As far as we can tell, life needs water. Cells can’t perform their functions without it. Some have suggested that other exotic liquids, like liquid methane, could do the job on worlds like Saturn’s moon Titan. That idea is highly speculative, though.
So, it makes sense that NASA is launching a spacecraft dedicated to the search for water.
SPHEREx stands for Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer. It’s scheduled to launch on February 27th. It has a single instrument and one observing mode. Part of its mission is to map the sky in near-infrared and measure the spectra of 450 million galaxies. The results will help scientists understand the expansion of the Universe and the origin and evolution of galaxies.
This image shows a semi-frontal view of the SPHEREx observatory during integration and testing at BAE Systems (Boulder, CO). Image Credit: NASA/JPL-Caltech.Its other scientific goal is to probe molecular clouds for water ice and other frozen pre-biotic molecules. These ices are frozen onto the surface of dust grains in molecular clouds, and somehow, through a long journey, they become part of planets, where they can form oceans and potentially foster the appearance of life.
Infrared observations show that in cold, dense regions of space in molecular clouds, chemicals critical to life are locked into dust grains. Water is the primary one, of course, but there are other pre-biotic molecules as well: carbon dioxide (CO2), carbon monoxide (CO), methanol (CH3OH), the nitrogen-bearing molecule ammonia (NH3) plus various carbon-nitrogen stretch molecules (XCN), and the important sulphur-bearing molecule, carbonyl sulphide (COS). Carbon-nitrogen stretch molecules are everywhere in organic and biological molecules and play critical roles in biological processes. Carbonyl-sulphide plays a role in the formation of peptides, which are the building blocks of proteins.
There’s a vast amount of water frozen in dust grains in molecular clouds, and scientists think this is where the bulk of the water in the galaxy and even in the Universe resides. These grains are the source of water for Earth’s oceans and for any exoplanets or moons that might harbour oceans.
SPHEREx will examine molecular clouds and try to understand how much water they contain. It will also examine stars in those clouds and the rings of material that form around them, out of which planets form.
Put succinctly, SPHEREx is trying to answer this question: How does ice content evolve from diffuse clouds to dense clouds to planetary disks and then to planets?
This photo by renowned astrophotographer Rogelio Bernal Andreo shows the Orion constellation and the surrounding nebulas of the Orion Molecular Cloud complex. The clouds in the complex hold frozen water and other chemicals critical to life. Image Credit: By Rogelio Bernal Andreo – http://deepskycolors.com/astro/JPEG/RBA_Orion_HeadToToes.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=20793252There’s little doubt that ices play an important role in the formation of planetesimals in disks around young stars. Likewise, there’s little doubt that these ices are sources of water and organic molecules, too. But how does it all happen? Ice’s journey from translucent to dense molecular clouds and then to protoplanetary disks is not well understood. Scientists want to know if the ices in the disks are simply inherited from the interstellar medium or if they’re altered in the disks somehow.
The SPHEREx mission hopes to answer this question and others with its infrared absorption spectroscopy.
SPHEREx will generate spectra for between 8 and 9 million sources and should transform our understanding of ices in molecular clouds, young stellar objects, and protoplanetary disks.
In infrared wavelengths, ices have unique spectral signatures. Prior to the JWST, scientists had only about 200 ice absorption spectra available. The JWST is changing that, but it has lots of other important work to do.
The JWST is already advancing our understanding of these ices. Like other infrared observatories, it can see through dust, but it is far more powerful and sensitive. A key to SPHEREx’s design and performance is its ability to be as accurate as the JWST.
The black line is the JWST spectrum of a source seen through a thick molecular cloud of interstellar dust, showing the strong features of the interstellar ice species H2O, CO2, and CO at wavelengths of 3.05, 4.27, and 4.67 microns (McClure et al. 2023, Nature Astronomy, 7, 431). Overlaid in red is a simulated spectrum, taken with SPHEREx’s lower spectral resolving power, of a background source with 100x the JWST brightness in the SPHEREx range that shows the same absorption features as seen by JWST. Note that SPHERE reproduces almost all of the spectral structure apparent in the JWST spectrum. Image Credit: NASA/JPLThere is no shortage of targets for SPHEREx. Some research shows that there are over 8,000 molecular clouds in the Milky Way. Not all of them are great targets for SPHEREx, but many are.
