Screaming Exoplanets: Detecting Alien Magnetospheres

Exoplanets may reveal their location through radio emissions (NASA)
Exoplanets may reveal their location through radio emissions (NASA)

In 2009, I wrote about a fascinating idea: in the hunt for “Earth-like” exoplanets, perhaps we could detect the radio emissions from a distant world possessing a magnetosphere. This basically builds on the premise that planets in the solar system, including Earth, generate electromagnetic waves as space plasma interacts with their magnetospheres. In short, with the right equipment, could we “hear” the aurorae on extra-solar planets?

In the research I reviewed, the US Naval Research Laboratory scientist concluded that he believed it was possible, but the radio telescopes we have in operation aren’t sensitive enough to detect the crackle of distant aurorae. According to a new study presented at the RAS National Astronomy Meeting in Llandudno, Wales, on Monday, this feat may soon become a reality, not for “Earth-like” worlds but for “Jupiter-like” worlds.

“This is the first study to predict the radio emissions by exoplanetary systems similar to those we find at Jupiter or Saturn,” said Jonathan Nichols of the University of Leicester. “At both planets, we see radio waves associated with auroras generated by interactions with ionised gas escaping from the volcanic moons, Io and Enceladus. Our study shows that we could detect emissions from radio auroras from Jupiter-like systems orbiting at distances as far out as Pluto.”

Rather than looking for the magnetospheres of Earth-like worlds — thereby finding exoplanets that have a protective magnetosphere that could nurture alien life — Nichols is focusing on larger, Jupiter-like worlds that orbit their host stars from a distance. This is basically another tool in the exoplanet-hunters’ toolbox.

Over 500 exoplanets have been confirmed to exist around other stars, and another 1,200 plus exoplanetary candidates have been cataloged by the Kepler Space Telescope. The majority of the confirmed exoplanets were spotted using the “transit method” (when the exoplanet passes in front of its host star, thereby dimming its light for astronomers to detect) and the “wobble method” (when the exoplanet gravitationally tugs on its parent star, creating a very slight shift in the star’s position for astronomers to detect), but only exoplanets with short orbital periods have been spotted so far.

The more distant the exoplanet from its host star, the longer its orbital period. To get a positive detection, it’s easy to spot an exoplanet with an orbital period of days, weeks, months, or a couple of years, but what of the exoplanets with orbits similar to Jupiter (12 years), Saturn (30 years) or even Pluto (248 years!)? If we are looking for exoplanets with extreme orbits like Pluto’s, it would be several generations-worth of observations before we’d even get a hint that a world lives there.

“Jupiter and Saturn take 12 and 30 years respectively to orbit the Sun, so you would have to be incredibly lucky or look for a very long time to spot them by a transit or a wobble,” said Nichols.

By assessing how the radio emissions for a Jupiter-like exoplanet respond to its rotation rate, the quantity of material falling into the gas giant from an orbiting moon (akin Enceladus’ plumes of water ice and dust being channeled onto the gas giant) and the exoplanet’s orbital distance, Nichols has been able to identify the characteristics of a possible target star. The hypothetical, “aurora-active” exoplanet would be located between 1 to 50 AU from an ultraviolet-bright star and it would need to have a fast spin for the resulting magnetospheric activity to be detectable at a distance of 150 light-years from Earth.

What’s more, the brand new LOw Frequency ARray (LOFAR) radio telescope should be sensitive enough to detect aurorae on Jupiter-like exoplanets, even though the exoplanets themselves are invisible to other detection methods. Nice.

As we’re talking about exoplanets, magnetospheres and listening for radio signals, let’s throw in some alien-hunting for good measure: “In our Solar System, we have a stable system with outer gas giants and inner terrestrial planets, like Earth, where life has been able to evolve. Being able to detect Jupiter-like planets may help us find planetary systems like our own, with other planets that are capable of supporting life,” Nichols added.

Although Nichols isn’t talking about directly detecting habitable alien worlds (just that the detection of Jupiter-like exoplanets could reveal Solar System-like star systems), I think back to the 2009 research that discusses the direct detection of habitable worlds using this method: Aliens, if you’re out there, you can be as quiet as you like (to avoid predators), but the screaming radio emissions from your habitable planet’s magnetosphere will give away your location…

Has Kepler Discovered a New Class of Celestial Object?

