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.
Was there ever life on Mars? That is one of the longest-running and most debated questions in planetary science, and while there have been tantalizing clues, solid evidence has been elusive. Now there is a new piece to add to the puzzle, which may be one of the most interesting yet. As first reported on Smithsonian.com, odd formations composed of silica seen by the Spirit rover, nicknamed “cauliflower” for their shapes, may have been produced by microbes, new research suggests. They are very similar to some silica formations on Earth which are found in hydrothermal environments and are known to have formed with the help of microscopic organisms.
New Horizons has shown Pluto to be a diverse world, more so than many scientists had anticipated, with tall mountain ranges, vast glaciers, a blue-colored layered atmosphere, and possible ice volcanoes. One thing, however, which seemed to be relatively lacking, was exposed water ice. Not much had been seen on the surface, not even in the glacial regions, which are composed of other ices instead. But now, new data indicates there actually is more water ice than had originally been thought.
We’ve all seen the commercials for the Energizer Bunny, which keeps going and going and going… it just never seems to stop. This makes for an interesting analogy with the Opportunity rover, which is just now passing its 12th anniversary on Mars. Not just 90 days, as hoped for, but 12 years and counting. Incredible. And in that time, Opportunity has helped to fundamentally alter our understanding of this fascinating world.
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?
As has been reported previously, there is something weird going on around a star which is a little over 1,400 light-years away. Astronomers are still baffled as to just what that is, and theories have ranged from a huge mass of comets to alien megastructures. Indeed, comets had become the leading explanation offered for the star’s odd behaviour, although that was really just the best of a bunch of ideas which all had flaws in them. Now, new research shows that the comet explanation is even less likely to be the answer, although the actual explanation is still as elusive as ever. Needless to say, this has resulted in a lot of discussion and debate in the past few months.
Another beautiful view of Pluto, taken by New Horizons as it passed by the dwarf planet on July 14, 2015. Pluto is backlit by the Sun, showing the hazy blue colour of its thin atmosphere, a view never possible from Earth. Image processing by Roman Tkachenko. It is also now the current header image for the blog. Larger version available here.
Instead of being little more than a frozen and unchanging rocky iceball, Pluto has been revealed to be a complex and dynamic little world, with mountains, valleys, vast icy plains, glaciers and a hazy, layered atmosphere. The New Horizons spacecraft is continuing to send back data, even though it is now long past Pluto since its historic flyby last summer. Seen up close for the first time ever, Pluto is starting to share its secrets, including how it can be a geologically active place despite being so far from the Sun; of particular interest to scientists are the icy, crater-free plains composed of nitrogen ice, which churns and moves very slowly, sort of like the globules in a lava lamp. These plains are like a huge nitrogen ice “sea,” bordered by tall mountains and glaciers.
The Dawn spacecraft just recently entered its lowest and final orbit around the dwarf planet Ceres, providing the closest look ever at the puzzling world. Dawn will, of course, be taking thousands more high-resolution photographs, but what else will it be doing during the remainder of its mission? Various aspects of the mission will study Ceres in unprecedented detail.
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.