SPHEREx has a catalogue of targets that includes molecular clouds in the Large and Small Magellanic Clouds and several constellations, including Monoceros, home of the Monoceros R2 Molecular Cloud.
The Monoceros R2 Molecular Cloud is one of SPHEREx’s targets. This image shows only a portion of the cloud, which is a large cloud with lots of active star formation. Star formation is particularly active in the location of the bright red nebula just below the center of the image. This image was obtained with the wide-field view of the Mosaic II camera on the Blanco 4-meter telescope at Cerro Tololo Interamerican Observatory on January 11th, 2012. Image Credit: T.A. Rector (University of Alaska Anchorage) and N.S. van der Bliek (NOIRLab/NSF/AURA)It’s axiomatic that stars and planets have the same compositions as the molecular clouds that fostered them. But the specifics of planet formation are mysterious and the study of the processes has produced some surprises.
In 1998, NASA launched the Submillimeter Wave Astronomy Satellite (SWAS). Similar to SPHEREx, it studied the chemical composition of interstellar clouds and surveyed the galaxy to determine how much water vapour was present in molecular clouds. Surprisingly, it found far less than expected.
“This puzzled us for a while,” said Gary Melnick, a senior astronomer at the Center for Astrophysics | Harvard & Smithsonian and a member of the SPHEREx science team. “We eventually realized that SWAS had detected gaseous water in thin layers near the surface of molecular clouds, suggesting that there might be a lot more water inside the clouds, locked up as ice.”
The SWAS team figured out that hydrogen and oxygen atoms were being frozen onto the surfaces of ice grains where they formed water ice. Subsequent research confirmed their suspicions. On the unprotected surfaces of molecular clouds, cosmic radiation can break the H2O molecules apart, but protected inside molecular clouds, the molecules persisted.
The water ice and other ices create spectroscopic signatures separate from their liquid counterparts, and SPHEREx is designed to detect them.
It will do more than detect them, though. The spacecraft will also determine how deep inside the clouds the ices form, how their abundance changes with cloud density, and how the abundance changes when a star forms.
SPHEREx will also cooperate with other telescopes, including the JWST, which will perform more powerful follow-up observations when merited.
“If SPHEREx discovers a particularly intriguing location, Webb can study that target with higher spectral resolving power and in wavelengths that SPHEREx cannot detect,” said Melnick. “These two telescopes could form a highly effective partnership.”
SPHEREx will launch on February 27th in a Falcon Heavy rocket from Vandenberg Air Base. It will follow a Sun-Synchronous orbit at about 700 km altitude. In its nominal 25-month mission, SPHEREx will map the entire sky four times.
The post NASA’s SPHEREx Launches Soon and Will Search For Water in Molecular Clouds appeared first on Universe Today.
Six days ago I posted a group letter to the Presidents of three ecology/evolution/systematics societies who had issued a joint statement that many of us found deeply misguided. As I wrote at the time:
The Presidents of three organismal-biology societies, the Society for the Study of Evolution (SSE), the American Society of Naturalists (ASN) and the Society of Systematic Biologists (SSB) sent a declaration addressed to President Trump and all the members of Congress (declaration archived here) Implicitly claiming that its sentiments were endorsed by the 3500 members of the societies, the declaration also claimed that there is a scientific consensus on the definition of sex, and that is that sex is NOT binary but rather some unspecified but multivariate combination of different traits, a definition that makes sex a continuum or spectrum—and in all species!
I objected to this declaration, and Luana Maroja of Williams College, who agreed with me, drafted a letter that was signed by about two dozen people, many but not all of them members of at least one of the three societies. The point was to show that there is not a biological consensus that sex is a spectrum—indeed, the societies’ letter implied that biologists agree that sex is a spectrum in all species. Nonsense!
Further, the “tri-societies letter” did not involve polling the members of the SSE, the ASN, and the SSB to see if they agreed with the Presidents. Finally, I am not sure that their letter, addressed to President Trump and “Members of the U.S. Congress,” has actually been sent. Because it may have been changed since the first iteration, I archived it at the link above as soon as it appeared.
When I put up our response, because we were collecting signatures and had not yet asked the signers whether their names could be publicized, it was signed publicly only by Luana and me. Since then, we’ve asked all the signers if they wanted to “go public” with their names. All but a few agreed, and so I am putting the signed letter below, except for the names of those who objected to going public.
