As telescopes and other instruments rain down data on researchers, each week brings interesting news:
From our galaxy:
Last week, planets orbiting M-type stars (common red dwarfs) appeared. Astronomers classify these planets in more detail: “‘We have discovered that the small planets orbiting this type of star can be classified into three distinct families: rocky planets very similar to Earth, planets whose half of their mass consists of water which we call water worlds. , and mini-Neptunes with extended hydrogen and/or helium atmospheres,” Pallé describes. – Institute of Astrophysics of Canarias (IAC) (September 8, 2022)
One feature of these worlds may come as a surprise: “Because they are tidally locked to their suns, these planets may also have liquid oceans on their sun-facing side, but frozen surfaces everywhere else – colloquially called “eyeball planets”. While astronomers have speculated that this class of exoplanets existed, these findings are the first confirmation of this new type of exoplanet. They also reinforce the growing case of water worlds forming past the so-called “snow line” in star systems (the boundary beyond which volatile elements freeze) and then migrate closer to their star.– Matt Williams, Universe today, (September 14, 2022)
Sasha Quanz, an astrophysicist at ETH Zurich, thinks that given all the new equipment, it’s “not ‘unrealistic'” that we could detect evidence of life on other planets in the next quarter of century. He shared the 1995 Nobel Prize for discovering the first exoplanet. His reasoning: “Of those thousands of exoplanets, dozens are believed to be at least potentially habitable, with conditions on their surfaces conducive to liquid water. And as he said, that number is growing all the time. – Noor Al-Sibai, Futurism, (September 13, 2022)
In our solar system:
Some search our solar system for evidence of intelligent extraterrestrials. This type of evidence is called technosignatures – artifacts that only an intelligent life form would create. An article on Universe today reviews methods and rationale. There is a new emphasis on physical objects via the new Vera C. Rubin Observatory (2023): “Focusing on physical artifacts is a new strategy in SETI, but Loeb and Laukien are optimistic. Artifacts, they point out, are necessarily less fleeting than radio signals. Although an object might be technically more difficult to detect than a signal, an object would not have to repeat itself somehow if missed the first time. Unlike light, most physical objects in our galaxy are gravitationally bound to it. This makes detection less urgent for a physical object. – Seth Lockman Universe today (September 13, 2022)
Next (March):
We are told that NASA Perseverance Rover “collected samples from one of the best places to search for ancient life on Mars.” This is the 3.5 billion year old Jezero crater, located at what appears to be a river meeting a lake. “Now in its second science campaign, the rover is studying the delta, where it has found organic material. While organic material has already been found on Mars by Perseverance and the Curiosity rover, this latest detection was made in an area where , in the distant past, sediments and salts were deposited in a lake under conditions in which life could potentially have existed.–Nancy Atkinson, Universe today (September 15, 2022) Details from NASA here.
To Futurism, Frank Landymore notes that NASA staff seem rather excited about their findings: “What [Perseverance] Sulphate-bound organic molecules were found, which likely means that as the lake dries up, this particular area has become highly concentrated in both sulphate and organic. The samples may not provide proof of life, but they are the ones to get. (September 16, 2022)
Also, we learn to Phys.org that the number of ancient Martian lakes could have been significantly underestimated by scientists. “We know about 500 ancient lakes deposited on Mars, but almost all the lakes we know are larger than 100 km2,” explains [Joseph] Michalsky. “But on Earth, 70% of lakes are smaller than this size, occurring in cold environments where glaciers have retreated. These small lakes are difficult to identify on Mars by satellite remote sensing, but many small lakes probably existed. It is likely that at least 70% of Martian lakes have yet to be discovered. Scientists monitor these small lakes on Earth to understand climate change. Small missing lakes on Mars could also hold critical information about past climates. – University of Hong Kong (September 16, 2022. Paper requires fee or subscription.)
As we explore…
As stated earlier, one of the reasons for believing that we can find life on other planets is that our universe is suitable for life. University of Western Australia cosmologist Luke Barnes offers a number of interesting examples. Here is another:
As an example of fine tuning for life, the cosmological constant problem is a near-perfect storm…
The cosmological constant has a very obvious and definitive effect on the conditions necessary for life. A positive cosmological constant causes the expansion of the universe to accelerate, freezing the formation of the structure. Increase the cosmological constant by a few orders of magnitude and the formation of the structure freezes before anything has formed. The universe will be a thin, uniform soup of hydrogen and helium, a diffuse gas where the occasional collision of particles is all that happens. A very simple way to make a universe lifeless is to make it devoid of any structure. Alternatively, a negative cosmological constant causes the universe to collapse.
Luke Barnes“The fine-tuning of the universe for life” at ArXiv (October 18, 2021)
But our universe has just the right one.
Here is the news from last month:
News from the search for extraterrestrial life 4. Just as much promising data about habitable planets is pouring in from telescopes, pioneering ET astronomer Frank Drake has died. A new class of planets – half rock and half water – has been discovered, and a super-Earth that is clearly in the habitable zone.
News from the search for extraterrestrial life 3: The Webb takes a closer look at an exoplanet. In other news, we learn about Europe’s oceans, an ancient Martian lake, a star with “square” waves – and asteroids too close to home. (September 3, 2022)
News from the search for extraterrestrial life 2: A new ocean planet, a planet with carbon dioxide and new discoveries about the chances of life on Mars. Progress? We now need the Artemis Accords to apportion nations’ rights to Moon exploration – and the far side could house a better telescope than the Webb. One of the reasons for hoping to find life elsewhere in the universe is that the universe seems to be fine-tuned for life. What the universe won’t do is tell us where life is. (August 27, 2022)
and
News from the search for extraterrestrial life I: Super-Earths that could have life, choosing life forms to take to Mars and self-replicating robots… NASA plans to develop a swarm of tiny robots to search for extraterrestrial life on oceanic worlds like Europa or Enceladus. (August 20, 2022)
