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Highlights of this week’s exoplanet feast at Goddard

October 21st, 2011 Comments off
Spiral signpost of planets

Spiral signpost of planets

This week, it’s been a feast of exoplanet science at Goddard, which hosted the Signposts of Planets meeting Oct. 18-20. The three-day conference gathered an international crowd of observers, computer modelers, and instrument builders to explore the relationship between exoplanets and the circumstellar disks in which they form.

Circumstellar what?

Circumstellar simply means “disks of gas and dust around a star or stars.” Astronomers have discovered some 687 planets around other stars, but ironically they rarely are able to “see” one directly. What the Hubble telescope and other instruments see are dusty disks.

Circumstellar disks are the “signposts of planets” referenced by the name of the conference. Want to find planets? Look for dusty disks.

Here is Goddard astrophysicist and Signpost meeting organizer Marc Kuchner explaining the lowdown on circumstellar disks, back when we only knew of about 400 extrasolar worlds:


The conference produced some show-stoppers in terms of new discoveries announced. Four were the subject of press releases:

Spiral signposts
At the meeting, Goddard astronomer Carol Grady announced the discovery of a type of exoplanet telltale predicted but never actually imaged before. In some circumstellar disks, the tug of a planet’s gravity can create subtle spiral features in the gas and dust. That is good news, because it means that disks with spirals could lead astronomers to planets.

“What we’re finding is that once these systems reach ages of a few million years, their disks begin to show a wealth of structure — rings, divots, gaps and now spiral features,” said John Wisniewski, a collaborator at the University of Washington in Seattle. “Many of these structures could be caused by planets within the disks.”

The newly imaged disk surrounds SAO 206462, a star located about 456 light-years away in the constellation Lupus.

Baby planet

Baby planet

Baby planet
Also at the conference, astronomer Adam Kraus explained how he used the mammoth Keck telescopes on Mauna Kea in Hawaii to image an infant planet. “LkCa 15 b is the youngest planet ever found, about 5 times younger than the previous record holder,” said Kraus, who is based at the University of Hawaii’s Institute for Astronomy.

Kraus did the work using a technique called interferometry, which allows a telescope to achieve the detail-resolving power equivalent to that of a much larger telescope.

Cool findings
In another report at the Signpost meeting, astronomer Kevin Luhman of Penn State University described his observations of a star with a cool planet-like companion. The object, a gaseous not-quite-a-star called a brown dwarf, has an outer temperature described as comparable to “a hot summer day in Arizona.”

Coolest brown dwarf ever

Coolest brown dwarf ever

Luhman commented:

“Its mass is about the same as many of the known extra-solar planets — about six to nine times the mass of Jupiter — but in other ways it is more like a star. Essentially, what we have found is a very small star with an atmospheric temperature about cool as the Earth’s.”

OK, not quite a planet — but not quite a star either. Brown dwarfs lie in between. But they lie along a spectrum of objects that exoplanet researchers study.

Ever since brown dwarfs first were discovered in 1995, astronomers have been trying to find new record holders for the coldest brown dwarfs because these objects are valuable as laboratories for studying the atmospheres of planets with Earth-like temperatures outside our solar system.

Comet storm

Comet storm

And last but not least, comet storms!

NASA’s Spitzer Space Telescope has detected signs of icy bodies raining down in an alien solar system. The downpour resembles our own solar system several billion years ago during a period known as the “Late Heavy Bombardment,” which may have brought water and other life-forming ingredients to Earth.

Carey Lisse, senior research scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland., announced the finding at the Signposts conference. The research will be published in the Astrophysical Journal.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.








Extra! Extra! NASA’s Kepler mission discovers possible ‘earthlike’ planets. What’s that mean anyway?

February 2nd, 2011 2 comments

artist view of solar system around another star

The big NASA news of the day is that the Kepler mission has discovered planets that are about the size of our own and may have similar conditions for life. Or as the press release explains:

“NASA’s Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet’s surface. Five of the potential planets are near Earth-size and orbit in the habitable zone of smaller, cooler stars than our sun.”

Recently a Kepler team acientist and famous exoplanet hunter, David Charbonneau, stopped by Goddard to give a talk and gogblog got a chanvce to ask a few dumb questions. Starting with: “What do you means by earthlike planet? And what is a super Earth?”



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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.



