Five New Worlds in the Universe

The first planets discovered by NASA’s satellite Kepler

The Kepler satellite, launched by NASA in March 2009, has started bearing its first fruits. The principal investigators of the space mission searching for planets outside our Solar System announced the first discoveries last Monday, at the annual meeting of the American Astronomical Society, taking place these days in Washington DC, USA.


Five new planets, orbiting stars at distances of more than 100 light-years from our Sun, have been detected during Kepler’s first months of observations. They now join the count of extra-solar planets discovered so far, amounting to over 400. Thanks to advances, obtained only in the past 15 years, astronomers can better understand how planets and planetary systems like our own form around other stars.

The new worlds discovered by Kepler are very different from our planet, being much larger and much hotter than the Earth. Four of them are even larger than Jupiter, the biggest planet in the Sun’s court; only one of them is slightly smaller, with a size similar to that of Neptune, another giant in the Solar System.

Due to their high temperatures of more than 1200 degrees Celsius, it is almost impossible to suppose that these planets host any form of “earth-like” life. However, the goal of the Kepler mission is ambitious: in the upcoming three years of observations it will be very likely that astronomers will detect planets similar to our own, somewhere in our galaxy.

The fact that the first planets to be discovered are giant ones is a sort of “drawback” of the method employed in the search. Kepler makes use of the so-called transit technique: when a planet orbiting a star intervenes between it and us, the star becomes clearly dimmer, as its light is obscured by the planet. Through monitoring hundreds of thousands stars over long time scales, astronomers study how their luminosity varies and can thus reveal the presence of one, or more, planets around them.

The bigger the planet, the more pronounced is its obscuring effect upon the star hence the easier it is to discover. But size isn’t everything, as also the distance from the parent star plays an important role. All five of these worlds lie very close to their sun, and only take a few days to complete an orbit around it. In comparison, the Earth takes a year and Mercury, the closest planet to our Sun, takes about three months to complete a so-called revolution.

The vicinity of these planets to their parent star is indeed another factor in their discoverability: as they orbit so fast around it, they obscure the star very often, thus making it more likely for astronomers to notice over human time scales. A planet that takes months or years to orbit its star is more elusive, although not absolutely impossible to detect.

“It's only a matter of time before more Kepler observations lead to smaller planets with longer-period orbits, coming closer and closer to the discovery of the first Earth analog,” said Jon Morse, director of the Astrophysics Division at NASA Headquarters in Washington.


The discovery of planets located at “reasonable” distances from the star they orbit is a crucial step towards the quest for other worlds that could theoretically host life forms. The so-called “habitable zone” defines the range of distances around a given star where the temperature is such to guarantee liquid water on a planet’s surface. In the case of our Sun, this distance corresponds roughly to Earth’s orbit — closer or farther away, the development of human life “as we know it” couldn’t have been possible.

None of the over 400 planets discovered so far lies in its parent star’s “habitable zone”. However, astronomers believe in Kepler’s capabilities and hope that it will be able to detect some in the upcoming years. Furthermore, the question about the existence of life elsewhere in the universe is not restricted to living forms similar to those inhabiting our own planet. “In other regions of this Universe, everything I can’t even imagine exists,” Bluvertigo (*) sang over ten years ago. Let us be surprised by the unimaginable.

(*) Bluvertigo are an Italian rock band formed in the mid-nineties and still active. The quote refers to the popular song “Altre forme di vita” (translated, “Other forms of life”) from 1997.

The image on top shows Kepler, launched on March 6th, 2009 from Cape Canaveral, Florida, USA. The image below is an artistic representation of one of the newly discovered worlds. Credits: NASA/Kim Shiflett and NASA/JPL-Caltech/T. Pyle (SSC), respectively.

Translated from Il Denaro, 07.01.10

Incidentally...

... since I've just mentioned Science in School, I guess there is no harm in a little publicity to this magazine I've been collaborating with for almost three years now - mostly translating into Italian, and finally with my first writing effort. ever. (despite the delay...)


It's a great tool for secondary school science teachers and students, with feature articles about the latest discoveries in every scientific field, bios and profiles of scientists and teachers, ideas for didactic activities, and much more...

If you subscribe on their website, you can receive a printed copy of the magazine in English for free. Otherwise, many translations in several European (and non) languages are available online, courtesy of many volunteers and enthusiasts - just like me!

Interview on Science in School

Finally, after a gestation longer than a year, my interview to Alessandro has finally been published on Science in School!
Here is an excerpt from it:

A star-struck teacher in Italy

Research offers exciting and challenging job opportunities, but sometimes the price to pay in terms of personal sacrifice is very high. CM interviews a young astronomer who found satisfaction in the classroom – teaching mathematics.

Astronomy has always been Alessandro Berton’s greatest passion: after his undergraduate studies at the University of Padua, Italy, he moved to the Max Planck Institute for Astronomy in Heidelberg, Germany, for his PhD. His research focused on the development of new, cutting-edge techniques to detect extrasolar planets. The quest for planets outside our solar system has been one of the most fascinating topics in astronomy for the past 15 years, and Alessandro was thrilled to be a part of it. Yet something was missing.

“During those years, I always felt the lack of social, human interaction – a lack that is typical of many research environments,” he explains. “I longed for a job where I could spend more time with other people than in front of my computer screen.” Hence, a few months after receiving his PhD, Alessandro enrolled in the Italian high-school teacher-training program, and at the same time he began to teach mathematics to his very first students.

[...]

Read the full text on the website of Science in School.

I'm finally on my way to becoming a science & society opinion writer... or, well, whatever. yay!

