Space and astronomy news
The habitable zone is the region around a star where planets can maintain liquid water on their surface. It’s axiomatic that planets with liquid water are the best places to look for life, and astronomers focus their search on that zone. As far as we can tell, no water equals no life.
But new research suggests another delineation in solar systems that could influence habitability: The Soot Line.
Continue reading “A New Place to Search for Habitable Planets: “The Soot Line.””
We’re lucky to have a neighbour like Venus, even though it’s totally inhospitable, wildly different from the other rocky planets, and difficult to study. Its thick atmosphere obscures its surface, and only powerful radar can penetrate it. Its extreme atmospheric pressure and high temperatures are barriers to landers or rovers.
It’s like having a mysterious exoplanet next door.
Continue reading “Venus is Like an Exoplanet that’s Right Next Door”
A team of astrophysicists has discovered a binary pair of ultra-cool dwarfs so close together that they look like a single star. They’re remarkable because they only take 20.5 hours to orbit each other, meaning their year is less than one Earth Day. They’re also much older than similar systems.
Continue reading “Binary Dwarf Stars Found Orbiting Each Other Every 20 Hours. They Were Once Almost Touching”
While the Earth absorbs a lot of energy from the Sun, a lot of it is reflected back into space. The sunlight reflected from Earth is called Earthshine. We can see it on the dark portion of the Moon during a crescent Moon. The Farmer’s Almanac said it used to be called “the new Moon in the old Moon’s arms.”
Earthshine is one instance of planetshine, and when we look at the light from distant exoplanets, we’re looking directly at their planetshine without it bouncing off another object.
If distant astronomers were looking at Earthshine the way we look at exoplanet shine, would the light tell them our planet is rippling with life?
Continue reading “Could Next-Generation Telescopes See That Earth Has Life?”
Here’s a thorny problem: What if life doesn’t always appear on planets that can support it? What if we find more and more exoplanets and determine that some of them are habitable? What if we also determine that life hasn’t appeared on them yet?
Could we send life-bringing comets to those planets and seed them with terrestrial life? And if we could do that, should we?
Continue reading “We Could Spread Life to the Milky Way With Comets. But Should We?”
Our understanding of habitability relies entirely on the availability of liquid water. All life on Earth needs it, and there’s every indication that life elsewhere needs it, too.
Can planets with frozen surfaces somehow have enough water to sustain life?
Continue reading “Could Life Survive on Frigid Exo-Earths? Maybe Under Ice Sheets”
Earth is about 29% land and 71% oceans. How significant is that mix for habitability? What does it tell us about exoplanet habitability?
Continue reading “What’s the Best Mix of Oceans to Land for a Habitable Planet?”
The Curiosity rover has now reached its primary target on Mount Sharp on Mars, the mountain in the middle of Gale Crater the rover has been climbing since 2014. This target is not the summit, but a region over 600 meters (2,000 feet) up the mountain that planetary geologists have long anticipated reaching.
Known as the “sulfate-bearing unit,” the region is a boundary between the rocks that saw a lot of water in their history and those that didn’t; a possible shoreline, if you will. That boundary is already providing insights into Mars’ transition from a wet planet to dry, filling in a key gap in the understanding of the planet’s history.
Continue reading “Curiosity Arrives in a Salty Region of Mars. Was it Left Over From a Dying Sea?”
How would Earth appear to alien astronomers? What would their observations tell them about Earth if they searched the heavens for signs of habitability like we are? It’s a fun thought experiment.
But the experiment is more than just fun: it’s scientifically instructive. In many ways, it’s easier to study our planet and how it appears and then extrapolate those results as far as they go.
A new study shows that finding evidence of life on Earth may depend on the season alien astronomers are observing.
Continue reading “If Earth Were an Exoplanet, it Would Still be Tricky to Figure Out if There’s Life Here”
Our Solar System contains eight planets and more than 200 moons. The large majority of those moons have no chance of being habitable, but some of them—Europa and Enceladus, for example—are strong candidates in the search for life.
Is it the same in other solar systems?
Continue reading “These are the Best Places to Search for Habitable Exomoons”