How was the universe formed? Are we really alone in the cosmos? This week science took giant steps towards potentially resolving these great mysteries. Even the first handful of pictures back from the James Webb Space Telescope, by far the most powerful space-based observatory humanity has ever built, have opened new vistas into the unknown by revealing images of galaxies from the dawn of time and chemical data from planetary atmospheres capable of harbouring life.
A staggering technological collaboration between US, European and Canadian space scientists – with some Irish input – the €10 billion telescope is now in orbit about 1.5 million km above Earth, a successor to the Hubble Telescope. It is likely to continue its work for at least 20 years.
From just one image, of Wasp-96b, a hot, Jupiter-like planet 1,150 light years away, analysis of the infrared spectrum has already revealed the presence of water vapour, an essential building block of life. It is only the first of what are likely to be many more discoveries.
The image of a distant star cluster called SMACS 0723 has revealed the presence of still more-distant hitherto unknown galaxies spilling across the sky. The light from those galaxies, magnified into visibility by the gravitational field of the cluster, originated more than 13 billion years ago. The telescope will allow scientists to peer back in time further than ever before to events billions of years closer to the Big Bang, providing vital insights into how stars and galaxies were formed.
Closer to home, apart from startling new images of Jupiter, one of the most striking pictures sent back is of the Carina nebula, a huge, swirling cloud of dust that is both a star nursery and home to some of the brightest and most explosive stars in the Milky Way. Seen in infrared, the nebula resembled a looming, eroded coastal cliff dotted with hundreds of stars that astronomers had never seen before. Other images show galaxies interacting with each other in a cosmic dance in which they trigger star formation in each other.