Category Astronomy/Space

NASA’s Cassini reveals surprises with Titan’s Lakes

This near-infrared, color view from Cassini shows the sun glinting off of Titan’s north polar seas.
Credit: NASA/JPL-Caltech/Univ. Arizona/Univ. Idaho

On its final flyby of Saturn’s largest moon in 2017, NASA’s Cassini spacecraft gathered radar data revealing that the small liquid lakes in Titan’s northern hemisphere are surprisingly deep, perched atop hills and filled with methane.

The new findings, published April 15 in Nature Astronomy, are the first confirmation of just how deep some of Titan’s lakes are (more than 300 feet, or 100 meters) and of their composition. They provide new information about the way liquid methane rains on, evaporates from and seeps into Titan – the only planetary body in our solar system other than Earth known to have stable liquid on its surface.

Scientis...

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Mercury has a Solid Inner Core: New Evidence

An illustration of Mercury’s interior based on new research that shows the planet has a solid inner core.
Credit: Antonio Genova

Scientists have long known that Earth and Mercury have metallic cores. Like Earth, Mercury’s outer core is composed of liquid metal, but there have only been hints that Mercury’s innermost core is solid. Now, in a new study, scientists report evidence that Mercury’s inner core is indeed solid and that it is very nearly the same size as Earth’s solid inner core.

Some scientists compare Mercury to a cannonball because its metal core fills nearly 85% of the volume of the planet. This large core – huge compared to the other rocky planets in our solar system – has long been one of the most intriguing mysteries about Mercury...

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Astronomers discover 3rd planet in the Kepler-47 Circumbinary system


This is an artistic rendition of the Kepler-47 circumbinary planet system. The three planets with the large middle planet being the newly discovered Kepler47d.
Credit: NASA/JPLCaltech/T. Pyle

Astronomers have discovered a third planet in the Kepler-47 system, securing the system’s title as the most interesting of the binary-star worlds. Using data from NASA’s Kepler space telescope, a team of researchers, led by astronomers at San Diego State University, detected the new Neptune-to-Saturn-size planet orbiting between two previously known planets.

With its three planets orbiting two suns, Kepler-47 is the only known multi-planet circumbinary system. Circumbinary planets are those that orbit two stars.

The planets in the Kepler-47 system were detected via the “transit method...

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TESS finds its 1st Earth-sized Planet

This is an artist’s conception of HD 21749c, the first Earth-sized planet found by NASA’s Transiting Exoplanets Survey Satellite (TESS), as well as its sibling, HD 21749b, a warm sub-Neptune-sized world.
Credit: Illustration by Robin Dienel, courtesy of the Carnegie Institution for Science

A nearby system hosts the first Earth-sized planet discovered by NASA’s Transiting Exoplanets Survey Satellite, as well as a warm sub-Neptune-sized world, according to a new paper from a team of astronomers that includes Carnegie’s Johanna Teske, Paul Butler, Steve Shectman, Jeff Crane, and Sharon Wang.

“It’s so exciting that TESS, which launched just about a year ago, is already a game-changer in the planet-hunting business,” said Teske, who is second author on the paper...

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