Space and astronomy news
There’s something menacing about red dwarfs. Human eyes are accustomed to our benevolent yellow Sun and the warm light it shines on our glorious, life-covered planet. But red dwarfs can seem moody, ill-tempered, and even foreboding.
For long periods of time, they can be calm, but then they can flare violently, flashing a warning to any life that might be gaining a foothold on a nearby planet.
Continue reading “Even the Calmest Red Dwarfs are Wilder than the Sun”
To date, 5,250 extrasolar planets have been confirmed in 3,921 systems, with another 9,208 candidates awaiting confirmation. Of these, 195 planets have been identified as “terrestrial” (or “Earth-like“), meaning that they are similar in size, mass, and composition to Earth. Interestingly, many of these planets have been found orbiting within the circumsolar habitable zones (aka. “Goldilocks zone”) of M-type red dwarf stars. Examples include the closest exoplanet to the Solar System (Proxima b) and the seven-planet system of TRAPPIST-1.
These discoveries have further fueled the debate of whether or not these planets could be “potentially-habitable,” with arguments emphasizing everything from tidal locking, flare activity, the presence of water, too much water (i.e., “water worlds“), and more. In a new study from the University of Padua, a team of astrobiologists simulated how photosynthetic organisms (cyanobacteria) would fare on a planet orbiting a red dwarf. Their results experimentally demonstrated that oxygen photosynthesis could occur under red suns, which is good news for those looking for life beyond Earth!
Continue reading “Do Red Dwarfs Provide Enough Sunlight for Plants to Grow?”
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”
Astronomers have found another Earth-sized planet. It’s about 31 light-years away and orbits in the habitable zone of a red dwarf star. It’s probably tidally locked, which can be a problem around red dwarf stars. But the team that found it is optimistic about its potential habitability.
Continue reading “Earth-Sized Planet Found At One of the Lightest Red Dwarfs”
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”
Future historians might look back on this time and call it the ‘exoplanet age.’ We’ve found over 5,000 exoplanets, and we’ll keep finding more. Next, we’ll move beyond just finding them, and we’ll turn our efforts to finding biosignatures, the special chemical fingerprints that living processes imprint on exoplanet atmospheres.
But there’s more to biosignatures than atmospheric chemistry. On a planet with lots of plant life, light can be a biosignature, too.
Continue reading “Worlds Bustling With Plantlife Should Shine in a Detectable Wavelength of Infrared”
Astronomers are very interested in the Habitable Zone of distant stars, which is the orbital radius where liquid water, and therefore potentially life, can exist on a planet in that region. But life itself changes the characteristics of a planet. New research suggestions that life is even capable of redefining what the Habitable Zone can mean.
Continue reading “How Life Reshapes the Habitable Zone”
For planet-hunters, finding an Earth-sized exoplanet must be special. NASA estimates there are about 100 billion planets in the Milky Way, but the large majority of the 5,000+ exoplanets we’ve found are extremely inhospitable. So finding one that’s similar to ours is kind of comforting.
In this case, it’s even more interesting because it’s the second Earth-sized planet orbiting the same star.
Continue reading “TESS has Found A Second Earth-Sized World in This System. Exoplanet Science is Maturing”
Astronomers are keenly interested in red dwarfs and the planets that orbit them. Up to 85% of the stars in the Milky Way could be red dwarfs, and 40% of them might host Earth-like exoplanets in their habitable zones, according to some research.
But there are some problems with their potential habitability. One of those problems is tidal locking.
Continue reading “Are Planets Tidally Locked to Red Dwarfs Habitable? It’s Complicated”
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”