Sunday, January 31, 2016

An "All-American" Eclipse of the Sun Next Year

On August 21, 2017, there will be a gorgeous total eclipse of the Sun visible from the U.S. (and only the US!) The path of what is being called the “All American” total eclipse is only about 60 miles wide and goes from a beach in Oregon to a beach in South Carolina, crossing the country diagonally. (None of our country's largest cities will see it, alas.) A less spectacular partial eclipse will be visible to 500 million people in the other parts of the US and North America.

Astronomers expect tremendous media and public interest in the eclipse and it is not too early to start thinking about how and where best to see it. Eclipse enthusiasts are already busy reserving lodging and viewing space in the narrow region where the total phase can be seen.
The non-profit National Science Teachers Association (NSTA) is making available a popular-level introduction to help explain the eclipse and how to view it. The free 8-page booklet, which I helped write, is available at:…/f…/solarscience/SolarScienceInsert.pdf
Feel free to share this free booklet with anyone who might be interested.
The eclipse information comes from a new book for educators, entitled Solar Science, which I had the pleasure of writing with my long-time colleague and friend Dennis Schatz. It includes 45 hands-on learning experiences (and lots of background information) about the Sun, the Moon, the sky, the calendar, the seasons, and eclipses. You can see the full table of contents and some sample activities at:
Shameless shopping hint: The book could be a wonderful gift for a teacher, a museum or nature center educator, a park ranger, or an amateur astronomer interested in public outreach. See:…
But quite separate from the book, please enjoy the free booklet, and, if you can, think about getting to the total eclipse path as part of your summer planning for next year. The image below, by French photographer Luc Viatour, gives you just a taste of how spectacular a total eclipse can be:

NASA is also planning activities and a national website for the eclipse, as is the American Astronomical Society, the main professional organization of astronomers.  I'll let people know when such other resources are available.  In the meantime, the free booklet from NSTA has an eclipse map and information about what will be visible when from many parts of the U.S.  At the end, there are links to sites where you can see very detailed maps of the eclipse path and even commentary about typical August weather at each place.

Wednesday, January 20, 2016

There is a Possible Super Earth in the Outer Solar System

Out there, way beyond the Sun's family, astronomers have discovered thousands of planets orbiting other stars. Among these alien planets, we have discovered a significant number of "Super Earths" -- planets more massive than our Earth but less massive than the smallest giants in our solar system, Uranus and Neptune. Our solar system has no such Super Earths, but many other systems do; they may be quite common.
Now, Michael Brown and Konstantin Batygin at Caltech, propose that we might just have a Super Earth in our solar system, but so far from the Sun, it takes between 10,000 and 20,000 years to make one orbit! (Pluto, for comparison, takes about 250 years.)
Brown and Batygin have been examining the orbits of icy chunks way beyond Pluto, in the region we call the Kuiper Belt. There are several chunks out there, including one Brown discovered in 2003, called Sedna, that move in an oddly aligned way. After testing many computer models to explain their odd orbit, their best model indicates there could be a planet 10 times the mass of our own Earth, whose stronger gravity is affecting the motions of many objects out where it orbits. Just a few of the affected chunks have been discovered so far and the planet itself has NOT be seen.
So this is a somewhat daring hypothesis, which the two astronomers explain in this brief video:
Please note that our image is a painting that Caltech commissioned. No one knows what this Planet Nine looks like.
Now here is the human side of the story. Michael Brown led the team that discovered Eris, the dwarf planet that is the same size as Pluto, in 2005. When he discovered it, he told his wife that he had just discovered a tenth planet and she had made a good decision in marrying him. Alas, instead of being acknowledged as the 10th planet, Eris caused astronomers to rethink the status of Pluto, and remove it from being the 9th planet. Brown was gracious about it, but you can imagine how disappointing it all was for him.
So now Brown may have "discovered" (or at least predicted) a real new planet. He is already nicknaming it "Planet Nine" and it's so big, no one will be able to call it a dwarf! If it is confirmed one day, he can go back to his wife and tell her, "Well, maybe I only discovered a dwarf planet before, but now I have discovered a real planet at last." Not a bad thing to discuss over dinner!
You can see a video where Brown discusses his role in the Pluto and Eris story at:

Brown and Batygin