We're trying to make stars on Earth. Luckily for everyone's weight, there isn't enough mass on Earth to make a star the usual way, via gravity. Instead, we're trying to initiate fusion in a controlled manner, the true holy grail of clean energy for many decades. Fuel for fusion is abundant and safe and the waste byproducts require far less special care than their fission counterparts. The standard joke about fusion is that it's always 50 years away. While true in some sense, people who actually work on fusion would tell you that it's been $80 billion away for decades. I always like to show this graphic made by Geoff Olynyk when "fusion will always be decades away" rears its ugly head.
Way back in 1976, these were the projections for when we might have fusion given various levels of funding. Even then, they had the humor to label the projected 1978 level of funding "fusion never." While I tend to take graphs like this with a grain of salt (predicting the future is hard), the absolutely dreadful level of actual funding is far more astonishing to me. Do you know how little money $80 billion spread over 15-30 years is compared to a decades-long Cold War?
Hyperbole aside, I let fusion lapse from my attention a bit. From the "NUCLEAR BAD!!!" camp to the "That's science fiction" to the blank stares, it just didn't seem like the collective fortitude required to attain fusion was there. I also saw that ITER, the main tokamak project in the world right now, was having difficulties, technical, economic and political.
Then, along came Weldenstein 7-X (W 7-X). Not being a nuclear engineer nor having quite the time to delve fully into all the tokamak alternatives, I didn't even know what a stellerator was a few months ago. Glossing over many details, I think Thomas Klinger, the Scientific Director of W 7-X, put it best. "They are both terrible beasts. Our's [stellerator] is a beast to build; your's [tokamak] is a beast to operate."
A tokamak is basically a giant magnetic donut. Intense magnetic fields confine a plasma hot enough to initiate nuclear fusion. The big problem: the plasma wants to radiate outwards from the center, forcing tokamak designers to jump through all kinds of hoops to keep it on its circular path. A stellerator, on the other hand, is ... is ... well ... hard to describe. Here's a picture.
You can go to ScienceMag, where I got this picture from, for further details. The idea is to fight the outward radiation that tokamaks contend with by making the plasma twist around as it "orbits." In my completely non-expert understanding, just when the plasma wants to go off course, you twist the course so it comes back in, which results in the weird, twisty thing pictured above. W 7-X just turned on for the first time Thursday (Dec 10). It did everything it was supposed to do and the project participants are pleased as punch. Even if W 7-X performs exactly as designed for the remainder of the project's duration, it still won't generate commercial levels of energy. However, it is an important research platform and demonstration of fusion's potential as a clean energy source.
I really hope some form of fusion finally makes its way to commercial usage eventually. We have enough fuel on Earth to produce energy at current levels for millions of years and that fuel (heavy water and lithium) is in places we don't have to fight wars to secure. If this really works and does so soon enough, perhaps the inaction at the Paris climate talks won't matter.
It may seem a bit odd to start a post about space with Earth. While we do for the most part study space because we're just plain interested, it is nice for knowledge gained by studying things beyond Earth to help us understand our home planet and vice versa. Here is a perfect example.
Some rocks found in Australia were found to have Carbon-12, a chemical consistent with known life processes. What makes these rocks interesting is that they are 4.4 billion years old. The Carbon-12 is dated to 4.1 billion years ago. Here is the primary image being shared of the discovery.
Why is this a big deal? Earth is only thought to be about 4.6 billion years old. Prior estimates of the oldest known life forms is 3.8 billion years. This discovery, if it holds up under scrutiny, effectively reduces the amount of time required for life to form by about 40%. Further, it shows that life can form under much more hostile conditions than previously thought. Around 4.1 billion years ago, Earth itself was much warmer, was getting hit by asteroids and comets a lot as well as experiencing much higher levels of volcanism than at the current time.
How does this affect our understanding of life beyond Earth? Well, life beyond Earth seems to only get more likely as our knowledge increases. The abundance of planets that can harbor liquid water, the abundance of water itself in space and the number of Earthbound extremophiles (organisms that thrive in conditions seemingly hostile to life) are all recent developments that increase the likelihood of life elsewhere. The fact that life could form so early on Earth ratchets up the likelihood of life elsewhere in the Universe just a little bit more.
Mars
Regarding the idea of life elsewhere in the Universe, Mars was once a darling. In some sense, it still is. However, the prospect for "life on Mars" has slowly been amended to "life on Mars in the past." What we see today on Mars is just not very encouraging in terms of finding life now. However, with regard to life on Mars in the past, things keep looking better.