The strange objects orbiting the two stars could be mangled white dwarfs... but the jury is still out (NASA)

The first results from NASA’s Kepler exoplanet hunter are in and a perplexing early result has been announced. Yes, the space telescope is working fine, and no, it hasn’t spotted an alien homeworld (yet), but the Kepler team have uncovered something pretty cool.

Kepler may have discovered a new class of celestial object (possibly).

But before we start scratching our heads in confusion or popping the champagne corks in celebration, let’s try to work out what Kepler has observed.

Kepler is currently monitoring 100,000 stars in an effort to seek out extra-solar planets (or “exoplanets”) orbiting these stars. Although Kepler was only launched in March 2009 and early doubts about the observatory’s capabilities caused some low-level concern, Kepler appears to be functioning well and mission controllers are already reporting early results.

Five new exoplanet discoveries by Kepler were announced at the American Astronomical Society (AAS) meeting in Washington D.C. on January 4th, and all seem to have very strange characteristics. Fortunately Discovery News blogger Ray Villard was on the scene at the AAS to hear what the Kepler team had to announce:

In sifting through the Kepler data taken so far, postdoctoral student Jason Rowe found a very curious light signature. When an object passed behind its central star, the light from the system dropped significantly. This means the object — called KOI 74b — must be glowing fiercely with its own light that was blocked out when the object was eclipsed.

Hold up, the light dimmed when the exoplanet passed behind its parent star? Something’s not right here. Kepler detects exoplanets when the worlds pass in front of their parent stars, thereby dimming the starlight, not vice versa!

Actually, this is exactly what’s happened. The “exoplanets” orbiting two otherwise ordinary stars appear to be brighter — and hotter — than their host stars. It’s as if the roles of the stars and the exoplanets have been reversed; the stars are dimming the exoplanetary light as the exoplanet passes behind the star.

Needless to say, there is currently no stellar model that predicts this kind of behavior from extra-solar planetary systems.

This means the object — called KOI 74b — must be glowing fiercely with its own light that was blocked out when the object was eclipsed […] It is seething at 70,000 degrees Fahrenheit while the parent star is 17,000 degrees Fahrenheit. The strange object can’t be a star because the transit data show that it is no bigger than Jupiter.Ray Villard, Discovery News.

One theory is that KOI 74b (and the other strange object, KOI 81b) could be a white dwarf star that migrated close to its stellar partner. Through binary interactions, the white dwarf was stripped of some of its mass, causing it to puff up and appear like a gas giant exoplanet. That would certainly go to some way of explaining why these two “exoplanets” are so hot.

Of course, the other option is that Kepler has made a groundbreaking discovery and identified a whole new class of celestial object… but I suspect there are other, more mundane reasons for these observations.

I suppose we’ll just have to wait and see until followup observations are made…

Source: Discovery News

What Will Happen When the Sun Turns into a White Dwarf?

Strong tidal interactions are thought to shred any asteroids or comets as they get too close to a white dwarf (NASA)

All the way back in January, I had the great fortune to attend the American Astronomical Society’s (AAS) conference in Long Beach, California. I had a lot of fun. However, between the free beer and desperately searching for wireless Internet signal, I also did some work. During my travels, I spent some time browsing the poster sessions, trying to get inspiration for an article or two. You’d think that when presented with hundreds of stunning posters that inspiration wouldn’t be that far away. However, I was repeatedly frustrated by information overload and defaulted to a clueless meander up and down the pathways walled with intense science debates.

But then I saw it, right at the end of one of the poster walls, a question that got my imagination bubbling: “Will The Sun become a Metal Rich White Dwarf After Post Main Sequence Evolution?” The Sun? After the Main Sequence? Metal rich? To be honest, these were questions I’d never really pondered. What would happen when the Sun turns into a white dwarf? Fortunately, I had Dr John Debes to help me out with the answers…
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Twitter Journalism: Methane on Mars, The Signature of Life?

