The announcement of a possible large ninth planet in our Solar System way beyond Neptune last month caused a lot of excitement, needless to say. If confirmed, it may be similar to “super-Earth” type exoplanets which have been found to be plentiful around other stars, although none, that we knew of, around ours. At this point, however, it is still a well-presented theory. Now, there’s another possibility which has been offered to explain the weird orbits of some of the small Kuiper Belt objects – not a large planet, but rather a second Kuiper Belt consisting of many smaller objects instead.
For a long time now, there have been theories and rumors regarding the possible existence of another planet in our Solar System, far beyond Neptune or even Pluto, often referred to as “Planet X.” Unfortunately, there has been little hard evidence to back up any claims made. But now, new evidence has been presented by astronomers at Caltech which increases the likelihood of another, and fairly large, distant planet in the far outer reaches of the Solar System. How does this compare to other discovery claims for Planet X?
To say that 2015 has been a great year for planetary exploration would be an understatement, with fantastic new discoveries from around the Solar System. From our first ever close-up look at Pluto and its moons, to more evidence for ancient lakes and rivers on Mars (and current briny streams) to weird bright spots and mountains on Ceres, to the continuing study of Saturn and its moons, notably Enceladus, to spectacular close-up views of a comet, it has indeed been quite a year.
Looking ahead to future planetary missions, NASA has selected five new science investigations for refinement over the next year. Later, one or two of those missions will be chosen to actually be launched, perhaps as early as 2020. The selections are part of NASA’s Discovery Program, which had requested the proposals in November 2014. Initially, 27 proposals had been submitted, from which the five current finalists were chosen. The five proposals would study Venus, near-Earth objects, an unusual metallic asteroid and Trojan asteroids.
Jupiter, the largest and most massive planet in our solar system, may be its own worst enemy. It turns out that its central core may …