News From the Search for Extraterrestrial Life 2A new ocean planet, a planet with carbon dioxide, and new information about life chances on Mars
What may be an ocean planet has been discovered in the region of the Constellation Draco:
An international team of researchers led by Charles Cadieux, a Ph.D. student at the Université de Montréal and member of the Institute for Research on Exoplanets (iREx), has announced the discovery of TOI-1452 b, an exoplanet orbiting one of two small stars in a binary system located in the Draco constellation about 100 light-years from Earth.
The exoplanet is slightly greater in size and mass than Earth and is located at a distance from its star where its temperature would be neither too hot nor too cold for liquid water to exist on its surface. The astronomers believe it could be an “ocean planet,” a planet completely covered by a thick layer of water, similar to some of Jupiter’s and Saturn’s moons.University of Montreal, “An extrasolar world covered in water?” at Phys.org (August 24, 2022) The paper is open access.
The astronomers note,
The exoplanet TOI-1452 b is probably rocky like Earth, but its radius, mass, and density suggest a world very different from our own. Earth is essentially a very dry planet; even though we sometimes call it the Blue Planet because about 70% of its surface is covered by ocean, water actually only makes up a negligible fraction of its mass—less than 1%.University of Montreal, “An extrasolar world covered in water?” at Phys.org (August 24, 2022) The paper is open access.
Also, the James Webb Space Telescope has found “unequivocal” evidence of carbon dioxide on a Jupiter-like gas giant at 700 light years away:
It’s called WASP-39 b and was first discovered in 2011, but only now were scientists able to train the Webb Telescope’s remarkable spectroscopic powers on the planet…
WASP-39 b is about as massive as Saturn but has a diameter about 33% larger than Jupiter’s, meaning it’s not very dense. The planet is hot; with a temperature of about 1,650 degrees Fahrenheit (900 degrees Celsius), a result of its intimate orbit around its host star.Isaac Schultz, “Webb Telescope Just Detected Carbon Dioxide in a Distant World” at Gizmodo (August 25, 2022)
The Webb’s ability to identify a planet’s specific chemical composition at that distance means researchers can focus on those exoplanets among the thousands spotted that are most likely to host carbon-based life.
Meanwhile, with NASA’s Artemis 1 Moon mission nearing blastoff, some analysts point to the far side of the Moon as a good place to base a radio telescope: that would see even further than the Webb:
“The argument for putting a radio telescope on the far side of the moon is to look at lower radio frequencies that are otherwise heavily polluted by human radio transmissions on Earth,” Steven Kahn, a physicist at Stanford University in California, told Space.com.Keith Cooper, “The moon’s far side could offer a view of the universe even deeper than the James Webb Space Telescope” at Space.com (August 25, 2022)
Artemis’s launch on August 29 can be viewed here.
Closer to home… in our own solar system:
Everybody loves Jupiter’s moon Europa, “one of the most fascinating planetary bodies ever observed,” and the projected 2024 launch of the Europa Clipper will provide more information about the moon’s ocean. How can an icy moon have an ocean?
Europa’s vast ocean swirls beneath its icy crust despite the moon’s incredible distance from the Sun, putting it well beyond our star’s habitable zone, which is the sweet spot where liquid water can exist on a planet’s surface. Instead, this ocean exists from what is known as tidal heating, or the constant stretching and compressing the small moon endures as it orbits the much more massive Jupiter throughout its elliptical orbit. Along with Jupiter, Europa is also being constantly tugged by Jupiter’s moons, Io and Ganymede, the first and third Galilean satellites, respectively. This tidal heating leads to friction within Europa’s core, corresponding to heat and ultimately melting the inner ice into what is now Europa’s massive ocean.Laurence Tognetti, “Will Europa finally answer, ‘Are we alone?’” at Universe Today (August 7, 2022)
Mars? Planetary scientists working with images from the Mars Reconnaissance Orbiter report that at various points, Mars may have been habitable. They have identified clay-bearing sediments in the Margaritifera Terra:
Clay points to the long-term presence of water, as it forms under neutral pH conditions with minimal water evaporation. The team thinks water flowed here from around 3.8 billion years ago up to around 2.5 billion years ago, a large stretch of Martian history.
“In addition, colorful light-toned layered sediments that display relatively low bedding dips and contain clays across 200 kilometers [124 miles] in distance are evidence that a lake was most likely present within Ladon basin and northern Ladon Valles,” says Catherine Weitz, a senior scientist at the Planetary Science Institute in Arizona.
“The low-energy lake setting and presence of clays support an environment that would have been favorable to life at that time.”David Nield, “Signs in Martian Soil Point to Habitable Conditions For Life Over A Long Period” at ScienceAlert (June 26, 2022) The paper requires a fee or subscription.
Another recent finding is that cyanobacteria could live in Martian dust:
At first glance, the inhospitable environment of the Red Planet seems to hold few usable resources for a life support system or food production. But the high-carbon (95%), nitrogen-containing atmosphere and red regolith soil, rich in iron and a wealth of other metals and minerals, are suitable for such bioprocesses—and the key are cyanobacteria. While on Earth they often appear as annoying blue-green algae and spoil our summer bathing pleasure, in the context of Mars they can be described as masters of survival. Fed with Martian dust and atmosphere, and with the capability of photosynthesis, some microorganisms within this phylum could produce oxygen and form biomass, which could serve various purposes—including food production.Birgit Kinkeldey, Zentrum für angewandte Raumfahrttechnologie und Mikrogravitation (ZARM), “Mars dust as a basis for life? No problem for certain bacteria” at Phys.org (August 11, 2022) The paper requires a fee or subscription.
And finally, much closer to home…
Infighting! As more nations try their luck in space, agreements must be worked out as to who owns or has a right to use what or be where on the Moon:
More than 20 nations have signed on to the NASA-led Artemis Accords, a set of agreements that lay out a framework for responsible exploration of the moon.
And Artemis will have an international flavor going forward. For example, Canada will get a seat on Artemis 2 thanks to its contribution of Canadarm3 robotics to the planned Gateway moon-orbiting station. And Japan will fly an astronaut on a future Artemis moon mission as well.Elizabeth Howell, “Artemis Accords: Why the international moon exploration framework matters” at Space.com (August 25, 2022)
Canada and Japan won’t likely go to war over Moon base rights. The best results will surely come from a combination of co-operation and friendly competition.
One reason for hope for finding life elsewhere in the universe is that the universe appears to be fine-tuned for life. As astronomer Geraint Lewis puts it at Cosmos, “Examining the huge number of potential universes, each with their own unique laws of physics, leads to a startling conclusion: most of the universes that result from fiddling with the fundamental constants would lack physical properties needed to support complex life.” (December 18, 2016)
What the universe won’t do is tell us where the life is.
You may also wish to read: News from the search for extraterrestrial life I: Super-Earths that might have life, choosing life forms to take to Mars, and self-replicating robots… NASA is looking at developing a swarm of tiny robots to look for extraterrestrial life on oceanic worlds like Europa or Enceladus. (August 20, 2022)