Maybe with the advent of NASA's James Webb Space Telescope the IB needs to be less parochial and broaden its horizons by encouraging intergalactic-mindedness rather than just international-mindedness?

Water is essential to life as we know it so any planet that can sustain life must contain water. Within our own solar system the Mars Perseverance Explorer is currently seeking out evidence of life in ancient rocks where water is known to have been present in the past. In the past few decades over 5000 exoplanets have been identified. These are all many light years away and so sending physical robots to explore them is currently impossible. However the James Webb Space Telescope, which was thirty years in the making, in now sending back spectacular images of far distant galaxies and is able to analyse the atmospheres of exoplanets in much greater detail than the Hubble telescope. 

Absorption of light by water in the atmosphere of exoplanet WASP-96 b (Image from NASA)

Students learn that for a substance to be IR active at least one of its vibrations must cause a change in dipole moment. Both the asymmetric and symmetric stretching vibrations of water molecules and also the symmetric bending vibration involve a change in dipole moment so are IR active.

As an exoplanet containing water in its atmosphere traverses across the front of its star some of the radiation from the star is absorbed by the water. The James Webb telescope is sensitive enough to monitor this change in absorption and confirm that water is present. This has recently been shown with exoplanet WASP-96 b.

Absorption of light as exoplanet WASP-96 b passes across its sun (Image from NASA)

This planet is in the Milky Way, approximately 1.15 x 10³ light years away from Earth. It is extremely close to its sun and has a very short year of only 3.5 Earth-days and a temperature greater than 540 ^oC so is unlikely to support life. However as the James Webb telescope goes on to analyse the atmospheres of other exoplanets the chances of finding one with properties similar to Earth that could support intelligent life look to be quite high.