This Sunday and Monday, Earth will be passing through the path of Comet Swift-Tuttle. This periodic comet approaches the Sun every 133 years and isn’t expected to come around again for more than a century, but Earth will encounter particles of dust lingering in the comet’s path.

When the comet’s frozen nucleus approaches the Sun, it heats up, and its outer layers of ice evaporate. This process releases dirt and dust embedded in the ice, and when this cosmic debris collides with Earth’s atmosphere at high speeds (up to 45 miles per second), it burns up, This causes the streak of light in the night sky that people sometimes refer to as a “shooting star.”

Shooting stars are properly called meteors, and meteor showers are named after the constellation from which the meteors seem to radiate.  From an Earthly point of view, the current display appears to emanate from the constellation Perseus the Hero, so we call these meteors the Perseids.

Although the meteors are actually falling in parallel paths, their trajectories, if traced backward, appear to converge in the distance—in this case pointing backward to the stars of Perseus.  This does not mean to look only toward that constellation, since the meteors can appear anywhere in the sky, so use your unaided eye to see the widest possible field of view. No telescope required!

The perfect time for this warm summer activity is the night of Sunday, August 11^th, to the morning of Monday the 12th, and the night of Monday the 12th to the morning of Tuesday the 13th. Ideally, head out after midnight, because then you will be facing the direction Earth is moving, directly into the trail of comet dust. And this year, the sky will also be darker because the moon will have set. Finally, if possible, get away from light pollution.

Andrew Fraknoi, Academy Fellow and astronomy professor at Foothill College in Los Altos, California, offers professional viewing advice: “It’s more important to decide WHERE to watch them, than WHEN to watch them. The crucial issue is that meteors are faint, so you need a location where the sky is DARK. That means getting away from city and car lights as much as possible. The darker your site, the more you will see.”

If you’re an amateur astronomer, this shower will be one of the most rewarding of the year. While casual observers might see 4–6 meteors per hour on any given night, the Perseids can produce approximately 60–80 meteors per hour at their peak and generate the most fireballs (bright meteors) of any shower! To keep count of the meteors you see, and to be a part of NASA meteor research, download an app called Meteor Counter.

Fraknoi offers even more incentive. “Since comets are ‘left-overs’ from the early days of our solar system, you can tell yourself that each flash you see is the ‘last gasp’ of cosmic material that formed about five billion years ago.”

Earth is estimated to accumulate between 37,000–78,000 tons of this cosmic material, so head out with warm clothes, a blanket, or sleeping bag to check out nature’s fireworks in the sky.

For more info, check out these top 10 facts on the Perseids, read more about their history, peruse this blog post from our friends at Zerve, or watch Tom Hanks being hit by a meteor while talking about the Perseids on the Tonight Show a few years ago (about 10:53 in, with Turkish subtitles).

Image: Andreas Möller/Wikipedia

Space gold is even rarer than Earth gold, which makes the precious metal special—on our planet and in the Universe at large.

A team of astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) observed a special gamma-ray burst last month; these powerful phenomena appear to originate in cataclysmic events… and in this case it was likely the collision of two neutron stars.

Neutron stars are the dense remains of imploded stars: they are up to three times the mass of the Sun, condensed into the area of San Francisco.

Deep in their cores, regular stars create elements that are eventually spewed into space when the stars explode. Chris Impey, professor of astronomy at the University of Arizona, explains, “We know that stars make heavy elements, and late in their lives, they eject gas into the medium between stars so it can be part of subsequent stars and planets (and people).” Carbon, oxygen, nitrogen, and a host of other elements—even nickel and iron—all originate within different types of stars.

But it takes a collision between two neutron stars to create rare elements such as gold. The lead author of a recent paper, Edo Berger, describes the phenomenon by paraphrasing one of Carl Sagan’s famous quotes, “We are all star stuff, and our jewelry is colliding-star stuff.” And it makes sense—gold requires 79 protons, 79 electrons and 118 neutrons, a concoction only a dense neutron star would have the atomic supplies to produce.

When two particular neutron stars collided about 3.9 billion light years away from Earth, astronomers named the resulting gamma-ray burst GRB 130603B. Although the burst lasted only two-tenths of a second, a slowly fading infrared glow told the Harvard research team that the burst was particularly valuable.

“We estimate that the amount of gold produced and ejected during the merger of the two neutron stars may be as large as 10 moon masses—quite a lot of bling!” says Berger.

