When imagining how our planet formed 4.6 billion years ago from the protoplanetary disk surrounding our sun, images of large pieces of marauding space rock slamming into the molten surface of our proto-Earth likely come to mind.
This strange detail of planetary evolution is described in a new study published in the American Association for the Advancement of Science (AAAS) journal Science Advances and it kinda makes logical sense.
Using the wonderfully-named Mars and Asteroids Global Hydrology Numerical Model (or “MAGHNUM”), planetary scientists Phil Bland (Cornell University) and Bryan Travis (Planetary Science Institute) simulated the movement of material inside primordial carbonaceous chondrite asteroids — i.e. the earliest asteroids that formed from the sun’s protoplanetary disk that eventually went on to become the building blocks for Earth.
It turns out that these first asteroids weren’t cold and solid lumps of rock at all. By simulating the distribution of rock grains inside these asteroids, the researchers realized that the internal heat of the objects would have melted the icy volatiles inside, which then mixed with the fine dust particles. Convection would have then dominated a large portion of these asteroids, causing continuous mixing of water and dust. Like a child squishing a puddle of dirt to create sloppy “mud pies,” this convection would have formed a ball of, you guessed it, space mud.
Travis points out that “these bodies would have accreted as a high-porosity aggregate of igneous clasts and fine-grained primordial dust, with ice filling much of the pore space. Mud would have formed when the ice melted from heat released from decay of radioactive isotopes, and the resulting water mixed with fine-grained dust.”
In other words: balls of mud held together by mutual gravity, gently convected by the heat produced by the natural decay of radioactive materials.
Should this model hold up to further scrutiny, it has obvious implications for the genesis of life on Earth and could impact the study of exoplanets and their habitable potential. The ingredients for life on Earth originated in the primordial protoplanetary soup, but until now the assumption has been that the space rocks carrying water and other chemicals were solid and frozen. If they were in fact churning away in space as dynamic mud asteroids, they could have been the “pressure cookers” that delivered those ingredients to Earth’s surface.
So the next question would be: how did these exotic asteroids shape life on Earth?
NASA’s Cassini mission sure has a knack for putting stuff into perspective — and this most recent view from Saturn orbit is no different. That dot in the center of the image isn’t a dud pixel in Cassini’s camera CCD. That’s us. All of us. Everyone.
To quote Carl Sagan:
“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives…”
Sagan wrote that passage in his book “Pale Blue Dot: A Vision of the Human Future in Space” when reflecting on the famous “Pale Blue Dot” image that was beamed back to Earth by NASA’s Voyager 1 spacecraft in 1990. That’s when the mission returned a profound view of our planet from a distance of 3.7 billion miles (or 40.5AU) as it was traveling through the solar system’s hinterlands, on its way to interstellar space. Since then, there’s been many versions of pale blue dots snapped by the armada of robotic missions around the solar system and Cassini has looked back at us on several occasions from its orbital perch.
Now, just before Cassini begins the final leg of its Saturnian odyssey, it has again spied Earth through a gap between the gas giant’s A ring (top) and F ring (bottom). In a cropped and enhanced version, our moon is even visible! The image is composed of many observations captured on April 12, stitched together as a mosaic when Saturn was 870 million miles (roughly 9.4AU) from Earth.
On April 20 (Friday), Cassini will make its final flyby of Titan, Saturn’s largest moon, using its gravity to fling itself through Saturn’s ring plane (on April 26) between the innermost ring and the planet’s cloudy upper atmosphere, revealing a view that we’ve never before seen. For 22 orbits, Cassini will dive into this uncharted region, possibly revealing new things about Saturn’s evolution, what material its rings contain and incredibly intimate views of its atmosphere.
This daring maneuver will signal the beginning of the end for this historic mission, however. On Sept. 15, Cassini will be intentionally steered into Saturn’s atmosphere to burn up as a human-made meteor. It is low in fuel, so NASA wants to avoid the spacecraft from crashing into and contaminating one of Saturn’s potentially life-giving moons — Titan or Enceladus.
So, appreciate every image that is captured by Cassini over the coming weeks. The pictures will be like nothing we’ve seen before of the ringed gas giant, creating a very bittersweet phase of the spacecraft’s profound mission to Saturn.
