James Webb observed 700 million years after the Big Bang
Utilization of the background radiation spread in outer space
Performed the first stellar and cosmic origins explorations
“With the probe equipment currently sent to Mars,
I wonder if it is possible to find traces of life.”
Humanity explores and observes space for two reasons: pure scientific curiosity and exploration of new habitats other than Earth. Recently, research results have come out that provide a clue to the answer. It is about the observation results of the James Webb Space Telescope (JWST) of the United States Aerospace Agency (NASA), which was launched on Christmas Day 2021, and the exploration rover, which was launched in 2020 and has been exploring the surface of Mars since the following year.
A joint research team involving 13 research institutes from four countries, Australia, the United States, Denmark, and Spain, observed a candidate group of giant galaxies estimated to have formed about 500 to 700 million years after the Big Bang using NASA’s JWST. The results of this study were published in the scientific journal ‘Nature’ on February 23.
The universe began 13.8 billion years ago with a big bang called the Big Bang and continues to expand. The strongest evidence of the Big Bang is the cosmic background radiation, the primordial light that spreads throughout all space in the universe. Early space research right after the Big Bang is getting more active thanks to the JWST. The JWST is the largest optical space telescope in existence and has excellent infrared resolution.
Giant galaxies up to 100 billion times the mass of the sun have been identified around the redshift z = 6, which corresponds to about 1 billion years after the Big Bang, but no giant galaxies formed earlier than this have yet been found. Redshift is a phenomenon in which an object is observed as blue-green when it is closer to the observer and red when it is farther away. A method used to determine the age of a celestial body, the expansion of the universe shifts the light emitted by stars toward the red end of the spectrum as distance increases. In other words, the redder the object, the more distant it is.
The research team discovered a group of galaxies with a z value of 6.5 to 9.1 as a result of observation with the JWST, and as a result of detailed analysis, they discovered a giant galaxy formed about 750 million years after the Big Bang. Six giant galaxy candidates with z-values redshifting between 7.5 and 9.1 were found, which are estimated to contain a number of stars up to 100 billion times the mass of the sun, the research team said.
Meanwhile, scientists from 20 research institutes in five countries, including Chile, France, and Japan, centered on the Space Biology Research Center in Spain and NASA’s Goddard Space Flight Center, said that it is difficult to find traces of life with only the exploration equipment currently deployed on Mars.
After the US Mars probe Viking 1 landed on the surface of Mars in 1975, attempts to find traces of life on Mars continued. Currently, the Curiosity and Perseverance exploration rovers sent by NASA are active on the surface of Mars.
As an example of an active Mars rover, the research team experimented with sedimentary layers in Chile’s Atacama Desert, a crater-like environment. This sedimentary layer was formed about 100 to 160 million years ago. The research team tested whether the equipment used in the Mars rover could capture the characteristics of microorganisms, and most of them failed.
Dr. Armando Azua Bustos of the Center for Astrobiology Research in Spain, who led the research, said, “It is not easy to confirm whether life exists on Mars only with the equipment currently used on Mars due to the limitations of equipment or the characteristics of the surface of Mars.” “The best way is to take a sample and send it back to Earth.”
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