Pavel Machalek, Ph.D.
Jeffrey Van Cleve, Ph.D.
Photometer Characterization Scientist for the Kepler Mission
A Day in the Life
Jeffrey Van Cleve spends much of his time looking at data that Kepler is about to release to MAST, the Multimission Archive at the Space Telescope Science Institute. MAST supports a variety of astronomical data archives, with a primary focus on scientifically related data sets in the optical, ultraviolet, and near-infrared parts of the spectrum. Jeff and other members of the Kepler Data Analysis Working Group (DAWG) participate in this data review in order to verify that the Kepler Science Processing Pipeline performs as expected in most cases, and to understand the exceptions. A different part of his day might be spent working on an important and interesting linear algebra puzzle to improve the Pipeline. This is one of Jeffrey’s favorite aspects of his work.
Another of Jeffrey’s tasks is working on file formats and coordinate system conventions for the MAST archive. He feels a “sense of mission that Kepler leave behind a legacy that people can use long after the mission is over to get some great science done. For example, even if almost every star system has a planet like the earth, more than 95% of Kepler’s targets will not show planets for geometrical reasons — a huge treasure trove of precise stellar light curves for astrophysical investigation. ”He and 4 or 5 other people who call themselves the FITS Fanatics work on this and though it might seem kind of dull to have lengthy discussions about file formats and header keywords, it is part of leaving behind a legacy which will make it easy for people to use and publish the data. Part of this process is to make the headers self-explanatory, so that they describe in detail how the data was collected, calibrated, and formatted.
To help with this work, two new members have been hired in the science office to work on the release notes, eventually taking over editing them and generating tables and figures. The bonus? Jeffrey will have more time to work on linear algebra puzzles!
What’s the most remarkable aspect of Kepler’s performance as an astronomical instrument? “It was the photometric precision of the CCD (visible light) sensors and the stability of the telescope pointing. It is amazing, when you think about it, that we can do 20 parts per million photometry, which requires both very stable CCDs and the ability to point the telescope to a millionth of a degree. It’s like looking at a light bulb 100 km (60 miles) away and being able to tell if a gnat is flying around it.”
Meaning of the Mission
I was curious to know what Kepler’s existence means to Jeffrey on a personal level. “The prevalence of habitable worlds, as measured by Kepler, helps us assess the probability of finding intelligence in other star systems in our Galaxy. What I really appreciate about Kepler is that it allows me to contribute to an optimistic vision of the human future, one that includes colonizing planets in other star systems, or communicating with intelligent species that have survived the perils we currently face. Their existence alone would be a beacon of hope.”
To read Jeffrey Van Cleve’s full biography, click here.
By Kepler blog contributor, Marlowe Primack
It was exciting to see how much work has been accomplished and overwhelming to see how much work still needs to be done. It was surpising to see so many new faces – the number of collaborators and contributors continues to grow – which is a very good thing. On Wednesday, the day after the science team meeting, there was an all-day session to discuss the follow-up observations of individual candidates. The participants rolled up their sleeves and worked extremely hard all day. By mid-afternoon it looked like the group had been locked up for a week – there were computer cords, styrofoam cups, jackets and sweaters, half-eaten doughnuts, empty soft-drink cans, and miscellaneous debris strewn everywhere, as people had not even left to get lunch. The single-mindedness, dedication, and teamwork demonstrated by the scientists as they struggled to interpret the myriad observations on a plethora of candidate planets was a joy to behold.
And now, for a bit of Kepler history…
by Fergal Mullally
Support Scientist for the Kepler Science Analysis Systems
Kepler Science Office, NASA Ames Research Center
Work on astronomy largely ground to a halt this morning as the Decadal Review was published outlining the direction the field should take over the next 10 years. With so many bright ideas floating around in astronomy, it can be hard to pick out the most interesting questions and the projects most likely to answer those questions. So every 10 years, the nation’s astronomers come together to take a look at the big picture, and to look to the future.
The report starts by looking back at the dramatic progress made in the past few years. It’s hard to believe that a mere 20 years ago, we had no idea that dark energy existed, or whether planets existed around any star in the Galaxy other than our own.
But while we’ve climbed some impressive scientific mountains in the past twenty years, there are even more impressive peaks on the trail ahead. The Decadal Review considers “the most profound discovery in the coming decade may be the detection of potentially habitable Earth-like planets orbiting other stars”. People have dreamed of that day ever since the times of the ancient Greeks.
This goal has two steps. First we need to find Earth-sized planets at just the right distance from their parent star, and then we will need to develop new technology to probe their atmospheres to search for oxygen, nitrogen, and the other elements we expect to find on a habitable, Earth-like, planet.
