space Launch System (SLS) rocket and Orion crew vehicle from the Kennedy Space Center, Florida. Credit: NASA/MSFC
Meanwhile, the spacecraft mass of the International Space Station is an astounding 932 horses, the total shuttle mass was 206 horses, and Apollo was 67 horses. There also are a few robotic spacecraft in there, such as Voyager, Vanguard 1, the Keyhole 3 spy satellite, and the upcoming James Webb Space Telescope.
The Mars Reconnaissance Orbiter took this image of a "circular feature" estimated to be 1.2 miles (2 kilometers) in diameter. Picture released in December 2014. Credit: NASA/JPL-Caltech/University of Arizona
NASA is puzzled by this “enigmatic landform” caught on camera by one of its Mars orbiters, but looking around the region provides some possible clues. This 1.2-mile (2-kilometer) feature is surrounded by relatively young lava flows, so they suspect that it could be some kind of volcanism in the Athabasca area that created this rippled surface.
“Perhaps lava has intruded underneath this mound and pushed it up from beneath. It looks as if material is missing from the mound, so it is also possible that there was a significant amount of ice in the mound that was driven out by the heat of the lava,” NASA wrote in an update on Thursday (Dec. 4).
“There are an array of features like this in the region that continue to puzzle scientists. We hope that close inspection of this … image, and others around it, will provide some clues regarding its formation.”
The picture was captured by the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE), a University of Arizona payload which has released a whole slew of intriguing pictures lately. We’ve collected a sample of them below.
These transverse aeolian ridges seen by the Mars Reconnaissance Orbiter are caused by wind, but scientists are unsure why this image (released in December 2014) shows two wavelengths of ripples. Credit: NASA/JPL-Caltech/University of ArizonaThis area south of Coprates Chasma is an example of sulfate and clay deposits on Mars, showing water once flowed readily in this region. Why the water evaporated from the Red Planet is one question scientists are hoping to answer with missions such as the Mars Reconnaissance Orbiter, which took this image (released in December 2014). Credit: NASA/JPL-Caltech/University of ArizonaArabia Terra, one of the dustiest regions on Mars, is filled with dunes such as this one captured by the Mars Reconnaissance Orbiter and released in December 2014. Credit: NASA/JPL/University of Arizona
Imagine, if you would, a potential future for humanity… Imagine massive space-elevators lifting groups of men, women, and children skyward off Earth’s surface. These passengers are then loaded onto shuttles and ferried to the Moon where interstellar starships are docked, waiting to rocket to the stars. These humans are about to begin the greatest journey humanity has ever embarked upon, as they will be the first interstellar colonists to leave our home Solar System in order to begin populating other worlds around alien stars.
There are many things we must tackle first before we can make this type of science-fiction scene a reality. Obviously much faster methods of travel are needed, as well as some sort of incredible material that can serve to anchor the aforementioned space elevators. These are all scientific and engineering questions that humanity will need to overcome in the face of such a journey into the cosmos.
But there is one particular important feature that we can begin to tackle today: where do we point these starships? Towards which system of exoplanets are we to send our brave colonists?
Of all of the amazing things we need to discover or invent to make this scene a reality, discovering which worlds to aim our ships at is something that is actually being worked on today.
Artistic view of a possible space elevator. Image Credit: NASA
It’s an exciting era in astronomy, as astronomers are currently discovering that many of the stars that we view in the night sky have their own planets in orbit around them. Many of them are massive worlds, all orbiting at varying distances from their parent star. It is no surprise that we are discovering a vast majority of these Jupiter-sized worlds first; larger worlds are much easier to detect than the smaller worlds would be. Imagine a bright spotlight pointing at you some 500 yards away (5 football fields). Your job is to detect something the size of a period on this page that is orbiting around it that emits no light of its own. As you can see, the task would be daunting. But nevertheless, our planet hunters have been utilizing methods that enable us to accurately find these tiny specks of gas and rock despite their rather large and luminous companion suns.