Imagine speeding down the highway and plowing into an unfortunate swarm of mosquitoes. Now imagine that you had the ability to precisely measure the mass of each mosquito, the speed at which it was traveling and the direction it was going before it exploded over your windscreen.
Granted, the technology to accomplish that probably isn’t feasible in such an uncontrolled environment. Factors such as vibration from the car’s motor and tires on the road, plus wind and air turbulence will completely drown out any “splat” from a minuscule insect’s body, rendering any signal difficult to decipher from noise.
The European LISA Pathfinder spacecraft is a proof of concept mission that’s currently in space, orbiting a region of gravitational stability between the Earth and the sun — called the L1 point located a million miles away. The spacecraft was launched there in late 2015 to carry out precision tests of instruments that will eventually be used in the space-based gravitational wave detector eLISA. Inside the payload is a miniaturized laser interferometer system that measures the distance between two test masses.
When launched in 2034, eLISA (which stands for Evolved Laser Interferometer Space Antenna) will see three spacecraft, orbiting the sun at the L1 point, firing ultra-precise lasers at one another as part of a space-based gravitational wave detector. Now we actually know gravitational waves exist — after the US-based Laser Interferometer Gravitational-wave Observatory (or LIGO) detected the space-time ripples created after the collisions of black holes — excitement is building that we might, one day, be able to measure other phenomena, such as the ultra-low frequency gravitational waves that were created during the Big Bang.
But the only way we can do this is to send stunningly precise interferometers into space, away from our vibration-filled atmosphere to stand a chance of detecting some of the faintest space-time rumbles in our cosmos that would otherwise be drowned out by a passing delivery truck or windy day. And LISA Pathfinder is currently out there, testing a tiny laser interferometer in a near-perfect gravitational free-fall, making the slightest of slight adjustments with its “ultra-precise micro-propulsion system.”
Although LISA Pathfinder is a test (albeit a history-making test of incredible engineering ingenuity), NASA thinks that it could actually be used as an observatory in its own right; not for hunting gravitational waves, but for detecting comet dust.
Like our mosquito-windscreen analogy, spacecraft get hit by tiny particles all the time, and LISA Pathfinder is no exception. These micrometeoroides come from eons of evaporating comets and colliding asteroids. Although measuring less than the size of a grain of sand, these tiny particles zip around interplanetary space at astonishing speeds — well over 22,000 miles per hour (that’s 22 times faster than a hyper-velocity rifle round) — and can damage spacecraft over time, slowly eroding unprotected hardware.
Therefore, it would be nice if we could create a map of regions in the solar system that contain lots of these particles so we can be better prepared to face the risk. Although models of solar system evolution help and we can estimate the distribution of these particles, they’ve only ever been measured near Earth, so it would be advantageous to find the “ground truth” and measure them directly from another, unexplored region of the solar system.
This is where LISA Pathfinder comes in.
As the spacecraft gets hit by these minuscule particles, although they are tiny, their high speed ensures they pack a measurable punch. As scientists want the test weights inside the spacecraft to be completely shielded from any external force — whether that’s radiation pressure from the sun or marauding micro-space rocks — the spacecraft has been engineered to be an ultra-precise container that carefully adjusts its orientation an exact amount to directly counter these external forces (hence the “ultra-precise micro-propulsion system”).
This bit is pretty awesome: Whenever these tiny space particles hit the spacecraft, it compensates for the impact and that compensation is registered as a “blip” in the telemetry being beamed back to Earth. After careful analysis of the various data streams, researchers are learning a surprising amount of information about these micrometeoroides — such as their mass, speed, direction of travel and even their possible origin! — all for the ultimate goal of getting to know the tiny pieces of junk that whiz around space.
“Every time microscopic dust strikes LISA Pathfinder, its thrusters null out the small amount of momentum transferred to the spacecraft,” said Diego Janches, of NASA’s Goddard Space Flight Center in Greenbelt, Md. “We can turn that around and use the thruster firings to learn more about the impacting particles. One team’s noise becomes another team’s data.”