Physics: the Nobel seizes the light

The prize goes to Willard Boyle and George Smith, fathers of digital photography

On Tuesday, October 6th, the Nobel Prize in Physics 2009 has been awarded to Willard S. Boyle and George E. Smith, the fathers of digital photography. In 1969, the two scientists from Bell Laboratories, in New Jersey, USA, invented a device able to capture light without using photographic film — the so-called CCD (Charge-Coupled Device).

The technology behind the CCD exploits the photoelectric effect, through which light is transformed into an electric signal. The explanation of the photoelectric effect won Albert Einstein the Nobel Prize in 1921. Boyle and Smith faced the challenge of converting this effect into a practical application, and designed a sensor able to catch light at several different points (called pixels) and to transform it, over an extremely short time lapse, into electric signals to then be transported and reproduced on a monitor or stored in a file.


The CCD has revolutionised photography and our approach to it for ever, as it is the very heart of tens of millions digital cameras produced in the world, including those integrated into many mobile phones and other gadgets. However, digital photography meant an even more remarkable revolution for science, and for astronomy in particular, a field which literally lives off the images of the sky.

All current professional telescopes are in fact equipped with digital sensors, vastly more sensitive than the old photographic plates astronomers made use of until only a few decades ago. Furthermore, CCDs can be used again many times and their output signal, being already in digital form, is ready to be stored and analysed by computers. In fact, without this new technology, it wouldn’t have been possible even to conceive the massive catalogues containing detailed information about hundred of millions of far-away galaxies, which allowed astronomers to understand the properties of the Universe better and better.

Boyle and Smith shared the most prestigious of all scientific awards with physicist Charles K. Kao, for his work concerning the transmission of light signals through optical fibres. Optical fibres, just like the CCD, also contributed to the digital revolution, making the sharing of data and information possible over increasingly short time intervals. Without them, the internet as we know it could not exist.

It is interesting to note how, during the International Year of Astronomy 2009, the Nobel Prize in Physics has been awarded to three scientist whose research focussed on light and has contributed to the production of vital tools for astronomers, professionals and amateurs alike.

Image credit: NASA

Translated from Il Denaro, 08.10.2009

Dr.Rer.Nat.

Planck and the Cosmic Microwave Background

The European Planck surveyor satellite will map the entire sky at microwave wavelengths - why is this important? Scientist will be able to scrutinize models which explain the formation of galaxies by measuring fluctuations in the distribution of dark matter, only a mere 300 000 years after the big bang. These fluctuations manifest themselves as small variations of the mean sky temperature of 3 degrees Kelvin and have been generated when the first atoms were formed in cosmic history. From these seed fluctuations larger and larger objects were assembled by gravity which finally resulted in the formation of galaxies and clusters of galaxies. Important cosmological parameters are the amplitude of these seed fluctuations and the mean density of matter, which Planck will be able to measure.


A large part of the scientific programme is devoted to so-called secondary anisotropies: these are fluctuations of the sky temperature which are generated by the interaction of photons of the microwave background with the large-scale distribution of galaxies. There are basically two categories of interactions: gravitational lensing, which can be used for precision measurements of cosmological parameters, and Compton-interactions with electrons of the hot gas inside clusters of galaxies - a potential new powerful way of detecting clusters of galaxies.

Planck's advantage over previous experiments is its high sensitivity and angular resolution: it can measure fluctuations of a few microKelvin, and its angular resolution is better than a tenth of a degree. The survey will be carried out from the Lagrange-point L2, at roughly 1.5 million kilometers from Earth - 5 times the mean Earth-Moon distance. The science team of Planck comprises about 500 scientists who are anxious to see the satellite launched on 14 May 2009, after 15 years of preparation.

Written by Bjoern Malte Schaefer
Appeared in the Italian translation on Il Denaro, 14.05.2009

Image: map of the microwave sky as observed by NASA's satellite WMAP, launched in 2001. Different colours represent the tiny fluctuations in temperature: the difference between red and blue spots is only 0.0002 degrees. Planck's maps will be even more precise than that. Credits: NASA/WMAP team.

A high for geeks

Ok, these days all the astronomers and astrophysicists I know - and, with me being a geek, this is a substantial fraction of the people I know and hang out with - have been overly excited with the launch of Planck and Herschel, the two satellites I mentioned in the previous post.

Will they launch them?
When?
Why is the launch being constantly delayed later and later?
Will they be launched eventually?
Today?
Tomorrow?
In two weeks?

Please, shoot the freaking rocket!
And indeed, they did. :-)


And, although I would have never expected neither me nor some of my friends exhibit a similar reaction, we were in fact all somehow high, and strangely happy for the two big thermometers finally flying in the sky.

They say Planck is super-cool.
The coolest thing in the universe.
Literally.
Well, almost.
Well, only for a year.

Well, whatever. Once a geek, always a geek.

In the previous post, I promised to write more about Planck and what it's going to probe, the CMB. Which is great, and cool, yay! However, I'm also *pretty* busy with something else, just this little thing, you know... my phd defense... so sorry, Planck high or not, I'm clearly busy. Busy freaking out.

But don't despair! I delegated the explanation of the mysteries of the universe that will be unravelled by Planck to my friend and colleague Bjoern, who happens to be a much more respected authority than myself, mainly about everything, and in the specific case, about the CMB, of course --> see next post.

Image: abridged from Andy Riley, The Book of Bunny Suicides.
Credits: well, my friends :-)

Disclaimer: the US flag is not supposed to be there!!! Planck is not a US mission, but mostly European (ESA)!!!

We decline responsabilities.
It's a poetic licence.
Please, forgive us.
Turns out, we're not that geek, after all.