Further, I have heard independently from several other prominent biologists who were peeved at the tri-societies letter and/or were writing their own individual letters to the societies.
This is only the first stab at a response, and we intend to collect more signatures and have devised a method for doing so. So think about it, and we would like signatures only of those people who don’t mind going public. You need not be a member of any of the societies (though it would be a boon), and can add your society affiliation if you wish. And, of course, you must be a biologist or affiliated with biology
In the meantime, I’m putting up what we have just so the letter at this stage of its evolution can have a public URL. Ponder whether you’d like to join in, and you should hear more by later today or tomorrow. Do not email me or put in the comments that you want to be included, as we have a much more efficient way.
What is below is just a start. Our letter is below the line:
Dear presidents of the Tri-societies: ASN, SSB and SSE,
We, Tri-society members and/or biologists, are deeply disappointed by your recent letter “Letter to the US President and Congress on the Scientific Understanding of Sex and Gender” issued last Wednesday, Feb 5, 2025, in response to Trump’s executive order “Defending Women From Gender Ideology Extremism And Restoring Biological Truth To The Federal Government”.
While we agree that Trump’s executive orders are misleading, we disagree with your statements about the sex binary and its definition. In animals and plants, binary sex is universally defined by gamete type, even though sexes vary in how they are developmentally determined and phenotypically identified across taxa. Thus, your letter misrepresents the scientific understanding of many members of the Tri-societies.
You state that: “Scientific consensus defines sex in humans as a biological construct that relies on a combination of chromosomes, hormonal balances, and the resulting expression of gonads, external genitalia, and secondary sex characteristics.”
However, we do not see sex as a “construct” and we do not see other mentioned human-specific characteristics, such as “lived experiences” or “[phenotypic] variation along the continuum of male to female”, as having anything to do with the biological definition of sex. While we humans might be unique in having gender identities and certain types of sexual dimorphism, sex applies to us just as it applies to dragonflies, butterflies, or fish – there is no human exceptionalism. Yes, there are developmental pathologies that cause sterility and there are variations in phenotypic traits related to sexual dimorphism. However, the existence of this variation does not make sex any less binary or more complex, because what defines sex is not a combination of chromosomes or hormonal balances or external genitalia and secondary sex characteristics. The universal biological definition of sex is gamete size.
If you and the signers of this letter do not agree on these points, then the Tri-societies were wrong to speak in our names and claim that there is a scientific consensus without even conducting a survey of society members to see if such a consensus exists. Distorting reality to comply with ideology and using a misleading claim of consensus to give a veneer of scientific authority to your statement does more harm than just misrepresenting our views: it also weakens public trust in science, which has declined rapidly in the last few years. Because of this, scientific societies should stay away from politics as much as possible, except for political issues that directly affect the mission of the society.
Respectfully,
Daniel A. Barbash, Professor, Molecular Biology and Genetics, Cornell University
Alexander T. Baugh, Associate Professor, Department of Biology, Swarthmore College
Kendall Clements, Professor, School of Biological Sciences, University of Auckland
Mark Collard, Chair in Human Evolutionary Studies, Simon Fraser University
Jerry Coyne, Professor Emeritus, Ecology and Evolution, University of Chicago
David Curtis, Honorary Professor, Genetics Institute, University College London UK
Richard Dawkins, Emeritus Professor, University of Oxford
Gilly Denham, SSE member, Williams College
Joan Edwards, Samuel Fessenden Clarke Professor of Biology, Williams College
Brian Gill, retired natural history curator from Auckland Museum, New Zealand
Emma Hilton, Developmental Biology, University of Manchester, U.K.
Carole Kennedy Hooven, Senior Fellow, AEI; Affiliate, Harvard Psychology.
Edward Lee, SSE member, Williams College
Luana S. Maroja, Professor of Biology, Williams College
Gregory C. Mayer, Professor of Biological Sciences, University of Wisconsin-Parkside
Axel Meyer, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz
Marcella McClure retired from Montana State University
Nicholas J. Matzke, Senior Lecturer, School of Biological Sciences, University of Auckland
Anthony M. Poole, Professor, School of Biological Sciences, University of Auckland
Philip Ward, Professor of Entomology, University of California Davis