At today’s prices, the explosion would produce the equivalent of  $10,000,000,000,000,000,000,000,000,000 (10 octillion dollars). But don’t get too excited: these types of explosions happen in our galaxy only once every 10,000 years, and you might find it difficult to go and collect the loot.

This is big money, but there are additional implications of the neutron star collision.

“We’ve been looking for a ‘smoking gun’ to link a short gamma-ray burst with a neutron star collision. The radioactive glow from GRB 130603B may be that smoking gun,” explains Wen-fai Fong, a graduate student and a co-author of the paper.

Now that we have better evidence linking gamma-ray bursts and neutron star collisions, perhaps we can gain insight into the mystery radio bursts found outside our galaxy!

Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and interns for the Morrison Planetarium.

Credit: NASA/Dana Berry

Seashells, tornados and spiral galaxies all feature similar spiral shapes. Patterns repeat themselves in nature over and over again.

Gravity produces more abstract patterns: in much the same way that moving boats produce waves on water, moving stars can create gravitational waves in the fabric of space-time. Both types of waves lose energy as they move farther away from their source. Unfortunately, gravitational waves are very hard to measure by the time they reach Earth, and to this point, astronomers have not managed to detect gravitational waves from anywhere in the Universe.

But that doesn’t mean astronomers have given up. The quest to detect these waves has inspired scientists to figure out all kinds of ways gravitational waves might be created…

Discovered three short years ago, “monster” stars have masses between 200 and 300 times that of our sun—vastly larger than any other stars. Astronomers hoped that collisions between their supermassive remnants would produce measurable gravitational waves. At the 10th Edoardo Amaldi Conference on Gravitational Waves, Dr. Krzysztof Belczyński of the Astronomical Observatory of the Faculty of Physics at the University of Warsaw revealed his most recent findings.

Stars frequently form binary systems (two orbit around each other). Components of such systems collide once one object’s atmosphere takes over the other in a “common-envelope event.” The end result produces gamma-ray bursts accompanied by gravitational waves.

It would seem that a monster binary system would produce monster gravitational waves that even our current detectors could measure. Unfortunately, it seems that these monster stars will never get close enough to collide in the first place.

“In a supermassive binary star system, the situation is different,” says Dr. Belczyński. “We know that the components of such a system must be formed at a relatively large distance from each other. We also know that supermassive stars do not expand, so there cannot be a common envelope phase. This means that there is no physical mechanism that would effectively cause the orbit to tighten!”

“We stand practically no chance of detecting the gravitational waves from such a collision in the heavens. Unless…” Dr. Daniel Holz of the University of Chicago trails off in mid-sentence. We might detect such a collision if our current model of binary systems is wrong, which would demand a revision in our understanding of how the Universe works.

Thus the search continues for possible sources of gravitational waves—particularly of sufficient strength for us to detect. And preferably without the need to turn physics on its head.

Image: NASA

To date, we have discovered 865 confirmed exoplanets orbiting distant stars. But a great mystery remains: how do these planets form?

Theories on planet formation seem to fall apart when astronomers run simulations based on the laws of physics. Computer models show that clumps of dust orbiting around a star would either become large enough to smash into other clumps then break apart, or drift too close to their parent star then break apart. Either way, the clumps of matter do not survive long enough to form anything as large as a planet. When theories fail, observations often come in handy, to help scientists refine their theories with better data.

Enter the Atacama Large Millmeter/Submillimeter Array (ALMA), which only recently started making observations but has already sharpened our view of distant astronomical objects.

When it imaged a region around a particular young star in the constellation of Ophiuchus, ALMA observed a cashew-shaped dust cloud rather than the expected dust ring. This unusual structure could possibly trap large dust grains, keeping them safe during the beginning stages of their development. Scientists have affectionately described the formation as a “dust trap.”

Nienke van der Marel, a PhD student at Leiden Observatory in the Netherlands, explains, “It’s likely that we are looking at a kind of comet factory as the conditions are right for the particles to grow from millimeter to comet size. The dust is not likely to form full-sized planets at this distance from the star. But in the near future ALMA will be able to observe dust traps closer to their parent stars, where the same mechanisms are at work. Such dust traps really would be the cradles for new-born planets.”

The researchers think that larger dust particles could grow in the dust trap long enough to form a planet’s core. While growing within the dust trap, the planetary seed would be protected from factors that could inhibit its growth.

“Trapping the large dust particles prevents the radial inward drift and therefore allows the particles to grow to much larger sizes, up to rocks as wide as a kilometer or more,” Van der Marel adds. “The existence of dust traps in disks around young stars provides a crucial step in the start of planet formation by dust coagulation.”

