May 9, 2013
In September 2009, after decades of speculation, evidence of water on the surface of the Moon was discovered for the first time. Chandrayaan-1, a lunar probe launched by India’s space agency, had created a detailed map of the minerals that make up the Moon’s surface and analysts determined that, in several places, the characteristics of lunar rocks indicated that they bore as much 600 million metric tonnes of water.
In the years since, we’ve seen further evidence of water both on the surface and within the interior of the Moon, locked within the pore space of rocks and perhaps even frozen in ice sheets. All this has gotten space exploration enthusiasts pretty excited, as the presence of frozen water could someday make permanent human habitation of the Moon much more feasible.
For planetary scientists, though, it’s raised a knotty question: How did water arrive on the Moon in the first place?
A new paper published today in Science suggests that, unlikely as it may seem, the Moon’s water originated from the same source as the water that comes out of the faucet when you open a tap. Just as many scientists believe the Earth’s entire supply of water was initially delivered via water-bearing meteorites that traveled from the asteroid belt billions of years ago, a new analysis of lunar volcanic rocks brought back during the Apollo missions indicates the Moon’s water has its roots in these same meteorites. But there’s a twist: Before reaching the Moon, this lunar water was first on Earth.
The research team, led by Alberto Saal of Brown University, analyzed the isotopic composition of hydrogen found in water within tiny bubbles of volcanic glass (supercooled lava) as well as melt inclusions (blobs of melted material trapped in slowly cooling magma that later solidified) in the Apollo-era rocks, as shown in the image above. Specifically, they looked at the ratio of deuterium isotopes (“heavy” hydrogen atoms that contain an added neutron) to normal hydrogen atoms.
Previously, scientists have found that in water, this ratio changes depending on where in the solar system the water molecules initially formed, as water that originated closer to the Sun has less deuterium than water formed further away. The water locked in the lunar glass and melt inclusions was found to have deuterium levels similar to that found in a class of meteorites called carbonaceous chondrites, which scientists believe to be the most unaltered remnants of the nebula from which the solar system formed. Carbonaceous chondrites that fall to Earth originate in the asteroid belt between Mars and Jupiter.
Higher deuterium levels would have suggested that water was first brought on to the Moon by comets—as many scientists have hypothesized—because comets largely come from the Kuiper belt and Oort Cloud, remote regions far beyond Neptune where deuterium is more plentiful. But if the water in these samples represents lunar water as a whole, the findings indicate that the water came from a much closer source—in fact, the same source as the water on Earth.
The simplest explanation for this similarity would be a scenario in which, when a massive collision between a young Earth and a Mars-sized proto-planet formed the Moon some 4.5 billion years ago, some of the liquid water on our planet was somehow preserved from vaporization and transferred along with the solid material that would become the Moon.
Our current understanding of massive impacts, though, doesn’t allow for this possibility: The heat we believe would be generated by such an enormous collision would theoretically vaporize all lunar water and send it off into space in a gaseous form. But there are a few other scenarios that might explain how water was transferred from our proto-Earth to the Moon in other forms.
One possibility, the researchers speculate, is that the early Moon borrowed a bit of Earth’s high-temperature atmosphere the instant it formed, so any water that had been locked in the chemical composition of Earth rocks pre-impact would have vaporized along with the rock into this shared atmosphere after impact; this vapor would have then coalesced into a solid lunar blob, binding the water into the chemical composition of lunar material. Another possibility is that the rocky chunk of Earth was kicked off to form the Moon retained the water molecules locked inside its chemical composition, and later on, these were released as a result of radioactive heating inside the Moon’s interior.
Evidence from recent lunar missions suggests that lunar rocks—not just craters at the poles—indeed contain substantial amounts of water, and this new analysis suggests that water originally came from Earth. So the findings will force scientists to rethink models of how the Moon could have formed, given that it clearly didn’t dry out completely.
April 19, 2013
Last year, to celebrate the 42nd Earth Day, we took a look at 10 of the most surprising, disheartening, and exciting things we’d learned about our home planet in the previous year—a list that included discoveries about the role pesticides play in bee colony collapses, the various environmental stresses faced by the world’s oceans and the millions of unknown species are still out in the environment, waiting to be found.
This year, in time for Earth Day on Monday, we’ve done it again, putting together another list of 10 notable discoveries made by scientists since Earth Day 2012—a list that ranges from specific topics (a species of plant, a group of catfish) to broad (the core of planet Earth), and from the alarming (the consequences of climate change) to the awe-inspiring (Earth’s place in the universe).