The distribution of atmospheric methane originating from three principal regions on the Martian surface (NASA)
The distribution of atmospheric methane originating from three principal regions on the Martian surface (NASA)

Today, NASA held a press conference detailing some significant discoveries from observations made of the Martian atmosphere. Using NASA’s Infrared Telescope Facility and Keck Telescope, scientists from the University of Hawaii and NASA were able to deduce the spectroscopic fingerprint of methane. Although scientists have known for a long time that methane exists in the Martian atmosphere, the big news is that there is lots of it, it appears to be constantly replenished and it is a huge indicator of biological processes under the surface.

Fortunately, I was able to watch the NASA TV broadcast of the press conference at 11am (PST), so I thought I’d try, for the first time, to do some live microblogging of the announcements using Twitter. So, rather than going into vast detail about today’s methane news (as the web has exploded with articles on the subject anyway), I thought I’d publish my Twitter feed during the conference
Continue reading “Twitter Journalism: Methane on Mars, The Signature of Life?”

Magnetars Born Through Quark Star Switch?

Could quark stars be magnetar progenitors? (© Mark Garlick)
Could quark stars be magnetar progenitors? (© Mark Garlick*)

If you thought neutron stars and magnetars were exotic, think again. In studies of magnetars that occasionally blink to life, generating an intense blast of X-rays and gamma-rays, astronomers have been at a loss to explain why these objects have such strong magnetic fields. After all, after a supernova, a neutron star remnant conserves the angular momentum and magnetic field of the parent massive star; it is therefore a rapidly spinning, magnetically dominant entity, often observed emitting intense radiation from its poles (a.k.a. a pulsar).

However, magnetars (the most magnetically powerful objects observed in the Universe) do not have such a reasonable explanation for their magnetic field, it is simply too strong.

During the AAS conference last week, one scientist presented his research, possibly indicating another state of matter may be at play. A massive neutron star may pass through a “quark star phase”, kick starting a mechanism known as colour ferromagnetism

*This image is copyright Mark A. Garlick and has been used with permission. Please do not use this image in any way whatsoever without first contacting the artist.
Continue reading “Magnetars Born Through Quark Star Switch?”

Slacker Astronomy Interviews Dr Michael Turner about Dark Energy

Dr Michael Turner
Dr Michael Turner (Slacker Astronomy)

I’m just listening to Slacker Astronomer Michael Koppelman’s excellent interview with Dark Energy’s Dr Michael Turner at last week’s AAS conference in Long Beach. You have to listen to Turner’s views on dark matter, dark energy, the LHC, the rights and wrongs of general relativity and some great opinion about the current state of cosmology. On checking out Turner’s bio on his website, anyone who has “Space” listed under “Areas of Expertise” has to be listened to!

I especially liked the Slacker question concerning the growing number of people opposed to the idea of dark energy accusing cosmologists of “drinking the same Kool Aid” (in reference to the perceived thought that dark energy might be a crazy idea), to which Turner replies with, “Well we do all drink the same Kool Aid, that is true. I’m Mr Kool Aid!

It is a really entertaining interview, providing an insight to the cutting edge of cosmological thought and excitement for the continuing work being done in the field.

Great work Slacker Astronomy! Now I feel like the slacker, didn’t manage any podcasts direct from the scene of the AAS… I must remember by dictaphone in June for the next AAS in Pasadena!

Source: Slacker Astronomy

365 Days of Astronomy Podcast: The Link Between Beer and Space Settlement!


The day has come. Finally, I get to promote my excitement for the importance of Space Beer. Ohhh yes! Incidentally, Space Beer has been the theme of the last few days of the AAS conference (free beer, special free Galileo limited edition Sierra Nevada beer. Did I mention it was free?), so it seems fitting to have my 365 Days of Astronomy podcast broadcast the day after returning from the conference fuelled by (free) space-themed booze.

So, today (January 9th), over at the 365 Days of Astronomy, celebrating the International Year of Astronomy 2009, you can tune into my contribution to the IYA2009: The Link Between Beer and Space Settlement.

Go to the 365 Days of Astronomy blog post for the transcript and podcast options »

Play the podcast mp3 NOW!

