Thanks to NASA, the Search for Habitable Worlds Just Got Easier


New NASA research will make it easier to find the planets out there that can support life. Detailed in the The Astrophysical Journal, the new model can simulate atmospheric conditions in a more comprehensive way, taking circulation of the atmosphere and other factors into account.

The search for habitable planets requires detailed modeling. The scope of the universe is simply too vast for scientists to spend time searching planet-by-planet. Instead, they calculate factors that would allow a planet to support liquid water—a requirement to support life as we know it—using simulations. For instance, it has to be just far enough from its parent star that the atmosphere isn't so cold that bodies of water freeze, but not so hot that they evaporate.

When planets are losing their oceans due to evaporation, they enter what's called a "moist greenhouse" state as the water vapor rises into the stratosphere and the hydrogen atoms break apart from the oxygen atoms to escape into space, eventually resulting in the loss of the planet's oceans. The new research details how a star's radiation influences how the atmosphere of an exoplanet circulates and plays a role in creating that moist greenhouse state. 

Planets that orbit a low-mass star—the most common kind of star in our galaxy—would have to be closer to that star than the Earth is to the Sun in order to support life, since a low-mass star is cooler and dimmer. The gravity from such a close star would slow down the rotation of the planet, and it might even become locked, with one side perpetually facing the star and one side perpetually facing away. (It would be as if the Eastern Hemisphere were always light and the Western Hemisphere were always dark.)

In turn, the planet would form a thick layer of clouds on the perpetually sunny side. The near-infrared radiation from the star—and cooler stars emit more of this radiation than hotter ones do—interacts with the water vapor in the air and the droplets and ice crystals in the clouds to warm up the air, creating the moist greenhouse state.

The moist greenhouse state could happen even at temperatures as low as those found in the tropical regions of Earth because of that near-infrared radiation interaction, according to the new model, but the study found that in exoplanets close to their stars, the process happens gradually enough that they could remain habitable. This more nuanced model will help guide scientists in their search for habitable planets near low-mass stars.

"As long as we know the temperature of the star, we can estimate whether planets close to their stars have the potential to be in the moist greenhouse state," study co-author Anthony Del Genio explained in a NASA press release. "Current technology will be pushed to the limit to detect small amounts of water vapor in an exoplanet's atmosphere. If there is enough water to be detected, it probably means that planet is in the moist greenhouse state."

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]

A Team of Young Women Wants to Send Kyrgyzstan's First Satellite to Space

José Furtado y Antel, Wikimedia Commons // CC0 1.0
José Furtado y Antel, Wikimedia Commons // CC0 1.0

Kyrgyzstan is one of 123 countries that doesn't have a national space agency. That could soon change, thanks to a group of young programmers and engineers taking the matter into their own hands.

As The Next Web reports, the Kyrgyz Space Program is made up of 12 women ranging in age from 17 to 25 years old. They met in 2017, when journalist and TED fellow Bektour Iskender started a free course in his home country of Kyrgyzstan teaching young women there how to build robots and satellites.

The team has since made it its mission to build a cube satellite (CubeSat)—a smaller type of satellite that costs about $150,000 to put together. If they are able to construct the spacecraft, launch it into orbit, and send it to the International Space Station as planned, the project will mark the first time Kyrgyzstan has sent a satellite into space.

The Kyrgyz Space Program now meets twice a week in the offices of Kloop, a media outlet that's known for its support of feminist causes in a country where women still have a long way to go to reach parity. Even as more women start to get involved in Kyrgyzstan's politics, domestic violence, child marriage, and bride kidnappings are still rampant.

In order to accomplish their goal of sending a Kyrgyz satellite to orbit, the program has launched a crowdfunding campaign. Reaching the $2500-a-month marker means they can construct the CubeSat with guidance from the team who launched Lithuania's first satellite. If they reach the $10,000-a-month threshold, they will be able to send the CubeSat to the International Space Station. You can join the 120 people who've already supported their Patreon page by pledging today.

[h/t The Next Web]