However, it is not the method of finding these planets that this article is about; but rather what we do to figure out which of these worlds are worthy of our limited resources and attention. We very well cannot point those starships in random directions and just hope that they happen across an earth-sized planet that has a nitrogen-oxygen rich atmosphere with drinkable water. We need to identify which planets appear to have these mentioned characteristics before we go launching ourselves into the vast universe.
How can we do this? How is it possible that we are able to say with any level of certainty what a planet’s atmosphere is composed of when this planet is so small and so very far away? Spectroscopy is the answer, and it just might be the key to our future in the cosmos.
Artistic impression of what Kepler-186f may look like. Image Credit: NASA Ames/SETI Institute/JPL-CalTech
Just so I may illustrate how remarkable our scientific methods are for this very field of research, I will first need to show you the distances we are talking about. Let’s take Kepler 186f. This is the first planet we have discovered that is very similar to Earth. It is around 1.1 times larger than Earth and orbits within the habitable zone of its star which is very similar to our own star.
Let’s do the math, to show you just how distant this planet is. Kepler 186f is around 490 lightyears from Earth.
Kepler 186f = 490 lightyears away
Light moves at 186,282 miles/ 1 second.
186,282 mi/s x 60s/1min x 60min/1hr x 24hrs/1day x 356days/1year = 5.87 x 1012 mi/yr
Kepler 186f: 490 Lyrs x 5.87 x 1012miles/ 1 Lyr = 2.88 x 1015 miles or 2.9 QUADRILLION MILES from Earth.
Just to put this distance into perspective, let’s suppose we utilize the fastest spacecraft we have to get there. The Voyager 1 spacecraft is moving at around 38,500 mi/hr. If we left on that craft today and headed towards this possible future Earth, it would take us roughly 8.5 MILLION YEARS to get there. That’s around 34 times longer than the time between when the first proto-humans began to appear on earth 250,000 years ago until today. So the entire history of human evolution from then till now replayed 34 times BEFORE you would arrive at this planet. Knowing these numbers, how is it even possible that we can know what this planet’s atmosphere, and others like it, are made of?
First, here’s a bit of chemistry in order for you to understand the field that is spectroscopy, and then how we apply it to the astronomical sciences. Different elements are composed of a differing number of protons, neutrons, and electrons. These varying numbers are what set the elements apart from one another on the periodic table. It is the electrons, however, that are of particular interest in the majority of what chemistry studies. These different electron configurations allow for what we call spectral signatures to exist among the elements. This means that since every single element has a specific electron configuration, the light that it both absorbs and emits acts as a sort of photon fingerprint; a unique identifier to that element.
A list of the elements with their corresponding visible light emission spectra. Image Credit: MIT Wavelength Tables, NIST Atomic Spectrum Database, umop.net
The standard equation for determining the characteristics of light is:
c= v λ
c is the speed of light in a vacuum (3.00 x 108 m/s)
v is the frequency of the light wave (in Hertz)
λ (lambda) represents the wavelength (in meters, but will usually be converted to nanometers) which will determine what color of light will be emitted from the element(s), or simply where the wavelength of light falls on the electromagnetic spectrum (infrared, visible, ultraviolet, etc.)
If you have either the frequency or the wavelength, you can determine the rest. You can even start with the energy of the light being detected by your instruments and then work backwards with the following equations:
The energy of a photon can be described mathematically as this:
Ephoton = hv
OR
Ephoton = h c / λ
What these mean is that the energy of a photon is the product of the frequency (v) of the light wave emitted multiplied by Planck’s Constant (h), which is 6.63 x 10-34 Joules x seconds. Or in the case of the second equation, the energy of the photon is equal to Planck’s Constant x the speed of light divided by the wavelength. This will give you the amount of energy that a specific wavelength of light contains. This equation is also known as the Planck-Einstein Relation. So, if you take a measurement and you are given a specific energy reading of the light coming from a distant star, you can then deduce what information you need about said light and determine which element(s) are either emitting or absorbing these wavelengths. It’s all mathematical detective work.