1. Trash is accumulating everywhere, even in Antarctica. As we’ve explored the most remote stretches of the planet, we’ve consistently left behind a trail of one supply in particular: garbage. Even in Antarctica, a February study found (PDF), abandoned field huts and piles of trash are mounting. Meanwhile, in the fall, a new research expedition went to study the Great Pacific Garbage Patch, counting nearly 70,000 pieces of garbage over the course of a month at sea.
2. Climate change could erode the ozone layer. Until recently, atmospheric scientists viewed climate change and the disintegration of the ozone layer as entirely distinct problems. Then, in July, Harvard researcher Jim Anderson (who won a Smithsonian Ingenuity Award for his work) led a team that published the troubling finding that the two might be linked. Some warm summer storms, they discovered, can pull moisture up into the stratosphere, an atmospheric layer 6 miles up. Through a chain of chemical reactions, this moisture can lead to the disintegration of ozone, which is crucial for protecting us from ultraviolet (UV) radiation. Climate change, unfortunately, is projected to cause more of these sorts of storms.
3. This flower lives on exactly two cliffs in Spain. In September, Spanish scientists told us about one of the most astounding survival stories in the plant kingdom: Borderea chouardii, an extremely rare flowering plant that is found on only two adjacent cliffs in the Pyrenees. The species is believed to be a relic of the Tertiary Period, which ended more than 2 million years ago, and relies on several different local ant species to spread pollen between its two local populations.
4. Some catfish have learned to kill pigeons. In December, a group of French scientists revealed a phenomenon they’d carefully been observing over the previous year: a group of catfish in Southwestern France had learned how to leap onto shore, briefly strand themselves, and swim back into the water to consume their prey. With more than 2,000,000 Youtube views so far, this is clearly one of the year’s most widely enjoyed scientific discoveries.
5. Fracking for natural gas can trigger moderate earthquakes. Scientists have known for a while that whenever oil and gas are extracted from the ground at a large scale, seismic activity can be induced. Over the past few years, evidence has mounted that injecting water, sand and chemicals into bedrock to cause gas and oil to flow upward—a practice commonly known as fracking—can cause earthquakes by lubricating pre-existing faults in the ground. Initially, scientists found correlations between fracking sites and the number of small earthquakes in particular areas. Then, in March, other researchers found evidence that a medium-sized 2011 earthquake in Oklahoma(which registered a 5.7 on the moment magnitude scale) was likely caused by injecting wastewater into wells to extract oil.
6. Our planet’s inner core is more complicated than we thought. Despite decades of research, new data on the iron and nickel ball 3,100 miles beneath our feet continue to upset our assumptions about just how the earth’s core operates. A paper published last May showed that iron in the outer parts of the inner core is losing heat much more quickly than previously estimated
, suggesting that it might hold more radioactive energy than we’d assumed, or that novel and unknown chemical interactions are occurring. Ideas for directly probing the core are widely regarded as pipe dreams, so our only options remains studying it from afar, largely by monitoring seismic waves.
7. The world’s most intense natural color comes from an African fruit. When a team of researchers looked closely at the blue berries of Pollia condensata, a wild plant that grows in East Africa, they found something unexpected: it uses an uncommon structural coloration method to produce the most intense natural color ever measured. Instead of pigments, the fruit’s brilliant blue results from nanoscale-size cellulose strands layered in twisting shapes, which which interact with each other to scatter light in all directions.
8. Climate change will let ships cruise across the North Pole. Climate change is sure to create countless problems for many people around the world, but one specific group is likely to see a significant benefit from it: international shipping companies. A study published last month found that rising temperatures make it probable that during summertime, reinforced ice-breaking ships will be able to sail directly across the North Pole—an area currently covered by up to 65 feet of ice—by the year 2040. This dramatic shift will shorten shipping routes from North America and Europe to Asia.
9. One bacteria species conducts electricity. In October, a group of Danish researchers revealed that the seafloor mud of Aarhus’ harbor was coursing with electricity due to an unlikely source: mutlicellular bacteria that behave like tiny electrical cables. The organisms, the team found, built structures that traveled several centimeters down into the sediment and conduct measurable levels of electricity. The researchers speculate that this seemingly strange behavior is a byproduct of the way of the bacteria harvests energy from the nutrients buried in the soil.
