The Hunt for "Planet Nine"

_Tombstone_

It seems the wonky orbits of small bodies out beyond Neptune may have been caused by a planet 10 times the mass of Earth, with an orbital axis 700 times longer than the distance from Earth to the sun. It's orbit is so large at 15,000 years they ain't no clue where to look and even if they could point Hubble at it, it would barely register.

The proposed planet is large enough to have retained a small amount of heat from its formation. Using Uranus and Neptune as a model, clever folk have calculated this would be just tens of degrees above absolute zero – which means it would faintly radiate millimetre-length radio waves.

So they have to get Clever to find it and are looking at using cosmic microwave background (CMB) Telescopes, these scopes look for remnants of the first light left over from the big bang, which is at the same wavelength as P9 but most of these scopes are down in Antartica so may be able to point in the right direction. But using Neptune as a calibration source they just have to look for big stuff moving and can do big chunks of the sky in a matter of Months.

Another way to find it is to use the Data from the Cassini Probe thats off out flying around Saturn for the last 10 years.

Astronomers have used radio-ranging data from the probe to make a model of the motion of all the large bodies in the solar system. Fienga’s team tried adding Planet Nine into the mix and found they could rule out the planet’s existence in around half of its potential orbit, as its tug from these locations would have shown up in the Cassini data.

The probe’s mission is due to end in 2017, but the team estimate that extending its life to 2020 would narrow the search even further. “It could help extend the forbidden zone,” says Fienga. Data from NASA’s New Horizons probe, which flew by Pluto last year, and Juno, due to arrive at Jupiter this July, could also rule out other parts of the orbit, she says.

Planet Nine hunters enlist big bang telescopes and Saturn probe

http://www.aanda.org/articles/aa/pdf/forth/aa28227-16.pdf

cnocbui

It would have been pure fairytale if they found it fairly quickly and it turned out they could redirect New Horizons to it, but being way off the plane of the ecliptic and 80° or so off to the side, that isn't going to happen.

animaal

Unfortunately, amateurs won't be able to see this planet, even with decent amateur equipment - despite being quite a large object, it's expected to be at the far end of a very elongated orbit.

But if we can hang on for 10,000 years or so, I wonder if it might pass close enough to be visible to us...

_Tombstone_

More evidence from weird kuiper Belt object movements.

http://www.independent.co.uk/news/science/planet-nine-scientists-find-more-evidence-that-hidden-planet-is-sitting-at-the-edge-of-our-solar-a6954986.html

_Tombstone_

Planet 9 takes shape

Astrophysicists at the University of Bern have modelled the evolution of the putative planet in the outer solar system. They estimate that the object has a present-day radius equal to 3.7 Earth radii and a temperature of minus 226 degrees Celsius.