Recently, the search for extrasolar planets (a.k.a. exoplanets) has centered around finding an Earth-like world, a place where life as we know it could exist. After all, wouldn’t it be exciting to discover extraterrestrials—or at least a new place humans could inhabit? Problematically, these small, potentially inhabitable planets are terribly challenging to detect. Twenty years of searching has yielded 941 (and counting) confirmed planets, but none very much like Earth… Although we are well on our way to finding such a “Goldilocks” world (not too hot, not too cold, but juuuust right), other, often larger exoplanets are proving easier to find and uniquely interesting.

A significant percentage of the exoplanets uncovered so far are “hot Jupiters”—colossal gas giant worlds that equal or surpass the mass of Jupiter and orbit very close to their parent stars, creating high surface temperatures as a result. One particularly interesting giant is HD 189733b, a massive world a mere 63 light years away. Though discovered in 2005, its proximity to our solar system makes it a good exoplanet to examine.

Some of the more interesting recent studies of this exoplanet leave behind the question of habitability to examine different planetary characteristics. In 2008, astrophysicists used polarimetry to detect and monitor the planet in visible light and determined an overall color of the world as it would appear to us. A second set of independent tests came back just this last month with the same result. The planet, as we would perceive it, is cobalt blue!

The discovery of another blue marble in the Milky Way is enticing. But this blue color is obviously not due to liquid oceans covering its surface. So where is the color coming from? It could be caused by a slow shower of molten glass. Observations have shown the likely presence of silicate particles in the lower atmosphere. This would scatter light in such a ways as to appear blue in the visible spectrum. Silicate is a component of glass which has lead some researchers to suspect the atmosphere might rain intensely heated bits of molten glass. Certainly not a storm you would want to be caught in!

Looking closer at the planet, all similarities to Earth continue to sizzle away. Orbiting 30 times closer to its star than Earth is to the Sun (which works out to about 13 times closer to its star than Mercury is from the Sun), this planet definitely qualifies as a HOT Jupiter: 1,200°F (650°C) on the night side to 1,700°F (930°C) on the day side with winds as fast as 6,000 miles per hour (nearly a thousand kilometers per hour). This is not a life-friendly place. In fact, Scott Wolk of the Center for Astrophysics estimates the atmosphere of the planet is boiling away at about 660,000 to 100 million tons of mass per second.

HD 189733b is a fantastic example of the surprises that continue to amaze us as we learn more about our universe. Hot Jupiters are not places we study in the hopes of finding life. Rather, we explore these fascinating places so different from our own world to learn about the diversity of planetary systems in our galaxy. They help us uncover more about the evolution of planets and allow us to probe the conditions that came together to form the immense diversity of worlds that we see. They provide clues and contrasts to our own planet, where the processes of life were able to take hold and evolve.

Could Earth have once been a hot Jupiter instead? Quite unlikely. Can HD 189733b ever be the next Earth? Not likely. But these bizarre and far-off worlds are certainly engaging in their own right.

Elise Ricard holds a master’s degree in museum education and is a presenter at Morrison Planetarium.

Images: X-ray: NASA/CXC/SAO/K. Poppenhaeger et al; Illustration: NASA/CXC/M. Weiss

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

On May 3rd, while preforming a semi-weekly checkup, NASA engineers found that the Kepler Space Telescope had entered “safe mode.”

What does this mean? Kepler is programmed to switch into a self-protective state in the event of an error. Powering off any non-essential systems allows Kepler to isolate probable causes for concern. The Kepler team can then interact with the spacecraft safely to turn on the systems that still work.

NASA engineers found that reaction wheel #4 had broken. After launch, Kepler used four of these spinning wheels to fine-tune and stabilize its area of observation. If the telescope is unable to point with a high level of precision, it can’t accurately measure a star’s brightness to determine if an exoplanet exists. Reaction wheel #2 failed last July, and although the spacecraft can point accurately using three reaction wheels, two will not suffice.

Unfortunately for Kepler, the spacecraft will have to wait for further notice. A diverse response team made up of people from NASA Ames, Ball Aerospace, JPL, and Goodrich Corporation are investigating wheel recovery options while Kepler resides in a fuel-efficient mode called Point Rest State.

Regardless of Kepler’s current health, researchers have already collected invaluable data revealing the diversity of planets around us. During its initial 3½-year mission plus the first few months of its extended mission, Kepler recorded light curves that show changes in brightness when a planet crosses between Kepler and the subject star. The spacecraft identified more than 2,700 planet candidates and 132 confirmed planets.

