Have We Detected Life on an Exoplanet?

Posted on by onespaceman2000
Credit: Image by Adis Resic from Pixabay.

The news is filled this week with a story about possible life on a distant exoplanet? What did scientists find?

The exoplanet is named K2-18b, and it orbits a red star that is about 124 light-years away. It is also about 2.6 times larger than the Earth and 8.6 times as massive.

Scientists using data from the James Webb Space Telescope have detected a biosignature similar to molecules – dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) – associated with marine phytoplankton on our planet.

Nikku Madhusudhan, professor of astrophysics and exoplanetary science at the University of Cambridge’s Institute of Astronomy, stated:

Earlier theoretical work had predicted that high levels of sulfur-based gases like DMS and DMDS are possible on Hycean worlds…And now we’ve observed it, in line with what was predicted. Given everything we know about this planet, a Hycean world with an ocean that is teeming with life is the scenario that best fits the data we have.

A Hycean planet is basically a world with liquid oceans and a hydrogen-rich atmosphere. Such planets are also more common around red dwarf stars.

Of course, more work is necessary to determine whether this finding could relate to something other than biological life, but its does offer exciting possibilities and a clear target for more study.

Pic of the Week: Cosmic Tornado

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Image (Credit): Herbig-Haro 49/50 captured by the JWST. (NASA, ESA, CSA, STScI)

This week’s image is from the James Webb Space Telescope (JWST). The transparent red cloud in the middle of the image, nicknamed the “cosmic tornado,” is outflow of gas and dust from a newly formed star. Moreover, the bright blue glow at the top of the cloud has nothing to do with what you are seeing. The blue glow is a distant spiral galaxy.

Here is more about the image from NASA:

Angled from the upper left corner to the lower right corner of the image is a cone-shaped orange-red cloud known as Herbig-Haro 49/50. This feature takes up about three-fourths of the length of this angle. The tip of the cone positioned at the upper left appears translucent with a rounded end. Coincidently, a background spiral galaxy appears right near the tip too. The galaxy has a concentrated blue center that fades outwards to blend in with red spiral arms. The cones-shaped feature widens slightly from tip down to the lower right. Along the way there are additional rounded edges, like edges of a wave, and intricate foamy-like details. The nebula appears even more translucent to the lower right providing a clearer view of the black background of space. The black background of space is clearer, speckled with some white stars and smaller, more numerous, fainter white galaxies.

Space Stories: JWST Exoplanet Images, Nearby Exoplanets Located, and Exoplanet Biosignatures,

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Image (Credit): Infrared view of the multi-planet system HR 8799. Colors are applied to filters from Webb’s NIRCam (Near-Infrared Camera). A star symbol marks the location of the host star HR 8799, whose light has been blocked by the coronagraph. (NASA, ESA, CSA, STScI, W. Balmer (JHU), L. Pueyo (STScI), M. Perrin (STScI))

Here are some recent stories of interest related to exoplanets.

—Webbtelescope.org: “NASA’s Webb Images Young, Giant Exoplanets, Detects Carbon Dioxide“

The first planet outside our solar system was discovered in the 1990’s, but it wasn’t until more than a decade later astronomers actually obtained a direct image of one. It’s extremely difficult to image an exoplanet, as stars in other planetary systems can be thousands of times brighter and bigger than their planets. NASA’s James Webb Space Telescope is equipped with a highly sensitive coronagraph, a tiny mask that blocks the light of the star, allowing Webb to image exoplanets. Webb’s new images of two iconic systems, HR 8799 and 51 Eridani, and their planets have stunned researchers, and provided additional information into the chemical make-up of the young gas giants.

—ABC News: “Several Planets Found Orbiting Star Less Than 6 light-years Away“

Astronomers have confirmed the existence of four planets orbiting a star less than 6 light-years away with help from some of the world’s most powerful telescopes. Research published in October 2024 revealed that one planet was rotating around Barnard’s Star, the second-closest single star system to Earth. But a combination of telescopes all over the world confirmed the presence of four small exoplanets, according to a study published last week in The Astrophysical Journal Letters.

—Universe Today: “Astronomers Think They’ve Found a Reliable Biosignature. But There’s a Catch“

The search for life has become one of the holy grails of science. With the increasing number of exoplanet discoveries, astronomers are hunting for a chemical that can only be present in the atmosphere of a planet with life! A new paper suggests that methyl halides, which contain one carbon and three hydrogen atoms, may just do the trick. Here on Earth they are produced by bacteria, algae, fungi and some plants but not by any abiotic, non biological processes. There is a hitch, detecting these chemicals is beyond the reach of current telescopes.

Pic of the Week: The Lynds 483 Hourglass

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Image (Credit): Lynds 483 as captured by the JWST. (NASA, ESA, CSA, STScI)

This week’s image is from the James Webb Space Telescope. It shows two actively forming stars that are 650 light-years away. The formation is called Lynds 483, or L483, after American astronomer Beverly Turner Lynds, who studied nebulae in the early 1960s.

Here is more information about the image from NASA:

The two protostars responsible for this scene are at the center of the hourglass shape, in an opaque horizontal disk of cold gas and dust that fits within a single pixel. Much farther out, above and below the flattened disk where dust is thinner, the bright light from the stars shines through the gas and dust, forming large semi-transparent orange cones.

It’s equally important to notice where the stars’ light is blocked — look for the exceptionally dark, wide V-shapes offset by 90 degrees from the orange cones. These areas may look like there is no material, but it’s actually where the surrounding dust is the densest, and little starlight penetrates it. If you look carefully at these areas, Webb’s sensitive NIRCam (Near-Infrared Camera) has picked up distant stars as muted orange pinpoints behind this dust. Where the view is free of obscuring dust, stars shine brightly in white and blue.

China is Building Its Own James Webb Space Telescope

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Image (Credit): Artist’s rendering of the China Space Station Telescope called Xuntian. (Changchun Institute of Optics, Fine Mechanics and Physics)

Just as we have competition with China for the next human to visit the Moon, we now have competition for the James Webb Space Telescope (JWST).

China has stated it plans to launch the China Space Station Telescope (CSST) in 2026, which should be as powerful as the JWST while having the extra benefit of remaining in Earth orbit. As a result, when compared to the JWST, the CSST will be easier to maintain as well as upgrade.

A Chinese paper on the new telescope noted the following regarding its potential:

It can simultaneously perform multi-band imaging and slitless spectroscopic wide- and deep-field surveys in ten years and an ultra-deep field (UDF) survey in two years, which are suitable for cosmological studies. Here we review several CSST cosmological probes, such as weak gravitational lensing, two-dimensional (2D) and three-dimensional (3D) galaxy clustering, galaxy cluster abundance, cosmic void, Type Ia supernovae (SNe Ia), and baryonic acoustic oscillations (BAO), and explore their capabilities and prospects in discovering new physics and opportunities in cosmology. We find that CSST will measure the matter distribution from small to large scales and the expansion history of the Universe with extremely high accuracy, which can provide percent-level stringent constraints on the property of dark energy and dark matter and precisely test the theories of gravity.

Of course, there is nothing wrong with a little competition. Let’s just hope NASA can get back on track after its latest budget problems as well as its current unstructured reorganization under the new White House. While the agency has other powerful telescopes under development, it doesn’t take much to throw things out of balance.