The second task is extraordinarily difficult. Earth-sized planets are small, far away, and hidden in the glare of their parent stars. A lot of development is still needed to build instruments to overcome those problems. Despite the challenges, the review places the challenge of imaging a habitable planet as a “Priority 1” goal, and Kepler as a key mission along the way.
In the meantime, Kepler is already hard at work answering the first question. Staring, unblinking, at 170,000 stars day after day, it will detect a minute change in brightness when a planet passes in front of the star it orbits. Before the decade is even half over, we hope to have found the first Earth-sized planet, and also to discover if such planets are commonplace, or rare.
The Decadal Review is mostly a dry, academic document with careful phrases and important caveats, but it rises to more poetic language when it attempts to describe the importance of this work. Hopefully, “one day, parents and children could gaze at the sky and know that a place somewhat like home exists around ‘THAT’ star”. That day (or night!) is probably still more than a decade away, but it’s an awful lot closer than it was ten years ago. And so, here on the Kepler Team, we’re putting down our Decadal Reviews, and getting back to the work of bringing that day a little nearer.
Kepler team members are sending in their well-wishes today, August 5, 2010, in honor of Neil Armstrong’s 80th birthday. All comments have been added to a poster (available here) that the team is sending to him. Some are reproduced below. Please join us in wishing Neil a…
Happy 80th Birthday!
“Neil — with warm wishes for a Happy Birthday — thank you for your contribution to space exploration.”
– Roger Hunter
Kepler Project Manager, on behalf of the Kepler Team
“When I look at the data Kepler sends down, I realize that in these bytes is something new — something no human has ever seen before. And I pause to think of those before me who also looked at something new and took risks and made sacrifices so that ALL of humanity would see too. Through your eyes, we saw something extraordinary that changed our perspective forever, and I thank you for that. Happy 80th Birthday!”
– Natalie Batalha
Deputy Science Team Director
“Apollo 11 was the inspiration for an untold number of people to pursue careers in engineering & the sciences. Back in the tumultuous 1960’s, this country emotionally needed the success you delivered. And we know you would be the first to say that you were just the visible part of the efforts of hundreds of thousands of people, but your coolness under stress during the mission and your grace and dignity since returning from the moon are all an inspiration. I am living the dream of being a NASA engineer because of you and and the people who worked around you back then. So beyond “Happy Birthday”, I want to say “Thank You”. “
– Jon Cowart
NASA KSC & friend of Kepler
“Happy 80th Birthday Neil! As we search for planets and their moons orbiting distant stars, I am often captured by the thought that the Universe must be filled with curious, awe-struck and awe-inspiring pioneers. Thank you for being one of ours.”
– Jessie Christiansen
“I remember fondly listening to the conversation as you searched for a spot to land the LEM and watching your famous “small step”. Your courage and actions were one of the reasons I chose a career in planetary sciences. Happy 80th birthday!”
– Jack Lissauer
Dimitar Sasselov, Co-Investigator, Kepler Science Team, Harvard Smithsonian Center for Astrophysics
Two weeks ago I gave a talk at TED Global 2010 which was very well received, but caused confusion. I referred to past results from the NASA Kepler mission. Indeed, Kepler has not discovered Earth-like planets in habitable zones. We have not found Earth-size planets; at this time we have found only planet candidates – 706 of them as of June 15, 2010, based on only 43 days of data with 306 released and discussed in a paper by the Kepler team. Planet candidates are just that: “candidates”. A sizable fraction will turn out not to be planets, and we do not know what that fraction is yet.
So that was my challenge – Kepler measures planet sizes, while I wanted to talk about geochemistry. In just 18 minutes. So, the expected number of planets, size and Earth-like chemistry got confused, and created a misunderstanding.
The family of our Solar System planets seems simple when sorted by size: half of the planets are large (giants) and half of the planets are small (terrestrial). The giants contain a lot of light gases (hydrogen and helium) in their bulk composition while the terrestrial ones contain mostly heavier elements. Too much hydrogen and helium dilute the surface chemistry, while heavy elements and solid surfaces tend to concentrate it. There is one planet in our Solar System where the chemistry has evolved to biochemistry and to a biosphere. In the search for life beyond Earth, the smaller planets are thus the favorite places to look.
The Kepler mission is designed to discover Earth-size planets by detecting and measuring their transits. The Kepler team collects additional information as it works to confirm a planet discovery, but one essential physical parameter Kepler provides is SIZE, the planetary radius. However, is “Earth-size” the same as “Earth-like”? And vice versa?
Kepler is capable of finding Earth-size planets in orbits of moderate temperatures. But most people consider the term “Earth-like” to mean that the planet has an atmosphere, liquid water on its surface, and a temperature conducive to life. In other words, “Earth-like” is often used to mean ‘habitable’. Therefore, Earth-size and Earth-like are certainly not the same. Take the example of Venus, an Earth-size planet whose surface will melt lead.