By analyzing light curves, astronomers can deduce a planet’s mass, density, and size, as well as how many planets exist in a star system, whether or not a planet orbits in its star’s habitable zone, and even some of the properties of the stars themselves.

Since Kepler has already gathered a large inventory of exoplanets, astronomers and citizen scientists have enough data to stay busy for some time to come.

The possibility of recovering reaction wheel #4 looks bleak, but don’t worry, with the data Kepler has already collected, the mission has definitely been a success!

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

Image: NASA

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

After avoiding exoplanets in my first post from this meeting, I’ll take a stab at the topic today, but I hope to put some of the announcements in context. And luckily, one of the presentations here provides a perfect launching-off point for thinking about the current state of affairs.

Like many professional organizations, the AAS hands out awards: one example, the Newton Lacy Pierce Prize, honors outstanding achievement in observational astronomy, and award winners deliver a lecture to conference attendees about their work. This year, John A. Johnson of Caltech received the honor, and he presented a lively talk, “Hot on the Trail of Warm Planets around Cool Stars.” (If you attended the Academy’s Benjamin Dean Lecture Series last spring, you might have caught Johnson’s presentation in the Morrison Planetarium.)

In the maelstrom of exoplanet announcements (I’ll mention a few below), the big picture sometimes gets lost. But Johnson avoided getting mired in minutiae by framing his talk with the overarching process of making sense of new discoveries… The first question to ask: do the objects in question actually exist? If so, as we discover more of them, what can we learn from the statistical ensemble, or how do we think of them as a collection of objects? And finally, what are their detailed properties?

For exoplanets, the first question was answered more than twenty years ago with the discovery of a planetary system around a pulsar (not someplace you’d want to call home), followed a few years later by the announcement of a planet orbiting a main-sequence (more ordinary) star. Thus, we confirmed that exoplanets exist.

Over the intervening years, the astronomical community—Johnson included—has moved onto the second and third challenges. The statistical challenges are especially evident at this meeting.

The all-important Kepler Mission has revolutionized the exoplanet-finding business, and indeed, the Kepler team announced 461 new planetary candidates this week, bringing the total to 2,740 (these have yet to be confirmed as planets, although the success rate seems to be greater than 90%). But the mission’s primary goals all center on cataloging extrasolar planetary systems in a fundamentally statistical fashion: look at one part of the sky in great detail and then extrapolate (mathematically, responsibly) those results to the galaxy as a whole.

Astronomers thus use the Kepler data to estimate how many stars have planets with specific characteristics. Johnson’s team, for example, announced this week that our galaxy is home to “at least 100 billion planets,” roughly equivalent to the number of stars in the galaxy. Using similar techniques, astronomer Courtney Dressing announced that, “with 95% confidence, there is a transiting Earth-sized planet in the habitable zone of small star within [roughly 100 light years].” Many other groups are trying to make similar statistical predictions.

And the third stage? Investigating the detailed properties of these objects? Johnson mentioned a few of his favorites: a planet that orbits its parent star in the opposite direction that the star itself rotates, a tiny planetary system that resembles Jupiter and its moons, and of course, the system that led to his aforementioned recent announcement. And many reports from this week’s meeting also fall into this category…

Paul Kalas and James Graham, both at U.C. Berkeley announced that the hotly-debated Fomalhaut planet (pictured above) appears to follow a highly elliptical orbit around its parent star, getting as “close” 4.6 billion miles (that’s about 40 times farther than Earth ever gets from the Sun) and as far as 27 billion miles away!

Another team of astronomers has detected evidence for an asteroid belt around the star Vega. This makes Vega much like Fomalhaut, and a nifty image compares the two systems.

Much talk centers on finding planets around stars like the Sun—mostly in hopes of finding Earth-like planets where life could exist. But we know of planets around other, weirder stars (cf. my mention of pulsar planets above), and these can shed light on how our own solar system has evolved. In particular, we’re seeing evidence that many white dwarfs have been “polluted” by debris from planets that orbited them previously: our own Sun will end its life as a white dwarf, and the net result of this discovery is that Earth-like planets could be quite common.

And finally, a combined effort by two space-based observatories has given us a glimpse at the weather on a brown dwarf, and similar techniques could eventually tease out weather on exoplanets as well.