So, the electrons that orbit around the nucleus of atoms exist in what we call orbitals. Depending on the atom (and the electrons associated with it), there are many different orbitals. You have the “ground” orbital for the electron, which means that the electron(s) there are closest to the nucleus. They are “non-excited”. However, there are “higher” quantum orbitals that exist that the electron(s) can “jump” to when the atom is excited. Each orbital can have different quantum number values associated with it. The main value we will use is the Principle Quantum Number. This is denoted by the letter “n”, and has an assigned integer value of 1, 2, 3, etc. The higher the number, the further from the nucleus the electron resides, and the more energy is associated with it. This is best described with an example:
A hydrogen atom has 1 electron. That electron is whipping around its 1 proton nucleus in its ground state orbital. Suddenly, a burst of high energy light hits the hydrogen. This energy is transferred throughout the hydrogen atom, and the electron reacts. The electron will instantaneously “vanish” from the n1 orbital and then reappear on a higher quantum orbital (say n4). This means that as that light wave passed over this hydrogen atom, a specific wavelength was absorbed by the hydrogen (this is an important feature to remember for later).
Diagram of an electron dropping from a higher orbital to a lower one and emitting a photon. Image Credit: Wikimedia Commons
Eventually, the “excited” electron will drop from its higher quantum orbital (n4) back down to the n1 orbital. When this happens, a specific wavelength of light is emitted by the hydrogen atom. When the electron “drops”, it emits a photon of specific energy or wavelength (dependent upon many factors, including the state the electron was in prior to its “excitement”, the amount of levels the electron dropped, etc.) We can then measure this energy (or wavelength, or frequency,) to determine what element the photon is coming from (in this case, hydrogen). It is in this feature that each element has its own light signature. Each atom can absorb and emit specific wavelengths of light, and they are all tied together by the equations listed above.
So how does this all work? Well, in reality, there are many factors that go into this sort of astronomical study. I am simply describing the basic principle behind the work. I say this so that the many scientists that are doing this sort of work do not feel as though I have discredited their research and hard work; I promise you, it is painstakingly difficult and tedious and involves many more details that I am not mentioning here. That being said, the basic concept works like this:
We find a star that gives off the telltale signs that it has a planet orbiting around it. We do this with a few methods, but how it all first started was by detecting a “wobble” in the star’s apparent position. This “wobble” is caused by a planet orbiting around its parent star. You see, when a planet orbits a star (and when anything orbits anything else), the planet isn’t really orbiting the star, the planet AND the star are orbiting a common focal point. Usually with this type of orbital system, that common focal point is fairly close to the center of the star, and thus it’s safe to say that the planet orbits the star. However, this causes the star to move ever so slightly. We can measure this.
Once we determine that there are planets orbiting the star in question, we can study it more closely. When we do, we turn our instruments towards it and begin taking highly detailed measurements, and then we wait. What we are waiting for is a dimming of the star at a regular interval. What we are hoping for is this newly-found exoplanet to transit our selected star. When a planet transits a star, it moves in front of the star relative to us (this also means we are incredibly lucky, as not all planets will orbit “in front” of the star relative to our view). This will cause the star’s brightness to dip ever so slightly at a regular interval. Now we have identified a prime exoplanet candidate for study.
Diagram of how we can use absorption spectral reading to determine the atmosphere of an exoplanet. Image Credit: A. Feild, STScl, NASA
We can now introduce the spectroscopic principles to this hunt. We can take all sorts of measurements of the light that is coming from this star. Its brightness, the energy it’s kicking out per second, and even what that star is made of (the emission spectrum I discussed earlier). Then what we do is wait for the planet to transit the start, and begin taking readings. What we are doing is reading the light passing THROUGH the exoplanet’s atmosphere, and then studying what we can call an Absorption Spectrum reading. As I mentioned earlier, specific elements will absorb specific wavelengths of light. What we get back is a spectral reading of the star’s light signature (the emission spectra of the star), but with missing wavelengths that show up as very tiny black lines where there used to be color. These are called Fraunhofer lines, named after the “father” of astrophysics Joseph Fraunhofer, who discovered these lines in the 19th century.