Gogblogcast #5: Marc Kuchner and the Search for Other Earths

January 20th, 2011 Comments off




Marc Kuchner is an astrophysicist at Goddard Space Flight Center who studies planetary systems around other stars. As he explains in this video, the trouble is that when you point a telescope — even one as powerful as the Hubble Space Telescope — at a star with a planetary system, you can’t see the actual planets very clearly. At best you see a glowing dot.

But what you CAN see very clearly is the thin dusty disk that occupies a vast volume of space around the star. Our solar system has one, too: It’s called the zodiacal cloud.

Marc and his students — most notably, Christopher Stark, now at the Carnegie Institution for Science in Washington, D.C. — have developed computer simulations of planetary dust. This is what the simulations show: Although it may be some time before we have a space telescope powerful enough to directly image the face of an alien planet, we should be able to detect the presence of planets by the effects they have on dusty disks. Most likely those planetary telltales will be structures such as rings and dimples.

Want to know more about dust simulations? See a previous gogblog post and the computer visualization below for the details.

By the way, when Marc mentions during the interview that there are “about 400 planets known,” it was accurate. But since this interview was recorded, the count has risen to 500!


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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.




W3Counter


WASP-12b: Shine on you crazy diamond planet

December 8th, 2010 2 comments

Artist's concept of a carbon planet with a tar covered surface. A meteor impact has exposed a diamond layer in the planet's interior. For permission to reproduce this figure, please contact Lynette R. Cook, lynette@spaceart.org. Credit: Lynette Cook (extrasolar.spaceart.org)

In this artist's concept of a tar-covered carbon planet, a meteor impact has exposed a diamond layer in the planet's interior. For permission to reproduce this figure, please contact Lynette R. Cook at lynette@spaceart.org. Credit: Lynette Cook (extrasolar.spaceart.org)

“There is no use trying, said Alice; one can’t believe impossible things. I dare say you haven’t had much practice, said the Queen. When I was your age, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”

This just in from our Department of Impossible Things: carbon-soaked planets harboring rock formations glittering with diamonds instead of quartz or other silicate minerals common on Earth. Imagine dark gray plains of graphite. Bubbling pools of tar. A smoggy methane atmosphere.

Scientists today report using the Spitzer Space Telescope to discover the carbon-rich recipe of a previously known exoplanet called WASP-12b. A press release today from Jet Propulsion Laboratory has more details:

Astronomers have discovered that a huge, searing-hot planet orbiting another star is loaded with an unusual amount of carbon. The planet, a gas giant named WASP-12b, is the first carbon-rich world ever observed. The discovery was made using NASA’s Spitzer Space Telescope, along with previously published ground-based observations.

Here at Goddard, exoplanet researcher Marc Kuchner received the news with barely concealed glee. In years past, his work contributed to establishing the hypothetical existence of carbon planets. The WASP-12b observations confirm it.

The implications are exotic. Weird things happen when the ratio of carbon to oxygen in a planetary system crosses the tipping point — that being a ratio greater than 1 to 1.

“When the relative amount of carbon gets that high, it’s as though you flip a switch, and everything changes,” Kuchner explains. “Everything would be different — like imagine, one day you’re a Yankees fan, the next day, Red Sox.”

WASP-12b is a gas giant, so its carbon-rich creations swirl within oceans of dense atmosphere. But what about terrestrial (i.e., rocky) carbon planets? Now it gets mighty interesting.

“If something like this had happened on Earth when it was formed,” Kuchner says, “your expensive engagement ring would be made of glass, which would be rare, because the atmosphere would be made of smog and the mountains would all be made of diamonds.”

artist concept of beta pic planetary system

Artist’s conception of the dust and gas disk surrounding the star Beta Pictoris. A giant planet may have already formed and terrestrial planets may be forming. The inset panels show two possible outcomes for mature terrestrial planets around Beta Pic. The top one is a water-rich planet similar to the Earth; the bottom one is a carbon-rich planet, with a smoggy, methane-rich atmosphere similar to that of Titan, a moon of Saturn. A team led by Aki Roberge of NASA’s Goddard Space Flight Center first presented the observation in the June 8, 2006, issue of Nature. Credit: NASA/FUSE/Lynette Cook


Kuchner says he thought initially carbon planets would probably be found in exotic stellar environs, like planetary systems whirling around pulsars or white dwarf stars. “But WASP 12 seems to be a pretty normal star, similar to the sun. If it could happen there, it could have happened here. And now that we know WASP-12b is a carbon planet. I bet we’ll start finding others.”

