New Horizons has provided our closest ever look at this fortunately found dwarf planet. Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Inst.
The planet Pluto was discovered because of a mistake.
In 1821 Alexis Bouvard published a table detailing the orbit of Uranus. Other astronomers quickly noted that there were some irregularities, and hypothesised the existence of another planet pulling Uranus out of line. After several more refined predictions, an approximate placement of the 8th planet was found. In 1846 Johann Gottfried Galle at the Berlin Observatory discovered Neptune, just where it was predicted to be.
It wasn’t long before tables of Neptune’s orbit were published and these appeared to show that they were being pulled out of whack by a 9th planet, dubbed Planet X, though the effect was much smaller.
In 1930 when Clyde Tombaugh discovered Pluto it was quickly touted as the famed 9th planet. However, fame soon turned to infamy. The planet was far too small to disrupt the orbit of the massive Neptune (1186km in diameter according to New Horizons).
Though the apparent perturbations have since been shown to be observational error, there are still people who hunt for Planet X (some believing it to be the harbinger of doom, or about to crash into Earth and kill us all). However he WISE infrared survey discounted the presence of a large body out to a distance of one light year, so its not looking likely for any killer planets.
The light of the corona is usually only visible on Earth during a total eclipse. It can be seen with specialist equipment though. Like a space telescope. Credit: Luc Viatour
The Sun’s corona, this aura of plasma that surrounds the main star, is many hundreds of times hotter than the photosphere, the surface that we see. While the temperature of the Sun’s surface is only 6,000K the corona can reach up to 1,000,000K.
Simulation of a cross section of a thread of solar material. All hail hypnothread. ALL HAIL. Credits: NAOJ/Patrick Antolin
No one is 100% sure why this is, though the current leading theory is that it’s probably magnets… or rather that magnetic waves generated by the motions of matter inside the star. These oscillate through the Sun and cause the plasma in the corona to move in a turbulent motion (queue mesmerising gif to left) and the friction heats up the corona.
The Square Kilometer Array (SKA), a radio telescope being built in both Australia and South Africa and expected to actually cover 5 square kilometres of ground, will produce enough raw data to fill 15 million 64GB iPods a day. That’s equivalent to every piece of information sent and received over the entire internet. Twice.
An artists impression of what the SKA antenna will look like. Thousands of these 12m diameter dishes, split between the two sites, will cover the square kilometre.
But it’s alright. You don’t have to rush out and panic buy iPods. Most of that information doesn’t tell us anything and gets thrown out straight away. Working out what to lose and what to keep, however, is one of the most challenging aspects of any project as big as the SKA.