Artist's impression of the Mars Moons Exploration (MMX) spacecraft. Credit: JAXA
In the coming decades, the world’s largest space agencies hope to mount some exciting missions to the Moon and to Mars. Between NASA, Roscosmos, the European Space Agency (ESA), the Chinese National Space Agency (CNSA) and the Indian Space Research Organization (ISRO), there is simply no shortage of proposals for Lunar bases, crewed missions to Mars, and robotic explorers to both.
However, the Japanese Aerospace Exploration Agency (JAXA) has a different mission in mind when it comes to the coming decades. Instead of exploring the Moon or Mars, they propose exploring the moons of Mars! Known as the Martian Moons Exploration (MMX) mission, the plan is to have a robotic spacecraft fly to Phobos and Deimos to explore their surfaces and return samples to Earth for analysis.
The Small Magellanic Cloud is one of the highlights of the southern sky. It can be seen with the naked eye. But it is obscured by clouds of interstellar gas and dust, which makes it hard for optical telescopes to get a good look at it. This image, taken with the ESO's VISTA. is the biggest-ever image of the SMC, and shows millions of stars. Credit: ESO/VISTA VMC
The Small Magellanic Cloud (SMC) galaxy. Credit: ESA/VISTA
The Small Magellanic Cloud (SMC) is one of the Milky Way’s nearest companions (along with the Large Magellanic Cloud.) It’s visible with the naked eye in the southern hemisphere. A new image from the European Southern Observatory’s (ESO) Visible and Infrared Survey Telescope for Astronomy (VISTA) has peered through the clouds that obscure it and given us our biggest image ever of the dwarf galaxy.
The SMC contains several hundred million stars, is about 7,000 light years in diameter, and is about 200,000 light years away. It’s one of the most distant objects that we can see with the naked eye, and can only be seen from the southern hemisphere (and the lowest latitudes of the northern hemisphere.)
The Small Magellanic Cloud is located in the Tucana constellation (The Toucan) in the southern hemisphere. The SMC is shown in green outline around the word ‘Tucana’. Also shown are NGC 104 and NGC 362, unrelated objects that are much closer to Earth. Image: ESO, IAU and Sky & Telescope
The SMC is a great target for studying how stars form because it’s so close to Earth, relatively speaking. But the problem is, its detail is obscured by clouds of interstellar gas and dust. So an optical survey of the Cloud is difficult.
But the ESO’s VISTA instrument is ideal for the task. VISTA is a near-infrared telescope, and infrared light is not blocked by the dust. VISTA was built at the ESO’s Paranal Observatory, in the Atacama Desert in Chile where it enjoys fantastic observing conditions. VISTA was designed to perform several surveys, including the Vista Magellanic Survey.
Explore the Zoomable image of the Small Magellanic Cloud. (You won’t be disappointed.)
The VISTA Magellanic Survey is focused on 3 main objectives:
The study of stellar populations in the Magellanic Clouds
The history of star formation in the Magellanic Clouds
The three-dimensional structure of the Magellanic Clouds
An international team led by Stefano Rubele of the University of Padova has studied this image, and their work has produced some surprising results. VISTA has shown us that most of the stars in this image are much younger than stars in other neighbouring galaxies. It’s also shown us that the SMC’s morphology is that of a warped disc. These are only early results, and there’s much more work to be done analyzing the VISTA image.
VISTA inside its enclosure at Paranal. VISTA has a 4.1 meter mirror, and its job is to survey large sections of the sky at once. In the background is the ESO’s Very Large Telescope. Image: G. Hüdepohl (atacamaphoto.com)/ESO
As the authors say in their paper, the SMC is a great target for study because of its “rich population of star clusters, associations, stellar pulsators, primary distance indicators, and stars in shortlived evolutionary stages.” In a way, we’re fortunate to have the SMC so close. But studying the SMC was difficult, until the VISTA came online with its infrared capabilities.
VISTA saw first light on December 11th, 2009. It’s time is devoted to systematic surveys of the sky. In its first five years, it has undertaken large surveys of the entire southern sky, and also studied small patches of the sky to discern extremely faint objects. The leading image in this article is from the Vista Magellanic Survey, a survey covering 184 square degrees of the sky, taking in both the Small Magellanic Cloud and the Large Magellanic Cloud, and their environment.
An interdisciplinary team from MIT (with support from NASA) is seeking to create an instrument that can performing in-situ test for life. Credit: setg.mit.edu
In 2015, then-NASA Chief Scientist Ellen Stofan stated that, “I believe we are going to have strong indications of life beyond Earth in the next decade and definite evidence in the next 10 to 20 years.” With multiple missions scheduled to search foe evidence of life (past and present) on Mars and in the outer Solar System, this hardly seems like an unrealistic appraisal.
But of course, finding evidence of life is no easy task. In addition to concerns over contamination, there is also the and the hazards the comes with operating in extreme environments – which looking for life in the Solar System will certainly involve. All of these concerns were raised at a new FISO conference titled “Towards In-Situ Sequencing for Life Detection“, hosted by Christopher Carr of MIT.
Carr is a research scientist with MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) and a Research Fellow with the Department of Molecular Biology at Massachusetts General Hospital. For almost 20 years, he has dedicated himself to the study of life and the search for it on other planets. Hence why he is also the science principal investigator (PI) of the Search for Extra-Terrestrial Genomes (SETG) instrument.
This artist’s rendering shows NASA’s Europa mission spacecraft, which will search for life on Europa beginning sometime in the 2020s. Credit: NASA/JPL-Caltech
Led by Dr. Maria T. Zuber – the E. A. Griswold Professor of Geophysics at MIT and the head of EAPS – the inter-disciplinary group behind SETG includes researchers and scientists from MIT, Caltech, Brown University, arvard, and Claremont Biosolutions. With support from NASA, the SETG team has been working towards the development of a system that can test for life in-situ.