Well, that sounds familiar. In the early days of exoplanet discovery, we found “hot Jupiters,” gas giant planets orbiting shockingly close to their host stars. They seemed exotic until we started finding them all over the place. Now it’s “another day, another hot Jupiter.”

So perhaps carbon-rich planets won’t seem so strange someday, too. Case in point: a star called Beta Pictoris. Kuchner says Beta Pic is “mostly quite similar to the sun, but which has a planetary system and a disk around it that’s carbon rich. Not just a little carbon rich. It has nine times as much carbon as oxygen.  That’s even more carbon-rich than WASP-12b.”

We can only imagine what a planet might look like in such a carbon-mad place. We may never know, but it’s fun to wonder. The WASP-12b discovery gives us permission. “People sort of didn’t take the carbon planets idea seriously at first,” Kuchner says, “but this changes things.”


image of beta pic dust diskRIGHT:  This image of the circumstellar disk around Beta Pictoris shows (in false colors) the light reflected by dust around the young star at infrared wavelengths. The Beta Pic disk is very likely an infant solar system in the process of forming terrestrial planets. Credit: Jean-Luc Beuzit, et al. Grenoble Observatory, European Southern Observatory
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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.


The birth, life, and death of alien planets: Goddard exoplanet scientists give you an update on what we (think) we know

December 6th, 2010 5 comments

exoplanet sun panorama

The official count of candidate planets around other stars recently hit a whopping 500. But when the first extrasolar planets — often called exoplanets — were discovered, many scientists weren’t sure if they should believe their own data. The first confirmed exoplanets were found around a stellar corpse called a pulsar, born of a supernova explosion of a star. And we also found lots of so-called hot Jupiters, huge steaming gasballs orbiting many times closer to their host stars than Mercury orbits the sun.

365 days of astronomy logoHow do exoplanets come to exist? How do they evolve over billions of years? And how do they die? If you’re curious and have 10 minutes, listen to my podcast, The Birth, Life, and Death of Alien Planets, on “365 Days of Astronomy.” (It’s a daily podcast produced by the International Year of Astronomy 2009.) You can also just download the (11 Mb) .mp3 file here and listen to it on your iPod or other media player. This blog post is adapted from the podcast transcript, if you prefer to read rather than listen to the 10-minute broadcast

The race is still on to discover more planets, and scores are promised thanks to missions like the Kepler space observatory. Meanwhile, down here on earth, exoplanets scientists are scratching their heads, mining their data, and tweaking their theoretical models to try and make sense of the diversity of alien worlds we have already found.

Here at NASA’s Goddard Space Flight Center, where I work as a science writer, we’ve got a whole group of scientists obsessed with exoplanets. They took me on a whirlwind tour of the birth, life, and death of planetary systems. It all starts with a collapsing cloud of gas that forms an infant stars surrounded by a spinning disk of gas and dust — the stuff of which planets are made. A protoplanetary disk.

JENNIFER WISEMAN: Young protostars are buried in a large envelope of dense gas, kind of flattened like a fluffy pancake, but it can extend out to thousands of astronomical units, the distance from the Sun to the Earth.”

DANIEL PENDICK: That’s Jennifer Wiseman. She studies star birth and is the new senior project scientist for the Hubble Space Telescope. She’s also the chief of Goddard’s ExoPlanets and Stellar Astrophysics Laboratory, which is home to many of the exoplanet researchers here at Goddard.

WISEMAN: You have this puffy but dense sort of pancake of gas, swirling around, and in the interior part of this, material is being gravitationally sucked into a tighter accretion disk that’s right around this young forming star.





PENDICK: OK, so far so good. We’ve got an accretion disk, which is where planets come from. What happens next? I asked Hannah Jang-Condell, a post-doctoral researcher at Goddard and the University of Maryland. She’s also a member of the Goddard Circumstellar Disks Group, about a dozen scientists here active in exoplanet research.

JANG-CONDELL: So basically you’ve got a star. It’s not burning hydrogen yet. You’ve got this disk of gas and dust surrounding it. And planets are starting to form in this disk.