The term “Earth-like” planet creates confusion. To some scientists like me, who model planet interiors, the term “Earth-like” is a simple short-hand for a bulk composition like Earth’s. It emphasizes the broad difference between gas giants and terrestrial planets, as seen in our Solar System. However, I understand that this is not how it was interpreted by the majority of the media coverage. My definition allows for a whole range of planet sizes to be “Earth-like” planets. Thus, the question – what size planets might be “Earth-like”?, is more interesting. According to my definition, it involves the so-called “super-Earths” – planets larger in size and mass than the Earth, yet smaller than the giant planets. Many super-Earths are expected to have the same properties and potential for life as habitable Earth-size planets.
Kepler planetary candidates, like the 306 released this past June 15th, have estimated orbits and sizes. Sorted by apparent size, the majority of the candidates are found to be Neptune-size and smaller. This is the good news. As of today none of the candidates smaller than 2 Earth radii is in the habitable zone; their orbits are too small, which is why it was easier to spot them after just 43 days. Habitable planets will take a lot more time, as Kepler needs to observe more than one transit.
The first data release is an encouraging first step along the road to Kepler’s ultimate goals, specifically, to determine the frequency of Earth-size planets in and near the habitable zone. However, these are candidates, not systems that have been verified sufficiently to be considered as planets. The distribution of planet sizes may also change. It will take more years of hard work to get to our goal, but we can do it.
The TED Global conference is about ideas worth spreading to a general audience. In my TED talk I decided to discuss the idea that science seems to be at the threshold of a new revolution – of synthetic biology. Ironically, this is happening at the completion of the previous, Copernican, revolution. My point was that the two events are related, and that, tantalizingly, progress in synthetic biology may be accelerated by input from planetary science. This is the core of the project I lead and we call the Origins of Life Initiative (not associated with the Kepler Mission).
The Origins of Life Initiative makes connections between geochemistry and biochemistry. The Kepler mission helps our project by establishing feasibility: if solid planets are common, then we have a shot at trying our lab experiments. This works as long as the planets have geochemical cycles that determine their atmospheric signatures. Hence, planets somewhat larger than Earth are more favorable (Sasselov & Valencia, Sci. American, Aug 2010). The Drake equation gives us an estimate of about 100 million such planets with habitable potential in the Milky Way galaxy. Kepler has not yet weighed in on this yet, but holds the potential to do so in the future.
Dimitar Sasselov: “On Completing the Copernican Revolution“
Characteristics of Kepler Planetary Candidates Based on the First Data Set: The Majority are Found to be Neptune-Size and Smaller
Borucki, W. and the Kepler Team, submitted to Astrophysical Journal
Claims of 100 Earth-Like Planets Not True
by Clara Moskowitz @ SPACE.com
Cosmic Log on MSNBC.com
Millions of Earths? Talk causes a stir
by Alan Boyle
Charlie Sobeck, Deputy Project Manager
Kepler: A Search for Habitable Planets was selected as an Official Honoree for the Science category in The 14th Annual Webby Awards.
What’s a “Webby Award?”
The Webby Awards is theInternet’s most respected symbol of success. Webby Honorees, Nominees andWinners truly represent the best of the Web. The 14th Annual Webby Awardsreceived nearly 10,000 entries from all 50 states and over 60 countriesworldwide.
The Webby Awards ispresented by the International Academy of Digital Arts and Sciences, a650-person judging academy whose members include Internet co-inventor VintonCerf, R/GA’s Chief Bob Greenberg, “Simpson’s” creator Matt Groening,Arianna Huffington, and Harvey Weinstein.
Winners will beannounced on May 4th, 2010 and honored at a star-studded ceremony in New YorkCity on June 14th where they will have an opportunity to deliver one of theWebby’s famous five-word speeches with the world. Past Webby Award winners -and their speeches – include Al Gore (“Please don’t recount thisvote.”), Stephen Colbert (“Me. Me. Me. Me. Me.”), and MichelGondry (“Keyboards are full of germs.”)
So now it’s time to turnthe spotlight on the talented folks who worked so hard to make it happen. Kudosto our website redesign team! Credit goes to Michael Greene for overseeing the project,to teams at JPL and Raytheon, including Joshua Rodriguez, Randal Jackson,Cornell Lewis, Joe Wieclawek, Maryia Davis and Ernest Koeberlein, Harman Smith,Randii Oliver, Erick Zwlaya ; and the Kepler EPO folks, Dave Koch, of NASAAmes, Edna DeVore, of SETI Institute and Alan Gould of Lawrence Hall ofScience, Berkeley.