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: https://www.youtube.com/watch?v=6poHQ2h00ZA

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: https://www.youtube.com/watch?v=7pbj_llmiMg

Brown and Batygin

Astronomy Talks Have a YouTube Channel

The Silicon Valley Astronomy Lectures, which I have the pleasure of moderating, feature noted scientists giving nontechnical illustrated talks on recent developments in astronomy. I am happy to announce that they are now available on their own YouTube Channel, at:
http://www.youtube.com/SVAstronomyLectures/

The talks include:

* Frank Drake (the father of the search for radio signals from civilizations in space) discussing his modern view of the Drake Equation,

* Michael Brown explaining how his discovery of the dwarf planet Eris led to Pluto being kicked out of the planet club,

* Alex Filippenko (selected as the U.S. Professor of the Year, a few years ago) talking about the latest ideas and observations of black holes,

* Natalie Batalha (mission scientist for the Kepler Project) sharing the latest planet discoveries from outside the solar system, and

* Chris McKay updating the Cassini discoveries about Saturn's moon Titan (the only moon known to have an atmosphere thicker than Earths).

The lectures are taped at Foothill College near San Francisco (where I teach), and co-sponsored by NASA's Ames Research Center, the SETI Institute, and the Astronomical Society of the Pacific.

Note that the top page of the YouTube channel shows the lectures in the order they happened to be uploaded to YouTube. If you want to see them in chronological order, select the Playlist option.

Both new and older talks in the series will be added to the channel as time goes by. Many well-known astronomers have given talks in this series since its founding in 1999; recent lectures are being recorded so that people around the world can "tune in."

(About the picture: This is a false color image of the Helix Nebula, the last gasp of a dying star located about 650 lightyears away.  A relatively low-mass star is collapsing and losing its outer layer in a final internal adjustment before it dies as a white dwarf.  The material the star loses is excited by the energy of the shrinking star and set to glow.  In this image, infrared radiation (as measured from the Spitzer telescope in space) is shown in green and red, ultraviolet radiation (as measured by the GALEX telescope in space) is shown in blue.)