In the year of the 30th anniversary of the Hubble Space Telescope, there have been many dazzling images descending on our empty inhabitants of Earth.
The European Space Agency (ESA) announced that Hubble has observed a total lunar eclipse, becoming the first space telescope to focus on the event. It was also the first time an eclipse was studied at ultraviolet wavelengths, per study to be published in De Astronomical Journal.
The telescope was trained at the eclipse using a method that NASA and ESA hope will serve “as a proxy for how they will observe Earth-like planets around other stars in search of life.” During a full lunar eclipse, the alignment of the three bodies involved is equal to what happens when an exoplanet passes over its local star. That, for this study of Earth, Hubble only looked at the moon during an eclipse, and observed the sunlight filtered through the Earth’s atmosphere to search for ozone.
However, there are important challenges to training the telescope on our moon. “The moon is so close to Earth that Hubble had to try to keep a close eye on one selection region, to accurately track the moon’s motion relative to the space observatory,” the announcement said. “It’s for these reasons that Hubble is very rarely shown on the moon.”
The data revealed “the strong spectral fingerprint of ozone” when using the moon as a mirror for the Earth’s atmosphere. This is important because it is a key sign of the possibility of the development or presence of life. “Finding ozone in the spectrum of an exo-Earth would be important because it is a photochemical by-product of molecular oxygen, which is a by-product of life,” said Allison Youngblood, lead researcher of Hubble’s observations at the Atmospheric Laboratory. and space physics in Colorado.
It’s a great step, but it’s not enough to determine if life exists on an exoplanet. The soon to be launched James Webb Space Telescope (JWST) will be able to continue this research in new and exciting ways. “We expect JWST to push the technology of transmission spectroscopy to unusual limits,” said Antonio Garcia Munoz of the Technical University of Berlin. “In particular, it will have the capacity to detect methane and oxygen in the atmosphere of planets orbiting, small large stars. This will open up the field of atmospheric characterization to ever smaller exoplanets.”
Between the launch of many Mars rovers in July, including NASA’s Perseverance, and studies like this, many agencies are deep in their search for life outside the barrier of the Earth’s atmosphere.
