NASA’s Hubble Space Telescope detected a planet possessing a similar atmosphere to Earth. The distant planet, WASP-33b, has a stratosphere – one of the primary layers of our planet’s atmosphere – which could indicate it is similar to Earth in more ways than one. Its discovery could also help astronomers study atmospheres around other potentially habitable worlds.
According to The Daily Mail, Wasp-33b is 380 light-years from Earth. Its estimated surface temperature is 5,800°F (3,200°C) and it is about 4.5 times the mass of Jupiter. It orbits at a distance of 3 percent Earth’s distance from the Sun. It completes its orbit every 1.22 Earth days and is almost certainly inhospitable to life as we know it.
Avi Mandell, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, MD, and co-author of the study, said that due to the temperature of this planet they were not expecting to find the molecules that would lead to multi-layered structures, according to a press release on EurekAlert.
Some of these planets are so hot in their upper atmospheres, they’re essentially boiling off into space. At these temperatures, we don’t necessarily expect to find an atmosphere that has molecules that can lead to these multilayered structures.
The atmosphere around Wasp-33b goes through a temperature inversion, which gives it a “sunscreen” layer, which blocks the radiation from the sun from getting to the surface. The planet’s stratosphere contains molecules that also absorb ultraviolet and visible light. Regardless, seeing as the surface temperature is as hot as it is, the planet is thought to be likely inhabitable.
Up until now, scientists had did not know if such layers could exist around similar planets. This is an important factor when studying exoplanets since previously it was not known that planets in such close proximity to the Sun could harbor an atmosphere similar to that which is found on Earth.
The difference is that in the Earth’s atmosphere, our stratosphere is above the troposphere, which reaches from the ground to the top. In the troposphere, the temperature is warmer at the bottom of the ground and cooler at the top. The stratosphere works the other way round, making the temperature warmer they higher it is. On Earth, temperature inversion happens because the ozone layer absorbs much of the sun’s ultraviolet radiation, therefore preventing it from reaching the surface and protecting the biosphere – as a result, warming the stratosphere instead.
Lead researcher Dr. Korey Hayens told The Daily Mail that the discovery was important because there have been many planets found similar to Wasp-33b, therefore they would serve as a good target for examination.
We can now move forward and look at other planets, and work out why some have stratospheres and others don’t, or what makes it stronger in certain planets.
Haynes and her colleagues also presented the first evidence that Wasp-33b’s atmosphere contains titanium oxide. It is one of only a few compounds that is a strong absorbent of ultraviolet radiation and capable of remaining in a gaseous form in an atmosphere as hot as this.
Co-author Nikku Madhusudhan of the University of Cambridge, United Kingdom, pointed out the importance of finding the links between stratospheres and chemical compositions.
Understanding the links between stratospheres and chemical compositions is critical to studying atmospheric processes in exoplanets. Our finding marks a key breakthrough in this direction.
According to a press release on PR Newswire, the researchers analyzed observations made with Hubble’s Wide Field Camera 3, which can capture a spectrum of the near-infrared region where the signature of water appears. Through the camera, scientists are able to employ spectrum analysis in order to identify water and other gases in a distant planet’s atmosphere and determine its temperature.
The discovery was made by scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and the University of Cambridge, England.