Editorial: New window on cosmos

The global scientific community could not have asked for a better Christmas gift. The successful launch of NASA’s James Webb Space Telescope (JWST), the most powerful and complex space observatory ever built, serves as a perfect gift that is expected to unravel the mysteries of the universe. The launch of the $10-billion telescope, a far more sophisticated successor to the Hubble Telescope, from French Guiana on the European Ariane 5 rocket, marks a historic milestone in the advancement of astrophysics and space science. The buzz surrounding the launch is similar to the excitement that followed the detection of the gravitation waves in 2016 and the release of the first-ever photograph of a black hole in 2019. Since 2004, thousands of scientists and engineers from 14 countries have worked on building the telescope; a new window on the cosmos that is set to examine all of cosmic history — billions of years of it —, from the first stars to possible signs of life in the solar system. It will take about a month for the Webb telescope to reach its destination: an orbit around the sun, about 1 million miles away from the Earth. During the high-risk journey, Webb will unfold its mirrors and unfurl the sunshield. This process involves thousands of parts that must work perfectly in the right sequence. If all goes well, astronomers will start to see the universe in a new light in the coming months. The Webb telescope is designed to capture ancient light emitted more than 13 billion years ago as the embryonic universe was still learning how to create stars and galaxies. This will provide a revolutionary new view of the cosmic firmament. The objective is to look at the first glows after the big bang that created our universe and the formation of the galaxies, stars and planets.

Unlike anything built earlier, the uniqueness of the Webb telescope is that it is an infrared detector, detecting light that is invisible to us and thereby revealing the otherwise hidden regions of space. Engineers had to invent 10 new technologies along the way to make the telescope far more sensitive and powerful than Hubble. Its capabilities will enable the observatory to answer questions about our own solar system and investigate faint signals from the first galaxies formed billions of years ago. Astronomers want to use the Webb, equipped with a mirror that can extend 6.5 metres, to study the atmospheres of the planets detected in recent years around distant stars, including Proxima b, a planet orbiting Proxima Centauri, the nearest star to the sun. Those observations could detect the presence of oxygen, methane and other molecules that could be signatures of extraterrestrial life. Understanding the atmospheres and the formation conditions for planets could help scientists better predict if certain planets are habitable or not.