Hi Kossacks! Since we can post more than one post a day I thought I'd try something in the late afternoon to wrap up the day. Nothing too serious, just a light and frothy drink to carry us through the end of the day. So welcome to Afternoon latte, hopefully there will be enough foam!
In one of the most under appreciated Sci-Fi books of all time, Lucifer’s Hammer by Larry Niven and Jerry Pournelle a heavy comet is dislodged from its orbit by a distant and undiscovered planet in the Oort Cloud and impacts the Earth with disastrous consequences. Your basic sci-fi yarn right? Well, the comet is not coming but two scientists think they have captured the data which will allow them to prove that Tyche (as they are calling it) is indeed out there in the deep dark of the Oort Cloud.
The scientists Professors John Matese and Daniel Whitmire have been hypothesizing about this planet for a long time. They have come to the conclusion that there must be something in out in the Oort Cloud because from an analysis of the long term comets that have been discovered since 1898. The Independent is reporting they are hopeful that they will be proved correct.
The basic theory about how the long term comets are brought out of their orbits and into the inner solar system is that what is called galactic tides (the minute sum of gravitational forces from the starts in our arm of the Milky Way) disturb some of the frozen ice balls in the outer system and they become comets. The problem for the two Profs is that there is a section of the Oort that is out of the plane of the elliptic (where the planets orbit) that way too many long term comets originate from. This number is 20% more than the galactic tides theory would predict and that is significant.
Given this data they think that gas giant is four times the size of Jupiter and if it is really out there it probably formed in another solar system all together. The Oort Cloud bodies are little left over remnants of the formation of the Solar System. About four billion years ago the big cloud of gas that had been condensing finally collapsed enough for our Sun to ignite and the rest of the material in the cloud eventually became the planets. There would not be enough material out there at the edges for something like this to form.
However if a gas giant planet formed in another solar system, perhaps even one a trinary one like the Centori system, the gravitational tug of war between the stars could cause it to reach escape velocity for the system and wonder away. The young Sol system would be strong enough to bring it into a tilted orbit but not bring it all the way into the inner solar system.
Up to now this has all been a lot of supposition, but with the help of NASA’s WISE (Wide-field Infrared Survey Explorer) Observatory there is a chance to prove it. Wise is an infrared observatory orbiting the Earth which was launched in 2009. It has been looking around at the universe for the last couple of years. Why this is important is that the hypothesized planet, Tyche, would be much much warmer than the surrounding objects. Drs. Whitmire and Matese expect that it would be somewhere around -73C because of the internal processes which would heat it. This is compared to the near absolute zero that the Oort bodies would be, somewhere around -273C. That would make Tyche stand out quite brightly in the area of sky.
We will have to wait to find out if Niven and Pournelle and Whitmire and Matese are right. The first tranche of data from WISE will be released in April and it will probably take two whole years to analyze the data enough to determine if there is anything out there hot enough to justify the idea. If it is, we will then be able to point telescopes at the object and determine if our solar system really has a 9th planet after all.
Call me a nerd if you like, it would be true, but I love, love, love this kind of stuff! It is possible, even probable that the Profs are barking up the wrong tree, but think about what it would mean if they are not! We would have a planet from another solar system in our own! Sadly it is not like we would be able to visit in any time in the near future even with and unmanned craft. This planets orbit would be 15,000 times the distance from the sun that the Earth is or about 1.3 trillion miles away. For those that like big numbers is looks like this 1,395,000,000,000 or just shy a quarter of a light year. It has taken the Voyager spacecraft thirty years to get that far.
This is kind of a crackpot theory, really. The balance that would have to happen for a planet to reach escape velocity of its own start system and still be intact is way more tricky to do than say, then there is the issue of our system catching it without bringing it in closer.
Still something the size of Mars hit the early Earth hard enough to knock the Moon off the planet and set it in orbit. That might have been the time when it happened. But since this is science these two Professors are going to find out. WISE is just perfect for testing this hypothesis and if they find that there is not a huge planet out there in the deep dark, they'll just have to come up with some other explanation of why there are too many comets coming from that point in our Solar System.
The floor is yours!