So, it turns out that you can precisely measure a mosquito impact on your car’s windshield — so long as that “mosquito” is a particle of space dust and your “car” is a spacecraft a million miles from Earth.
NASA put together a great video, watch it:
Aside: So it turned out that I inadvertently tested the “car-mosquito” hypothesis when driving home from Las Vegas — though some of these were a lot bigger than mosquitoes…
“Super Moon,” “Harvest Moon,” “Blood Moon,” “Super-Blood Moon” … we have a lot of weird names for the moon’s phases depending on the time of year and today plays host to yet another kind of moon. Ready for it? (drumroll) Introducing the “Worm Moon,” possibly my favorite moon name.
March’s Full Moon is traditionally called the Full Worm Moon by the Native Americans who used the Moons to track the seasons; Colonial Americans also used these names, especially those of the local Algonquin tribes who lived between New England and Lake Superior. At the time of this Moon, the ground begins to soften enough for earthworm casts to reappear, inviting the return of robins and migrating birds.
So there you have it, the Worm Moon is the first full moon of March and I was able to get a nice view of it from my backyard late last night. Enjoy!
We always seem to be “overdue” a devastating asteroid impact, but how can we be overdue if asteroids don’t have an impact schedule?
Humans are naturally tuned to seek out patterns in seemingly random events. It’s an evolutionary trait that has helped us become the smart Homo sapiens we are today.
This ability to spot patterns and predict cyclical events continues to dominate our everyday lives. For example, geologists chart seismic activity in hopes of seeing a tell-tail earthquake signal before the “big one” happens; farmers track seasonal cycles in an attempt to predict periods of drought; Wall Street traders use complex numerical models to warn of the next financial crisis (or, indeed, profit from the downturn). Also, astronomers try to find patterns in cosmic occurrences that could pose an existential threat.
We are, of course, talking asteroid impacts — cataclysmic events that have shaped all of the planets in our solar system. Although Earth’s atmosphere is very good at eroding away ancient impact craters, evidence for asteroid impacts in the geological history of our planet is very common. Frankly, it’s perfectly natural to be hit by large asteroids and comets; that’s how planets accrete rocky material, collect water and accumulate organic chemistry for life (on Earth, at least).
But should we get hit by a massive asteroid in the near future, it could be curtains for our civilization. So it sure would be handy if we could somehow use the geologic record of our planet, see how often we get punched, spot a cycle or some kind of pattern, predict then the next impact is likely to happen and — hopefully — plan for the next marauding space rock to make an appearance in our skies! (Whether we’ll be able to do anything about it is an entirely different matter.)
But what could drive periodic asteroid or comet impacts in the first place? One hypothesis claims that the solar system’s “wobble” through the galactic plane may destabilize comets in the Oort Cloud periodically, causing an uptick in massive planetary impacts. Also, the much hyped solar twin, Nemesis, could gravitationally jumble asteroids during its long orbit around the sun. But neither hypothesis stands up to scrutiny and the existence of an extremely dim solar partner is becoming increasingly unlikely.
Regardless, previous studies have suggested that extinction-level impacts (of the magnitude of the one that wiped out, or at least greatly contributed to the extinction of the dinosaurs) occur roughly every 26 million years (the cause of which is open to debate), but researchers from ETH Zurich and Lund University in Sweden now refute this claim.
“We have determined … that asteroids don’t hit the Earth at periodic intervals,” Matthias Meier, of ETH Zurich’s Institute of Geochemistry and Petrology, said in a statement.
After studying precisely-dated impact craters around the world that were formed in the past 500 million years, Meier and Sanna Holm-Alwmark of Lund University dated some 22 craters with dates of impacts known to a precision of one percent.
Then, using a technique known as circular spectral analysis (CSA), they attempted to find the approximate-26 million year period in this set of craters. They found no such period.
Interestingly, Meier and Holm-Alwmark also found that some of the impact craters were of the same age, hinting at a common source. “Some of these craters could have been formed by the collision of an asteroid accompanied by a moon,” said Meier. “But in other cases, the impact sites are too far away from each other for this to be the explanation.”
