What would we look for on a distant planet on the hunt for Earth-like worlds, and perhaps life? A recent observation by the Hubble Space Telescope found narrative cues from our home planet by looking at a familiar source under unusual circumstances: Earth’s Moon , during a total lunar eclipse.
The experiment was carried out by the Hubble Space Telescope, launched in 1990 and has been around for 30 years. Orbiting Earth every 96 minutes, Hubble typically targets faint galaxies in the distance, not the nearby bright Moon. Researchers at the University of Colorado (Boulder) and the Space Telescope Institute of Science decided to do just that, during the January 2019 full lunar eclipse of the Moon.
A total lunar eclipse occurs when the Moon enters the shadow of the Earth. As eclipse fans know, the Moon does not completely disappear when it enters the shadowy area, but instead has a slightly red color. This is because light from thousands of sunsets is filtered through Earth’s atmosphere, reaching back on the Moon. Looking back from the Moon’s surface, you will see a total eclipse. Furthermore, not all total lunar eclipses are the same. In its entirety, a lunar eclipse can appear anywhere from pale orange to dark brick red. The color seen depends on the depth of the Moon in the Earth’s shadow and the amount of dust and aerosols suspended in Earth’s atmosphere.
‘Extraterrestrial solar eclipse’
Researchers realized that the light reflected from the Moon would mimic something researchers are currently hunting for: light travels through the atmosphere of a distant alien planet, while it transitions towards before its host star. The current number of planets is 4,302 and is increasing. Furthermore, a new generation of space observatories led by the James Webb Space Telescope (scheduled to launch in October 2021) will soon be able to regularly image the planets directly. alien. Another future mission, the Large Ultraviolet Infrared Surveyor (LUVOIR) could also directly image exoplanets in ultraviolet rays, an important wavelength. This will usher in an exciting new era of alien science, allowing astronomers to capture spectra. This in turn tells us something about what the atmospheres of these bizarre worlds are made of. This could also give us hints about any interesting chemical processes at work in these distant worlds.
Hubble discovered a key chemical during eclipses: ozone. The combination of three oxygen and ozone atoms on Earth is the result of photosynthesis over geological periods.
“The discovery of ozone is a photochemical byproduct of molecular oxygen, which is itself a byproduct of life,” said Allison Youngblood (the Laboratory for Space and Atmospheric Physics). “You will need spectral markers other than ozone to conclude that there is life on the planet and that these signs are not necessarily visible in ultraviolet light.”
Although ozone is not produced by life – ozone can also be the result of nitrogen and oxygen exposure to sunlight – seasonal fluctuations in ozone levels would be a strong biological marker. Likewise, ample amounts of oxygen and methane – both reactive and need to be replenished in order to last over long periods of time – will be a strong indication that something interesting is happening on a distant world.
This also marks the first time that a space telescope has performed ultraviolet wavelength observations during a total lunar eclipse. The discovery of ozone on the ground, along with the oxygen and methane seen in Earth’s ‘eclipse spectrum’, is aided by terrestrial observations during the same January 2019 lunar eclipse. , terrestrial observatories had to adjust to see through the Earth’s atmosphere, while these unobstructed space observatories.
Another clue we could spot in the spectrum of an alien planet is what’s called the ‘red edge’, a sign made solely by plants and photosynthesis. While this will be a remarkable discovery, it will also be mostly tantalizing as a bright spot on the graph. What we want really Like to see as alien forests …
“Photosynthesis is possibly the most efficient metabolic process that can grow on any planet, because it is powered by starlight and used,” said Giada Arney (NASA / GSFC). The abundant elements in the universe like water and carbon dioxide, ”said Giada Arney (NASA / GSFC) in a recent press release. “These essential ingredients should be common on habitable planets.”
e have broadcast our very own biological signature across the galaxy for anyone who can come across it over the past 2.4 billion years. That is since the beginning of the Mesozoic era, when oxygen first began to form in Earth’s atmosphere.
However, it’s nice to see that there’s real science that happens during total eclipses. Your next chance to see the crimson Moon will be during the next full lunar eclipse on May 26.order, 2021. Perhaps, science gathered by Hubble will soon usher in a new era of alien science.
Read the full study here.
Key image credit: An artist’s conception of Hubble staring at Earth’s Moon during a total lunar eclipse. Image Provider: M. Kornmesser / ESA / NASA.