New Study Says We Could Be Alone in the Universe

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satellite
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There's a good chance that humans are the only intelligent life in the galaxy, according to a new study submitted to the journal Proceedings of the Royal Society of London A. As Quartz reports, researchers at Oxford University's Future of Humanity Institute applied existing knowledge of biology, chemistry, and cosmology to the Drake equation (below). It was created by astronomer Frank Drake in 1961 as an attempt to calculate the number of intelligent civilizations that could be in our galaxy. He included factors like the average rate of star formation and the average lifespan of intelligent civilizations.

Image showing text of the Drake equation and explaining what each variable means
Equation: University of Rochester; Image: Hannah McDonald

They estimate there’s a 53 to 99.6 percent chance we’re alone in the galaxy, and a 39 to 85 percent chance we’re the only intelligent life to be found in the entire universe.

“Where are they?” the researchers ask, referring to the classic Fermi Paradox, which asserts that intelligent extraterrestrial beings exist and that they should have visited Earth by now. “Probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable.”

Seth Shostak doesn’t buy it. Shostak is senior astronomer at the SETI Institute, a research organization that analyzes radio signals for signs of extraterrestrial intelligence. Part of the challenge with mathematical modeling like this, Shostak says, is that the data are limited; scientists just haven’t looked at very many star systems.

“I could walk outside here in Mountain View, California and not see too many hippos strolling the streets,” he tells Mental Floss. “But it would be incorrect for me to say on that rather limited basis that there’s probably no hippos anywhere. It’s a big conclusion to make on the basis of a local observation.”

Moreover, they may not even know what to look for in the solar systems they have reviewed. The SETI Institute examines radio communications and light signals, but there’s always the possibility that an intelligent civilization has attempted to contact us using means we may not have developed or even considered yet.

The Fermi Paradox itself may be naïve in its understanding of the universe, Shostak says. “You could have said the same thing about Antarctica in the 1700s. A lot of people wondered, ‘Is there a continent down there?’ On the one hand, you could argue there was [a continent], and on the other hand, you could say, ‘Look, there’s an awful lot of water in the Pacific and the Atlantic, and there’s no continents there, so why should there be one at the bottom of the ocean?’”

In other words, any conclusions about the existence of extraterrestrial intelligence are likely to be presumptive, made before any solid data is released or discovered. The truth may be out there, Shostak says. We just haven’t found it yet.

[h/t Quartz]

The Leonid Meteor Shower Peaks This Weekend—Here's the Best Way to See It

NASA/Getty Images
NASA/Getty Images

The Leonid meteor shower will be making its annual appearance in the sky this weekend. As NPR reports, the best time to catch it will be late Saturday night into Sunday morning (November 17-18)—so if you really want to catch this dazzling light show, you may want to drink some coffee to help you stay up.

The waxing gibbous Moon will dull the meteors’ shine a little, so plan to start stargazing after the Moon has set but before dawn on Sunday. (You can use timeanddate.com to figure out the moonset time in your area. The site also features an interactive meteor shower sky map to track visibility conditions.)

If you'll be in parts of the South or Midwest this weekend, you're in luck. Florida, Alabama, Mississippi, Nebraska, and Nevada are expected to enjoy the best view of the Leonids this time around, according to Popular Mechanics.

The Leonids occur every year around November 17 or 18, when Earth drifts across the long trail of debris left behind by the comet Tempel-Tuttle. The comet takes 33 years to complete its orbit around the Sun, and when it reaches perihelion (its closest approach to the Sun), a Leonid storm may occur depending on the density of the comet's existing debris. This sometimes results in hundreds of thousand of meteors streaking across the sky per hour, viewable from Earth. The last Leonid storm occurred in 2001, but Earth may not see dense debris clouds until 2099, according to the American Meteor Society.

This year, if skies are clear and you can secure a secluded spot away from city lights, you might be able to see around 15 to 20 meteors per hour. They travel at 44 miles per second “and are considered to be some of the fastest meteors out there,” NASA says. They’re also known for their “fireballs”—explosions of light and color—which tend to last longer than a typical meteor streak.

[h/t NPR]

Two Harvard Scientists Suggest 'Oumuamua Could Be, Uh, an Alien Probe

ESO/M. Kornmesser
ESO/M. Kornmesser

An odd, cigar-shaped object has been stumping scientists ever since it zoomed into our solar system last year. Dubbed 'Oumuamua (pronounced oh-MOO-ah-MOO-ah), it was first seen through the Pan-STARRS 1 telescope in Hawaii in October 2017. 'Oumuamua moved at an unusually high speed and in a different kind of orbit than those of comets or asteroids, leading scientists to conclude that it didn't originate in our solar system. It was the first interstellar object to arrive from somewhere else, but its visit was brief. After being spotted over Chile and other locales, 'Oumuamua left last January, leaving lots of questions in its wake.

Now, two researchers at Harvard University bury a surprising suggestion in a new paper that analyzes the object's movement: 'Oumuamua could be an alien probe. Sure, why not?

First, astrophysicists Shmuel Bialy and Abraham Loeb argue that 'Oumuamua is being driven through space by solar radiation pressure, which could explain its uncharacteristic speed. But for that theory to work, they calculate that the object must be unusually thin. Bialy and Loeb then analyze how such a slender object might withstand collisions with dust and gases, and the force of rotation, on its interstellar journey.

Then things get weird.

"A more exotic scenario is that 'Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization," they write [PDF]. They suggest that ‘Oumuamua could be be a lightsail—an artificial object propelled by radiation pressure—which also happens to be the technology that the Breakthrough Starshot initiative, of which Loeb is the advisory committee chair, is trying to send into space. "Considering an artificial origin, one possibility is that 'Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment,” they write.

Their paper, which was not peer-reviewed, was posted on the pre-print platform arXiv.

Loeb is well known for theorizing about alien tech. He previously suggested that intense radio signals from 2007 could be the work of aliens who travel through space on solar sails. However, Loeb acknowledged that this theory deals more with possibility than probability, The Washington Post noted. “It’s worth putting ideas out there and letting the data be the judge,” Loeb told the paper last year.

[h/t CNN]

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