The number of planets falling outside of our solar system (exoplanets) is ever-increasing, as we venture through a new era of space-related discoveries. Armed with sophisticated space telescopes, astronomers have discovered an Earth-sized planet, situated so close to its star that it is likely to be home to large expanses of lava. According to Space.com, the same team also discovered an exoplanet that primarily consists of iron, enabling it to survive the tidal forces exerted by its host star, whilst a separate blue planet is hypothesized to be “raining molten glass.”
This appears to be the tip of the iceberg, as thousands of potential exoplanets await official declaration of their exoplanet statuses. So far, over 800 planets across a number of systems, within the Milky Way, have been discovered. In contrast, scientists’ search for planets similar to Earth have often proven fruitless.
Enormous, high temperature exoplanets, called “Hot Jupiters,” on the other hand, have been rather easy to locate. These planets orbit their host stars at a much shorter distance than Jupiter orbits the Sun, between 0.015 and 0.5 astronomical units (AU); for reference, Jupiter is much further away from our Sun, orbiting at just over 5 AU. These Hot Jupiters partially block rays of light from their stars during orbit, instigating mini-eclipses, which are readily detectable.
An exoplanet (HD 189733b) discovered by the Haute-Provence Observatory, situated in France, has garnered recent attention from astronomers. This exoplanet is capable of blocking only a fraction of the light emitted from its parent star and looks similar to Earth. Despite the media’s insistence on referring to the planet as “the other blue planet,” NASA stress that it is anything but.
The planet’s blue appearance could be caused by high levels of silicate particulate within its atmosphere, reflecting blue wavelengths of light from the orange-dwarf that it orbits. This has lead many researchers to argue that the planet might be raining glass, as silicon dioxide is one of the chief constituents.
The lava and iron planets, called Kepler-78b and KOI 1843.03, respectively, were discovered by NASA’s Kepler telescope. These analyses also measured the degree of blockage of light, which occurred as the exoplanets passed in front of their stars.
Although the extremes of temperature make Kepler-78b a non-viable location to sustain life, there are other planets that closely orbit their host stars, which might be more suitable.
Josh Winn, working from Massachusetts Institute of Technology, and one of the lead authors who delved into the mysteries of these exoplanets, suggests that life might be possible on planets that closely orbit brown dwarfs:
“If you’re around one of those brown dwarfs, then you can get as close in as just a few days… It would still be habitable, at the right temperature.”
The correct temperature is critical to ensuring the exoplanet has sufficient water to sustain life; however, too close and the temperature will destroy any chance of biological entities sparking into life.
Unfortunately, one of the main telescopes responsible for the discovery of these numerous exoplanets, Kepler, has experienced significant malfunction, preventing much of the work from continuing. One of three control wheels was badly damaged, impeding the telescope’s ability to accurately aim, and it would seem that NASA is unable to make reparations. However, Kepler has been hugely successful, confirming the existence of 3,500 potential planetary bodies, and has yielded a fantastic body of data throughout its operation; excitingly, of these 3,500 candidates, 135 have been definitively confirmed as exoplanets by Kepler.
Within a short space of time, astronomers have uncovered a dizzying array of exoplanets, including a massive lava planet, a close-orbiting iron world, as well as an Earth-sized planet that could be “raining molten glass.” Here’s hoping these awe-inspiring space discoveries continue.
By: James Fenner