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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.

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.”

On Wednesday, NASA released an image of a series of enormous sunspots snapped by at the Solar Dynamics Observatory, an orbiting telescope. The sunspots—the dark spots in the center of the image—are estimated to be larger in diameter than six Earths placed next to each other.

These sunspots pose no inherent danger—they’re merely temporary areas of intense magnetic activity that inhibit the sun’s normal convection currents—but, on occasion, the unstable area around a sunspot can trigger an unusually large solar flare (below), flinging streams of radiation outward from the sun. And a big enough solar flare can lead to an alteration in solar wind significant enough to set off a geomagnetic storm here on Earth, with the potential to short the circuitry on satellites and disrupt our telecommunications infrastructure worldwide.

To be clear, such a scenario seems unlikely to occur from this current set of sunspots—SpaceWeather.com indicates there is just a 15% chance of X-class flares at the moment, the minimum level necessary to knock out satellites and ground-based communications technologies. But we decided to take this opportunity to imagine just how far-reaching the effects of a massive solar flare would be in today’s ultra-connected world.

It so happens that at least once during recorded history, a solar event of this magnitude did occur: the solar storm of 1859. On September 1 and 2 of that year, the largest geomagnetic storm in recorded history occurred, causing aurorae (the northern and southern lights) to be visible around the world. The Baltimore American and Commercial Advertiser wrote:

Those who happened to be out late on Thursday night had an opportunity of witnessing another magnificent display of the auroral lights…The light appeared to cover the whole firmament, apparently like a luminous cloud, through which the stars of the larger magnitude indistinctly shone. The light was greater than that of the moon at its full, but had an indescribable softness and delicacy that seemed to envelop everything upon which it rested.

Of course, the massive solar storm also caused damage, triggering telegraph malfunctions (even giving operators electrical shocks) and causing some telegraph pylons to suddenly spark and catch fire.

A much smaller solar storm occurred in 1989, knocking out power throughout much of Quebec for over 9 hours, disrupting communications with several satellites in orbit and interfering with the broadcast of short-wave radio in Russia. Aurorae were reportedly visible as far south as Florida and Georgia; given the ongoing Cold War and the fact that many had never seen this phenomenon before, some feared that a nuclear strike was in progress.

How did solar activity 93 million miles away lead to such destruction? These types of storms are the result of a sudden coronal mass ejection (CME)—a massive burst of solar plasma (electrons, protons, and ions) that is hurtled out into space—which often occurs alongside particularly large solar flares.

The solar wind is a continuous stream of charged particles thrown out from the sun towards earth, but a particularly large CME can lead to a big enough surge in the speed and energy of the particles to disrupt the magnetic field surrounding Earth. This, in turn, causes aurorae and the disruptions to our telecommunications equipment, which rely upon electromagnetic forces.

If a CME as large as the one that triggered the 1859 storm were to occur today, the consequences could be devastating. Given the increase in our reliance on electricity and telecommunications (even since 1989), the effects would certainly be far more significant than malfunctioning telegraph pylons.

It’s hard to appreciate just how many aspects of modern life rely on technologies that could be affected. As Daniel Baker of the University of Colorado’s Laboratory for Atmospheric and Space Physics told National Geographic in 2011, ”Every time you purchase a gallon of gas with your credit card, that’s a satellite transaction.” A giant storm could disrupt our GPS systems, communication with planes in flight and other crucial satellite-based technologies.

But the biggest concern, experts say, would be disruptions to our power grid—as a 2011 OECD report (PDF) on the impacts of solar storms points out, “Electric power is modern society’s cornerstone technology on which virtually all other infrastructures and services depend.” A surge in solar wind can blow out power transformers by melting their copper windings, and especially in highly interconnected regions (such as the East Coast), transformer failures can trigger cascading effects, spreading power outages over wide areas.

