Each and everyone of us – no matter how daredevil we are – will find it a little scary to step into the unknown. Now imagine the space. We have not stepped outside a certain point in our solar system. What’s beyond that is totally unknown to us. How scary can it be? Now imagine the horror of discovering something where everything we know, everything we have constructed on basis of our preconceived assumptions just breaks. Rules of physics and that of chemistry just change! That is what the Death Planet is all about. It is an extrasolar planet that has changed every notion of ours as far as we have learned and hypothesized about the creation of planets. So, what is so unusual about this exoplanet? Why are scientists so baffled? Let’s find out…
Where is the Death Planet located?
At a distance of 325 light years from our home planet Earth, the Death Planet sits in the Phoenix Constellation. This means that in order to even reach the planet, we need to travel the distance equivalent to the distance traveled by light in 325 years. That’s quite far but in astronomical terms, it is very close to us.
Death Planet name, size and discovery
This extrasolar planet or exoplanet that has been nicknamed as the Death Planet is actually cataloged as WASP-18b. It orbits around a star that has been named as WASP-18. This Death Planet is also categorized as ‘hot Jupiter’.
The WASP-18b is a gas giant that orbits its host star at a very close distance. The proximity of the orbital distance makes the planet a really hot one. The high temperature of the planet is what compels the astronomers to call it as a ‘hot Jupiter’.
Now the question is, ‘just how big is the Death Planet?’
It is really massive. In fact, it is 10 times more massive than our own gas giant – Jupiter. So, it is really an enormous planet that is Odd, really Odd!
The planet was first observed in 2009. The two telescopes responsible for its discovery are the Hubble Space Telescope and the Spitzer Space Telescope.
What makes Death Planet so Odd?
You must be wondering by now that a planet big is not that unusual. There are far massive planets such as the OGLE-2016-BLG-1190Lb. So, what really makes the Death Planet so odd?
The answer to this question lays hidden in its atmosphere. We know that the atmosphere of a planet is actually made of molecules that behave like sunscreen. These molecules trap the UV rays from the star and convert them into heat energy and sends it directly down below on the planet. In case of Earth, it is ozone that works as the sunscreen. In case of other observed exoplanets, the job of the sunscreen can be done by titanium oxide or other compounds. This titanium oxide on Earth is present in sunscreen ingredients and also as paint pigment. The sunscreen layer is present in the Stratosphere of the atmosphere.
The problem with the Death Planet or WASP-18b is that its stratosphere consists of no known sunscreen as found on exoplanets discovered so far. Astronomers have studied the light that is emitted at infrared wavelength by the atmosphere of the planet. Infrared wavelengths are used for studying the spectral fingerprints of water and various other important molecules.
The problem is that when WASP-18b’s atmosphere’s infrared wavelengths were studied using computer modeling, the scientists at Goddard Space Flight Center of NASA found something very peculiar. They found that the stratosphere had almost no water vapor but there was Carbon Monoxide in abundance. Even University of Cambridge conducted the study in conjunction with Goddard scientists.
The scientists concluded with intensive data they had on the Death Planet that the stratosphere of the exoplanet has hot carbon monoxide layer followed by a colder carbon monoxide layer in the layer of atmosphere below stratosphere (known as the troposphere).
The team of researchers, while studying the data, found two different signatures of of a single molecule type. Of the two signatures the researchers found, one of the signatures was that of emission with the wavelength of nearly 4.5 micrometers. The other signature was that of absorption with a wavelength of approximately 1.6 micrometers. This was possible only if the atmosphere was composed mainly of Carbon Monoxide.
Some problems with the atmosphere of the Death Planet
Scientists also considered the fact that the observed wavelengths could have also come from Carbon Dioxide. However, if the atmosphere had Carbon Dioxide, the atmosphere should also have enough Oxygen from CO2 to produce some water vapor. The problem is that the atmosphere of WASP-18b has almost no water vapor and hence, the possibility of Carbon Dioxide making up most of the atmosphere was technically not possible. The only candidate left was Carbon Monoxide.
However, compared to other hot Jupiter exoplanets that have been discovered so far, the atmosphere of the Death Planet or WASP-18b should have at least 300x more metals or at least those elements that are heavier than both Helium and Hydrogen. For higher metallicity, according to the scientists, WASP-18b should have managed to garner greater amounts of solid ice while it was in the phase of formation compared to our own Jupiter. This according to the scientists, suggests that the method of formation of WASP-18b is different from that of other hot Jupiters.
Scientists say that this interesting find will allow them to understand the physiochemical processes that are found in the atmospheres of other exoplanets. NASA is now waiting for the launch of James Webb Space Telescope (in 2019) that will be laced with more sophisticated and updated equipment, which can give more information on the Death Planet and other exoplanets.
Why is it nicknamed as Death Planet?
NASA didn’t officially give this nickname. Some news outlets did. The reason for such nickname is that life as we know on Earth can neither exist in carbon monoxide and nor can it exist without water. So, the nickname is actually quite apt.