In the recent issue of Nature is an article reporting the most earth-like planet yet discovered outside our solar system and, importantly, one that is very likely to be watery...perhaps as much as 50% water.

From the News and Views in this week's Nature:

The hunt for Earth-like worlds has taken a major step forward with the discovery of a planet only 2.7 times larger than Earth. Its mass and size are just as theorists would expect for a water-rich super-Earth...

Charbonneau's team1 has found that the small, faint star GJ 1214 undergoes repeated dimming of 1.3% for 52 minutes every 1.6 days. The only plausible interpretation is that a planet orbits the star with an orbital period of 1.6 days and that it has a radius that is 12% that of the star. Good estimates of the star's radius (21% that of the Sun) put the planet's radius at only 2.7 Earth radii. Such a small planet orbiting a star other than the Sun is an extraordinary find. With the tools currently available, only one other extrasolar planet has been reported that is thought to be close in size to Earth, namely CoRoT-7b, at 1.7 Earth radii. The new planet, which is only about 13 parsecs away, is named GJ 1214b. Importantly, it pulls gravitationally on its host star, causing the star to move with a speed of 12 m s−1, which the team has detected through measurements of wavelength shifts in the star's light (the Doppler effect). The planet's inferred mass is a mere 6.6 Earth masses, which, when combined with its radius, leads to a density of 1.9 g cm−3. By contrast, Earth's average density is much higher, at 5.5 g cm−3. Because water has a low density of about 1 g cm−3, the chemical composition of the new planet is probably some admixture of rock and water, with perhaps a small atmosphere of hydrogen and helium...

That solid material forms the building blocks of large planets such as Saturn and Neptune, and perhaps smaller planets as well, such as the new one1. But the density of 1.9 g cm−3 for this new planet imposes a constraint on the relative amounts of each constituent. To keep the planet's density that low requires that it contains large amounts of water. If the planet were pure Fe and silicates, its density would be similar to Earth's. It must contain a huge amount of water, roughly 50% by mass.  read more »

Sometimes you meet someone you like and respect and can talk to, but don't always agree with on every issue. The best part about such encounters is it gives you a chance to hone your arguments in a respectful environment.

Argue abortion with Sarah Palin and it is useless because she is an idiot. Argue abortion with an intelligent, respectful opponent and you get the chance to refine your arguments.

Which is what I am doing now.

The fight over abortion comes down to two fundamental, and in this case seemingly (but not necessarily) opposing, values: the value of life and the value of a person's right to have legal jurisdiction over their own body. Both are important values, so in many debates over abortion where people are not respectful of eachother, it appears that one of these two values is being neglected by each side. I believe this does not have to be true.  read more »

No...not "Jon Stewart." I'm talking about John Stewart, Provost of John Muir College at the University of California, San Diego. I found out this morning that John Stewart, a man who had a profound affect on my life in college, died last year.  read more »

Here are some events going on in Brooklyn:

Brooklyn Children's Museum

Grab your mittens and your magnifying glass, it's time to become a snow scientist at Brooklyn Children's Museum! The Science of Snow, Saturday, January 27 from 1-3pm, gives you an up-close look at this icy winter wonder. Learn how animals survive in the winter, and explore snowy weather strategies used by different cultures. Conduct experiments to see how salt effects ice, and investigate snowflake crystals. Make a snowy decoration to take home. Ages 6+

Please note: Due to the Museum's ongoing expansion, the Totally Tots gallery will be closed January 16, 2007. A special early learner gallery will open February 10, 2007. Please contact (718) 735-4400 x321 for additional information and questions.

145 Brooklyn Avenue

Brooklyn Museum

Come to the Brooklyn Museum to see the newly opened Ancient Egyptian Magic: Manipulating Image, Word, and Reality, a special exhibition in the galleries containing Brooklyn MuseumÂ’s world-famous collection of ancient Egyptian art. Magic presents twenty-one objects that explore how the early Egyptians addressed the unknown forces in the universe. It is also the opening weekend of The Eye of the Artist: The Work of Devorah Sperber. Sperber, a New York artist presents seven works including her eye-catching thread-spool installations recreating Da VinciÂ’s The Last Supper and the Mona Lisa that can only be fully seen by looking through an optical device. This weekend will also be your last chance to see Ron MueckÂ’s amazingly life-like figure sculptures that have been leaving thousands of visitors in awe!  read more »

Torrington, Connecticut

For normal people, Christmas is a one or maybe two-day holiday. For me, by virtue of having married into a vast Italian-Irish family, it is a weeklong, inescapable frenzy, and I am beginning to buckle under the strain.

Again, normalcy, the way things should be. You have dinner on Christmas Eve, unwrap presents that night or the next day, get drunk on eggnog, done. Finished. Move on.

We, that is hubby and myself, don't do that. We set out, this year, on Friday. We are still here, midway in our peregrinations to visit, it seems, every single individual in North America with whom hubby shares even the tiniest sliver of DNA. And at every stop along the route, the ritual continues: god-awful music - I am ready to exhume Bing Crosby and burn the remains - too much food, too much drink, too much too much too much. We do this death march by rental car; at last checking, the damned thing had recorded over five hundred miles of travel. This is not, emphatically, the way things should be.

And we're not done yet. The agony continues.