Water, Water Everywhere?

Water was once a commodity only thought to exist on our blue planet (once we got past thinking that Mars had a canal system and Venus was a tropical paradise!), but as we have advanced our technology and our observation techniques we’ve found evidence of water on our Moon and Mars and now on exoplanets a 1000 light-years away.  The more we look, the more we see that elements and conditions for life as we know it in the Universe are more common than we thought.

NASA has released a study that has detected water in the atmospheres of five exoplanets: WASP-17b, HD209458b, WASP-12b, WASP-19b and XO-1b. These planets are very large and orbit very closely to their stars, earning the moniker, “hot Jupiters”. So they may not be havens for life as we see on Earth.  But, it does point to water being present in those solar systems, and there may be other planets around those stars yet to be discovered in the habitable zone that also have water and moderate temperatures more conducive for life.  Not to mention moons about those planets that also may be habitable.

The Hubble Space Telescope was used to observe the starlight as it passed through the atmospheres of these planets and astronomers teased-out the water signatures from the resulting spectra. The video below describes this discovery and the techniques used in finding the water. It moves along pretty quickly, presenting a lot of information, so you might want to pause it or play it again to pick up on the details.

(NASA’s Goddard Space Flight Center.  Additional animations courtesy ESA/Hubble)

What amazes me is that we are able to glean this information about these planets’ atmospheres at the distances of 500 to 1000 light-years. This is only one more example of the ingenuity and inventiveness the astronomical community has applied to pushing the boundaries of our knowledge.

There was a time when the consensus was that we would not be able to detect planets around another star, but in 1992 two planets were discovered around the pulsar PSR 1829-10. This was a surprise in that astronomers didn’t think a pulsar would have planets orbiting them. The first planet found around a Sun-like star was discovered three years later and is labeled as 51 Pegasi b, which is about 50 light-years away.

Many didn’t believe we would be able to directly image a planet around a star, but that was all changed in 2008 when a team of astronomers using the Gemini telescope in Mauna Kea photographed a planet about 8 times the mass of Jupiter around the star 1RXS J160929.1-210524, which is about 500 light-years from Earth.

Exoplanet circled in red around parent star. Image courtesy of Gemini Observatory

There were a number of other planetary images released later in 2008 by Gemini and Hubble.

As one might imagine, detecting elements and compounds in an exoplanet’s atmosphere was also thought to be beyond our reach, but that too has been disproven with this latest discovery. How long before we find oxygen, indicative of biological processes or the compounds of smog, indicating a potential industrialized society, around some other exoplanet?

These are good examples of what the human species can achieve when facing a challenge. We should have more faith in our abilities and realize that there is very little we can not do if we set out minds to it.  Who knows what else is out there to amaze us!

Till next time,

RC Davison

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