Following a successful launch on June 26, NASA is poised to launch two more probe rockets from northern Australia during the first fortnight of July.
These missions will help astronomers understand how starlight influences a planet’s atmosphere, possibly making or breaking its ability to sustain life as we know it.
The two missions will look at Alpha Centauri A and B, two Sun-like stars close to ours, with extreme and distant ultraviolet light. Ultraviolet light, which has shorter wavelengths than light visible to the human eye, is a critical factor in the search for life. A little ultraviolet light can help form the molecules needed for life, but too much can erode an atmosphere, leaving an inhospitable planet behind.
“Ultraviolet radiation from the Sun played a role in how Mars lost its atmosphere and how Venus became a dry, arid landscape,” said Brian Fleming, an astronomer at the University of Colorado, Boulder, and lead researcher on ‘one of the missions, the Dual Channel Extreme Ultraviolet Continuous Experiment or DEUCE. “Understanding ultraviolet radiation is extremely important to understanding what makes a planet habitable.”
Of the more than 5,000 known exoplanets throughout the galaxy, only Earth is known to host life. In search of other exoplanets that could harbor life as we know it, astronomers have focused on planets orbiting the habitable zone, defined as the distances from a star where a planet’s surface temperature could withstand. Water.
“But that’s a rudimentary way to characterize habitability,” Fleming said.
While water is a part of making a planet hospitable, for a planet to support an Earth-like biosphere, it also needs an atmosphere. If the habitable zone is bathed in too much ultraviolet radiation, any water vapor from the upper atmosphere could escape, quickly drying out the planet. Atmospheres can also be eroded by the radiation and extreme eruptions of a planet’s host star, exposing the surface to harsh ultraviolet radiation, which can break down molecules such as DNA.
But the amount of ultraviolet radiation emitted by different types of stars is little known. Without accurate knowledge, astronomers cannot accurately predict which planets could host life.
“We need to understand the stars to be able to understand any planet we find there,” said Kevin France, an astronomer at the University of Colorado, Boulder and principal investigator of the suborbital imaging spectrograph for the region’s irradiation. transition of the host stars from the nearby exoplanet. or SISTINE, mission.
DEUCE and SISTINE will take these important measures of ultraviolet light to help reduce the search for habitable planets. With just one week to go, the two missions will work together to get a complete picture of the ultraviolet light from Alpha Centauri A and B.
The researchers selected Alpha Centauri A and B because they can serve as a useful reference for calibrating observations of the Sun, the only other star for which we have complete ultraviolet measurements. Ultraviolet light is absorbed by dust and gas in space. This makes it almost impossible to measure ultraviolet light from farther stars at the level required for this type of analysis. The Alpha Centauri system, however, is only 4.3 light-years away, close enough for much of its ultraviolet light to reach us before it is absorbed.
Ultraviolet light is also blocked mainly by the Earth’s atmosphere, so researchers must send instruments into space to measure it. Because the full range of ultraviolet light cannot be measured with a single instrument, DEUCE will measure the shortest and most extreme ultraviolet wavelengths and SISTINE will measure the longest and most distant ultraviolet wavelengths. Wavelength coverage will overlap slightly so that the data collected can be calibrated and used as a data set. This information will be used to create models that can help astronomers assess what other stellar systems might support habitable environments.
“Looking at Alpha Centauri will help us check if other stars like the Sun have the same radiation environment or if there are a variety of environments,” France said. “We have to go to Australia to study it because we can’t easily see these northern hemisphere stars to measure them.”
SISTINE is slated for release on July 4th and DEUCE on July 12th.
The two missions, aboard NASA’s two-stage Black Brant IX spacecraft, will be launched from the Arnhem Space Center in East Arnhem Land, Northern Australia. The Arnhem Space Center is owned and operated by Equatorial Launch Australia, or ELA, in the land of the Yolngu, Traditional Custodians and landowners.
Along with a third mission, the X-ray Quantum Calorimeter, or XQC, which flew on June 26, these scientific studies can only be conducted from the southern hemisphere.
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