One interesting example is the apparent close similarity in age of the famous 66 million-year-old, 110 mile-wide Chicxulub Crater in Mexico (that has been linked with the extinction of the dinosaurs) and the 15 mile-wide Boltysh Crater in the Ukraine. As pointed out by the researchers, although a definitive explanation for this coincidence isn’t immediately clear, the two impactors may have originated from a collision in the asteroid belt, sending fragments to Earth, hitting the planet within a very short period of one another.
And it’s these kinds of clustering impacts that the researchers have identified as being potential problems with previous statistical studies — they assumed each impact is distinct, when in fact, they happened at the same time, possibly skewing results and creating a pattern when, in fact, there wasn’t one.
“Our work has shown that just a few of these so-called impact clusters are enough to suggest a semblance of periodicity,” said Meier.
I have little doubt that these new findings will be disputed, spawning more studies pointing to other statistical techniques and a bigger impact crater data set, but it is interesting to think that, as far as extinction-level impact events go, there really may be no pattern to their occurrence.
We know that a doomsday asteroid is out there, and it will hit us, but it has a random impact date that is only known to our planet’s geological future.
In case you haven’t heard, one of the Republican presidential candidate hopefuls, Newt Gingrich, has stellar plans for the U.S. in space. Should he make it though the GOP primaries and beat President Obama in this year’s presidential elections and make it to a second second term in office, the United States of America is going back to the Moon! *applause* *cheers* *ticker tape raining down on Times Square*
“By the end of my second term, we will have the first permanent base on the moon and it will be American!” Gingrich declared on Wednesday when he was outlining his plans for NASA and the U.S. space industry during his Florida GOP campaign.
A lot of what Gingrich said seemed to make sense — less NASA bureaucracy, more commercial investment, space prizes — but the one thing the majority of the media fixated on is the “Moon base” thing.
Generally speaking, any promises made during a presidential campaign, let alone a GOP presidential candidate primary, should be taken with a big pinch of salt. Gingrich, who has been hammered by bad press and negative ad campaigns by opponent Mitt Romney, decided to go “all in” during his Space Coast speeches in the hope of persuading Florida — a key swing state — that he was their man to reinvigorate the state’s major industry.
But it looks like his promises have gone a little too far.
Sending men to the moon during the Apollo era cost the U.S. $170 billion (in today’s money). This cost encompassed the development of manned space flight technology — from the massive Saturn V rockets to the Lunar Modules. But to set up a Moon base (an American Moon base no less) the costs of developing the technology, building the base, creation of a Earth-Moon transportation infrastructure and maintaining lunar assets for many years would spiral into hundreds of billions of dollars.
But it’s OK, NASA wouldn’t be expected to pick up the bill, which is fortunate as the U.S. space agency’s budget stands at less than $18 billion (for 2012). In 1966, 60 percent of NASA’s entire budget was pumped into the Apollo Program, so if that were to happen again, NASA science would be a thing of the past.
Using incentives, Gingrich’s plan is to heavily involve private industry. 10 percent of NASA’s budget will be set aside for industrial “prizes” — presumably X PRIZE-like programs. Also, the lunar surface would be a “free-for-all” — corporations would dig in, mine and pillage the lunar surface for its treasures. And then there’s science! Don’t forget the science! SCIENCE will be done, because science is all kinds of awesome.
But there’s a juicy fly in the ointment that Gingrich appears to be ignoring: Where’s the incentive?
As we’ve already established, spaceflight is really, really expensive. Setting up a Moon base would be really, really, really expensive. The International Space Station (ISS) took international collaboration to build and maintain (not forgetting that NASA can’t even access this huge chunk of orbiting real estate without asking Russia for a hand), so whether or not you think $100 billion is a lot of dough for an orbiting outpost, “hundreds of billions” seems like a reasonable estimate for a Moon base. NASA simply can’t “go it alone” to set up an American base, it would need to be an international collaboration, or there would need to be a huge investment made by U.S. commercial interests.
Now, I’m no businessman, so I might be wrong, but companies like to see a return on their investments, right?
We could see similar deals between NASA and private space companies to courier people and cargo into space (like the COTS program that invigorates partnerships like the one between NASA and SpaceX), but again, we’d need to see significant investment by a government agency: NASA. How to get out of this government-funded loop? Let companies profit from the Moon’s resources — there must be gazillions of dollars to be made from that, right?