Introducing the search for extra-terrestrial life, Carr described the basic approach as follows:
“We could look for life as we don’t know it. But I think it’s important to start from life as we know it – to extract both properties of life and features of life, and consider whether we should be looking for life as we know it as well, in the context of searching for life beyond Earth.”
Towards this end, the SETG team seeks to leverage recent developments in in-situ biological testing to create an instrument that can be used by robotic missions. These developments include the creation of portable DNA/RNA testing devices like the MinION, as well as the Biomolecule Sequencer investigation. Performed by astronaut Kate Rubin in 2016, this was first-ever DNA sequencing to take place aboard the International Space Station.
Building on these, and the upcoming Genes in Space program – which will allow ISS crews to sequence and research DNA samples on site – the SETG team is looking to create an instrument that can isolate, detect, and classify any DNA or RNA-based organisms in extra-terrestrial environments. In the process, it will allow scientists to test the hypothesis that life on Mars and other locations in the Solar System (if it exists) is related to life on Earth.
The theory of Lithopanspermia states that life can be shared between planets within a planetary system. Credit: NASA
To break this hypothesis down, it is a widely accepted theory that the synthesis of complex organics – which includes nucleobases and ribose precursors – occurred early in the history of the Solar System and took place within the Solar nebula from which the planets all formed. These organics may have then been delivered by comets and meteorites to multiple potentially-habitable zones during the Late Heavy Bombardment period.
Known as lithopansermia, this theory is a slight twist on the idea that life is distributed throughout the cosmos by comets, asteroids and planetoids (aka. panspermia). In the case of Earth and Mars, evidence that life might be related is based in part on meteorite samples that are known to have come to Earth from the Red Planet. These were themselves the product of asteroids striking Mars and kicking up ejecta that was eventually captured by Earth.
By investigating locations like Mars, Europa and Enceladus, scientists will also be able to engage in a more direct approach when it comes to searching for life. As Carr explained:
“There’s a couple main approaches. We can take an indirect approach, looking at some of the recently identified exoplanets. And the hope is that with the James Webb Space Telescope and other ground-based telescopes and space-based telescopes, that we will be in a position to begin imaging the atmospheres of exoplanets in much greater detail than characterization of those exoplanets has [allowed for] to date. And that will give us high-end, it will give the ability to look at many different potential worlds. But it’s not going to allow us to go there. And we will only have indirect evidence through, for example, atmospheric spectra.”
Enceladus in all its glory. NASA has announced that Enceladus, Saturn’s icy moon, has hydrogen in its oceans. Image: NASA/JPL/Space Science Institute
Mars, Europa and Enceladus present a direct opportunity to find life since all have demonstrated conditions that are (or were) conducive to life. Whereas there is ample evidence that Mars once had liquid water on its surface, Europa and Enceladus both have subsurface oceans and have shown evidence of being geologically active. Hence, any mission to these worlds would be tasked with looking in the right locations to spot evidence of life.
On Mars, Carr notes, this will come down to looking in places there there is a water-cycle, and will likely involve some a little spelunking:
“I think our best bet is to access the subsurface. And this is very hard. We need to drill, or otherwise access regions below the reach of space radiation which could destroy organic materiel. And one possibility is to go to fresh impact craters. These impact craters could expose material that wasn’t radiation-processed. And maybe a region where we might want to go would be somewhere where a fresh impact crater could connect to a deeper subsurface network – where we could get access to material perhaps coming out of the subsurface. I think that is probably our best bet for finding life on Mars today at the moment. And one place we could look would be within caves; for example, a lava tube or some other kind of cave system that could offer UV-radiation shielding and maybe also provide some access to deeper regions within the Martian surface.”
As for “ocean worlds” like Enceladus, looking for signs of life would likely involve exploring around its southern polar region where tall plumes of water have been observed and studied in the past. On Europa, it would likely involve seeking out “chaos regions”, the spots where there may be interactions between the surface ice and the interior ocean.
Exploring Europa’s “chaos terrain”, where the is interaction between the interior ocean and the surface ice, could yield evidence of biological organisms. Credit: NASA/JPL-Caltech
Exploring these environments naturally presents some serious engineering challenges. For starters, it would require the extensive planetary protections to ensure that contamination was prevented. These protections would also be necessary to ensure that false positives were avoided. Nothing worse than discovering a strain of DNA on another astronomical body, only to realize that it was actually a skin flake that fell into the scanner before launch!
And then there are the difficulties posed by operating a robotic mission in an extreme environment. On Mars, there is always the issue of solar radiation and dust storms. But on Europa, there is the added danger posed by Jupiter’s intense magnetic environment. Exploring water plumes coming from Enceladus is also very challenging for an orbiter that would most likely be speeding past the planet at the time.
But given the potential for scientific breakthroughs, such a mission it is well worth the aches and pains. Not only would it allow astronomers to test theories about the evolution and distribution of life in our Solar System, it could also facilitate the development of crucial space exploration technologies, and result in some serious commercial applications.
Looking to the future, advances in synthetic biology are expected to lead to new treatments for diseases and the ability to 3-D print biological tissues (aka. “bioprinting”). It will also help ensure human health in space by addressing bone density loss, muscle atrophy, and diminished organ and immune-function. And then there’s the ability to grow organisms specially-designed for life on other planets (can you say terraforming?)
Is life in our Solar System, and the Universe for that matter, universal in nature? Credit: NASA/Jenny Mottor
On top of all that, the ability to conduct in-situ searches for life on other Solar planets also presents scientists with the opportunity to answer a burning question, one which they’ve struggled with for decades. In short, is carbon-based life universal? So far, any and all attempts to answer this question have been largely theoretical and have involved the “low hanging fruit variety” – where we have looked for signs of life as we know it, using mainly indirect methods.
By finding examples that come from environments other than Earth, we would be taking some crucial steps towards preparing ourselves for the kinds of “close encounters” that could be happening down the road.
