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”
If there are alien civilizations in the Universe, some of them could be super advanced. So advanced that they can rip apart planets and create vast shells surrounding a star to capture all its energy. These Dyson spheres should be detectable by modern telescopes. Occasionally astronomers find an object that resembles such an alien megastructure, but so far, they’ve all turned out to be natural objects. As best we can tell, there are no Dyson spheres out there.
Continue reading “Will Advanced Civilizations Build Habitable Planets or Dyson Spheres”
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”
There’s something poetic about humanity’s attempt to detect other civilizations somewhere in the Milky Way’s expanse. There’s also something futile about it. But we’re not going to stop. There’s little doubt about that.
One group of scientists thinks that we may already have detected technosignatures from a technological civilization’s Dyson Spheres, but the detection is hidden in our vast troves of astronomical data.
Continue reading “Astronomers are on the Hunt for Dyson Spheres”
One of the fascinating things about being a human in this age is that we can do more than wonder about other life and other civilizations. We can actually look for them, although there are obvious limitations to our search. But what’s equally fascinating is that we can wonder if others can see us.
Continue reading “Can Alien Civilizations Detect Humanity?”
In 1960, Dr. Frank Drake led the first Search for Extraterrestrial Intelligence (SETI) experiment at the National Radio Astronomy Observatory in Green Bank, West Virginia. In the more than sixty years that have since passed, astronomers have conducted multiple surveys in search of technological activity (aka. technosignatures). To date, Breakthrough Listen is the most ambitious SETI experiment, combining data from the Robert C. Byrd Green Bank Telescope, the Parkes Murriyang Telescope, the Automated Planet Finder, and the MeerKAT Radio Telescope and advanced analytics.
The program includes a survey of the one million closest stars to Earth, the center of our galaxy and the entire galactic plane, and the 100 closest galaxies to ours. In a recent paper, members of Breakthrough Listen presented the results of their radio technosignature search of the centers of 97 nearby galaxies observed by the Robert C. Byrd Green Bank Telescope. This search was one of the largest and broadest
searches for radio evidence of extraterrestrial intelligence ever undertaken, surveying trillions of stars at four frequency bands. Unfortunately, no compelling candidates were found.
There are several ways we can measure the progress of human civilization. Population growth, the rise and fall of empires, our technological ability to reach for the stars. But one simple measure is to calculate the amount of energy humans use at any given time. As humanity has spread and advanced, our ability to harness energy is one of our most useful skills. If one assumes civilizations on other planets might possess similar skills, the energy consumption of a species is a good rough measure of its technological prowess. This is the idea behind the Kardashev Scale.
Continue reading “When Will Humanity Become a Type I Civilization?”
Are we alone in the Universe? Could there be countless sentient life forms out there just waiting to be found? Will we meet them someday and be able to exchange knowledge? Will we even recognize them as intelligent life forms if/when we meet them, and them us? When it comes to astrobiology, the search for life in the Universe, we don’t know what to expect. Hence why all the speculation and theoretical studies into these questions are so rich and varied!
One such study was conducted by famed Soviet and Russian astrophysicist and radio astronomer Nikolai Kardashev (1932 – 2019). While considering an important question related to the Search for Extraterrestrial Intelligence (SETI) in 1964, Kardashev proposed a classification scheme for ranking a civilization’s development. This would come to be known as the Kardashev Scale, which remains one of the most influential concepts in SETI to this day.
Continue reading “What is the Kardashev Scale?”