Stay tuned for more astronomy the rest of the week…

Image: NASA, ESA, and P. Kalas (University of California, Berkeley and SETI Institute)

I’m not going to get into exoplanet announcements such as this one or this one from yesterday morning’s meeting (as one attendee tweeted in summary, “There’s more exoplanets than you can shake an exostick at.”). We have ten press conferences scheduled, and three of them revolve around (pun intended) exoplanet discoveries. So I’ll plan for an exoplanet wrap-up toward the end of the conference.

Instead, I’d like to talk about the work of a few of those spiffy space-based telescopes—yes, the ever-popular Hubble Space Telescope, but also Chandra X-Ray Observatory and a new mission known as NuSTAR.

A grand effort known as the Hubble Ultra Deep Field (HUDF) has imaged the same, small, seemingly-dull part of the sky repeatedly at numerous, finely-tuned wavelengths of light, revealing distant galaxies that reside farther than just about anything we can see. Looking out into space means looking back into time, so the HUDF reveals an important epoch in the history of the Universe.

It turns out the Universe in its youth went through an unusual phase when most of the hydrogen in deep space was in the form of molecules, with no net electrical charge… By the time the Universe reached the age of about 800 million years, however, most of the hydrogen had become ionized, which is to say broken down into electrons and protons (both of which have electrical charge). But it takes energy to ionize hydrogen, so where did that energy come from?

This is the kind of puzzle that keeps astronomers busy (and employed) for decades. Since 2004, astronomers have refined and extended the HUDF observations to eke out more information about this epoch, and the most recent observations have allowed scientists to reach some well-founded, long-sought conclusions.

We know that young galaxies would emit radiation that could ionize the Universe, but can they produce enough radiation to light up the “Cosmic Dawn,” as it’s sometimes called? Astronomers love to come up with more exotic theories, such as the annihilation of dark matter, to explain things like this, but are such puzzling processes required?

Turns out they aren’t. Galaxies can do the job on their own. That’s not the sexiest answer, but it should ultimately feel quite satisfying: the Universe behaves in a way that we understand and can predict. But it took a remarkable amount of sleuthing to come up with this relatively mundane response.

First off, we tally up the galaxies we see, and we estimate how much radiation they would emit. And the first surprise? Small, faint (the researchers like to call ’em “feeble”) galaxies make a significant contribution to the total energy output, and the large, luminous can’t do the job on their own.

Turns out that the currently-observed population of galaxies does not produce enough radiation to ionize all that intergalactic hydrogen. Bummer. But we know that we’re not seeing all the galaxies! We can detect only the brightest ones at these great distances, and the HUDF team’s work suggests that an earlier generation of galaxies existed before the ones we’re seeing. So how can we estimate the energy contribution from what we’re not seeing directly?

The team of astronomers undertook the challenge of tallying the luminous galaxies versus the number of feeble galaxies, and projecting those estimates back in time. Based on HUDF and other observations from, for example, the Wilkinson Microwave Anisotropy Probe (WMAP), we can determine when stars and galaxies started lighting up the Universe, so when the team added up all the light from all the galaxies they estimated to have existed over that time… Bingo! Just enough light energy to ionize the Universe’s hydrogen.

All this work actually pushed Hubble to its limits. And it promises many more discoveries from the James Webb Space Telescope, due to launch in 2018, which will peer back farther in time to see earlier generations of galaxies.

Hubble isn’t alone out there, and x-ray astronomy in particular benefits from having telescopes in space. Stephen S. Murray from Johns Hopkins gave a review of “50 Years of X-Ray Astronomy,” describing remarkable successes in the field. From 1962 to 1999, x-ray astronomy has experienced an increase in sensitivity of 10 billion! (And Murray noted that it took astronomers 400 years to achieve that kind of gain in optical sensitivity…) That kind of revolutionary change has led to spectacular discoveries related to some of the most exotic objects in astronomy—including black holes, pulsars, and supernovae.

An impressive video from Chandra shows a curlicue jet streaming from the pulsar at the center of the Vela Supernova Remnant. This complex structure provides a nifty puzzle for astronomers to describe its origin.

And the recently-launched Nuclear Spectroscopic Telescope Array (NuSTAR), one of the least expensive missions ever launched by NASA, has released its first images. The pair of telescopes spotted two bright, energetic sources of x-rays in the galaxy IC 342—capturing black holes in the process of “feeding” (as NuSTAR team leader Fiona Harrison puts it).

