Imagine living on a planet where you could celebrate almost three birthdays in one day - Think that is just out of this world? Well actually it is - About 700 million light years away in the small constellation of Lyra, where scientists have discovered an exoplanet that zips around its star in a speedy 8.5 hours!
The discovery of Kepler 78B that was revealed on August 19th, was made by a team of researchers from Boston's Massachusetts Institute of Technology (MIT), who were investigating how close a planet could get to its sun before it got obliterated. While they had encountered planets that were close enough to orbit their stars within a few days, finding one that could do it a few hours seemed almost impossible.
That's because the closer the planet is to its sun or moon, the stronger the gravitational force - At some point it reaches what is called the Roche limit, a distance that is so close that it turns into a molten volcanic planet or even worse, is torn apart or burnt by its own sun.
In order to try discover these super close planets, the scientists began by carefully weeding through the data collected by NASA's Kepler Space Probe. Launched in 2009, its mission is to search for earth-size and smaller planets within what scientists call the 'habitable' zone, in the hopes that one of them may be sustaining life. It does this by monitoring thousands of stars for dips in their light that occur when a planet is passing between the unmanned space telescope and its star. Once the researchers had found possible suspects they supplemented it with their own ground observation. As you can imagine, the whole process was like looking for a 'needle in a haystack'!
But the scientists persevered and after examining readings from over 150,000 stars, finally came across Kepler 78b, which is 40 times closer than Mercury is to our sun. In fact the Earth-size planet is so close that researchers believe they will be able to measure its gravitational influence on its sun. This will allow them to calculate Kepler 78-b's mass, something that has never been possible for a planet of this size.
But before you start packing your bags in hopes of more birthday gifts, not to mention an ultra-short school year, here are a few things you may want to keep in mind. Kepler 78-b is tidally locked, which means that it does not rotate around its own axis. This means that one side is permanently light and the other, pitch dark! And if that is not enough to deter you, how about this? Thanks to its proximity to its sun the temperatures on this exoplanet exceed 5,000°F on the side that faces the star and about 4,400°F on the side that is away. This means that the planet's surface resembles one giant boiling pot of lava!
And if you think Kepler 78-b is impressive, how about this? Another team from the same institution believes that they may have discovered one that is so close, that it can zip around its star in 4.2 hours! Called KOI 1843.03, it still needs to be vetted further but the researchers who published their research in the August edition of Astrophysical Journal Letters, speculate that given how close it is to its sun, the only way it could be surviving the tidal forces is if it was made from solid iron!
And while neither of these planets are habitable, the scientists maintain that close proximity to stars does not always mean that the planets will not be able to sustain life. There may be some that are revolving around cooler dwarf stars, in which case, their closeness would not result in harsh temperatures. Unfortunately until they find those, we will all have to settle for just one birthday, every 365 days!
Resources: csmonitor.com, gizmag.com