Now, don’t get me wrong, Science Fiction is awesome. Like almost everyone working in the field of space and astronomy, I was deeply influenced by science fiction. For me, it was Star Trek and Star Wars. I had a toy phaser that made this awesome really loud phaser sound, and I played with it non-stop until it disappeared one day. And I was sure I’d left it in the middle of my floor, like I did with all my toys, but I found it a few years later, hidden up in a closet that I couldn’t reach. And I always wondered how it got there.
Anyway, back to science fiction. For all of its inspiration, science fiction has put a few ideas into our brains which aren’t entirely helpful. You know, warp drives, artificial gravity, teleportation, and rockets that take off, fly to space, visit other planets orbiting stars, land again.
The Millennium Falcon, Firefly, and Enterprise Shuttles are all examples of single stage to orbit to orbit spacecraft, or SSTOs.
Consider the rockets that exist in reality, you know, the Atlases, Falcons and Deltas. They take off from a launch pad, fly for a bit until the fuel is used up in a stage of the rocket, then they jettison that stage and thrust with the next stage. The mighty Saturn V was so powerful that it had three stages, as it made it’s way to orbit.
Diagram of Saturn V Launch Vehicle. Credit: NASA/MSFC
As we discussed in a previous article, SpaceX is working to make the first stage, and maybe even the second stage reusable, which is a vast improvement over just letting everything burn up, but there are no rockets that actually fly to orbit and back in a single stage. In fact, using the technology we have today, it’s probably not a good idea.
Has anyone ever worked on a single stage to orbit? What technological advances will need to happen to make this work?
As I said earlier, a single stage to orbit rocket would be something like the Millennium Falcon. It carries fuel, and then uses that fuel to fly into orbit, and from world to world. Once it runs out of fuel, it gets filled up again, and then it’s off again, making the Kessel Run and avoiding Imperial Blockades.
This concept of a rocket matches our personal experience with every other vehicle we’ve ever been in. You drive your car around and refuel it, same with boats, airplanes and every other form of Earth-based transportation.
But flying into space requires the expenditure of energy that defies comprehension. Let me give you an example. A Falcon 9 rocket can lift about 22,800 kilograms into low-Earth orbit. That’s about the same as a fully loaded cement truck – which is a lot.
SpaceX Falcon 9 poised for Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying ten Iridium NEXT comsats to orbit. Credit: SpaceX
The entire fueled Falcon 9 weighs just over 540,000 kg, of which more than 510,000 kgs of it are fuel, with a little extra mass for the engines, fuel tanks, etc. Imagine if you drove a car that was essentially 95% fuel.
The problem is specific impulse; the maximum amount of thrust that a specific kind of engine and fuel type can achieve. I’m not going to go into all the details, but the most efficient chemical rockets we have, fueled by liquid hydrogen and oxygen, can just barely deliver enough thrust to get you to orbit. They have a maximum specific impulse of about 450 seconds.
Because the amount of fuel it takes to launch a rocket is so high, modern rockets use a staging system. Once a stage has emptied out all its fuel, it detaches and returns to Earth so that the second stage can keep going without having to drag along the extra weight of the empty fuel tanks.
After stage separation of the Falcon 9 rocket, flames are barely visible around nozzle as the second stage engine ignites and the first stage falls back to the Earth below. Credit: SpaceX
You might be surprised to know that many modern rockets are actually capable of reaching orbit with a single stage. The problem is that they wouldn’t be able to carry any significant payload.
At the end of the day, considering the chemical rockets we have today, the multi-staged profile is the most efficient and cost-effective strategy for carrying the most payload to space for the lowest cost possible.
Has anyone tried developing SSTOs in the past? Definitely. Probably the most widely publicized was NASA’s X-33/VentureStar program, developed by Lockheed Martin in the 1990s.
The proposed X-33 spacecraft. Credit: NASA
The purpose of the X-33 was to test out a range of new technologies for NASA, including composite fuel tanks, autonomous flight, and a new lifting body design.
In order to make this work, they developed a new kind of rocket engine called the “aerospike”. Unlike a regular rocket engine which provide a fixed amount of thrust, an aerospike could be throttled back like a jet engine, using less fuel at lower altitudes, where the atmosphere is thickest.
The test of twin Linear Aerospike XRS-2200 engines, originally built for the X-33 program, was performed on August 6, 2001 at NASA’s Sternis Space Center, Mississippi. The engines were fired for the planned 90 seconds and reached a planned maximum power of 85 percent. Credit: NASA’s Marshall Space Flight Center
Lockheed Martin was working on a 1/3rd scale prototype, but they struggled with many of the new technologies. In the end, their failure to be able to build a composite fuel tank that could contain the liquid oxygen and hydrogen forced them to abandon the project.
Even if they could get the technology working, so the X-33 was fully reusable, its ability to carry a payload would have been dramatically lower than a traditional multi-staged rocket.
In order to really achieve the dream of single stage to orbit, we need to step away from chemical rockets and move to a type of engine that can deliver thrust more efficiently.
We know that jets work more efficiently than rockets, because they only need to carry fuel. They pull oxygen in from the atmosphere, to burn the fuel. So one intriguing idea is to make a rocket that acts like a jet engine while in the atmosphere, and then acts like a rocket once it’s out in space.
And that’s the plan with the British Skylon rocket. It would take off from a regular runway, accelerate to about 6,600 km/h reaching an altitude of 26 kilometers. All this time, its SABRE engine would be pulling in oxygen from the atmosphere, combining it with hydrogen fuel.
An artist’s conception of Reaction Engines’ Skylon spacecraft. Credit: Reaction Engines
From this point, it would switch over to an internal liquid oxygen tank to provide oxidizer, and complete the flight to orbit. All the while using the same flexible SABRE engine. Once in orbit, it would release its 15-tonne payload and then return to Earth, landing on a runway like the space shuttle orbiter did. It’s a really creative idea.