The dark lines represent the light frequencies that were absorbed by specific chemicals that this particular light passed through. Image Credit: Wikimedia Commons
What we now have in our possession is a chemical fingerprint of what this exoplanet’s atmosphere is composed of. The star’s spectrum is splayed out before us, but the barcode of the planet’s atmospheric composition lay within the light. We can then take those wavelengths that are missing and compare them to the already established absorption/emission spectra of all of the known elements. In this way, we can begin to piece together what this planet has to offer us. If we get high readings of sulfur and hydrogen, we have probably just discovered a gas giant. However if we discover a good amount of nitrogen and oxygen, we may have found a world that has liquid water on its surface (provided that this planet resides within its host star’s “habitable” zone: a distance that is just far enough from the star to allow for liquid water). If we find a planet that has carbon dioxide in its atmosphere, we may just have discovered alien life (CO2 being a waste product of both cellular respiration and a lot of industrial processes, but it can also be a product of volcanism and other non-organic phenomena).
What this all means is that by being able to read the light from any given object, we can narrow our search for the next Earth. Regardless of distance, if we can obtain an accurate measurement of the light moving through an exoplanet’s atmosphere, we can tell what it is made of.
We have discovered some 2000 exoplanets thus far, and that number will only increase in the coming decades. With so many candidates, it will be a wonder if we do not find a planet that we humans can live on without the help of technology. Obviously our techniques will further be refined, and as new technologies, methods, and instruments become available, our ability to pinpoint planets that we can someday colonize will become increasingly more accurate.
With such telescopes like the James Webb Space Telescope launching soon, we will be able to image these exoplanets and get even better spectroscopic readings from them. This type of science is on the leading edge of humanity’s journey into the cosmos. Astrophysicists and astrochemists that work in this field are the necessary precursors to the brave men and women who will one day board those interstellar spacecraft and launch our civilization into the Universe to truly become an interstellar species.
Possible glimpse into our future… Image Credit: Battlestar Wiki Media
But that didn’t come cheap. Four astronaut servicing missions (including one to fix a mirror that was launched with myopia) were required to keep the telescope going since 1990. Hubble has never been more scientifically productive, according to a recent NASA review, but a new article asks if Hubble is destined to die a fiery death when its orbit decays in the next eight to 10 years.
“NASA doesn’t have any official plans for upgrading the telescope, meaning its hardware will grow old and out-of-date in the coming years,” reads the article in Popular Science. “Without assistance, Hubble can’t maintain its orbit forever, and eventually Earth’s gravity will pull the telescope to a fiery death.”
That’s not to say NASA is going to abandon the cosmos — far from it. Besides NASA’s other space telescopes, the successor James Webb Space Telescope is planned to launch in 2018 to chart the universe in other wavelengths. But a review from April warns that ceasing operations of Hubble would not be prudent until James Webb is up, running, and doing its own work productively. That’s a narrow window of time considering Hubble is expected to work well until about 2020.
The Hubble Space Telescope shows the shrinking size of Jupiter’s Great Red Spot in this series of images taken between 1995 and 2014. Credit: NASA, ESA, and A. Simon (Goddard Space Flight Center)
The Hubble Space Telescope senior review panel submitted a report on March that overall praised the observatory’s work, and which also talked about its potential longevity. As is, Hubble is expected to work until at least 2020, the review stated. The four science instruments are expected to be more than 85% reliable until 2021, and most “critical subsystems” should exceed 80% until that same year.
The report urges that experienced hands are kept around as the telescope degrades in the coming years, but points out that Hubble has backups that should keep the observatory as a whole going for a while.
There are no single-point failure modes on Hubble that could take down the entire observatory. It has ample redundancy. Planned mitigations for numerous possible sub-system failures or degraded performance have been developed in advance via the project’s Life-Extension Initiatives campaign. Hubble will likely degrade gracefully, with loss or degradation of individual science instrument modes and individual sub-system components.
In NASA’s response to the Senior Review for several missions (including Hubble), the agency said that the telescope has been approved (budgetarily speaking) until 2016, when an incremental review will take place. Further in the future, things get murky.
The Hubble Ultra Deep Field seen in ultraviolet, visible, and infrared light. Image Credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)
The just-tested Orion spacecraft won’t be ready to take crews until the mid-2020s, and so far (according to the Popular Science article) the commercial crew program isn’t expected to include a servicing mission.