Deep Lakes
Mars appears to have had very deep lakes in the past. By analyzing sedimentary data collected by theCuriosityrover, it looks like a lake may have been as deep as 800m (half a mile). For perspective, that's twice as deep as the deepest point in the Great Lakes. Here is one of the images studied.
Such large standing bodies of water would be very helpful for the development of life as we know it. Mind you, sedimentary data can only be collected in Curiosity's immediate vicinity. Who knows what else might be found if we could only look elsewhere?
Atmosphere Stripping
Another Mars result was the confirmation that the solar wind is stripping Mars' atmosphere. The usual story told about Earth is that our magnetic field keeps the solar wind from being too strong when it hits our atmosphere. As a result, Earth loses very little of its atmosphere. Mars stands in stark contrast. With no global magnetic field, the solar wind plows into Mars' atmosphere, flinging portions of it beyond the planet's gravitational reach. This story of atmospheric erosion was confirmed numerically byMAVEN'sdata, which was used to produce the following video.
If we run the process of the solar wind stripping Mars' atmosphere back billions of years, a rather significant atmosphere would have been possible. Between this and the deep lakes, an ancient Mars and current Earth would be more similar to each other than the current-day Mars.
Jupiter
TheHubble Space Telescopestared directly at Jupiter for a solid 10 hours. The average day on Jupiter is about 10 hours, which means almost every point on the planet was imaged twice. This is part of theOPALprogram, which will fully image every outer planet annually. Often, it is not the single still image that provides useful information, but the accumulation of data over time. It isn't clear exactly what will be learned through future imaging of the other outer planets, but the pictures sure are pretty.
Already, the rate of the Great Red Spot's shrinking has been measured and a band of wave-like structures was observed. These waves had only been observed once before. Until now, it had been presumed a fluke, which is now clearly not the case.
Enceladus (Saturn)
The Cassini spacecrafttook its deepest dive through Enceladus's plume. Early on in Cassini's tour around Saturn, images showing huge geysers spewing material out of Enceladus flung it to fame. Follow-up missions determined that there is a sub-surface ocean sourcing the plumes. It was also discovered that these geysers help to source the E-ring with material. Only a few images have been released so far of this latest deep dive. Because of the size of the full data and the bandwidth available, full sets of high resolution images won't be available until 2016. However, the detail of the surface in the pictures already released is pretty amazing. Each pixel represents 50 feet across, the size of a fairly modest home.
The principal purpose of this dive, however, is not close-up imaging of Enceladus' surface, though that is a nice benefit. Scientists are most interested in the chemical composition and make-up of the plume. They are also interested in the physical nature of the plume. Though it has been imaged, the depth, density and rate of material discharge is not well-known or understood. All of this information will paint a better picture of what mechanisms are actually producing the plumes and how long they have been going on. As usual when water is involved, the conclusions will also have strong implications regarding life on the moon.
Overlapping Stars (aka VFTS 352)
Two stars were found to be so close that they are actually sharing material. Collectively, the binary is known as VFTS 352. Binary star systems that share material are known as "contact binaries" or "overcontact binaries." VFTS 352 is by no means the first contact binary system discovered. However, it is the most massive, collectively about 57 times the mass of our sun. I'm not sure why theESOdidn't release an image used by the scientists; but this artist's rendition is kinda pretty.
VFTS 352 is also unusual in how close in size the two components of the binary are. As a result, material isn't being sucked from one to the other, as is most common. Instead, the two stars are actually sharing material in what might be thought of as a stable configuration. What is potentially unique about this system is that the stars may both go supernova. If that happens, a binary black hole may form, something that hasn't been accounted for by current models of stellar evolution. Personally, I'm a little skeptical that such a thing will occur; but, I'm far less qualified to speculate about such things than the experts at ESO.
Comets
Comets are mainly from the Kuiper Belt and Oort Cloud. The material in these regions is considered primordial in the sense that they have changed very little since our sun began fusing. As such, they are a proxy for the conditions in the very early formation of our solar system. Discoveries related to comets, particularly their composition and chemistry, not only helps us determine which theories of solar system formation are more likely, but how quickly the complex reactions required for life might have formed. This month, two comets shed some light on these issues.
