Space and astronomy news
That’s the kind of headline that can leave us scratching our heads. How can you see tree shadows on other worlds, when those planets are tens or hundreds of light years—or even further—away. As it turns out, there might be a way to do it.
One team of researchers thinks that the idea could potentially be used to answer one of humanity’s long-standing questions: Are we alone?
Continue reading “Here’s a Clever Idea, Looking for the Shadows of Trees On Exoplanets to Detect Multicellular Life”
The discovery of phosphine in Venus’ atmosphere has generated a lot of interest. It has the potential to be a biosignature, though since the discovery, some researchers have thrown cold water on that idea.
But it looks, at least, like the discovery is real, and that one of NASA’s Pioneer spacecraft detected the elusive gas back in 1978. And though it’s not necessarily a biosignature, the authors of a new study think that we need to rethink the chemistry of Venus’ atmosphere.
Continue reading “Did Pioneer See Phosphine in the Clouds of Venus Decades Ago?”
The detection of phosphine in Venus’ atmosphere was one of those quintessential moments in space science. It was an unexpected discovery, and when combined with our incomplete understanding of planetary science, and our wistful hopefulness around the discovery of life, the result was a potent mix that lit up internet headlines.
As always, some of the headlines were a bit of an over-reach. But that’s the way it goes.
At the heart of it all, there is compelling science. And the same, overarching question that keeps popping up: Are we alone?
Continue reading “Maybe Volcanoes Could Explain the Phosphine in Venus’ Atmosphere”
Most everybody knows that the dinosaurs perished rapidly in a tumultuous extinction, caused by an asteroid strike about 66 million years ago. But it looks like another extinction prior to the appearance of the dinosaurs paved the way for their long reign. That extinction took place about 233 million years ago.
And scientists have only now discovered it.
Continue reading “A New Mass Extinction has been Discovered, Wiping Out Life 233 Million Years Ago, and Leading to the Rise of the Dinosaurs”
We know that the carbon in your bones was formed long ago in the heart of a star. But how did that carbon actually make its way to your bones? It’s a bit of a complicated puzzle, and recent observations with the SOFIA observatory show how Mira stars do the trick.
Continue reading “Mira-type variable stars are constantly throwing the key chemicals for life out into space”
Bacteria come in two basic forms: the kinds that use a lot of hydrogen, and the kinds that don’t. And recently researchers think they’ve found a new bacteria that appear to do both at the same time, allowing it to live in a variety of extreme environments, like the ocean floor.
Its name is Acetobacterium woodii, often shortened to A. woodii, and it seems like it’s a superhero of the small-sized world.
Continue reading “An ocean floor bacteria has been found with a totally bizarre metabolism”
After a lot of hard work spanning many years, a team of scientists have discovered something surprising. They’ve found abundant bacterial life in tiny cracks in undersea volcanic rock in the Earth’s crust. The bacteria are thriving in clay deposits inside these tiny cracks.
This discovery is generating new excitement around the hope of finding life on Mars.
Continue reading “Seriously, Life Really Does Get Around. It was Found in Rocks Deep Beneath the Seafloor”
The building blocks of life can, and did, spontaneously assemble under the right conditions. That’s called spontaneous generation, or abiogenesis. Of course, many of the details remain hidden to us, and we just don’t know exactly how it all happened. Or how frequently it could happen.
Continue reading “Life Could be Common Across the Universe, Just Not in Our Region”
Scientist Carl Sagan said many times that “we are star stuff,” from the nitrogen in our DNA, the calcium in our teeth, and the iron in our blood.
It is well known that most of the essential elements of life are truly made in the stars. Called the “CHNOPS elements” – carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur – these are the building blocks of all life on Earth. Astronomers have now measured of all of the CHNOPS elements in 150,000 stars across the Milky Way, the first time such a large number of stars have been analyzed for these elements.
“For the first time, we can now study the distribution of elements across our Galaxy,” says Sten Hasselquist of New Mexico State University. “The elements we measure include the atoms that make up 97% of the mass of the human body.”
Astronomers with the Sloan Digital Sky Survey made their observations with the APOGEE (Apache Point Observatory Galactic Evolution Experiment) spectrograph on the 2.5m Sloan Foundation Telescope at Apache Point Observatory in New Mexico. This instrument looks in the near-infrared to reveal signatures of different elements in the atmospheres of stars.
While the observations were used to create a new catalog that is helping astronomers gain a new understanding of the history and structure of our galaxy, the findings also “demonstrates a clear human connection to the skies,” said the team.