10. Our Earth isn’t alone. Okay, this one might not technically be a discovery about Earth, but over the past year we have learned a tremendous amount about what our Earth isn’t: the only habitable planet in the visible universe. The pace of exoplanet detection has accelerated rapidly, with a total of 866 planets in other solar systems discovered so far. As our methods have become more refined, we’ve been able to detect smaller and smaller planets, and just yesterday, scientists finally discovered a pair of distant planets in the habitable zone of their stars that are relatively close in size to Earth, making it more likely than ever that we might have spied an alien planet that actually supports life.
April 9, 2013
Ever since the collective “YOU” became Time Magazine’s Person of the Year in 2006, campaigns to get our attention have increasingly sought out our digital selves. You can name a Budweiser Clydesdale. You can pick Lays’ new potato chip flavor. And it’s not just retail that wants your online opinions: You can vote for who will win photography contests. You can play the futures market on who will win elected offices. And with enough signatures, you can get the White House to read your petitions.
Many science endeavors rely on such crowdsourcing. With a simple app, you can let researchers know the exact date that your lilacs or dogwoods bloom, helping them to track how seasonal cycles are shifting as a result of climate change. You can join the search for ever-larger prime numbers. You can even help scientists scan radio waves in space to search for intelligent life outside of Earth. These more traditional crowdsourcing efforts allow users to brainstorm ideas and process data from computers at home.
But now, a few projects are allowing us to put our virtual selves beyond Earth’s atmosphere through recently launched space missions. Who said that rovers, space probes, a handful of astronauts and pigs were the only ones in space? No longer are we just bystanders watching spacecraft launch and cooing over images returned of other planets and stars. Now, we can direct cameras, help run experiments, even send our avatars–of sorts–to inhabit nearby planetary bodies or return to us in a time capsule.
Here are a few examples:
Asteroid Chimney Rock: On April 10 (tomorrow), the Japan Aerospace Exploration Agency will open up a campaign that allows visitors to their site the opportunity of sending their names and brief messages to the near-Earth asteroid (162173) 1999 JU3. Called the “Let’s meet with Le Petit Prince! Million Campaign 2,” the effort aims to get people’s names onto the Hayabusa2 mission, which will likely launch in 2014 to study the asteroid. When Hayabusa 2 lands on the asteroid, the names submitted–embedded in a plaque of sorts on the spacecraft–will stand as a testament to the idea that humans (or at least their robotic representatives) were there.
The campaign is reminiscent of how NASA got more than 1.2 million people to submit their names and signatures, which were then etched on two dime-sized microchips and affixed to the Mars Curiosity rover. Sure, it’s a bit gimmicky–what useful function is brought by having people’s names out in space? But the idea of “tagging” a planet or an asteroid–preserving a bit of yourself on what will over decades become space junk–has powerful pull. It is why Chimney Rock, with its etchings from early explorers and pioneers, is the historical marker it is today, and why gladiators scored their names into the Colosseum before they fought to the death. For mission leaders hoping to get the public enthusiastic about space, nothing’s more exciting than a bit of digital graffiti.
Interplanetary time capsules: A key goal of Hayabusa2 is to return return a sample from the asteroid in 2020. Mission creators saw this as a perfect way to get the public to fill a time capsule. Those seeking to participate are encouraged to send to mission coordinators their thoughts and dreams for the future along with their hopes and expectations for recovery from natural disasters, the latter likely a way to get people to express their feelings on the 2011 Tohoku earthquake and tsunami that devastated Japan’s east coast. Names, messages, and illustrations will loaded onto a microchip that will not only touch down on the asteroid’s surface, but will also be a part of the probe sent back to Earth with asteroid dust.
But why stop at a mere 6-year time capsule? The European Space Agency, UNESCO, and other partners are blending crowd sourcing with space technology to create the KEO mission–so named because the letters represent common sounds across all of Earth’s languages–which will bundle thoughts and images of anyone who seeks to participate and will launch this bundle in a probe that will only return to Earth in 50,000 years.
Project operators write on KEO’s website: “Each one of us have 4 uncensored pages at our disposal: an identical space of equality and freedom of expression where we can voice our aspirations and our revolts, where we can reveal our deepest fears and our strongest beliefs, where we can relate our lives to our faraway great grandchildren, thus allowing them to witness our times.” That’s 4 pages for every person who chooses to participate.
On board will be photographs detailing Earth’s cultural richness, human blood encased in a diamond, and a durable DVD of humanity’s crowdsourced thoughts. The idea is to launch the time capsule from an Ariane 5 rocket into an orbit more than 2,000 kilometers above Earth, hopefully sometime in 2014. “50,000 years ago, Man created art thus showing his capacity for symbolic abstraction.” the website notes. And in another 50,000 years, “Will Earth still give life? Will human beings still be recognizable as such?”Another logical question: Will whatever’s left on Earth know what’s coming back to them and will be able to retrieve it?