This observation provides a crucial step in understanding how planets are formed, although it raises new questions about how dust traps are created in the first place. And so it goes: scientific mysteries often lead to more questions, followed by new theories and new observations.

Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and interns for the Morrison Planetarium.

Image: NASA

Like humans, stars have life cycles. And new data emerging about stellar life cycles allow us to create new diagrams of the stars’ anatomy.

Stars come in all different sizes, and a star’s mass determines its fate: an extremely massive star produces a supernova when it “dies.” But that’s not quite the end of the story… Sometimes the core of a massive star will collapse in on itself, forming a neutron star.

These extremely dense, hot, and pressurized stellar remnants are tiny—about the diameter of San Francisco—but up to three times the mass of our Sun!

It gets crazier. Stars like these spin at hyper speeds—full rotations occurring many times per second! Astronomers can measure the number of rotations by counting the radio pulses that some neutron stars emit with each spin. It turns out that the rate of rotation slows with age as the spinning stars lose momentum.

The gradual slowing of rotational velocity over time is occasionally accented with moments of abrupt velocity increase, known as glitches. Astronomers thought they knew what caused these glitches, until they measured a new type of glitch, as reported recently in Nature.

“I looked at the data and was shocked—the neutron star had suddenly slowed down,” says co-author Rob Archibald, a graduate student at McGill University.

Archibald and his colleagues discovered that spin velocities of unique stars are accented with moments of abrupt velocity decrease, or, an “anti-glitch.”

Anti-glitches were found in a type of neutron star called a magnetar, cleverly named after the unusually intense magnetic field within the star that results in bursts of X-ray radiation.

“We’ve seen huge X-ray explosions from magnetars before, but an anti-glitch was quite a surprise,” says lead author Victoria Kaspi, leader of the Swift magnetar monitoring program. “This is telling us something brand new about the insides of these amazing objects.”

Anti-glitches were not predicted in original neutron star models, so astrophysicists may need to reevaluate all of glitch theory. New models for neutron star anatomy (that accommodate the physics behind anti-glitches) could be on the way!

Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and interns for the Morrison Planetarium.

Image: NASA’s Goddard Space Flight Center

When is exoplanet news “juicy”? Yesterday at a Kepler press conference held at NASA Ames, Roger Hunter, Kepler project manager, introduced the proceedings as juicy. And as three scientists presented the findings, it turned out to be a good adjective. The researchers believe they have discovered the first water worlds (besides Earth) in our galaxy.

Two systems are providing new evidence of rocky Earth-like planets in the habitable zone—the range of distance from a star where the surface temperature of an orbiting planet might be suitable for liquid water. Kepler 62 has five planets total, but two of those, 62e and 62f, orbit inside the habitable zone. Kepler 69 has two planets but only one in the habitable zone, 69c.

For exoplanets and their stars, size matters when it comes to habitability. At 1,200 light years away, the star Kepler 62 is two-thirds the size of our Sun. That brings the habitable zone in a bit closer to the star. The two planets of interest, 62e and 62f, are 1.6 and 1.4 times the diameter of Earth, respectively. This also puts them in the “just-right” size for habitability.

At the press conference, William Borucki, Kepler science principal investigator at NASA Ames, said that 62e and 62f “are the best candidates to be habitable, not just within the habitable zone.”

Computer models suggest that the largest rocky planets will have a diameter no greater than 1.5 times that of Earth’s, explained Lisa Kaltenegger of the Max Planck Institute for Astronomy and Harvard-Smithsonian Center for Astrophysics. And a planet’s mass, between 1.2-2.5 times Earth’s mass, can be an indicator for liquid water. While Kepler 62e and 62f are too small to measure their mass, Kaltenegger and her team’s modeling makes these planets very wet, indeed.

Kepler 69c, on the other hand, is 2,700 light years away and 1.5 times Earth’s diameter. It orbits near the inner, hotter edge of its star’s habitable zone. Thomas Barclay, Kepler scientist from the Bay Area Environmental Research Institute, likens it to a super Venus, rather than a super Earth. “We don’t have anything like it in our solar system,” he said.

“The Kepler spacecraft has certainly turned out to be a rock star of science,” said John Grunsfeld, at NASA Headquarters in Washington. “The discovery of these rocky planets in the habitable zone brings us a bit closer to finding a place like home. It is only a matter of time before we know if the galaxy is home to a multitude of planets like Earth, or if we are a rarity.”