Stay tuned for more spacy stuff the rest of the week…

NuSTAR image courtesy of CalTech

The third Thursday of every month, give or take, Morrison Planetarium hosts “Universe Update” at the 6:30 planetarium shows during NightLife. We select our favorite astronomy stories from the past month, and give a brief run-down of current discoveries while taking audiences on a guided tour of the Universe.

We always start at Earth and work our way out to cosmological distances, and we’ll list the news stories in the same order—from closest to farthest from home.

Let’s start at Mars. Curiosity, the latest addition to our growing team of Martian rovers, landed on the Red Planet just a few months ago.  Previous landers sent back pictures and performed basic measurements, but Curiosity brought an entire geology and chemistry lab on a 225-million-kilometer expedition to Gale Crater, where the rover is using its instruments to search for evidence of Mars’s past.

In its “rocknest,” Curiosity found wind-swept dunes containing material similar to volcanic soil in Hawaii.  After vaporizing samples with its onboard laser, Curiosity’s CheMin instrument then used X-ray diffraction to search for clues to understanding the history of Mars’s atmosphere.  Evidence suggests that Mars once had a much thicker atmosphere, which disappeared a long time ago, leaving the thin layer we observe today.  As previous landers found layers of frozen water beneath Mars’s surface, Curiosity is taking the next step, equipped to hunt for methane, an organic molecule that’s a good indicator of life.  So far, Gale Crater seems devoid of this malodorous precursor, but Curiosity has two years and many kilometers of Martian soil to cover.

Our next stop is the giant asteroid Vesta: over 500 kilometers in diameter (the distance from San Francisco to Los Angeles), it’s the second-largest asteroid in our solar system.  The Dawn mission photographed it for over a year, looking at Vesta as a good example of what Earth may have looked like when it was just a wee baby protoplanet.  The big differences between light and dark in these photos puzzled scientists, since asteroid terrain isn’t usually so varied.  Space weathering should homogenize the surface, leaving a matte gray all over the surface.  But scientists now think that the dark material comes not from Vesta but from 300 smaller asteroid impacts over the last 3.5 billion years, each of which brought material such as the metallic dust, carbon, and hydrated minerals (minerals containing water) Dawn detected.  This mélange can account for the difference in light and dark areas, wrapping Vesta in powdered asteroid debris, one-to-two meters thick.

With a constant influx of data, astronomers are discovering new exoplanets faster than ever.  Re-examining old data can produce useful results, too, and astronomers have just announced that a planet somewhere between Earth- and Neptune-sized is orbiting HD 40307.  Despite only being three quarters as massive as our Sun, this star hosts six planets in total.  Most importantly, the new planet is orbiting right in that habitable sweet spot: not too cold and not too hot, this is a strong contender to have liquid water, that necessary ingredient for life on Earth (and very possibly elsewhere).

Our view of the stars from Earth is strictly two-dimensional, and even with visualizations like the planetarium’s Digital Universe, we still rely on our Earth-bound view to determine distances to objects in space.  A new image (see above) from a 340-megapixel camera on a telescope in Hawaii has found a heretofore unidentified cluster of stars in the familiar Orion constellation.  The most studied part of our night sky, the Orion Nebula turns out to have many layers, and the stars we see in the middle are in fact older stars closer to us than we previously suspected.

Two twelve-billion-year-old supernovae live far, far from our starting point on Earth: because looking out into space also means looking back in time, the Universe has changed a lot since these stars exploded, so it’s hard to give you a distance in kilometers or even lightyears, but one of them holds the record as the most distant supernova yet observed.  Needless to say, these are very, very old explosions that came from even older, supermassive stars, the likes of which don’t exist in the nearby, more recent Universe.

As the Universe continues to accelerate outward, the light we can see here on Earth fades into the cosmos.  In a few billion years, information from these distant galaxies simply won’t make it to Earth anymore, and we’ll be living in a rather empty neighborhood.  The parallels with the economic downturn are a little alarming, and a press release from a group of European cosmologists hammers it home.  It turns out that stars in the Universe are only forming at 1/30 the rate they once were: a cosmic market crash that looks to continue till the end of time.  The Universe seemed to peak about 11 billion years ago… Let’s hope the same isn’t true for the American GDP!

Dan Brady is a planetarium presenter at the California Academy of Sciences. He earned his BS in Physics from UCLA and has taught science since 2008.

Image: CFHT/Coelum (J.-C. Cuillandre & G. Anselmi)

Two researchers hypothesize that an asteroid belt, just the right size and distance from its star, might be necessary for a star system to support a life-bearing planet.