PENDICK: Hold on — did she say dust? As in those fluffy dust bunnies that inhabit the underside of my couch? Not exactly. When astronomers say dust, they mean tiny bits of solid stuff, like minerals and ices, floating around in space. The dust grains are on the scale of a micron—a millionth of a meter—in diameter.

JANG-CONDELL: It’s assumed that as you build these things up from the micron size to the centimeter size, that things stay fluffy. So sort of loosely bound aggregates. So they are a lot like dust bunnies at that stage.

PENDICK: So much for interstellar dust bunnies. Now, back to the planet building stage of our story.






JANG-CONDELL: So there’s two main scenarios for the way planets form. There is the core accretion scenario. So you start out with dust particles and they collide and coagulate and become larger and larger bodies. When it gets about 10 to 20 times Earth’s mass it’s able to accrete gas, and then the gas will stay on it. From that point it can accrete gas and become a gas giant planet like Jupiter.

The alternative scenario is called gravitational instability. In that case, you have a massive disk, and it’s cool enough and dense enough for it to start self-gravitating. So in other words, the disk will fragment, it will start to form a clump, the clump will become self gravitating, and eventually it will collapse to form a giant planet.

PENDICK: This all takes place in the space of a few million years — a cosmic blink of an eye. Gas giants have to form before all the gas in the system has either accreted onto the star or is blown away by the star’s radiation.

Once the gas goes away, the infant planetary system evolves into something called a debris disk. As Goddard exoplanet researcher Aki Roberge explains, the planet-building process continues in debris disks, creating larger and larger bodies called planetesimals. In today’s solar system, planetesimals are known as asteroids and comets.

AKI ROBERGE: They start colliding and sticking. Roughly speaking, it’s just hit-stick-hit-stick, get bigger and bigger and bigger.

PENDICK: Sometimes the collisions are not so sticky. The planetesimals smash together and generate lots of smaller debris particles. In fact, huge dusty disks were discovered around other stars for the first time in the 1980s. Astronomers dubbed them ‘debris disks.’

ROBERGE: Over the years, there’s been lots of pieces of evidence collected that these debris disks, they really are young planetary systems. So they are like young, dense versions of our own Kuiper and asteroid belts, and our own solar system probably went through a phase very much like it, a debris phase, when it was young.

So any giant planets that would form in the system have already formed because there is no gas left to form any giant planets. And some planetary embryos, maybe Mars sized bodies, are there already. So what’s happening is the late stage of terrestrial planet formation. So you are building up from Mars to real Earths.

PENDICK: Terrestrial planets can have violent births, as embryonic planets up to the size of Mars slam into others and build up larger planets. Also at this time, water rich comets may stream in and collide with the young terrestrial planets. This provides the raw material for oceans and atmospheres.

Theory tells us these events must be happening in the dusty disks astronomers study. But we don’t see any of this directly.

ROBERGE: All you can really see, ironically enough, is the very smallest portion. So what you see is the dust, tiny, tiny little dust [grains.] This is the dust that’s produced when two asteroids crash together and break up, or the dust that’s in a comet’s coma that’s being expelled as they evaporate. So actually we see the indirect signs. We can see the tiniest material but we know it has to be coming from bigger things.

PENDICK: At some point, things do settle down a bit. But even in a mature planetary system, the action is far from over. Planets continue to migrate in their orbits, or even be ejected from the system in hair-raising close encounters. And if a planet orbits close enough to its star — even closer than Mercury orbits the sun — it could spiral inward and be consumed. In short, entire planets disappear from planetary systems. Goddard exoplanet researcher Brian Jackson explains.

BRIAN JACKSON: Once you get that close, tides raised on the host star and tides raised on the planet can affect the orbit of the planet. Because the rotation of the star is so much slower than the rate at which the planet is going around, the bulge tends to point a little bit behind the planet. And you can think about the gravitational interaction with that bulge always pointing behind the planet a little bit kind of yanks back on the planet and that can reduce the orbital distance between the host star and the planet.

Eventually its orbit will shrink enough that it will be destroyed. That can happen within a few billion years. So a lot of these close-in planets that we see aren’t going to last more than a few billion years.

PENDICK: And even planets farther out from the star can experience dramatic changes because of tidal forces.