Unfortunately, the development of the Skylon has taken a long time, with shrinking budgets limiting the amount of tests they’ve been able to do. If everything goes well, the first prototype might fly within a few years, so stay tuned to this story.
Another idea which has had some testing is the idea of a nuclear rocket. Unlike a chemical rocket, which burns fuel, and blasts it out the back for thrust, a nuclear rocket would carry a reactor on board. It would heat up some kind of working fuel, like liquid hydrogen, and then blast it out the back for propulsion.
The key elements of a NERVA solid-core nuclear-thermal engine. Credit: NASA
NASA did some tests a few decades ago with a nuclear thermal rocket called NERVA, and found that they could sustain high levels of thrust for very long periods of time. Their final prototype, provided continuous thrust for over 2 hours, including 28 minutes at full power.
NASA calculated that a nuclear-powered rocket would be roughly twice as efficient as a traditional chemical rocket. It would have a specific impulse of more than 950 seconds. But flying a nuclear rocket into space comes with a significant downside. Rockets explode. It’s bad when a chemical rocket explodes, but if a nuclear reactor detonated while making its way up through the atmosphere, it would rain down radioactive debris. For now, that’s considered too much of a risk; however, future interplanetary missions may very well use nuclear rockets.
There’s one more exotic fuel system that’s really exciting – metallic hydrogen. This solid form appears naturally at the heart of Jupiter, under the incredible pressure of the planet’s gravity. But earlier this year, researchers at Harvard finally created some in the lab. They used a tiny vice to squeeze hydrogen atoms with more force than the pressures at the center of the Earth.
Microscopic images of the stages in the creation of atomic molecular hydrogen: Transparent molecular hydrogen (left) at about 200 GPa, which is converted into black molecular hydrogen, and finally reflective atomic metallic hydrogen at 495 GPa. Credit: Isaac Silvera
It took an enormous amount of energy to squeeze hydrogen together that tightly, but in theory, once crafted, it should be relatively stable. And here’s the best part. When you ignite it, you get that energy back.
If used as a rocket fuel, it would provide a specific impulse of 1700 seconds. Compare that to the mere 450 from chemical rockets. A rocket powered by metallic hydrogen would easily get to orbit with a single stage, and travel efficiently to other planets.
Single Stage to Orbit rockets would be awesome. Science fiction has foretold it. That said, at the end of the day, whatever gets the most amount of payload into orbit for the lowest price is the most interesting rocket system. And right now, that’s staged rockets.
However, a bigger issue might be reliability and reusability. If you can get a single vehicle that takes off, travels to orbit and then returns to its launch pad, you can’t get anything simpler than that. No rockets to restack, no barges to navigate. You just use and reuse the same system again and again, and that’s a really exciting idea.
Right this moment, reusable staged rockets like SpaceX has the edge, but if and when the Skylon gets flying, I think we’ll have some serious competition.
Once we master metallic hydrogen, spaceflight will look very very different. Science reality will nearly match science fiction, and I’ll finally be able to fly my own personal Millennium Falcon.
Watch for the Eta Aquarid shower this week, so called because meteors will appear to radiate from near the star Eta Aquarii. The meteors originate from fragments of Halley’s Comet strewn about its orbit. Every May, Earth crosses the stream and we get a meteor shower. At maximum on Saturday morning May 6, 25-30 meteors per hour might be seen from the right location under dark skies. Map: Bob King, Source: Stellarium
Halley’s Comet may be at the far end of its orbit 3.2 billion miles (5.1 billion km) from Earth, but this week fragments of it will burn up as meteors in the pre-dawn sky as the Eta Aquarid meteor shower. The comet last passed our way in 1986, pivoted about the Sun and began the long return journey to the chilly depths of deep space.
Comet Halley’s still hanging around in the evening sky a few degrees to the west of the head of Hydra the Water Snake not far from Procyon in Canis Minor. It’s currently 3.2 billion miles from Earth. Created with Stellarium
Today, Halley’s a magnitude +25 speck in the constellation Hydra. Although utterly invisible in most telescopes, you can imagine it below tonight’s half-moon near the outermost point in its orbit four Earth-sun distances beyond Neptune. Literally cooling its jets, the comet mulls its next Earth flyby slated for summer 2061.
Halley’s Comet follows an elongated orbit that takes 76 years to complete. Solar heating boils off debris that peppers the comet’s path coming and going. Earth intersects the stream twice: first in May on the outbound portion of Halley’s orbit, and again in October, on the inbound leg. Each time, the planet plows into the debris at high speed and it burns up in our atmosphere. Credit: Bob King
Some meteor showers have sharp peaks, others like the Eta Aquarids, a broad, plateau-like maximum. The shower’s been active since mid-April and will continue right up till the end of this month with the peak predicted Saturday morning May 6. Observers in tropical latitudes, where the constellation Aquarius rises higher than it does from my home in northern Minnesota, will spy 25-30 meteors an hour from a dark sky in the hour or two before dawn.
Skywatchers further north will see fewer meteors because the radiant will be lower in the sky; meteors that flash well below the radiant get cut off by the horizon, reducing the rate by about half ( about 10-15 meteors an hour). That’s still a decent show. I got up with the first robins a couple years back to see the shower and was pleasantly surprised with a handful of flaming Halley particles in under a half hour.
A long-trailed, earthgrazing Eta Aquarid meteor crosses a display of northern lights on May 6, 2013. Credit: Bob King
While a low radiant means fewer meteors, there’s an up side. You have a fair chance of seeing an earthgrazer, a meteor that skims tangent to the upper atmosphere, flaring for many seconds before either burning up or skipping back off into space.