This might sound surprising, since asteroids can occasionally impact Earth and trigger mass extinctions. Ouch! But an emerging view proposes that asteroid collisions with planets may provide a boost to the birth and evolution of complex life.

For one thing, asteroids delivered water and organic compounds to the early Earth. Consistent with the theory of punctuated equilibrium, occasional asteroid impacts might also accelerate the rate of biological evolution by disrupting a planet’s environment to the point that species must evolve new adaptation strategies.

Rebecca Martin, of the University of Colorado, and Mario Livio, of the Space Telescope Science Institute, looked at our solar system and used theoretical models and actual observations of other star systems and exoplanets to study the theory that life needs an asteroid belt.

They suggest that the location of an asteroid belt relative to a Jupiter-like planet is particularly favorable to life. The asteroid belt in our solar system, located between Mars and Jupiter, is a region of millions of space rocks sitting near the “snow line,” beyond which volatile materials such as water ice are far enough from the Sun’s heat to remain intact.

Our solar system’s formation was just right for life, Livio says. “To have such ideal conditions you need a giant planet like Jupiter that is just outside the asteroid belt [and] that migrated a little bit, but not through the belt,” he explains. “If a large planet like Jupiter migrates through the belt, it would scatter the material. If, on the other hand, a large planet did not migrate at all, that, too, is not good because the asteroid belt would be too massive. There would be so much bombardment from asteroids that life may never evolve.”

Using our solar system as a model, Martin and Livio proposed that asteroid belts in other solar systems would always be located approximately at the snow line. They created models of protoplanetary disks, the dense gas and dust around a newly formed star; then they looked at observations from NASA’s Spitzer Space Telescope of 90 such regions that have warm dust, which could indicate the presence of an asteroid belt-like structure. The warm dust fell right near the snow line.

But for life to exist, the system also needs a large gas giant, like Jupiter, to “manage” the size of the asteroid belt. So Martin and Livio looked at data for 520 giant planets found outside our solar system. Only 19 of them reside outside the snow line, suggesting that most of the giant planets that formed outside the snow line have migrated too far inward to preserve the right-sized asteroid belt needed to foster life on an Earth-like planet near the belt. The team calculated that less than four percent of the observed systems may actually harbor such a compact asteroid belt.

“Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet,” says Martin. “Our study suggests that our solar system may be rather special.”

Their findings are published in the Monthly Notices of the Royal Astronomical Society: Letters.

Image: NASA, ESA, and A. Feild (STScI)

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

It was a weekend full of aliens and black hole theories at the Hyatt Regency in Santa Clara, California. Scientists, professors, artists, authors, and science enthusiasts gathered for SETIcon II, a conference organized by the SETI Institute to learn about and celebrate recent developments in the search for extraterrestrial intelligence.

The conference consisted of a series of panels discussing everything from potential asteroid resources to Hollywood Sci-Fi movies.

Each discussion had a diverse set of panelists that complimented each other—each speaker with a different background, adding different perspectives to each panel. For example, in a panel titled “Black Holes in Space—Hearts of Darkness”, Robert J. Sawyer, Andre Bormanis, Alex Filippenko, and Leonard Mlodinow discussed theories about black holes while also calling upon movies and books to identify and clarify any misconceptions.

Alex Filippenko, Seth Shostak, Richard Rhodes, and Marc Okrand even discussed religion (with much sensitivity… especially because SETI has been accused of being a religion) during the “Did the Big Bang Require a Divine Spark?” panel.

The panelists Cynthia B. Phillips, Mark R. Showalter, and Charles Lindsay informed the audience about planetary art in “The Magnificence and Majesty of the Outer Solar System” while a slideshow of the artfully embellished planets played in the background.

In addition to the regular excitement about science, the conference was heavily fueled by Kepler’s recent success. The Kepler telescope is currently looking for planets in the habitable zone, because these planets are likely to be more earth-like and therefore more likely to be suitable for life.

The telescope has already found over 2,000 transiting planets, an abundance that led NASA to approve the extension of the Kepler mission until 2016. The panelists could not hide their enthusiasm: such success in the search for extraterrestrial intelligence is worthy of celebration.

The conference also included an evening honoring Jill Tarter, director of the search for intelligent life and inspiration for Jodie Foster’s role in the movie, “Contact”.

Whether a Battlestar Galactica enthusiast or a NASA researcher, it was truly a conference for everyone.

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