JACKSON: If the planet’s orbit is non-circular, then what happens is the size of the tidal bulge when the planet is closest to its host star is bigger than when the planet is farther away. The shape of the planet will change as it goes around in its orbit. That change, that periodic flexing of the planet, dissipates energy inside of the planet. It can drive volcanism, which can cause outgassing and provide an atmosphere for the planet. And we see this sort of volcanism powered by tides in our own solar system, for example, Jupiter’s moon Io undergoes the same sort of tidal heating…and that drives the volcanoes that erupt on the surface of Io.

PENDICK: In fact, tidal flexing could hypothetically turn the surface of a rocky planet into a lava sea fuel massive supervolcanoes. Or it could cause just enough heating to maintain a warm and stable climate, as earthly plate tectonics does on our world.

We used to think that solar systems eventually settle down and become middle-aged and sedentary, with stable and predictable behavior. But this does not appear to be the case.

JACKSON: Among planetary systems, the rule seems to be that interactions can be very violent and dynamic and the orbits can evolve pretty dramatically over time.

PENDICK: Planetary systems can even come back from the dead after the most violent event nature has to offer — the supernova explosion of a star. Goddard post-doctoral scientist John Debes has studied these born-again planetary systems. In fact, the first planets ever discovered around other stars were found orbiting a pulsar — the superdense rotating remnant of a star that went supernova.

JOHN DEBES: What people think happened is that after the initial supernova explosion some of the material fell back into a disk, and that allowed these smaller planets to form. And the only reason we found them is because pulsars are amazingly precise clocks, and you could measure the timing of the pulses of the pulsar, and see that that would change due to the orbital wobble of these planets.

What’s great about that system, even though it’s the only one that’s been found, is it really shows the sort of basic process for forming a planet must be pretty easy to do, because if you can do it in the fallback disk of a supernova, you can do it just about anywhere if you have the right amount of material and the right conditions.

PENDICK: Hot Jupiters spiraling to their fiery doom… planets par boiled in molten lava… worlds born from the ashes of dying stars. It sure isn’t your grandfather’s solar system science anymore, with well-behaved old planets in their stately settled orbits. As telescopes give us even sharper views of alien worlds, it’s hard to predict what strange world await discovery.


Astronomer Carolyn Crow, also the center of the solar system.
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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.



A peek at the behind-the-scenes movie magic that created ‘Using colors to search for alien Earths’

November 3rd, 2010 1 comment

Astronomer Carolyn Crow, also the center of the solar system.

Carolyn Crow, UCLA graduate student and center of the solar system.

Someday, when we have space telescopes that can narrow in on the exceedingly weak light from incredibly distant planets around other stars, what will we do with those precious photons?

If you want to know, read the latest web feature and watch the video from NASA Goddard. I wrote the feature, “Using planet colors to search for alien Earths.”

I also had a chance to sit in on the studio work that produced the video featuring Carolyn Crow, a young scientist who led the research on planet colors. (She is currently a graduate student at UCLA.) As commonplace as green-screen technology is today, it’s movie magic that never fails to impress — especially when used as cleverly as it is in this video.

Producer/director Scott Wiessinger created a colorful digital landscape in which Crow strolled among the planets of our solar system in a modern version of Gulliver’s Travels. NASA/Goddard astrophysics writer Frank Reddy provided a concise and clear script.

Here is a behind-the-scenes peek at the movie magic.


looking stage left

Carolyn Crow stands ready to gesture at imaginary planets on Goddard TV’s green screen stage. To eliminate shadows and get the best results from the green screen process, the stage is brightly lit.



carolyn crow being filmed in front of a green screen

carolyn_after
Carolyn after being inserted into a digital landscape with starry background and planet Earth.


And here is the final result:


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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.



See the new video about Hubble Space Telescope exoplanet science

July 29th, 2010 1 comment

exoplanet sun panorama_600


“I don’t know — when I was growing up, there was no such thing as planets around other stars. If you were to talk about it at a scientific meeting, people would laugh at you….”

Oh, how times change. And so begins a new short documentary by Goddard video producer Ryan Fitzgibbons and videographer Jamal Smith. 20 Years of Hubble Science: Exoplanets highlights the Hubble Space Telescope’s contributions to the study of planets around other stars.

In the video, Goddard scientists Marc Kuchner, Aki Roberge, and Jennifer Wiseman discuss how Hubble’s coronagraph and resulting images have helped scientists find exoplanets, dusty disks around other stars, and infant solar systems. All three astronomers are members of our Exoplanets and Stellar Astrophysics Laboratory.