Drunk Comet (Lovejoy, of course)
Comet Lovejoy was found to have large amounts of alcohol in its tail. There are lots of forms of alcohol, but we are in fact talking about the kind that gets Samuel L Jackson drunk. Alcohol is a relatively complex molecule in the context of a pre-planetary solar system. If the extreme heating and cooling from the sun arising from comets' highly eccentric orbits brings about such complex chemistry, then life on Earth would not necessarily have had to start from complete scratch. The process that led to life on Earth could have been jump-started with complex chemicals brought by comets rather than having to synthesize everything from simple molecules like water, carbon monoxide and nitrogen.
Oxygen From Comet 67P (Churyumov-Gerasimenko)
The oxygen atom is very abundant in the Universe. However, molecular oxygen (O2) is quite rare in space because it is so reactive. O2can easily combine with hydrogen to make water, for example, and can even combine with free oxygen atoms to create ozone (O3). Nonetheless, the Rosetta spacecraftdetected O2in the tail of Comet 67P. Finding O2in a comet doesn't fit with our current models of solar system formation. The mechanisms required to trap O2within a comet are simply not there. Such a mechanism will now have to be added to account for theobservations made by Rosetta.
On July 11, 2015, we lost one of the world's leaders and pioneers in space science, Claudia Alexander. I had seen her on the Science Channel a few times talk about planetary evolution and thus was happy to see her familiar face as part of the Rosetta team when it rendezvoused with Comet 67/P. As anyone who follows this blog knows, I actually stay up late for news on Rosetta/Philae. Claudia had a genuineness and grace about her that is a rare gift in the sciences and she will be sorely missed.
Here are a few links for those who want to get to know her a little better.
The bulk of the second half of All Space Considered was spent hearing from David Helfand, Chair of the Astronomy Department at Columbia University. He didn't talk much about Columbia University, instead focusing on his past seven years at Quest University in British Columbia, Canada. I'm not much for discussion on the process of education, but Dr Helfand made many very good points and shared how Quest University has attempted to address them.
His first critique of the modern University system is its adherence to traditional lecturing. In the age of the mobile Internet, the idea that some wizened elder can bestow knowledge upon a class of curious children in a way they couldn't obtain themselves is a bit archaic.
His second critique was the isolation of disciplines. It's rare for an economics professor to talk to a music professor and even rarer for either to talk to the physics departments (I guess physics is notoriously exclusive).
His third critique was that many of the skills required to succeed in the modern world are lacking. When employers are asked what they find problematic in their interviewees, it's never a lack of coding speed or inability to use a particular piece of software. What concerns them is someone's ability to communicate and ability to think about issues from many different perspectives.
To that end, Quest University has block scheduling, no departments and a very open-ended means of earning a degree. Block scheduling means that each student only has one class at any given time. That class lasts a month and they have no other educational obligations during that month. This completely eliminates scheduling conflicts and allows for studying topics in incredible depth. When the geology class goes to Hawaii to study a particular type of volcano (which is a typical sort of experience in Quest's classes), no one can say "Oh, but I have a test I need to study for."
Instead of departments, the faculty offices are all in one giant oval and are assigned by random lot. Not only does this get people thinking about creative and original collaborations, it really serves the open-ended degree mechanism well (which I'll get to next). Of course, any University could set up physical environments to encourage cross-disciplinary mixing (though most would balk at the very mention), the lack of the very concept of "department" sets all the instructors completely free. They don't have to adhere to some special set of rules for their own department that no one else even knows about.
The open-ended degree is the most interesting part to me. After the first year, students are asked to write a problem statement. They then spend the remainder of their time addressing the problem statement. That's it. Dr Helfand went into further details about the nuts and bolts of how that's done, but from a philosophical standpoint, the student chooses what to study and is simply guided by the faculty on how that might best be accomplished.
Honestly, the whole thing sounded a little too good to be true. But then again maybe that's just jealousy. I think I would definitely have enjoyed myself quite a bit in such an environment. Everyone around me seemed to think the same.
As usual, the fine folks at Griffith Observatory held All Space Considered on the first Friday of June 2015. Here's what they had to say about the goings-on beyond our solar system.
Galactic Jets
For the first time, a collision of material within a black hole jet was observed. Black holes have event horizons, a proverbial point of no return. Once something crosses that event horizon, it will never escape. However, a particle with enough energy can get arbitrarily close to the event horizon and still get out. Due to the dynamics of black holes (most notably spin) those high energy particles form jets focused along the black hole's axis.