The Eta Aquarids will be active all week. With the peak occurring Saturday morning, you should be able to see at least a few prior to dawn each morning. The quarter-to-waxing gibbous moon will set in plenty of time through Friday morning, leaving dark skies, but cuts it close Saturday when it sets about the same time the radiant rises in the east.
The annual Eta Aquarids meteor shower captured from Otago Harbour at Aramoana in New Zealand. Eta Aquarids are fast, striking the atmosphere at more than 147,000 mph (66 km/ sec). The photographer stacked multiple unguided 30-second exposures over 50 minutes taken with an 8mm fisheye lens @ f/3.5, Nikon D90, ISO 3200. Credit: Starman_nz
For best viewing, find as dark a place as possible with an open view to the east and south. I like to tote out a reclining lawn chair, face east and get comfy under a warm sleeping bag or wool blanket. Since twilight starts about an hour and three-quarters before your local sunrise, plan to be out watching an hour before that or around 3:30 a.m. I know, I know. That sounds harsh, but I’ve discovered that once you make the commitment, the act of watching a meteor shower becomes a relaxed pleasure punctuated by the occasional thrill of seeing a bright meteor.
You’ll be in magnificent company, too. The Milky Way rides high across the southeastern sky at that hour, and Saturn gleams due south in Sagittarius at the start of dawn. If you’d like to contribute observations of the shower to help meteor scientists better understand its behavior and evolution, check out the International Meteor Organization’s Eta Aquariids 2017 campaign for more information.
Image of the "Face of Mars" by the Mars Reconnaissance Orbiter, with the Viking 1 image inset (bottom right). Credit: NASA/JPL
The search for life in the Universe takes many paths. There’s SETI, or the Search for Extraterrestrial Intelligence, which is searching for signals from a distant ancient civilization. There’s the exploration of our own Solar System, on Mars, or underneath the subsurface oceans of Europa and Enceladus, to see if life can be anywhere there’s liquid water and a source of energy. And upcoming space telescopes like James Webb will attempt to directly image the atmospheres of distant extrasolar planets, to see if they contain the distinct chemical signatures of life.
But according to Jason Wright, an astronomer at the Center for Exoplanets and Habitable Worlds at Penn State University, we could consider searching for evidence of ancient civilizations right here on Earth, or across the Solar System. Don’t get excited, though, so far “there is zero evidence for prior indigenous species in the Solar System.”
Artist’s impression of the terraforming of Mars, from its current state to a livable world. Credit: Daein BallardIn a paper, recently submitted to the arXiv electronic preprint archive entitled Prior Indigenous Technological Species, Dr. Wright describes how we might go about searching for the technological artifacts left behind by ancient civilizations that have evolved in the Solar System. Perhaps on an ancient, cooler Venus, or on Mars in a time when it was wetter and had a thicker atmosphere. Those civilizations could have arisen millions or even billions of years ago, destroyed themselves or left the Solar System, and only ancient traces of their culture and technology would still be around.
If a civilization had reached a high level of technology, where did it go? Wright suggests a variety of catastrophes, like a swarm of comets, self destruction, or even a nearby supernova explosion that irradiated the whole Solar System with high energy gamma rays. Even without a specific event, a civilization might have simply just died out, or became permanently non-technological. Of course, these possibilities face our own human civilization. It’s hard to read the paper and not consider the fate of humanity. Will future aliens search for scraps to learn about us?
Where should we look? According to Wright, Earth is the obvious, most habitable place in the Solar System, and it’ll be the easiest to search. Humans have dramatically changed the landscape of Earth. Our open pit mines, for example, are a clear indication that an intelligent species dug out a specific mineral from the ground. These might be obvious for millions of years, but over the course of billions of years, plate tectonics will have recycled those regions, absorbing the evidence back into the ground. Radioactive isotopes from ancient nuclear reactors, or fossils of ancient beings will have about the same lifespan. Beyond a few hundred million years, the Earth itself would have completely obscured any evidence of a technological civilization.
Inhospitable surface of Venus. Credit: MagellanVenus is inhospitable today, but it might not have always been the case. Billions of years in the past, when the Sun was cooler, it might have had a thinner atmosphere and milder temperatures. It’s worth searching. That said, it appears that Venus has gone through major geological resurfacing events, where the entire planet’s surface turned inside out. Venus could easily hide its secrets.
Scientists are accumulating more and more evidence that Mars was warmer and wetter in the past, with eras when liquid water could exist on the surface for long periods of time. And unlike Earth and Venus, it doesn’t have active plate tectonics. Landscapes on the surface have remained there for billions of years. Well, okay, they’ve been pounded by meteorites, but they’re still there.
What should we be looking for? One idea is technological structures: ancient mining facilities, factories, even cities. On Mars, these structures could get covered by dust or worn down by erosion, so it’s entirely possible our space-based observations could have missed them. Even structures on asteroids and the Moon get eroded by micrometeorites wearing them down. Over the course of millions years, an ancient factory would look very similar to a small rocky outcrop. The real evidence could be hidden underground, safely protected from the surface erosion. We need more rovers and orbiters with ground penetrating radar to see below the surface.
The Lunar Laser Ranging Experiment placed on the Moon by the Apollo 14 astronauts. Credit: NASAThere could be free-floating objects in the Solar System, like ancient space stations. Of course, if they’ve been abandoned long ago, they wouldn’t be functional, and that same micrometeorite erosion would have worn them down over the vast timescales. Furthermore, their orbits might not be stable, and could eventually crash into another world, or get kicked out of the Solar System entirely. Space stations out in the Kuiper Belt would be subject to less erosion, and better preserved over vast timescales. We need better telescopes and deeper surveys to answer this question.
The bottom line is that Dr. Wright doesn’t conclude there’s any evidence for ancient civilizations in the Solar System so far. But the reality is that we’ve only just begun to look. NASA’s Mars Reconnaissance Orbiter, which contains the most powerful telescope to ever travel away from the Earth has only mapped a few percent of the Martian surface at its highest resolution. Astronomers have only mapped a tiny fraction of the asteroids and comets zipping around the Solar System. And we’ve only had single glimpses at places in the outer Solar System, like Uranus, Neptune and Pluto.