The science is at the leading edge and the graphics are awesome — especially the animated timeline showing all exoplanet discoveries to date. Go to the Scientific Visualization Studio website to download and view this film at the highest possible resolution. It’s worth the download time.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.



Did I Forget To Mention? Happy 5 Years, Deep Impact Mission!

July 13th, 2010 2 comments
comet crash_202

This spectacular image of comet Tempel 1 was taken 67 seconds after it obliterated Deep Impact's impactor spacecraft.

In last week’s That Was The Week That Was, I neglected to celebrate a significant milestone: July 4, 2010, marked the 5th anniversary of the Deep Impact encounter with Comet 9P/Tempel. On July 4, 2005, the Deep Impact spacecraft hurled a heavy mass into the comet, excavating a crater and exposing fresh interior comet stuff to scientific analysis. Feel free to pause and feast on dramatic comet-smashing images and then catch up on the scientific findings.

Mike A’Hearn at the University of Maryland headed the Deep Impact science team, and NASA’s Jet Propulsion Laboratory in California managed the project. So why is gogblog nattering on about Deep Impact?

One Goddard connection to Deep Impact is asteroid and meteorite scientist Lucy McFadden. She was a member of the Deep Impact science team and led the mission’s education and public outreach effort. She recently joined Goddard as Chief of University and Post-doctoral Programs. Although her job here is administrative, she remains an active researcher.

In Deep Impact’s present configuration, the Goddard links increase.

First, some brief background. The spacecraft is very much alive, and it’s still working for planetary science. The reincarnation of Deep Impact is called EPOXI. It’s actually two missions in one: the Extrasolar Planet Observation and Characterization (EPOCh) mission and the Deep Impact Extended Investigation (DIXI).

Deep Impact Earth-Moon_202EPOCh scrutinized a small number of stars in order to learn more about planets that we know are orbiting those stars, and to search for clues to other planets that might be orbiting the same stars. It also imaged Earth to get insights into how we might recognize an Earth-like world around another star. DIXI will study comet 103P/Hartley 2 during a November 2010 encounter.

McFadden is now working with EPOCh’s observations of Earth — more on this in a  future blog post. And Goddard’s Drake Deming, a leading exoplanet scientist, heads the EPOCh component of EPOXI.

Yep, that’s a lot of acronyms. A little confusing, even. But stay tuned, because you’ll be seeing them more often in the future in the science press and on gogblog.



cell_phone_moon_50***INFO UPDATE: There is a new way to get involved in International Observe the Moon Night: invite yourself on the Facebook Event Page.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center.




Blogolicious Fun Facts from the National Capital Area Disks Meeting

July 1st, 2010 Comments off
The universe: planets aplenty?

Universe: planets aplenty?

Building 34 is all abuzz with talk of disks today. A bunch of exoplanet investigators have gathered at Goddard for the National Capital Area Disks meeting. It’s all about the disks of gas and dust around young stars that evolve into planets. Why that happens, how that happens, how fast that happens, and where it happens — all are open for discussion at the meeting.

Dropping in to listen to talks sporadically, Gogblog has gleaned a few blogolicious disk facts:

When a disk forms and is still in its “primordial” phase, it may contain up to 100 times the mass of Jupiter in gas and dust. But as the era of planet formation ends, and much of the gas has boiled off or been consumed building planets, the disk mass plummets to a few times the mass of Earth’s moon.

10 to 20 percent of stars surveyed — so far — have planets and planetary systems. It’s the minority, to be sure, but think of how many stars fill the universe and therefore how many planets must exist. It makes the odds sound pretty good that the universe is positively dirty with life. Well, at least a few festively hued fungi and bacterial mats.

The first dusty “debris disk was discovered in 1984 around Vega. Astronomers detected it from the star’s “infrared excess.” The dust absorbs energy from its star; it then re-radiates it in the form of infrared light. That infrared signature is the telltale sign of a debris disk.

The zodiacal cloud in our solar system contains a blob of dust that trails Earth.

Stars can “eat” the planets that form closest to them in the first few billion years of a planetary system’s lifetime. Fast-orbiting planets that take mere days to encircle their stars are most at risk.

***UPDATE: Friday July 2. . . . Since Galileo first looked at the sky through a telescope, exoplanet Fomalhaut b has made about one-half of an orbit around its star.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center.