Galactic jets are not very well understood due to their highly relativistic nature. In layman's terms, things moving that freakin fast are hard to see clearly. What was observed for the first time in the series of pictures from Hubble taken over the span of 20 years (animated in the video below) was a collision of black hole jet material with other black hole jet material.
This in itself is a wonderful observation, but more important is that it gives us a target of observation for further study of this phenomenon. We can now watch the evolution of these jets and see how the energy is dissipated, hopefully across the entire spectrum.
Gassy Andromeda
The halo of gas surrounding Andromeda, our nearest galactic neighbor, was probed much in the same way the Milky Way's jets were probed as reported in the February, 2015 edition of All Space Considered. Background quasars were used to see how far out the gassy halo extended (see image below for further explanation) and it turned out to be much larger than anticipated. In previous studies of this sort looking at halos around other galaxies, only one quasar could be used due to the distance of the galaxy and rather small portion of the sky covered as seen from Earth. Because Andromeda is so close, it appears about 6 times the diameter of the moon from Earth. This halo would cover a gargantuan 100 times the diameter of the moon in the sky. That's about half the distance from the Milky Way to Andromeda. If the Milky Way has a similar halo, it could be that the galaxies are already merging on the fringes, long before the main parts of the galaxies merge, roughly 4 billion years from now.
Dark Globular Clusters
Globular clusters with much higher mass than predicted have been found in nearby elliptical galaxy Centaurus A. This observation was made comparing the motions of over a hundred of Centaurus A's globular clusters and looking at the motions of the stars and the clusters themselves around the galaxy. When comparing the masses of the clusters from that data to the mass predicted by surveying the observable stars in the cluster, it became apparent that much of the mass is invisible. For now, it's not clear where the mass comes from. The leading candidate is dark matter. For reasons beyond my understanding, it is generally thought that globular clusters such as M13, depicted below, do not contain very much dark matter. If the clusters do indeed end up harboring dark matter, it would be a new classification of astronomical object.
Supernovae
It's starting to look like there are at least two different ways for Type 1a supernova to occur. In most popular science media I've seen, the "single-degenerate" model is shown. This is where a white dwarf sucks material off of a companion star until it hits critical mass, at which point the Type 1a supernova happens. There is also the "double-degenerate" model in which two white dwarfs merge, collectively going over the critical mass. Between two different papers published in May, evidence for both types was seen. In one paper, a supernova exhibited a spike in ultraviolet radiation, thought to be generated by the supernova slamming into the companion star. In the picture below, the brown region represents the supernova. It is shown as it engulfs the companion star, shown in white and blue.
In the other paper studying type 1a supernovae, three were examined that did not exhibit this spike. This would seem to indicate these supernovae were a result of the double-degenerate model. If the term "degenerate" confuses you, it merely refers to the number of white dwarfs involved in the supernova. White dwarfs are "degenerate" in the sense that they have stopped fusing material.
The reason cosmologists care so much about Type 1a supernova is they are a key component to the body of evidence for dark energy, that which is responsible for the accelerating expansion of the universe. The more we understand Type 1a supernovae, the more we can say about what we've seen about them at all cosmic distances, from within the Milky Way to the edge of the observable universe.
As usual, the fine folks at Griffith Observatory held All Space Considered on the first Friday of June 2015. Here's what they had to say about the goings-on in our solar system. Unfortunately, due to the timing of Independence Day, there will be no July 2015 All Space Considered, but that will give you more time to prepare for Plutopalooza.
Dwarfs
We currently have two probes studying dwarf planets. Not that long ago, "dwarf planet" wasn't even a real term. The discovery of Eris, thought by its discoverers to be the 10th planet, forced astronomers to reconsider what exactly a planet is. In doing so, it came up with three criteria.
It must orbit the sun
It must be more or less spherical in shape due to its own gravity
It must have cleared its orbital neighborhood
This, of course, led to the downfall of Pluto from planet status because it failed to meet criteria 3. Along with the above definition of "planet," it was decided any other body that meets criteria 1 and 2 but fails 3 would be called a "dwarf planet." This seemed an unfair fate for Pluto, beloved for decades as a planet. However, it did lift Ceres out of non-planet status. These two dwarf planets are the ones we have probes studying right now.