One analysis looked at a 1921 storm—which was ten times more powerful than the 1989 event—and estimated that if it occurred today, it would leave some 130 million people without power, potentially affecting water and food distribution, heating and air conditioning, sewage disposal and a host of other aspects of the infrastructure we take for granted daily. The total cost of an even larger storm, such as the 1859 event, could be enormous: an estimated $1 to $2 trillion in the first year alone, and a total recovery that could take 4 to 10 years in total.

The good news is that CMEs large enough to trigger a disruptions like the 1859 storm are rare–for the most severe damage to occur, a CME has to be directed in such away that Earth receives the brunt of the blast. Fortunately, solar activity occurs in a cycle with a duration of roughly 11 years, during which all kinds of solar activity (including the number of sunspots, the frequency of flares and the level of mass ejections) fluctuate from high to low and back to high again. However, we’re near the peak of the cycle, which NASA predicts will occur this fall.

Both NASA and the National Weather Service’s Space Weather Prediction Center monitor solar activity and issue warnings when CMEs and other alterations in the solar wind occur. The SWPC’s current 3-day forecast predicts no storms over the weekend, despite this new enormous sunspot.

If a massive CME were spotted, such 3-day forecasts give us some lead time: there are some measures electric utilities could take to protect their equipment, such as quickly disconnecting transformers. Polar flights, which travel at the highest altitudes, could be rerouted to avoid contact with damaging solar particles, and some satellites could be switched into a safe mode to minimize damage. Here on Earth, at the very least, we’d have some time to prepare for potential power blackouts and other problems.

This Friday afternoon at approximately 2:26 Eastern time, an asteroid roughly half the size of a football field (147 feet) in diameter will pass extremely close to the Earth—just 17,200 miles from our planet’s surface. That said, there’s no need to worry, as NASA scientists confirmed with certainty nearly a year ago that the asteroid will not make an impact and poses absolutely no threat.

Nevertheless, the proximity of the asteroid’s path is noteworthy: it will come within a distance 2 times the Earth’s diameter, passing us by even closer than some geosynchronous satellites that broadcast TV, weather and radio signals. As Phil Plait writes in his comprehensive post on the asteroid over at Slate, “This near miss of an asteroid is simply cool. It’s a big Universe out there, and the Earth is a teeny tiny target.”

The asteroid—likely made of rock and referred to as 2012 DA14 by scientists—was first spotted last February by astronomers at Spain’s Observatorio Astronómico de La Sagra. Asteroids, like planets, orbit the Sun, and this one passed us by on its last orbit as well, but at a much greater distance—it came within roughly 1.6 million miles last February 16. After this year’s near miss, the rock’s orbit will be altered significantly by the influence of Earth’s gravity, and scientists calculate that it won’t come near us again until the year 2046 at the soonest.

On Friday, though, it will pass by Earth between 18:00 and 21:00 UTC (1-4 p.m. Eastern time, or 10 a.m.-1 p.m. Pacific) and come closest at roughly 19:26 UTC (2:26 p.m. Eastern, 11:26 a.m. Pacific). That means that observers in Eastern Europe, Asia and Australia get to see its closest pass at nighttime, whereas those in North America, Western Europe and Africa will have to wait until after sunset, when the asteroid has already begun to move away.

For all observers, the asteroid will be too small to see with the naked eye, though it should be viewable with binoculars or a telescope. Universe Today has the technical details on where exactly to spot the asteroid in the sky. A number of observatories and organizations will also broadcast video streams of the asteroid live, including NASA.

A fly-by like the one on Friday isn’t particularly rare in terms of mere proximity. There are seven closer asteroid passes on record—in 2011, a tiny asteroid set the record for near misses by coming within 3300 miles of Earth, and in 2008, an even smaller one actually made contact with the atmosphere, burning up over Africa.

Both of those rocks, though, were less a meter across.What distinguishes this asteroid is that it’s passing close by and theoretically large enough to cause major damage if an impact were to occur. While an asteroid of this size passes this closely roughly every 40 years on average, a collision with an object this size only happens once every thousand years or so.