There’s so much more searching that needs to be done. But while we’re at it, we should keep an eye out for ancient civilizations. If we did find an old factory, space station, or even the dumping ground of a precursor species, it would be a boon to our knowledge.
And might just give us a warning; advanced knowledge of what the future holds for our own civilization.
NASA's Wide Field Infrared Survey Telescope (WFIRST) will capture Hubble-quality images covering swaths of sky 100 times larger than Hubble does. These enormous images will allow astronomers to study the evolution of the cosmos. Its Coronagraph Instrument will directly image exoplanets and study their atmospheres.
Credits: NASA/GSFC/Conceptual Image Lab
We humans have an insatiable hunger to understand the Universe. As Carl Sagan said, “Understanding is Ecstasy.” But to understand the Universe, we need better and better ways to observe it. And that means one thing: big, huge, enormous telescopes.
In this series we’ll look at the world’s upcoming Super Telescopes:
It’s easy to forget the impact that the Hubble Space Telescope has had on our state of knowledge about the Universe. In fact, that might be the best measurement of its success: We take the Hubble, and all we’ve learned from it, for granted now. But other space telescopes are being developed, including the WFIRST, which will be much more powerful than the Hubble. How far will these telescopes extend our understanding of the Universe?
“WFIRST has the potential to open our eyes to the wonders of the universe, much the same way Hubble has.” – John Grunsfeld, NASA Science Mission Directorate
The WFIRST might be the true successor to the Hubble, even though the James Webb Space Telescope (JWST) is often touted as such. But it may be incorrect to even call WFIRST a telescope; it’s more accurate to call it an astrophysics observatory. That’s because one of its primary science objectives is to study Dark Energy, that rather mysterious force that drives the expansion of the Universe, and Dark Matter, the difficult-to-detect matter that slows that expansion.
WFIRST will have a 2.4 meter mirror, the same size as the Hubble. But, it will have a camera that will expand the power of that mirror. The Wide Field Instrument is a 288-megapixel multi-band near-infrared camera. Once it’s in operation, it will capture images that are every bit as sharp as those from Hubble. But there is one huge difference: The Wide Field Instrument will capture images that cover over 100 times the sky that Hubble does.
Alongside the Wide Field Instrument, WFIRST will have the Coronagraphic Instrument. The Coronagraphic Instrument will advance the study of exoplanets. It’ll use a system of filters and masks to block out the light from other stars, and hone in on planets orbiting those stars. This will allow very detailed study of the atmospheres of exoplanets, one of the main ways of determining habitability.
WFIRST is slated to be launched in 2025, although it’s too soon to have an exact date. But when it launches, the plan is for WFIRST to travel to the Sun-Earth LaGrange Point 2 (L2.) L2 is a gravitationally balanced point in space where WFIRST can do its work without interruption. The mission is set to last about 6 years.
Probing Dark Energy
“WFIRST has the potential to open our eyes to the wonders of the universe, much the same way Hubble has,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate at Headquarters in Washington. “This mission uniquely combines the ability to discover and characterize planets beyond our own solar system with the sensitivity and optics to look wide and deep into the universe in a quest to unravel the mysteries of dark energy and dark matter.”
In a nutshell, there are two proposals for what Dark Energy can be. The first is the cosmological constant, where Dark Energy is uniform throughout the cosmos. The second is what’s known as scalar fields, where the density of Dark Energy can vary in time and space.
We used to think that the Universe expanded at a steady rate. Then in the 1990s we discovered that the expansion had accelerated. Dark Energy is the name given to the force driving that expansion. Image: NASA/STSci/Ann Feild
Since the 1990s, observations have shown us that the expansion of the Universe is accelerating. That acceleration started about 5 billion years ago. We think that Dark Energy is responsible for that accelerated expansion. By providing such large, detailed images of the cosmos, WFIRST will let astronomers map expansion over time and over large areas. WFIRST will also precisely measure the shapes, positions and distances of millions of galaxies to track the distribution and growth of cosmic structures, including galaxy clusters and the Dark Matter accompanying them. The hope is that this will give us a next level of understanding when it comes to Dark Energy.
If that all sounds too complicated, look at it this way: We know the Universe is expanding, and we know that the expansion is accelerating. We want to know why it’s expanding, and how. We’ve given the name ‘Dark Energy’ to the force that’s driving that expansion, and now we want to know more about it.
Probing Exoplanets
Dark Energy and the expansion of the Universe is a huge mystery, and a question that drives cosmologists. (They really want to know how the Universe will end!) But for many of the rest of us, another question is even more compelling: Are we alone in the Universe?
There’ll be no quick answer to that one, but any answer we find begins with studying exoplanets, and that’s something that WFIRST will also excel at.
Artist’s concept of the TRAPPIST-1 star system, an ultra-cool dwarf that has seven Earth-size planets orbiting it. We’re going to keep finding more and more solar systems like this, but we need observatories like WFIRST to understand the planets better. Credits: NASA/JPL-Caltech
“WFIRST is designed to address science areas identified as top priorities by the astronomical community,” said Paul Hertz, director of NASA’s Astrophysics Division in Washington. “The Wide-Field Instrument will give the telescope the ability to capture a single image with the depth and quality of Hubble, but covering 100 times the area. The coronagraph will provide revolutionary science, capturing the faint, but direct images of distant gaseous worlds and super-Earths.”
“The coronagraph will provide revolutionary science, capturing the faint, but direct images of distant gaseous worlds and super-Earths.” – Paul Hertz, NASA Astrophysics Division
The difficulty in studying exoplanets is that they are all orbiting stars. Stars are so bright they make it impossible to see their planets in any detail. It’s like staring into a lighthouse miles away and trying to study an insect near the lighthouse.
