Mass-radius relationships for water-rich terrestrial planets are usually calculated assuming most water is present in condensed (either liquid or solid) form.
Planet density estimates are then compared to these mass-radius relationships even when these planets are more irradiated than the runaway greenhouse irradiation limit (around 1.06x the Earth irradiation for planets orbiting a Sun-like star), for which water has been shown to be unstable in condensed form and should rather form a thick H2O-dominated atmosphere.
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Alien hunters might want to look first to planets like Star Wars' Tatooine - CNET
What's even more encouraging for the proposition of finding E.T. is that star systems like the one hosting imaginary Tatooine are far from just science fiction.
"Multiple-star systems are common, and about 50 percent of stars have binary companion stars. So, this study can be applied to a large number of solar systems," said assistant professor Gongjie Li, the study's co-investigator along with Quarles.
In other words, our solar system is the relative weirdo in the universe. The arrangement of single stars orbited by multiple planets is more rare than what Luke Skywalker grew up with.
Starry: See planets in early morning sky
Greetings everyone! If you've been watching the evening sky this month, you've probably figured out what's going to happen this weekend but if you haven't, plan to watch our lovely sunsets all week. By the weekend, as it begins to grow dark you will see a magnificent conjunction of Jupiter and Venus.
They'll make their closest approach on Sunday but will be close together on Saturday and Monday too. Of course, the two planets are really nowhere near each other, they just happen to be lined up from our point of view. Jupiter is getting closer to the western horizon because we're circling to the other side of the sun from the biggest planet and it will soon disappear from our early evening sky. But Venus will be there for several months.
Telescopes and satellites combine to map entire planet's ground movement
"The height of the Earth's surface is constantly changed by geological forces like earthquakes and the effects of human activities, such as mining or ground water extraction," Dr. Parker said.
"This is the first time we have thought about how to integrate these measurements on a global scale, and the potential benefits of this approach in terms of our understanding of the processes that shape our planet's crust are significant."
"By harnessing the power of these radio telescopes, we hope to shed new light on the processes that shape the Earth's crust including a complete, consistent assessment of the contribution of land displacements to relative sea-level rise," Dr. Parker said. Explore further
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TESS helps astronomers study red-giant stars, examine a too-close planet
Both stars are known to host their own planets. And the TESS data indicate one of those "exoplanets" (the general term for planets that orbit stars other than our sun) is so close to its host star it shouldn't have survived the star's expansion as a red giant—if, that is, the star is old enough to have expanded and retreated.
Steve Kawaler, an Iowa State University distinguished professor of physics and astronomy, and Miles Lucas, a recent Iowa State graduate and current doctoral student at the University of Hawaii at Manoa, are part of the TESS asteroseismology study team.
Impact of Clouds and Hazes on the Simulated JWST Transmission Spectra of Habitable Zone Planets
Integrated cloud water column in kg.m−2 for aquaplanets TRAPPIST-1e (top row), 1f (middle row) and 1g (bottom row) for Charnay et al. (2013) case A (left), case B (middle) and case C (right) Archean Earth atmospheres. TRAPPIST-1g case C is missing because CO2 in the atmosphere has condensed to the night side leading to the crash of the simulation.
The TRAPPIST-1 system, consisting of an ultra-cool host star having seven known Earth-size planets will be a prime target for atmospheric characterization with JWST.
NASA Administrator Jim Bridenstine: Six reasons Pluto is a planet | Columnists | tulsaworld.com
Four images from New Horizons Long Range Reconnaissance Imager LORRI were combined with color data from the spacecraft Ralph instrument to create this enhanced color global view of Pluto.
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Correction : This column has been corrected to reflect the correct year Nicolaus Copernicus determined that the sun was at the center of the solar system.
Some say Pluto is a planet. Some say Pluto is not. Regardless, the debate is sparking interest from the general public, and I hope we can all agree that this discussion is good for science.
Science Shows Us Just How Frozen Star Wars' Ice Planet Hoth Must Be
This frozen terrain (in Iceland) shows how even flowing water, in the form of a waterfall, can ... [+] freeze if the temperatures are consistently cold enough. The amount of mass an ice sheet is capable of withstanding is entirely dependent on the thickness of the ice itself.
Each winter, one of the most spectacular phenomena that appears over Earth's continents is when natural freshwater — including lakes, rivers, and even waterfalls — freezes over. But even after extreme cold spells and weeks or even months of below-freezing temperatures, that ice is only a certain, finite thickness. If you put too much weight over too small an area, the ice will give way, and you'll fall through to the dangerously cold waters below.
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