To top the whole experience off, I had the superb fortune to meet the musician behind the 365 Days of Astronomy theme tune, plus we were also treated to a mini-concert by him during the official USA opening of the International Year of Astronomy 2009 at the AAS conference on Tuesday. Written and performed by George Hrab, the entire audience at the IYA2009 grand opening ceremony had a great time singing along to the lyrics. I’m assuming the song is called “Far”, for obvious reasons. Funnily enough, in the audience participation parts of the tune, avatars participating in the Second Life virtual world were also singing along. George not only entertained the real world, he transcended this life to make the Second Life rock! Now that is inspirational!

Photos after the jump…
Continue reading “365 Days of Astronomy Podcast: The Link Between Beer and Space Settlement!”

The AAS Finale: Astronomy Cast Meet-up (Photos)

A unique beer-fuelled AAS camera angle. Clockwise from top right: Pamela Gay, Fraser Cain, Chris Lintott and Ian O'Neill
A unique beer-fuelled AAS camera angle. Clockwise from top right: Pamela Gay, Fraser Cain, Chris Lintott and Ian O'Neill

It’s Thursday afternoon and the hangover is finally subsiding. This morning wasn’t a nice experience, having stumbled back to the hotel at 2am, knowing very well I had to get up at 7am for the final round of sessions at the AAS conference, I knew the lack of sleep might be a problem.

After all, there would be no presentations in the afternoon and I was very motivated to get the scoop on some more breaking astro news. Unfortunately, 7am turned into 10:30am, and although I tried, I couldn’t make it past the hotel lobby. For me, Thursday was cancelled. Oh well, at least the previous night was awesome
Continue reading “The AAS Finale: Astronomy Cast Meet-up (Photos)”

AAS Session 328: Supermassive Black Holes, Kicked or Spun?


Events are amping up at the AAS conference in Long Beach. Tonight, we were treated to the official US opening of the International Year of Astronomy 2009 (plus superb live music by George Hrab, a Second Life IYA2009 ribbon-cutting and the premier of “400 Years of the Telescope“). In the day, I had a stack of presentations to go to including a session on black holes and another on white dwarfs… I never knew white dwarfs were so interesting!

For an exclusive look into the supermassive black hole session this morning, be sure to have a read of AAS Session 328: Black Holes I, January 6th over at the Universe Today

AAS Update: The Story So Far

The galactic centre in unprecidented detail from Hubble (NASA, ESA, and Q.D. Wang)
The galactic centre in unprecidented detail from Hubble (NASA, ESA, and Q.D. Wang)

Day One: Information overload! When Fraser and I turned up in Long Beach, CA yesterday for the 213th American Astronomical Society meeting, I had an overwhelming feeling that I should have done my homework before travelling to the event. Hundreds of participants, hundreds of posters and hundreds of presentations… as an astrophysicist, I feel like a kid in a candy shop, but as a blogger, it’s hard to know where to start!

A shredded asteroid around a white dwarf star (NASA/JPL)
A shredded asteroid around a white dwarf star (NASA/JPL)

Fortunately Team Universe Today has some strong backup in the form of Nancy Atkinson who is operating from home, delivering a huge amount of AAS coverage on the Universe Today. This is good, as the Internet connection at the Long Beach Convention Center is patchy at best. It’s great to meet Pamela and everybody else involved in the Astronomy Cast effort, and everyone seems to be finding articles and lining up the press releases rather nicely.

Also, I echo Scott Miller’s sentiments about “Rock Bottom” pub. Had a couple there last night. The “Mad Lizard” beer. 8.2%. Never again… (well, not till Wednesday in any case!)

I am just about to attend the 10am Session 328 Black Holes I presentations, and I’ll hopefully be adding a long “live blogging” post about each of the speakers. All going well a couple of interviews might come out of the session too. Until then, here’s a brief run-down of the Universe Today coverage of the various press releases, from supermassive black holes, brand new Hubble views of the galactic centre, shredded asteroids around white dwarfs to the heavy Milky Way…

Young Stars Forming Near Galactic Black Hole

The Case of the Disappearing Planetary Disks

Broken-up Asteroids Found Orbiting White Dwarfs

Hubble, Spitzer Collaborate for Stunning Panorama of Galactic Center

Triple Whammy: Milky Way More Massive, Spinning Faster and More Likely to Collide

But ultimately, be sure to keep an eye on Astronomy Cast LIVE, for ALL coverage from us in Long Beach!