You’ll hear many people discuss Helium-3 with huge enthusiasm, which is found in abundance on the lunar surface. Helium-3 is the much-touted fuel for fusion power plants. Fusion power is the world’s cleanest, most abundant energy resource; whoever controls the supply of Helium-3 from the surface of the moon could stand to make trillions!
What about using the Moon as a massive resource of precious metals? After all, the moon is made from the same stuff Earth is made of, gold and platinum should be hiding in that Moon rock. Why not set up vast strip mines and refineries? Hell, it would be far easier to extract raw materials and refine them in-situ on the Moon than mining asteroids.
But once again, there’s a big problem; it would cost far more to extract, refine and transport the material back to Earth (let alone the huge health & safety/insurance concerns with flying the stuff back to Earth, reentering tons of materials over populated regions) than the profit a company could stand to make from such an operation.
So, in summary, to build a Moon base it would cost a lot of money. In the current political and financial climate, there isn’t a cat in hell’s chance of seeing a U.S. government agency like NASA footing the bill. Private investment would need to be found. But companies don’t like risking tens (to hundreds) of billions of dollars unless they can see some potential for profit. A Moon base, for now, is not an investment.
Also, the Outer Space Treaty forbids any nation from “owning” any portion of the Moon — so sending U.S. companies to mine the Moon could be a pretty awkward scenario. This alone invalidates the “American Moon base” idea if it was being used for anything other than science purposes. Seeing a mining operation pop up in the Sea of Tranquility would be like BP building a refinery in the Antarctic. Sure, it can be done, but the international fallout would be horrendous (another factor that might dissuade corporate investment in the first place).
The modern world’s economy is based on growth, profit and the politics they motivate. Making money from space, in the near term, doesn’t involve bases on the Moon. Profit and growth can be found in government contracts and investment in cheap space launch alternatives. Space tourism, in the near-term, is also showing some promise. These areas of growth focus on basic space infrastructure — simply blasting stuff into orbit is a difficult and expensive task, private enterprise is currently innovating to fulfill this need. And they are doing it for profit.
A few decades from now, when our planet finally has a viable, sustainable infrastructure in space, talk of Moon bases and company profits may make more sense. But talk of building a base (let alone a Moon colony) when we don’t even have the rockets or spacecraft to get us there, is a bit like saying I’m moving to Hawaii, but there’s no aircraft or boats to get me there and… oh, by the way… I have to ship the bricks of my house to the middle of the Pacific Ocean so I can actually build a house when I get there.
Try selling that profit-making scheme to the CEO of Home Depot.
The video is actually composed of 22,000 high-definition photographs, stitched together is a finely crafted time lapse video. The photographer in question is Terje Sorgjerd who braved -22C temperatures in the Arctic Circle to bring us this stunning perspective of the Aurora Borealis, or the Northern Lights. Throw in the Hans Zimmer “Gladiator” theme tune “Now We Are Free” and we get a timeless classic video that can be watched over and over again and never get bored.
So, sit back and enjoy the Sun-Earth interaction at its most spectacular.
This rather outlandish, sci-fi notion comes straight from the fertile minds of researchers from MIT, the Massachusetts General Hospital and Harvard University who are proposing a biology experiment that could be sent on a future Mars surface mission. If their hypothesis is proven, we wouldn’t only have an answer for the age old question: Are we alone? but we’d also have an answer for the not-so-age-old question: Did life from Mars spawn life on Earth?
The idea goes like this: countless tons of material from Mars has landed on Earth. We know this to be true; meteorites have been discovered on Earth that originate from the Red Planet. These rocks were blasted from the Martian surface after eons of asteroid impacts, and the rocks then drifted to Earth.
If there was once life on Mars — a concept that isn’t that far-fetched, considering Mars used to boast liquid water in abundance on its surface — then perhaps some tiny organisms (not dislike the hardy cyanobacteria that is thought to have been one of the earliest forms of life to evolve on our planet) hitched a ride on these rocks. If some of these organisms survived the harsh conditions during transit from Mars to Earth and made it though the searing heat as the meteorite fell through our atmosphere, then perhaps (perhaps!) that is what sparked life on Earth.
