Astronomers are Starting to Find Planets in Much Longer Orbits. Cooler, More Habitable Planets

We’re getting better and better at detecting exoplanets. Using the transit method of detection, the Kepler Space Telescope examined over 530,000 stars and discovered over 2,600 explanets in nine years. TESS, the successor to Kepler, is still active, and has so far identified over 1800 candidate exoplanets, with 46 confirmed.

But what if, hidden in all that data, there were even more planets? Astronomers at Warwick University said they’ve found one of these “lost” planets, and that they think they’ll find even more.

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Astronomers Define the “Really Habitable Zone”. Planets Capable of Producing Gin and Tonic

A hospitable star that doesn’t kill you with deadly flares. A rocky planet with liquid water and an agreeable climate. Absence of apocalyptic asteroid storms. No pantheon of angry, vengeful, and capricious gods. These are the things that define a habitable planet.

Now some scientists are adding one more criterion to the list: gin and tonic.

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Without a Magnetosphere, Planets Orbiting Flare Stars Don’t Stand a Chance

superflare

Earthlings are fortunate. Our planet has a robust magnetic shield. Without out magnetosphere, the Sun’s radiation would’ve probably ended life on Earth before it even got going. And our Sun is rather tame, in stellar terms.

What’s it like for exoplanets orbiting more active stars?

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Planet Sizes Matter for Habitability Too.

In order to be considered habitable, a planet needs to have liquid water. Cells, the smallest unit of life, need water to carry out their functions. For liquid water to exist, the temperature of the planet needs to be right. But how about the size of the planet?

Without sufficient mass a planet won’t have enough gravity to hold onto its water. A new study tries to understand how size affects the ability of a planet to hold onto its water, and as a result, its habitability.

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Better Than Earth? Are There Superhabitable Worlds In The Milky Way?

I’ve said many times in the past that the Earth is the best planet in the Universe. No matter where we go, we’ll never find a planet that’s a better home to Earth life than Earth. Of course, that’s because we, and all other Earth life evolved in this environment. Evolution adapted us to this planet, and it’s unlikely we could ever find another planet this good for us.

However, is it the best planet? Are there places in the Universe which might have the conditions for more diversity of life?

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There Could be Planets Out There Which are Even More Habitable than Earth

When searching for potentially habitable exoplanets, scientists are forced to take the low-hanging fruit approach. Since Earth is the only planet we know of that is capable of supporting life, this search basically comes down to looking for planets that are “Earth-like”. But what if Earth is not the meter stick for habitability that we all tend to think it is?

That was the subject of a keynote lecture that was recently made at the Goldschmidt Geochemistry Congress, which took place from Aug. 18th to 23rd, in Barcelona, Spain. Here, a team of NASA-supported researchers explained how an examination of what goes into defining habitable zones (HZs) shows that some exoplanets may have better conditions for life to thrive than Earth itself has.

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Snowball Exoplanets Might Be Better for Life Than We Thought

When astronomers discover a new exoplanet, one of the first considerations is if the planet is in the habitable zone, or outside of it. That label largely depends on whether or not the temperature of the planet allows liquid water. But of course it’s not that simple. A new study suggests that frozen, icy worlds with completely frozen oceans could actually have livable land areas that remain habitable.

The new study was published in the AGU’s Journal of Geophysical Research: Planets. It focuses on how CO2 cycles through a planet and how it affects the planet’s temperature. The title is “Habitable Snowballs: Temperate Land Conditions, Liquid Water, and Implications for CO2 Weathering.”

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The Closest Star to the Sun, Proxima Centauri, has a Planet in the Habitable Zone. Life Could be There Right Now

In August of 2016, astronomers from the European Southern Observatory (ESO) announced the discovery of an exoplanet in the neighboring system of Proxima Centauri. The news was greeted with consider excitement, as this was the closest rocky planet to our Solar System that also orbited within its star’s habitable zone. Since then, multiple studies have been conducted to determine if this planet could actually support life.

Unfortunately, most of the research so far has indicated that the likelihood of habitability are not good. Between Proxima Centauri’s variability and the planet being tidally-locked with its star, life would have a hard time surviving there. However, using lifeforms from early Earth as an example, a new study conducted by researchers from the Carl Sagan Institute (CSI) has shows how life could have a fighting chance on Proxima b after all.

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Which Habitable Zones are the Best to Actually Search for Life?

Looking to the future, NASA and other space agencies have high hopes for the field of extra-solar planet research. In the past decade, the number of known exoplanets has reached just shy of 4000, and many more are expected to be found once next-generations telescopes are put into service. And with so many exoplanets to study, research goals have slowly shifted away from the process of discovery and towards characterization.

Unfortunately, scientists are still plagued by the fact that what we consider to be a “habitable zone” is subject to a lot of assumptions. Addressing this, an international team of researchers recently published a paper in which they indicated how future exoplanet surveys could look beyond Earth-analog examples as indications of habitability and adopt a more comprehensive approach.

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Now that TESS is Operational, Astronomers Estimate it’ll Find 14,000 Planets. 10 Could Be Earthlike Worlds in a Sunlike Star’s Habitable Zone

An artist’s illustration of the Transiting Exoplanet Survey Satellite. Credits: NASA Goddard Space Flight Center

How many exoplanets are there? Not that long ago, we didn’t know if there were any. Then we detected a few around pulsars. Then the Kepler spacecraft was launched and it discovered a couple thousand more. Now NASA’s TESS (Transiting Exoplanet Survey Satellite) is operational, and a new study predicts its findings.

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