The findings are published this week in Science (Kepler 62) and the Astrophysical Journal (Kepler 69).

For an interactive on Kepler’s planetary discoveries and their orbits, click here.

Image: NASA Ames/JPL-Caltech

Hard to believe—they’re insects, not astronomers, for goodness sakes! As Discover mentions, the dung-dining coleopteran are in good company, navigation-wise:

Christopher Columbus traveled by following the stars, as did Harriet Tubman.

Some of the same Swedish researchers who tested dung beetles’ sense of direction and published last year, have now found that these brilliant beetles dabble in celestial navigation of a sort.

Publishing last week in Current Biology, the researchers tested one species of dung beetle, Scarabaeus satyrus, in a planetarium in Johannesberg. They found that the beetles used the entire Milky Way to guide their dung in a straight line to their destination. As Ed Yong notes in National Geographic:

If they left out this galactic stripe, or only added the 18 brightest stars, the beetles took much longer to find their way out.

The researchers were thorough, too. In their experiments, they gave the beetles caps to block the light from reaching their eyes. Once again, the beetles wandered from the most direct route.

The scientists believe that although the beetles’ eyes are too weak to distinguish individual constellations, they use the gradient of light to dark provided by the Milky Way to ensure they keep rolling their balls in a straight line and don’t circle back to competitors at the dung pile. The New Yorker offers a particularly charming description of the experiment.

Not sure, even with a ball of poop, I could navigate as well as dung beetles—day or night!

Image: Maria Dacke

As Einstein might say, speed is relative. It certainly captures our imagination. For example, you may think you’re sitting still, but by some reckoning, you are moving incredibly fast—as Earth spins and orbits within the Solar System and as the Sun makes its way around the Milky Way. In fact, for us to make a full rotation around the galactic center every 250 million years, we have to be moving at the brisk pace of half a million miles an hour!

But as fast as we are moving, it’s a leisurely stroll compared to some stars that have made recent headlines. These so called “hypervelocity stars” are allowing scientists a first hand view of the incredible and mysterious super-massive black hole at the center of our Milky Way galaxy. Since we cannot observe the black hole directly, we study the motion of nearby matter—stars, gas, and dust—to learn much about the black hole’s mass and how it distorts space around it. These observations grant astrophysicists an opportunity to test the inner workings of Einstein’s theory of relativity on a grand scale.

Another group of super-fast superstars out there seems to be related. They are not gravitationally bound to the black hole, or anything else in the galaxy. In fact, they have been flung out from the Milky Way at speeds so great that they will actually escape it entirely! Some scientists have speculated that these “runaway” or “rogue” stars may have once been the companions of the very same hypervelocity stars that orbit within the Milky Way, but these rogue stars were flung off long ago when their partners were pulled into the supermassive black hole’s gravitational influence.

Another possible origin for the stellar speedsters could be a companion or nearby star that went supernova and blasted them out into the great beyond. Astronomers search for these stars before they exit the galaxy by looking for the tell-tale bow shock they create as they pass through the thin gas of the Milky Way, much like the wake a speedboat creates on a calm lake.

No matter their origins, hypervelocity stars and any other super speedy things provide critical windows into relativity and the nature of space and time. Special relativity predicts the ways in which physics will change as something approaches the speed of light; general relativity describes the behavior of objects in intense gravitational fields (like you might find near a black hole, hmm…). These stars and others like them give us a great chance to challenge our ideas about the nature and workings of our universe and get a view “beneath the hood” to understand how it has changed and evolved over time.

Josh Roberts is a program presenter and astronomer at the California Academy of Sciences. He also contributes content to Morrison Planetarium productions.

Image: Ethan Tweedie

Phil Plait seemed to appreciate the news just as much. His Discover headline read in all-caps, “ALPHA CENTAURI HAS A PLANET!”

Let’s analyze all of this excitement…

Yesterday, astronomers announced they discovered an Earth-sized planet orbiting Alpha Centauri. The finding is also published in Nature today.

Alpha Centauri lies only 4.3 light-years away—closer than any other star system. And it’s not one star but three—two binary stars similar to the Sun orbiting close to each other, called Alpha Centauri A and B, plus a more distant and faint red companion known as Proxima Centauri. Since the nineteenth century, astronomers have speculated about planets orbiting these bodies, the closest possible abodes for life beyond the Solar System, but searches of increasing precision had revealed nothing. Until now.