The Coronagraphic Instrument on board WFIRST will excel at blocking out the light of distant stars. It does that with a system of mirrors and masks. This is what makes studying exoplanets possible. Only when the light from the star is dealt with, can the properties of exoplanets be examined.
This will allow detailed measurements of the chemical composition of an exoplanet’s atmosphere. By doing this over thousands of planets, we can begin to understand the formation of planets around different types of stars. There are some limitations to the Coronagraphic Instrument, though.
The Coronagraphic Instrument was kind of a late addition to WFIRST. Some of the other instrumentation on WFIRST isn’t optimized to work with it, so there are some restrictions to its operation. It will only be able to study gas giants, and so-called Super-Earths. These larger planets don’t require as much finesse to study, simply because of their size. Earth-like worlds will likely be beyond the power of the Coronagraphic Instrument.
These limitations are no big deal in the long run. The Coronagraph is actually more of a technology demonstration, and it doesn’t represent the end-game for exoplanet study. Whatever is learned from this instrument will help us in the future. There will be an eventual successor to WFIRST some day, perhaps decades from now, and by that time Coronagraph technology will have advanced a great deal. At that future time, direct snapshots of Earth-like exoplanets may well be possible.
But maybe we won’t have to wait that long.
Starshade To The Rescue?
There is a plan to boost the effectiveness of the Coronagraph on WFIRST that would allow it to image Earth-like planets. It’s called the EXO-S Starshade.
The EXO-S Starshade is a 34m diameter deployable shading system that will block starlight from impairing the function of WFIRST. It would actually be a separate craft, launched separately and sent on its way to rendezvous with WFIRST at L2. It would not be tethered, but would orient itself with WFIRST through a system of cameras and guide lights. In fact, part of the power of the Starshade is that it would be about 40,000 to 50,000 km away from WFIRST.
Dark Energy and Exoplanets are priorities for WFIRST, but there are always other discoveries awaiting better telescopes. It’s not possible to predict everything that we’ll learn from WFIRST. With images as detailed as Hubble’s, but 100 times larger, we’re in for some surprises.
“This mission will survey the universe to find the most interesting objects out there.” – Neil Gehrels, WFIRST Project Scientist
“In addition to its exciting capabilities for dark energy and exoplanets, WFIRST will provide a treasure trove of exquisite data for all astronomers,” said Neil Gehrels, WFIRST project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This mission will survey the universe to find the most interesting objects out there.”
With all of the Super Telescopes coming on line in the next few years, we can expect some amazing discoveries. In 10 to 20 years time, our knowledge will have advanced considerably. What will we learn about Dark Matter and Dark Energy? What will we know about exoplanet populations?
Right now it seems like we’re just groping towards a better understanding of these things, but with WFIRST and the other Super Telescopes, we’re poised for more purposeful study.
Welcome, come in to the 507th Carnival of Space! The Carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. I’m Susie Murph, part of the team at Universe Today and CosmoQuest. So now, on to this week’s stories! Continue reading “Carnival of Space #507”
This metallic "space fabric" was created using 3-D printed techniques that add different functionality to each side of the material. Credits: NASA/JPL-Caltech
One would think NASA was preparing for a some sword fights in space! At least, that’s the impression one might get when they see the new armor NASA is developing for the first time. Officially, they are referring to it as a new type of “space fabric“, one which will provide protection to astronauts, spaceships and deployable devices. But to the casual observer, it looks a lot like chain mail armor!
The new armor is the brainchild of Polit Casillas, a systems engineer from NASA’s Jet Propulsion Laboratory. Inspired by traditional textiles, this armor relies on advances made in additive manufacturing (aka. 3-D printing) to create woven metal fabrics that can fold and change shape quickly. And someday soon, it could be used for just about everything!
As the son of a fashion designer in Spain, Casillas grew up around fabrics and textiles, and was intrigued by how they are used for the sake of design. Much in the same way that textiles are produced by weaving together countless threads, Casilla’s prototype space fabric relies on 3-D printing to create metal squares in one piece, which are then strung together to form a coat of armor.
Another example of a 3-D-printed metallic “space fabric.” The bottom and top sides of the fabric are designed to have different functionality. Credits: NASA/JPL-Caltech
In addition to his work with this new space fabric, Casillas co-leads JPL’s Atelier workshop, which specialized in the rapid-prototyping of advanced concepts and systems. This fast-paced collaborative environment works with different technologies and looks for ways to incorporate new ones (such as 4-D printing) into existing designs. As Casillas described this concept in a NASA press release:
“We call it ‘4-D printing’ because we can print both the geometry and the function of these materials. If 20th Century manufacturing was driven by mass production, then this is the mass production of functions.”
The space fabrics have four essential functions, which includes reflectivity, passive heat management, foldability and tensile strength. With one side reflecting light and the other absorbing it, the material acts as a means of thermal control. It can also fold in many different ways and adapt to shapes, all the while maintaining tensile strength to ensure it can sustain forces pulling on it.
These fabrics could be used to protect astronauts and shield large antennas, deployable devices and spacecraft from meteorites and other hazards. In addition, they could be used to ensure that missions to extreme environments would be protected from the elements. Consider Jupiter’s moon Europa, which NASA is planning on exploring in the coming decade using a lander – aka. the Europa Clipper mission.
Artist’s concept of a Europa Clipper mission. Credit: NASA/JPL
Here, and on other “ocean worlds” – like Ceres, Enceladus, Titan and Pluto – this sort of flexible armor could provide insulation for spacecraft. They could be used on landing struts to ensure that they could change shape to fit over uneven terrain as well. This kind of material could also be used to build habitats for Mars or the Moon – like the South Pole-Aitken Basin, where permanently-shadowed craters allow for the existence of water ice.
