Three NASA rockets will check if the Alpha-Centauri is habitable

The Alpha Centauri star system is 4.3 light years from Earth. Alpha Centauri A and B form a binary pair, while Proxima Centauri is more divergent. About the first two planets, which are very similar to the Sun, no planet has yet been identified, but the red dwarf Proxima Centauri hosts at least two, Proxima b and Proxima c, the first of which, moreover, is in the “habitable zone” of the star, so Water can be on its surface.

At the right scale, ultraviolet light is able to break down simple organic molecules, such as methane, and cause the fragments to turn into more complex molecules necessary for life. However, too much ultraviolet light can separate water vapor, leaving it vulnerable to stripping from the planet’s atmosphere by the solar wind and leaving the planet dry and barren, like Mars today.

“Understanding ultraviolet radiation – explains Brian Fleming, principal investigator on one of the missions – is critical to understanding what makes the planet habitable.” The three rockets had to be launched from the southern hemisphere because the Alpha Centauri system is not visible above 29 degrees north latitude.

difficult observation

Observing stars in ultraviolet light is not an easy task, because the ozone layer in the Earth’s atmosphere blocks light at this wavelength, forcing scientists to send ultraviolet telescopes into space. In addition, the interstellar medium of interstellar gas and dust also absorbs ultraviolet light, so no stars can be seen at a clearly noticeable distance in this system.

As a result, there are only complete ultraviolet observations of one star, the Sun. But how typical are solar UV emissions? Astronomers do not know. They need UV readings from other stars to find out. Alpha Centauri A and B are good targets for study for two reasons. First, they are close to each other, so their ultraviolet light does not dim the interstellar medium. And secondly, they have similar masses and temperatures to the Sun.

“Looking at Alpha Centauri – says Kevin France, another researcher on the mission – will help us check whether other stars like the Sun have the same radiative environment or, conversely, there are a variety of environments.

The launch of these three sounding rockets from Australia’s Ahmim Space Center is the first NASA launches from a commercial port outside the United States. For Thomas Zurbuchen, Administrator of NASA, these launches “open a new entrance into the night sky in the Southern Hemisphere, expanding the possibilities for future science missions.”