Hayabusa2 and KEO will join capsules already launched into space on Pioneer 10 and 11 and Voyager 1 and 2. But the contents of these earlier capsules were picked by a handful of people; here, we get to choose what represents us in space, and will get to reflect (in theory) on the thoughts bound in time upon their return.
You, the mission controller and scientist: Short of going to Mars yourself, you can do the next best thing–tell an instrument currently observing Mars where to look. On NASA’s Mars Reconnaissance Orbiter is the University of Arizona’s High Resolution Imaging Science Experiment (HiRISE), a camera designed to image Mars in great detail. Dubbed “the people’s camera,” HiRISE allows you–yes, you!– to pick its next targets by filling out a form specifying your “HiWishes.”
A recently launched nanosatellite is allowing the crowdsourced winners of a crowdsourced screaming contest the chance to test whether screams can be heard in space. Launched in February, the nanosatellite’s smartphone-powered brain will broadcast the screams–no word yet on results. But you may find just listening to the yelling therapeutic! This guy’s roar got the most votes:
March 20, 2013
Update: Since the press release announcing Voyager 1′s exiting the solar system, NASA has clarified that the final indicator of this event—a change in the direction of the magnetic field surrounding the craft—has still not been observed. As was first observed in December 2012, Voyager 1 is in a new outermost region of the solar system called “the magnetic highway,” not true interstellar space. This post has been edited to reflect the clarification.
Since the dawn of the Space Age, our manned missions and unmanned probes have reached the Moon, asteroids and other planets. But only now do we have confirmation that a human-made object has reached a new milestone: The Voyager 1 space probe is at the furthermost edge of the solar system.
According to a paper recently accepted for publication by the journal Geophysical Research Letters, data transmitted by probe—which is now more than 11 billion miles away from the Sun—reveal that it has exited the heliosphere. The heliosphere (also called the heliosheath) is the region of space influenced by the solar wind and is commonly accepted as the outer border of the solar system. Thirty-five years, 6 months and 15 days after its launch, the spacecraft will soon enter the second phase of its mission—studying the interstellar medium that exists between our galaxy’s star systems.
Bill Webber of New Mexico State and F.B. McDonald of the University of Maryland (who has passed away since the paper was written) came to the conclusion after analyzing radiation data transmitted by Voyager 1 last August 25. The probe’s sensors detected that the levels of radiation from cosmic rays that had come from the Sun dropped to less than 1 percent of what they’d been previously, while radiation from galactic cosmic rays (which originate from beyond the solar system) doubled in intensity.
Although there is no exact boundary that defines the edge of the solar system, the point at which the Sun’s cosmic rays and galactic cosmic rays meet indicates the edge of the region dominated by our Sun’s solar wind, and thus the outside border of our star’s system. Webber says that the sudden change in radiation indicates Voyager 1 passed this point.
“Within just a few days, the heliospheric intensity of trapped radiation decreased, and the cosmic ray intensity went up as you would expect if it exited the heliosphere,” he said in a press release issued by the American Geophysical Union today. He also noted that it’s possible the probe hasn’t reached true interstellar space, but rather a separate, not-yet-understood region that lies in between our solar system and the interstellar medium.
Since its launch in 1977, the spacecraft has conducted a grand tour of the solar system, passing by and photographing Jupiter and Saturn and providing us with some of the first-ever close-ups of the gas giants. Voyager 2, a twin probe, visited Jupiter, Saturn, Uranus and Neptune, and is still firmly within the solar system for now, 9.4 billion miles away from the Sun.
In 2005, Voyager 1 entered the heliosheath (the region in which the solar wind begins to slow down due to encountering the interstellar medium), and last October, researchers reported that it may have left the heliosphere altogether. Soon afterward, though, scientists cautioned that it may not have exited the heliosphere’s outer boundary, because a shift in the direction of the magnetic field had not yet been detected.
Despite the announcement alongside the new paper, this may still be the case—Voyager 1 may have finally exited the heliosphere, but not yet entered interstellar space per se. According to NASA, “A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed.” Thus, the probe is in an unexpected region in between the heliosphere and interstellar space, previously referred to as a magnetic highway.
Either way, though, it’s still in the starting stages of its journey, set to spend millennia—yes, millenia—traveling through the interstellar medium, though it will probably not be able to record or send back data after around 2025.