According to STS-125 astronaut Michael Good, who currently serves in the Commercial Crew Program, the space agency isn’t looking into the possibility of using private companies to fix Hubble, but he says there’s always a chance that could happen. “One of the reasons we’re doing Commercial Crew is to enable this capability to get into lower Earth orbit,” says Good. “But it’s certainly in the realm of possibility.”
Much can happen in a decade — maybe a surge in robotic intelligence would make an automated mission more possible — but then there is the question of priorities. If NASA chooses to rescue Hubble, are there other science goals the agency would need to push aside to accomplish it? What is best? Feel free to leave your feedback in the comments.
Dr. Neil deGrasse Tyson contemplates the Big Bang. Image courtesy of Fox.
This spring, space fans had a virtual campfire to flock to: the new Cosmos series, which aired on Fox and National Geographic for 13 science-filled episodes.
The series attracted at least three million viewers a week, generated discussions (positive and negative) on social media, brought host Neil deGrasse Tyson to even higher heights of fame, and once again, showed the general public how neat space is.
Well, guess what. According to producer Seth MacFarlane, Cosmos could come back for a second run — which would supercede the predecessor series from the 1980s, narrated by Carl Sagan!
“Early, preliminary discussions for a 2nd season of #Cosmos– If you want to see more of the great @neiltyson, tweet him your love!” MacFarlane wrote on Twitter yesterday (Dec. 3).
His comments follow a posting on Reddit that surfaced in a couple of news reports yesterday, one from a reported viewer of a deGrasse Tyson talk in New York City:
“I just attended a presentation by Tyson at NJPAC in Newark, NJ,” the posting read. “During the Q&A portion, he told the audience that he’s meeting with producers tomorrow in NYC to discuss the next “season” (for lack of better term) of COSMOS. He didn’t go into further detail, but thought this was interesting since up until this point the updated show was just considered a one-off series (ie 13 episodes).”
Carbon dioxide ice begins to feel the heat in the south pole region every spring. In this image of 'Inca City' taken in August 2014, you can see a few fans coming out from channels (araneiforms) that are created when pressurized gas escapes from the melting ice. Picture taken by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona
We’ve been watching Mars with spacecraft for about 50 years, but there’s still so little we know about the Red Planet. Take this sequence of images in this post recently taken by a powerful camera on NASA’s Mars Reconnaissance Orbiter. Spring arrives in the southern hemisphere and produces a bunch of mysteries, such as gray-blue streaks you can see in a picture below.
That’s where citizen scientists can come in, according to a recent post for the University of Arizona’s High Resolution Imaging Science Experiment (HiRISE) camera that took these pictures. They’re asking people with a little spare time to sign up for Planet Four (a Zooniverse project) to look at mysterious Mars features. With amateurs and professionals working together, maybe we’ll learn more about these strange changes you see below.
On Aug. 20, 2014, Martian dust mounds are on top of the araneiforms in ‘Inca City’, as well as dark areas on the terrain showing where the ice cap in the southern hemisphere burst and sent gas and dust into the surroundings. Fans in the area are pointing in multiple directions, showing how the wind has changed. Image taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of ArizonaOn Aug. 25, 2014, more fans and blotches appear on the Martian landscape around “Inca City”, a location in the southern polar region, as the ice bursts in the springtime sun. Image obtained by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of ArizonaAs of Sept. 6, 2014, fans in “Inca City” in the Martian southern hemisphere are now blue-gray. Why this color appears in the spring is unknown. It could be because of particles falling into ice underneath, or gas bursting from the ice condensing and falling as frost. It could even be a combination of the two. Image taken by the Mars Reconnaissance Orbiter’s HiRISE orbiter. Credit: NASA/JPL/University of ArizonaAs spring takes hold in the southern polar region of Mars on Sept. 27, 2014, cracks are now developing in the ice at “Inca City” with multiple new dust fans appearing. Cracks develop when the ice does not have a path to easily rupture and release gas. Picture taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of Arizona
