“If you say, ‘We have evidence for Planet X,’ almost any astronomer will say, ‘This again? These guys are clearly crazy.’ I would, too,” said co-author of the study Mike Brown. “Why is this different? This is different because this time we’re right.”
The story of “Planet X” is a long one. Time after time scientists have put out studies claiming to have evidence for a new outer planet, but none have come to fruition. But now a group of scientists truly believe they have found firm evidence for a ninth planet of the Solar System, way beyond the orbit of Neptune. The planet, estimated to be about ten times more massive than Earth, orbits around twenty times further out from the Sun that the current outermost planet Neptune does.
Mike Brown and Konstantin Batygin, researchers at the California Institute of Technology (Caltech), have produced a study that concludes that “Planet X” probably exists. The strong belief they have that such a planet orbits on the outskirts of the Solar System is based on models produced of Kuiper Belt Objects and their orbital properties.
The Kuiper Belt is an icy region of the Solar System beyond the orbit of Neptune. There are six Kuiper Belt objects in particular that researchers are focused on, one of which being the minor planet Sedna. The objects all orbit the Sun in elliptical paths of the same direction, and share the same 30 degree tilt relative to the plane of the planets of the Solar System. It is believed the odds that this is purely a coincidence is 0.007%.
“Basically, it shouldn’t happen randomly,” said Brown. “So we thought something else must be shaping these orbits.”
“We realised the only way we could get them to swing in one direction is if there is a massive planet, also very distant in the Solar System, keeping them in place while they all go around the Sun,” explained Brown.
However, planetary scientist David Jewitt believes this not to be the case. The renowned professor of astronomy says that a 3-sigma percentage based on just six KBOs strongly weakens their case.
“I worry that the finding of a single new object that is not in the group would destroy the whole edifice,” says Jewitt, who is at UC Los Angeles. “It’s a game of sticks with only six sticks.”
Regardless, Brown and Batygin now believe that they have a rough idea as to where to look for the mysterious planet. No doubt, in the next few weeks, months and years astronomers around the world will be pointing their telescopes towards this region of the sky in the hunt for the ninth planet.
“There are many telescopes on the Earth that actually have a chance of being able to find it,” said Brown. “And I’m really hoping that as we announce this, people start a worldwide search to go find this ninth planet.”
Indeed, Brown and Batygin plan to also join the hunt using Japan’s Subaru 8-meter telescope based in Hawaii. The telescope has the light-gathering ability to detect an object as faint as “Planet X” and has an enormous field of view, ideal for covering large areas of the night sky. Brown believes that it will take around 5 years for a full scan on the region to be completed.
Primary source: http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22/meta
The Cassini-Huygens spacecraft is one of the great collaborations in spaceflight history, with the combination of NASA, ESA and the Italian Space Agency proving to be a resounding success. The mission is considered by most in the field of space and astronomy to be one of the greatest scientific endeavours in space, giving us a greater knowledge of the ringed gas giant Saturn and its intriguing moons. The Huygens lander visited the surface of Titan in 2005 and Cassini has orbited the ringed planet since arriving in 2004, collecting valuable data for scientists back on Earth.
The spacecraft was launched on October 15, 1997 by the Titan-IVB/Centaur rocket from Space Launch Complex 40 at Cape Canaveral, Florida. In order to reduce the fuel required, the spacecraft used a number of gravity assists to increase velocity and extend its orbit around the Sun further out. Cassini flew past Venus twice (in April 1998 and June 1999), once by Earth (in August 1999) and finally Jupiter (in December 2000). In July 2004 the spacecraft at last arrived at the ringed gas giant Saturn.
In December the Huygens probe was ejected from the spacecraft and set on a trajectory towards Titan. The probe arrived at Saturn’s largest moon in January and began descending through Titan’s atmosphere on January 14, 2005. The probe revealed an unprecedented view of a mysterious world as it descended through the moon’s atmosphere. Huygens survived for 72 minutes on the surface, before the batteries ran out and data ceased to be sent back to Earth.
Cassini has maintained orbit around Saturn and its moon since its arrival in 2004. It carries 12 scientific instruments able to carry out scientific measurements such as examining the gravitational field of Saturn and its moons, determining structural and chemical composition of surfaces and atmospheres of the Saturn system, and much, much more. The probe is powered by radioisotope thermoelectric generators (RTGs), designed to power the probe for way over a decade. Cassini communicates with scientists back on Earth using three microwave antennas. The large white dish located at the head of the spacecraft is the high-gain antenna, making it the fastest antenna to send and receive data with. This is used to send back the incredible images we stare in awe at.
Like all good things, they must come to an end. Indeed, the Cassini-Huygens spacecraft will complete its mission in 2017. The Cassini probe will carry out daring new orbits, known as proximal orbits, in 2016 as NASA scientists aim to gather as much data with the remaining fuel available. Assuming all goes to plan, the Cassini spacecraft will plunge into Saturn’s gaseous atmosphere to a fiery finale, marking the end of one of the greatest missions in spaceflight.