“Our observations extended over more than four years using the HARPS instrument and have revealed a tiny, but real, signal from a planet orbiting Alpha Centauri B every 3.2 days,” says Xavier Dumusque, lead author of the paper. “It’s an extraordinary discovery and it has pushed our technique to the limit!”

A period of 3.2 days means that this new planet orbits extremely close to its parent star, “roasting at perhaps 2,200 degrees Fahrenheit with a surface likely composed of molten lava,” writes Adam Mann in Wired. Not exactly a hospitable neighbor! (Sorry, Mr. Rogers.)

This news comes right on the heels of another exoplanet discovery. On Monday, our friends at Zooniverse announced the first ever confirmed exoplanet discovered by the citizen scientists at Planet Hunters—a gas giant dubbed “PH1” with a radius about 6.2 times that of Earth, making it a bit bigger than Neptune. PH1 resides in a four-star system—twin suns that in turn are orbited by a second distant pair of stars.

These discoveries provide further evidence that, with the number of eyeballs looking for exoplanets (professional astronomers and citizen scientists alike), an Earth-like exoplanet can’t be far off. Again from the Bad Astronomer:

…we’re zeroing in on Terra Nova, folks, and statistically speaking there should be millions of them in the galaxy. It’s only a matter of time before we find the first one.

Image: ESO/L. Calçada

Reporting from day two of the American Astronomical Society meeting in Austin, Texas…

Much like people, stars live and die. But the processes of stellar birth and death present many mysteries for astronomers to resolve. Stars tend to form in clusters, in dense regions rich in gas and dust.

Joseph Hora, of the Harvard-Smithsonian Center for Astrophysics, described a detailed look at the star-forming region Cygnus X—and the Spitzer Science Center released a gorgeous, high-resolution image of the region to coincide with the announcement. (Today’s photo shows Robert Hurt, Visualization Scientist with Spitzer, describing details of the image displayed on a high-resolution power wall at the NASA science display.)

An infrared survey of about 25 square degrees (equivalent to the area of more than a hundred full moons) revealed nearly 26,000 possible “young stellar objects” (or YSOs), stars captured early in their evolution, still enshrouded by dense dust. The bright, young stars heat up all that dust, so astronomers look for excess emission in infrared light, and the high-resolution image allowed astronomers to find lots of (relatively) tiny objects and put them in context with the larger region. You can read more about the image and the discoveries in the official Spitzer press release.

Xavier Koenig, from NASA Goddard, presented infrared imagery from the Wide-field Infrared Survey Explorer (WISE) and described his work in studying how star formation is triggered inside one of these regions. Extremely massive stars tend to form first, near the center of a collapsing gas cloud, but what happens next can prove difficult to disentangle: stars don’t arrive on the scene with birth certificates, after all, so astronomers need to determine which ones formed when.

Koenig’s data suggest that the massive stars set of a chain reaction of star formation, with smaller stars forming outward from the center of a gas cloud. Or as the WISE team describes it:

The results suggest that stars are born in a successive fashion, one after the other, starting from a core cluster of massive stars and moving steadily outward.

Massive stars can also wreak havoc on their surroundings. Erick Young, science mission operations director for NASA’s Stratospheric Observatory For Infrared Astronomy (SOFIA),described observations of the W3 star-forming complex that reveal the effects of the stellar winds and radiation from the largest stars in the region. Eventually, all this activity will tear apart the very gas cloud that gave birth to the stars.

NASA describes the image in some detail:

The SOFIA observations reveal the presence of some 15 massive stars in various stages of their birth process. Toward the left of the inset image, a small bubble (arrow) has been cleared out of the gas and dust by the most massive star in this cluster. This bubble is surrounded by a dense shell (green) of material in which some of the dust and all of the large molecules have been destroyed. That shell is surrounded by mostly untouched cloud material, traced by the red emission from cooler dust. Astronomers have evidence that the expansion of such bubbles around massive newly born stars acts to compress nearby material and trigger the condensation of more stars.

SOFIA, by the way, has its home in California: headquartered at NASA Ames, the flying observatory takes off from the Dryden Aircraft Operations Facility in Palmdale. A 747SP equipped with a 2.7–meter telescope (and a big hole in the side of the aircraft), SOFIA flies high enough to make observations at wavelengths of light that don’t make it to Earth’s surface. And on February 6th, Erick Young will speak at the Morrison Planetarium as part of our Benjamin Dean Lecture Series, so attendees can learn more about the observatory—and star formation, I’m guessing—from Erick in person.

Ryan Wyatt is the director of the Morrison Planetarium and Science Visualization at the California Academy of Sciences.