You may have heard a few variations of this mechanism, it is of course the “panspermia” hypothesis. Panspermia assumes that life isn’t exclusive to just one rocky body like Earth, perhaps life has the ability to hop from one planet to the next, helped on its way by asteroid impacts. Not only that, but perhaps (perhaps!) tiny microorganisms could drift, encased in interstellar dust, akin to pollen drifting in the wind, seeding distant star systems.
Naturally, when considering the distance between the planets (let alone the light-years between the stars!), one might be a little skeptical of panspermia. But it certainly would help us understand how life first appeared on Earth. After all, it’s not as if the solar system has a natural quarantine system in place — if Mars had (or has) bacteria on its surface, perhaps they have been spread to Earth, like an interplanetary flu bug. Also, as experiments are showing us, microorganisms have an uncanny ability to survive in space for extended periods of time.
So, according to my esteemed Discovery News colleague Ray Villard, the MIT team led by Christopher Carr and Maria Zuber and Gary Ruvkun, a molecular biologist at the Massachusetts General Hospital and Harvard University, are proposing to build an instrument to send to Mars. But this instrument won’t be looking for signs of life, it will be testing the hypothetical Martian DNA and RNA. Should this interplanetary paternity test prove positive, proving a relationship between Earth Brand™ Life and Mars Brand™ Life, then this could be proof of some extraterrestrial cross-pollination.
Although this is complete conjecture at this time, as there is no proof that life has ever existed on Mars (despite what research in dodgy research journals tell us), it is certainly an interesting idea that would not only test the hypothesis of panspermia, but also give us a clue about the potential human colonization of Mars.
This could give us pause about sending humans to a germ-laden alien world. It would be an ironic twist on the H.G. Wells classic 1898 novel “The War of the Worlds,” where invading Martians succumb to the common cold from Earth microbes.
See, Wells’ Martian warriors should have done genome testing first.
Original post: On Saturday, a NASA astrobiologist announced his “irrefutable proof” that aliens — the size of bacteria — exist. Using a sophisticated electron microscope, Richard Hoover looked deep into meteorite samples to see complex fossilized microscopic structures that looked suspiciously like bacteria found here on Earth.
Some of the suspect alien microorganisms even resemble cyanobacteria, a basic microorganism that helped make early-Earth hospitable to life by producing oxygen. Cyanobacteria can live in space for extended periods of time; tests on the International Space Station have shown the single-celled specks are hardy little buggers, surviving in a kind of “suspended animation,” sleeping for months (even years) in vacuous, frozen, high-radiation conditions. When brought back to Earth, the critters come back to life.
Needless to say, when Hoover announced this discovery of “alien” microbes, I wasn’t the only one who was thinking panspermia, the hypothetical mechanism where life — in the form of a microbe like cyanobacteria — hops from one planet to the next encased inside meteoroids.
Is this really proof of aliens? Is it evidence for panspermia? Does this mean life on Earth may have been seeded by alien microbes stowing away inside chunks of space rock? Does mankind need to invent an anti(alien)bacterial handwash?! (I’ve watched The Andromeda Strain.)
As mentioned in my Discovery News article on the subject, I’m skeptical about Hoover’s claims. This isn’t because I think Hoover’s work is rubbish (I have yet to finish digesting his lengthy paper), it’s just the way he decided to publish his work. The online Journal of Cosmology isn’t exactly the best place to submit your paper if you want your research to be taken seriously. And why the hell he gave FOX News the “exclusive,” I have no idea.
Sure, Hoover has discovered some odd-looking, alien-looking, bacteria-sized shapes in meteorite samples (he’s even done some interesting chemical analysis on the micro-“fossils”), but he’s going to have to do a far better job at convincing the scientific community that they are extraterrestrials.
Personally, I think these dinky “fossils” are a little too well preserved. Perhaps a far simpler explanation can be found? *cough* Contamination. *cough*
I’d love to know what NASA’s official line is, they seem to be staying remarkably quiet considering one of their employees has just announced the discovery of ET…