While humans are 65% oxygen by mass, oxygen makes up less than 1% of the mass of all of elements in space. Stars are mostly hydrogen, but small amounts of heavier elements such as oxygen can be detected in the spectra of stars. With these new results, APOGEE has found more of these heavier elements in the inner part of the galaxy. Stars in the inner galaxy are also older, so this means more of the elements of life were synthesized earlier in the inner parts of the galaxy than in the outer parts.
So what does that mean for those of us out on the outer edges of one of the Milky Way’s spiral arms, about 25,000 light-years from the center of the galaxy?
“I think it’s hard to say what the specific implications are for when life could arise,” said team member Jon Holtzman, also from New Mexico State, in an email to Universe Today. “We measure typical abundance of CHNOPS elements at different locations, but it’s not so easy to determine at any given location the time history of the CHNOPS abundances, because it’s hard to measure ages of stars. On top of that, we don’t know what the minimum amount of CHNOPS would need to be for life to arise, especially since we don’t really know how that happens in any detail!”
Holtzman added it is likely that, if there is a minimum required abundance, that minimum was probably reached earlier in the inner parts of the Galaxy than where we are.
The team also said that while it’s fun to speculate how the composition of the inner Milky Way Galaxy might impact how life might arise, the SDSS scientists are much better at understanding the formation of stars in our Galaxy.
“These data will be useful to make progress on understanding Galactic evolution,” said team member Jon Bird of Vanderbilt University, “as more and more detailed simulations of the formation of our galaxy are being made, requiring more complex data for comparison.”
“It’s a great human interest story that we are now able to map the abundance of all of the major elements found in the human body across hundreds of thousands of stars in our Milky Way,” said Jennifer Johnson of The Ohio State University. “This allows us to place constraints on when and where in our galaxy life had the required elements to evolve, a sort ‘temporal Galactic habitable zone’”.
The catalog is available at the SDSS website, so take a look for yourself at the chemical abundances in our portion of the galaxy.
Source: SDSS
Evidence of water and a warmer, wetter climate abound on Mars, but did life ever put its stamp on the Red Planet? Rocks may hold the secret. Knobby protuberances of rock discovered by the Spirit Rover in 2008 near the rock outcrop Home Plate in Gusev Crater caught the attention of scientists back on Earth. They look like cauliflower or coral, but were these strange Martian rocks sculpted by microbes, wind or some other process?
When analyzed by Spirit’s mini-TES (Mini-
Both at Yellowstone, the Taupo Volcanic Zone in New Zealand and in Iceland, heat-loving bacteria are intimately involved in creating curious bulbous and branching shapes in silica formations that strongly resemble the Martian cauliflower rocks. New research presented at the American Geophysical Union meeting last month by planetary geologist Steven Ruff and geology professor Jack Farmer, both of Arizona State University, explores the possibility that microbes might have been involved in fashioning the Martian rocks, too.
A sizzling visit to El Tatio’s geysers
The researchers ventured to the remote geyser fields of El Tatio in the Chilean Atacama Desert to study an environment that may have mimicked Gusev Crater billions of years ago when it bubbled with hydrothermal activity. One of the driest places on Earth, the Atacama’s average elevation is 13,000 feet (4 km), exposing it to considerably more UV light from the sun and extreme temperatures ranging from -13°F to 113°F (-10° to 45°C). Outside of parts of Antarctica, it’s about as close to Mars as you’ll find on Earth.
Ruff and Farmer studied silica deposits around hot springs and geysers in El Tatio and discovered forms they call “micro-digitate silica structures” similar in appearance and composition to those on Mars (Here’s a photo). The infrared spectra of the two were also a good match. They’re still analyzing the samples to determine if heat-loving microbes may have played a role in their formation, but hypothesize that the features are “micro-stromatolites” much like those found at Yellowstone and Taupo.
Stromatolites form when a sticky film of bacteria traps and cements mineral grains to create a thin layer. Other layers form atop that one until a laminar mound or column results. The most ancient stromatolites on Earth may be about 3.5 billion years old. If Ruff finds evidence of biology in the El Tatio formations in the punishing Atacama Desert environment, it puts us one step closer to considering the possibility that ancient bacteria may have been at work on Mars.
Silica forms may originate with biology or from non-biological processes like wind, water and other environmental factors. Short of going there and collecting samples, there’s no way to be certain if the cauliflower rocks are imprinted with the signature of past Martian life. But at least we know of a promising place to look during a future sample return mission to the Red Planet. Indeed, according to Ruff, the Columbia Hills inside Gusev Crater he short list of potential sites for the 2020 Mars rover.
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