Pluto
The New Horizons spacecraft is the first dedicated to the study of Pluto. Back in January, Alan Stern, the Principal Scientific Investigator, visited with All Space Considered. He stated then that we would soon get our best pictures of Pluto ever and New Horizons has not disappointed. While the released images still look all blurry and pixelated, their resolution exceeds any image we've ever taken of Pluto, including by the Hubble space telescope. Also, they are getting sharper every day. Even since All Space Considered, new images have been released at even higher resolution.
The closest approach will be quite early in the morning on July 14. However, there is no need to stay up late or get up early for the occasion for several reasons. First, it takes a few hours for radio signals sent from Pluto to reach Earth. Second, the transmissions data rate is very low (about 1kbps). Third, New Horizons has no moving parts. This means only very infrequently can it point a camera at Pluto and simultaneously point an antenna at Earth. Most of the data will be gathered and stored during the closest approach and be sent back to Earth later.
Hubble has not been ignoring Pluto just because New Horizons is on its way. It has been peering at Pluto's moons and has found that they tumble rather chaotically. Due to the high relative mass of Charon (Pluto's largest moon) to Pluto, the smaller moons are effectively navigating a binary gravitational system. This causes them to wobble in their orbits and tumble around in their rotations. This would be very disorienting because it means if you were sitting stationary on the moon's surface, you would see the sun rise from a different direction each day. Below is a video of what Nix would look like from the center of mass of the Pluto-Charon system.
NASA also has a pretty cool web app to show where New Horizons is at the moment, as well as a few others showing which of the receiving stations on Earth is collecting data from it. Due to the different directions all of our various satellites are in the solar system from Earth, several ground-based stations receive data from any given satellite.
Ceres
While the Dawn spacecraft continues to take many images of Ceres of breathtaking detail, the most notable features have definitely been the bright spots in one of the craters. It almost looks like a light seen through a napkin with holes in it. Such brightness amidst so many craters has not been observed thus far on any other body in the solar system. Below is one of the pictures of the bright spots.
Since All Space Considered, it has been concluded that the spots are composed of highly reflective material. What the specific material is or what process deposited them there (volcanism, erosion, etc) is still unknown.
Comet 67/P (Churyumov/Gerasimenko)
The biggest news since All Space Considered involving Comet 67/P is, of course, the awakening of Philae, the spacecraft that landed on Comet 67/P as part of ESA's Rosetta mission. Unfortunately, there has been little news from Philae. Due to its exact position on the comet being unknown and the relatively surprising nature of the initial contact, the orbiter, Rosetta, was not in an ideal position to communicate with Philae. Mission control is, of course, doing everything within reason to gather as much information from Philae as possible. The comet has become very active of late, making getting closer a somewhat dangerous affair.
Prior to this announcement, however, there was some interesting science returned from Rosetta. It was discovered that the water and carbon dioxide plumes break down in a two-step process. From Earth, all we can deduce is that these molecules have been broken up and it had always been assumed that this was a result of ultraviolet light. Even the most powerful Earth-based and Earth-orbiting observatories can only observe the phenomenon to a resolution of miles. Rosetta is able to observe at much higher resolution and discovered that the direct breakdown of these molecules form ultraviolet light is just the first stage. Once a molecule has been broken up by ultraviolet light, energetic electrons are emitted that break up yet another molecule. They were able to deduce this by looking at the relative energies of the broken-up molecules in the ultraviolet spectrum. The following diagram illustrates this two-stage process.
Io Volcanism
We often refer to Titan, the largest moon of Saturn, as the only celestial body besides Earth to harbor standing liquid on its surface. It's possible it still is, but Io is trying to share in Titan's glory. Recent images from LBTO (a pretty badass binocular telescope) show a hot spot in a depression known as a patera. It's been well-known for some time that Io is the most volcanic body in the solar system. Naturally, some of that volcanism leads to liquid lava on its surface. What this new observation points to, however, is a lake of lava. Parts of it solidify, but other parts stay liquid and vent the heat. Below is the LBTO image (orange) overlaid on a black and white Voyager surface image at the same location.
As I prepare my posts from the most recent All Space Considered, the ESA has released news that Philae is awake! I simply can not contain my joy, despite not knowing what data Philae has sent back. As yet, there are no details, but I nonetheless rejoice.
Philae was a lander deployed by the Rosetta mission to study comet 67/P, Churyumov-Gerasimenko. Simply getting Rosetta into orbit around the tiny gravity of a comet was quite a smashing success. Being able to deploy Philae onto the comet's surface is nothing short of miraculous.