What kind of damage would that impact wreak? For a comparison, many are noting the Tunguska event, an explosion over a remote area Russia in 1908 that was likely caused by an asteroid of similar size burning up in the atmosphere. The explosion knocked down more than 80 million trees covering an area of some 830 square miles; scientists estimate it released more than 1,000 times as much energy as the nuclear bomb dropped on Hiroshima and triggered shock waves that would have registered a 5.0 on the Richter scale.

Of course, unlike in 1908, we now have the power to observe approaching asteroids well ahead of time—and might have the ability to prevent potential collisions. Bill Nye is among those who argue that this event should serve as a wake-up call for the importance of investing in asteroid-detecting infrastructure, such as observatories and orbiting telescopes. The B612 Foundation supports this mission, and advocates for the development of technologies that could slightly alter the path or speed of an approaching object to avoid an impact.

This time, at least, we’re lucky. But Ed Lu, a former astronaut and head of B612, says this event should not be taken lightly. ”It’s a warning shot across our bow,” he told NPR. “We are flying around the solar system in a shooting gallery.”

 

Space added several stunning new images to its photo album this week, including the one above of spiral galaxy M106, located 23.5 million light-years away in the constellation Canes Venatici, Notice something?

The image, released yesterday, actually contains two spirals overlain on each other. One is the cloudy, blue-white spiral with a yellow core. The core itself is a composite of images take by the Hubble Space Telescope‘s Advanced Camera for Surveys, Wide Field Camera 3, and Wide Field Planetary Camera 2 detectors. Spiraling outward, the cloudy arms also come from Hubble, but were colorized with ground-based images captured from relatively small telescopes (12.5-inch and 20-inch) as they imaged from dark, remote sites in New Mexico. The telescopes, owned by photo-astronomers Robert Gendler and R. Jay GaBany, helped these astronomy enthusiasts fill in gaps left by Hubble’s cameras. The images were meticulously assembled into a mosaic by Gendler, a physician by training, to form the base spiral of the photo illustration above.

But what about the second spiral? Emanating at odd angles is a glowing red swirl, known as the “anomalous arms” of M106, These arms, captured by Hubble imagery and GaBany’s telescope, are enormous streamers of irradiated hydrogen gas molecules which glow red when seen through special filters. This begs the question–what’s cooking the hydrogen?

The answer is…a black hole! As astronomer Phil Plait blogs in Slate, “Every big galaxy has a supermassive black hole in its core. The Milky Way has one, and it has about 4 million times the mass of the Sun. The black hole at M106’s heart is about 30 million times the mass of our Sun. Besides being heftier it’s also actively feeding, gobbling down material swirling around it (our own galaxy’s black hole is quiescent; that is, not eating anything at the moment).”

While this photo shows stars at the brink of death within M106, another photo released yesterday shows the environment of stars at their birth:

Tinged an eerie green–like smoke from a witch’s brew–the new image from NASA’s Wide-field Infrared Survey Explorer (WISE) was taken after zooming in on bright dot in the “sword” of the constellation Orion. Visible to the naked eye as a single fuzzy star (also known as M42), the dot is actually a cluster of stars, surrounded by the Orion nebula. Here, stars are born.

The image captures the infrared nimbus formed as newborn stars are compressed from vast clouds of gas and heat the wisps that remain. White regions are the hottest part of these stars’ first dust bath, while greens and reds show lukewarm dust. Carving holes through the dust are massive stars–newly formed–such as the one seen at the picture’s center.

The Orion nebula is a site of star formation close to the Earth, giving scientists the opportunity to study its characteristics and hypothesize on how our Sun was born five billion years ago, perhaps from a similar cloud of dust. The white orbs seen here are less than 10 million years old.

The images of the death and birth of stars–both hauntingly beautiful–showcase the evolving nature of space. Mirrored by our own cycles of life and death, the pictures help to link our daily grind with the vastness beyond Earth.