Another benefit of this material is the fact that it is considerably cheaper to produce compared to materials made using traditional fabrication methods. Under ordinary conditions, designing and building spacecraft is a complex and costly process. But by adding multiple functions to a material at different stages of development, the whole process can be made cheaper and new designs can be implemented.
Andrew Shapiro-Scharlotta is a manager at the JPL’s Space Technology Office, an office responsible for funding early-stage technologies like the space fabric. As he put it, this sort of production process could enable all kinds of designs and new mission concepts. “We are just scratching the surface of what’s possible,” he said. “The use of organic and non-linear shapes at no additional costs to fabrication will lead to more efficient mechanical designs.”
In keeping with how 3-D printing has been developed for use aboard the ISS, the JPL team not only wants to use this fabric in space, but also manufacture it in space as well. In the future, Casillas also envisions a process whereby tools and structural materials can be printed from recycled materials, offering additional cost-savings and enabling rapid, on-demand production of necessary components.
Such a production process could revolutionize the way spacecraft and space systems are created. Instead of ships, suits, and robotic craft created from many different parts (which then have to be assembled), they could be printed out like “whole cloth”. The manufacturing revolution, it seems, loometh!
SpaceX Falcon 9 rocket carrying classified NROL-76 surveillance satellite for the National Reconnaissance Office successfully launches shortly after sunrise from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. 1st stage accomplished successful ground landing at the Cape nine minutes later. Credit: Ken Kremer/Kenkremer.com
SpaceX Falcon 9 rocket carrying classified NROL-76 surveillance satellite for the National Reconnaissance Office successfully launches shortly after sunrise from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. 1st stage accomplished successful ground landing at the Cape nine minutes later. Credit: Ken Kremer/Kenkremer.com
KENNEDY SPACE CENTER, FL – SpaceX today staged the stupendously successful Falcon 9 rocket launch at sunrise of a mysterious spy satellite in support of U.S. national defense for the National Reconnaissance Office (NRO) while simultaneously accomplishing a breathtaking pinpoint land landing of the boosters first stage that could eventually dramatically drive down the high costs of spaceflight.
Liftoff of the classified NROL-76 payload for the NRO took place shortly after sunrise this morning, Monday, May 1, at 7:15 a.m. EDT (1115 GMT), from SpaceX’s seaside Launch Complex 39A on NASA’s Kennedy Space Center in Florida.
The weather was near perfect and afforded a spectacular sky show for all those who descended on the Florida Space Coast for an up close eyewitness view of the rockets rumbling thunder.
The rocket roared off pad 39A after ignition of the nine Merlin 1D first stage engines generated some 1.7 million pounds of thrust.
The Falcon sped skyward darting in and out of wispy white clouds and appeared to head in a northeasterly direction from the space coast.
“A National Reconnaissance Office (NRO) payload was successfully launched aboard a SpaceX Falcon 9 rocket from Launch Complex 39A (LC-39A), Kennedy Space Center (KSC), Florida, at 7:15 a.m. EDT, on May 1, 2017,” the NRO said in a post launch statement.
“Thanks to the SpaceX team for the great ride, and for the terrific teamwork and commitment they demonstrated throughout. They were an integral part of our government/industry team for this mission, and proved themselves to be a great partner,” said Betty Sapp, Director of the National Reconnaissance Office.
The launch of the two stage 229 foot tall Falcon 9 was postponed a day after a last moment scrub was suddenly called on Sunday by the launch director at just about T minus 52 seconds due to a sensor issue in the first stage.
SpaceX engineers were clearly able to fully resolve the issue in time for today’s second launch attempt of the super secret NROL-76 for the NRO customer.
Barely nine minutes after the launch, the 156 foot tall first stage of the SpaceX Falcon 9 rocket made an incredibly precise and thrilling soft touchdown on land at Cape Canaveral Air Force Station’s Landing Zone 1, located a few miles south of launch pad 39A.
SpaceX Falcon 9 deploys quartet of landing legs moments before precision propulsive ground touchdown at Landing Zone 1 on Canaveral Air Force Station barely nine minutes after liftoff from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com
The quartet of landing legs attached to the base of the first stage deployed only moments before touchdown – as can be seen in my eyewitness photos herein.
Multiple sonic booms screamed across the space coast as the 15 story first stage plummeted back to Earth and propulsively slowed down to pass though the sound barrier and safely came to rest fully upright.
This counts as SpaceX’s first ever launch of a top secret US surveillance satellite. It also counts as the fourth time SpaceX landed a first stage fully intact on the ground.
As is typical for NRO missions, nothing is publically known about the satellite nor has the NRO released any details about this mission in support of national security other than the launch window. SpaceX Falcon 9 deploys quartet of landing legs moments before precision propulsive ground touchdown at Landing Zone 1 on Canaveral Air Force Station barely nine minutes after liftoff from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com
Overall SpaceX has now recovered 10 first stages via either land or at sea on an oceangoing platform.
NROL-76 marks the fifth SpaceX launch of 2017 and the 33rd flight of a Falcon 9.
Blastoff of SpaceX Falcon 9 delivering NROL-76 spy satellite to orbit on 1 May 2017 for the U.S. National Reconnaissance Office. Credit: Julian Leek
NROL-76 is the second of five launches slated for the NRO in 2017. The next NRO launch is on schedule for August 14 from Vandenberg Air Force Base (VAFB), California by competitor ULA.
Until now launch competitor United Launch Alliance (ULA) and its predecessors have held a virtual monopoly on the US military’s most critical satellite launches.
The NRO is a joint Department of Defense–Intelligence Community organization responsible for developing, launching, and operating America’s intelligence satellites to meet the national security needs of our nation, according to the NRO.
Watch for Ken’s continuing onsite launch reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station in Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
SpaceX Falcon 9 rocket carrying classified NROL-76 surveillance satellite for the National Reconnaissance Office stands raised erect poised for sunrise liftoff from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com