After an estimated 40,000 years, it will come relatively close (within a light year) to another star—and at that point, could serve as something of a time capsule. The Voyager 1 carries a Golden Record, designed to present a virtual snapshot of humankind to other life forms, contains everything from images of DNA and the Taj Mahal to recordings of whale sounds and Chuck Berry’s “Johnny B. Goode.”
As Timothy Ferris wrote in Smithsonian last May when he reflected on the 35th anniversary of the Voyager mission, “The Voyagers will wander forever among the stars, mute as ghost ships but with stories to tell…Whether they will ever be found, or by whom, is utterly unknown.”
February 26, 2013
Picture a telescope orbiting in space, and your mind probably flies to the Hubble Space Telescope. At roughly 43 feet long and weighing 25,000 pounds, its footprint is the size of a small house and it’s just a little shy of the weight of a subway car. But not all satellite telescopes are behemoths–one launched yesterday from India, designed and developed by the Space Flight Laboratory of the University of Toronto Institute for Aerospace Studies, is roughly the size of a cooler you’d bring to a picnic.
The telescope is part of the Bright Target Explorer (BRITE) mission, an effort designed to observe stars and record changes in their brightness over time. Launched into orbit above the masking effects of our atmosphere, the telescope and its simultaneously launched twin will focus on the brightest stars–such as those in well-known constellations like Orion and the Big Dipper–looking for pulsations and reverberations in brightness that indicate spots on a star, a planet or another celestial object crossing its orbit, or flickering energy intensities within the star itself. These flickers, called “starquakes,” give clues to the composition and internal structure of stars.
BRITE ‘s telescopes are nanosatellites, meaning that they weigh less than ten kilograms. At seven kilograms–about as heavy as a large bowling ball–and measuring 20 centimeters on each side, they are the smallest telescopes in orbit. The cubic satellites did not require a dedicated rocket to get there–these hitched a ride on India’s Polar Satellite Launch Vehicle. Future launches of similar twin nanosatellites will help BRITE to become a satellite constellation that scans the sky for different wavelengths of light pulsing from stars.
Nanosatellites, part of a recent trend to conduct space-based science at low cost and with fast results, “can be developed quickly, by a small team and at a cost that is within reach of many universities, small companies and other organizations,” said Cordell Grant, manager of satellite systems for the Space Flight Laboratory, in a statement. “A nano-satellite can take anywhere from six months to a few years to develop and test,” he added. In contrast, Hubble took more than 12 years to design and construct before it launched with space shuttle Discovery in 1990.
But nanosatellites aren’t the only kind of small satellites out there. Here are some other tiny orbiters:
First launched on the last flight of Endeavour, sprites–also called femtosatellites–look about the size of a postage stamp. Developed by Cornell University scientists, these satellites are in interplanetary space collecting data about chemistry, radiation and particle impacts. Lead engineer Mason Peck, now a chief technologist at NASA, told the Cornell University Chronicle that “Their small size allows them to travel like space dust.” He added, “Blown by solar winds, they can ‘sail’ to distant locations without fuel.”
The grapefruit-sized CubeSat, a type of picosatellite, measures 10 centimeters on each side. “I got a 4-inch beanie baby box and tacked on some solar cells to see how many would fit on the surface,” Bob Twiggs, the satellite’s lead designer, told Space.com. “I had enough voltage for what I needed so I decided that would be the size.” Developed in 1999 with the help of Jordi Puig-Suari of California Polytechnic State University, along with students at Stanford University while Twigg was a professor there, CubeSats are now the go-to small satellite. They appeal to universities–at roughly $65,ooo to $80,000 a pop, they can fit within research budgets, allowing students the opportunity to design and build a research satellite.
Some, like GeneSat-1 provides life support for bacterium and are aimed at helping scientists learn more about how spaceflight affects the human body. Another–SwissCube-1–examines nightglow in Earth’s atmosphere. Launched alongside BRITE, the STRaND-1–a string of 3 CubeSats stacked together–is the first smartphone-powered satellite ever launched into space. The Android phone that serves as the device’s brain will run apps that will photograph its orbit, monitor the Earth’s magnetic field, and–perhaps most exciting–will allow people to upload videos of themselves screaming to test whether sounds broadcasted in space can be heard by the satellite playing them. Other CubeSats in development will assist researchers understand space weather, phenomena that could short out the other satellites that orbit Earth.
It’s interesting to remember that the first satellite–Sputnik-1, launched in 1957–was a 23-inch diameter sphere. These nano-, pico-, and femto-satellites harken back to those roots. But their size, cost, and ability to be developed quickly may make them the most useful satellites of the future. Hopefully they won’t lead to oodles more space junk!