Space and astronomy news
Sometimes in science you have to step back and take another look at underlying assumptions. Sometimes its necessary when progress stalls. One of the foundational questions of our day concerns the Fermi Paradox, the contradiction between what seems to be a high probability of extraterrestrial life and the total lack of evidence that it exists.
What assumptions underlie the paradox?
Continue reading “Advanced Civilizations Could be Indistinguishable from Nature”
One of the most challenging aspects of astrobiology and the Search for Extraterrestrial Intelligence (SETI) is anticipating what life and extraterrestrial civilizations will look like. Invariably, we have only one example of a planet that supports life (Earth) and one example of a technologically advanced civilization (humanity) upon which to base our theories. As for more advanced civilizations, which statistically seems more likely, scientists are limited to projections of our own development. However, these same projections offer constraints on what SETI researchers should search for and provide hints about our future development.
In a series of papers led by the Blue Marble Space Institute of Science (BMSIS), a team of researchers examines what Earth’s level of technological development (aka. “technosphere”) will look like in the future. In the most recent installment, they offer a reinterpretation of the Kardashev Scale, which suggests that civilizations expand to harness greater levels of energy (planet, host star, and galaxy). Instead, they suggest that the Kardashev Scale establishes upper limits on the amount of stellar energy a civilization can harness (a “luminosity limit”) and that civilizations might circumvent this by harnessing stellar mass directly.
Continue reading “New Study Examines How Extraterrestrial Civilizations Could Become “Stellarvores.””
Eventually, every stellar civilization will have to migrate to a different star. The habitable zone around all stars changes as they age. If long-lived technological civilizations are even plausible in our Universe, migration will be necessary, eventually.
Could Extraterrestrial Intelligences (ETIs) use stars themselves as stellar engines in their migrations?
Continue reading “A Spider Stellar Engine Could Move Binary Stars Halfway Across a Galaxy”
Earth’s average global temperatures have been steadily increasing since the Industrial Revolution. According to the National Oceanic and Atmospheric Agency (NOAA), Earth has been heating up at a rate of 0.06 °C (0.11 °F) per decade since 1850 – or about 1.11 °C (2 °F) in total. Since 1982, the average annual increase has been 0.20 °C (0.36 °F) per decade, more than three times as fast. What’s more, this trend is projected to increase by between 1.5 and 2 °C (2.7 to 3.6 °F) by mid-century, possibly more! This is a direct consequence of burning fossil fuels, which has increased exponentially since the mid-19th century.
Depending on the extent of temperature increases, the impact on Earth’s habitability could be catastrophic. In a recent study, a team of scientists examined how temperature increases are a long-term issue facing advanced civilizations and not just a matter of fossil fuel consumption. As they argue, rising planetary temperatures could be an inevitable result of the exponential growth of energy consumption. Their findings could have serious implications for astrobiology and the Search for Extraterrestrial Intelligence (SETI).
Continue reading “Advanced Civilizations Will Overheat Their Planets Within 1,000 Years”
The Search for Extraterrestrial Intelligence (SETI) is regularly plagued by the fact that humanity has a very limited perspective on civilization and the nature of intelligence itself. When it comes right down to it, the only examples we have to go on are “life as we know it” (aka. Earth organisms) and human civilization. On top of that, given the age of the Universe and the time life has had to evolve on other planets, it is a foregone conclusion that any advanced life in our galaxy would be older than humanity. Luckily, this presents an opportunity to develop and test theoretical frameworks in the field.
To paraphrase Freeman Dyson, if we can conceive of a concept (and the physics are sound), an advanced species will likely have built it already. In this respect, imagining where humanity will be centuries or eons from now could provide potential “technosignatures” to look for. In a recent paper, a team from the Blue Marble Space Institute of Science (BMSIS) and NASA’s Goddard Space Flight Center modeled a series of scenarios that attempt to predict what humanity’s “technosphere” could look like 1,000 years from now. Their research could have implications for future SETI studies.
Continue reading “Projecting what Earth will Look Like 1000 years from now Could Assist in the Search for Advanced Civilizations”
In 1971, English mathematical physicist and Nobel-prize winner Roger Penrose proposed how energy could be extracted from a rotating black hole. He argued that this could be done by building a harness around the black hole’s accretion disk, where infalling matter is accelerated to close to the speed of light, triggering the release of energy in multiple wavelengths. Since then, multiple researchers have suggested that advanced civilizations could use this method (the Penrose Process) to power their civilization and that this represents a technosignature we should be on the lookout for.
Examples include John M. Smart’s Transcension Hypothesis, a proposed resolution to the Fermi Paradox where he suggested advanced intelligence may migrate to the region surrounding black holes to take advantage of the energy available. The latest comes from Harvard Professor Avi Loeb, who proposed in a recent paper how advanced civilizations could rely on a “Black Hole Moon” to provide their home planet with power indefinitely. The way this black hole would illuminate the planet it orbits, he argues, would constitute a potential technosignature for future SETI surveys.
Continue reading “New Study Proposes how a Black Hole in Orbit Around a Planet Could be a Sign of an Advanced Civilization.”
In 1977, astronomers received a powerful, peculiar radio signal from the direction of the constellation Sagittarius. Its frequency was the same as neutral hydrogen, and astronomers had speculated that any ETIs attempting to communicate would naturally use this frequency. Now the signal, named the Wow! Signal has become lore in the SETI world.
But what was it?
Continue reading “The Wow! Signal Deciphered. It Was Hydrogen All Along.”
Humanity is facing an atmospheric threat of our own device, and our internecine squabbles are hampering our ability to neutralize that threat. But if we last long enough, the reverse situation will arise. Our climate will cool, and we’ll need to figure out how to warm it up. If that day ever arises, we should be organized enough to meet the challenge.
If there are other civilizations out there in the galaxy, one may already be facing a cooling climate or an ice age. Could we detect the greenhouse chemicals they would be purposefully emitting into their atmosphere in an attempt to warm their planet?
Continue reading “Could We Detect an Alien Civilization Trying to Warm Their Planet?”
The search for life has to be one of the most talked about questions in science. The question is, what do you look for? The Odysseus lunar lander has recently detected signs of a technologically advanced civilisation…on Earth! The lander is equipped with an instrument called ROLSES which has probed the radio emissions from Earth as if it was an exoplanet to se if it could detect signs of life!
Continue reading “Moon Lander Detects Technosignatures Coming from Earth”
If alien technological civilizations exist, they almost certainly use solar energy. Along with wind, it’s the cleanest, most accessible form of energy, at least here on Earth. Driven by technological advances and mass production, solar energy on Earth is expanding rapidly.
It seems likely that ETIs (Extraterrestrial Intelligence) using widespread solar energy on their planet could make their presence known to us.
Continue reading “Could Alien Solar Panels Be Technosignatures?”