Understanding Pluto's Neighbors

Later this month Chicago's Adler Planetarium will be premiering its new show Planet Nine. The program will discuss the New Horizons mission to Pluto, the dwarf planet's neighbors, and the search for Planet Nine (though I still argue Pluto should remain the ninth planet).

And in case you would like to read a little more on some of the other dwarf planets in the show (including the one that cost Pluto its place among planets), here is what the Adler Planetarium shared on its website:

Eris

The discovery of Eris prompted the International Astronomical Union to agree on an official definition of “planet” in 2006. Eris is almost exactly the same size as Pluto, yet it weighs 25 percent more. It is also remarkably bright, reflecting 97 percent of the light it receives from the Sun. To put that in perspective, the Moon reflects just 12 percent of the Sun’s rays.

Haumea

Shaped like a football, Haumea rotates incredibly fast—once every four hours! This object’s fast rotation causes its unusual shape. Were it rotating more slowly, gravity would pull it into a sphere, which is why it qualifies as a dwarf planet even though it isn’t round.

Sedna

Sedna’s orbit takes it deep into the far reaches of the Solar System, almost 20 times as far as Pluto ever goes. A year on Sedna is 11,400 times as long as a year on Earth! But perhaps the most interesting thing about Sedna is the hints it gives us that there are many more objects yet to be found at the edges of our cosmic backyard.

In the meantime, here is a video sharing more about the proposed Planet Nine from Astronomer Konstantin Batygi.

Another Finding on a New Ninth Planet

Poor Pluto.  Even after all the amazing images from the New Horizons spacecraft, telescopes are peering beyond the dwarf planet looking for a ninth "planet," since the solar system is now one short and Pluto does not stack up. 

Researchers  and Mike Brown at the California Institute of Technology (Caltech) found indications that a planet about 10 times the size of Earth is lurking further our in our solar system.  This planet would be between the size of Earth and Neptune (shown below). 

One of the researchers is Mike Brown, the scientist that found the Kuiper Belt dwarf planet Eris that led to the demotion of Pluto. You can certainly call him determined. 

This assumed planet is so far out that it may take between 10,000 and 20,000 Earth years to circle the sun.  If you don't like winter, you certainly will not like a winter that lasts thousands of years (and any planet that far out would not have much of a summer anyway). 

Also, being about 200 astronomical units from our sun, it is five times more distant than Pluto.  Hence, we can point the New Horizons spacecraft at the proposed planet if we are willing to wait at least another 40 years for an answer (assuming the spacecraft has sufficient fuel and a clear destination). 

Here is a video from Caltech that explains this recent discovery.  You can also view more on the search for the ninth planet on this very helpful site at findplanetnine.com.