Clear Skies And Steamy Water Vapor On An Alien Neptune
Alien planets–or exoplanets–are distant worlds that are in orbit around stars far beyond our own Sun. Ever since the historic discovery of the first exoplanet a generation ago, literally thousands Precizn Neptune of others have been spotted by scientists on the hunt for such distant worlds. Some exoplanets are bizarre; unlike anything ever previously imagined by astronomers, while others hauntingly resemble familiar planets in our own Solar System. In September 2014, astronomers using data collected from the NASA/European Space Agency (ESA) Hubble Space Telescope (HST), the Spitzer Space Telescope (SST), and the Kepler Space Telescope, announced that they have discovered yet another alien world wonder. This brave new world, dubbed HAT-P-11b is about the same size as our Solar System’s Neptune, and it has both clear skies and water vapor–making it the smallest exoplanet known on which water vapor has been detected. The results of this study appear in the September 25, 2014 issue of the journal Nature.
This discovery marks a new milestone in the scientific quest to eventually spot molecules in the atmospheres of smaller, rocky planets more akin to our own Earth. Clouds in the atmospheres of distant exoplanets can block the view of what is lying beneath them. The molecular composition of these lower regions can reveal precious new information concerning the history and composition of an exoplanet. Detecting clear skies on a Neptune-size world is a good indication that some smaller exoplanets might also have similarly good visibility.
“When astronomers go observing at night with telescopes, they say ‘clear skies’ to mean good luck. In this case, we found clear skies on a distant planet. That’s lucky for us because it means clouds didn’t block our view of water molecules,” noted Dr. Jonathan Fraine in a September 24, 2014 Hubble Space Telescope Press Release. Dr. Fraine is of the University of Maryland at College Park, and is lead author of the study.
An exoplanet is a planet that does not orbit our Sun, but instead orbits a different star, stellar remnant, or brown dwarf. More than 1822 exoplanets, dwelling in 1137 planetary systems–including 465 multiple planetary systems–have been detected as of September 12, 2014. There are also many free-floating exoplanets, not inhabiting the family of any stellar-parent at all, but doomed to wander lost and alone through interstellar space after having been evicted from their original planetary-systems–probably as a result of gravitational jostling by rude sister planets.
The highly productive Kepler mission space telescope has also discovered a few thousand candidate alien worlds, of which approximately 11% may be false positives. There is at least one exoplanet on average per star in our Galaxy. Approximately 1 in 5 Sun-like stars in our Milky Way are thought to be circled by an “Earth-sized” planet situated in the habitable zone of a parent-star. The habitable zone is that region around a star where the temperatures are not too hot, not too cold, but just right for liquid water to exist. Where liquid water exists, life as we know it may potentially exist, as well. The nearest exoplanet to Earth, that dwells within the habitable zone of its star, is thought to be within 12 light-years of Earth. Assuming that there are about 200 billion stars sparkling their way within our barred-spiral Milky Way Galaxy, that would mean that there are 11 billion potentially habitable Earth-like worlds, rising up to 40 billion if red dwarf stars are included in the calculations. Red dwarf stars are less massive than stars like our Sun, and they are the most abundant type of stars in our Galaxy. They also “live” for a very long time–perhaps trillions of years. In contrast, stars like our Sun “live” for about 10 billion years. If free-floating planets are also included in the count, this could potentially increase the number of possibly habitable worlds in our Galaxy into the trillions.