Planetary Science

Scientists Finally Know What Time It Is on Saturn

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Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif. 

JoAnna Wendel 
NASA Headquarters, Washington DC

 

A view from NASA’s Cassini spacecraft shows Saturn’s northern hemisphere in 2016 as that part of the planet nears its northern hemisphere summer solstice. A year on Saturn is 29 Earth years; days only last 10:33:38, according to a new analysis of Cassini data. Credit: NASA/JPL-Caltech/Space Science Institute

 

Using new data from NASA’s Cassini spacecraft, researchers believe they have solved a longstanding mystery of solar system science: the length of a day on Saturn. It’s 10 hours, 33 minutes and 38 seconds. 

The figure has eluded planetary scientists for decades, because the gas giant has no solid surface with landmarks to track as it rotates, and it has an unusual magnetic field that hides the planet’s rotation rate.

The answer, it turned out, was hidden in the rings. 

 

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NASA’s InSight Places First Instrument on Mars

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Jia-Rui Cook / Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.

 

NASA’s InSight lander placed its seismometer on Mars on Dec. 19, 2018. This was the first time a seismometer had ever been placed onto the surface of another planet. Image Credit: NASA/JPL-Caltech

 

NASA’s InSight lander has deployed its first instrument onto the surface of Mars, completing a major mission milestone. New images from the lander show the seismometer on the ground, its copper-colored covering faintly illuminated in the Martian dusk. It looks as if all is calm and all is bright for InSight, heading into the end of the year.

 

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The Mars InSight Landing Site Is Just Plain Perfect

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This artist’s concept depicts the smooth, flat ground that dominates InSight’s landing ellipse in the Elysium Planitia region of Mars. Credits: NASA/JPL-Caltech

No doubt about it, NASA explores some of the most awe-inspiring locations in our solar system and beyond. Once seen, who can forget the majesty of astronaut Jim Irwin standing before the stark beauty of the Moon’s Hadley Apennine mountain range, of the Hubble Space Telescope’s gorgeous “Pillars of Creation” or Cassini’s magnificent mosaic of Saturn?

 Mars also plays a part in this visually compelling equation, with the high-definition imagery from the Curiosity rover of the ridges and rounded buttes at the base of Mount Sharp bringing to mind the majesty of the American Southwest. That said, Elysium Planitia – the site chosen for the Nov. 26 landing of NASA’s InSight mission to Mars – will more than likely never be mentioned with those above because it is, well, plain. 

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What Uranus Cloud Tops Have in Common With Rotten Eggs

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Uranus
Arriving at Uranus in 1986, Voyager 2 observed a bluish orb with extremely subtle features. A haze layer hid most of the planet’s cloud features from view. Credit: NASA/JPL-Caltech

  

Even after decades of observations and a visit by NASA’s Voyager 2 spacecraft, Uranus held on to one critical secret — the composition of its clouds. Now, one of the key components of the planet’s clouds has finally been verified. 

A global research team that includes Glenn Orton of NASA’s Jet Propulsion Laboratory in Pasadena, California, has spectroscopically dissected the infrared light from Uranus captured by the 26.25-foot (8-meter) Gemini North telescope on Hawaii’s Mauna Kea. They found hydrogen sulfide, the odiferous gas that most people avoid, in Uranus’ cloud tops. The long-sought evidence was published in the April 23rd issue of the journal Nature Astronomy.

The detection of hydrogen sulfide high in Uranus’ cloud deck (and presumably Neptune’s) is a striking difference from the gas giant planets located closer to the Sun — Jupiter and Saturn — where ammonia is observed above the clouds, but no hydrogen sulfide. These differences in atmospheric composition shed light on questions about the planets’ formation and history. 

 
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NASA Engineers Dream Big With Small Spacecraft

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MarCO CubeSat
An artist’s rendering of the twin Mars Cube One (MarCO) spacecraft as they fly through deep space. The MarCOs will be the first CubeSats — a kind of modular, mini-satellite — attempting to fly to another planet. They’re designed to fly along behind NASA’s InSight lander on its cruise to Mars. If they make the journey, they will test a relay of data about InSight’s entry, descent and landing back to Earth. Though InSight’s mission will not depend on the success of the MarCOs, they will be a test of how CubeSats can be used in deep space. Credit: NASA/JPL

 

Many of NASA’s most iconic spacecraft towered over the engineers who built them: think Voyagers 1 and 2, Cassini or Galileo — all large machines that could measure up to a school bus.

But in the past two decades, mini-satellites called CubeSats have made space accessible to a new generation. These briefcase-sized boxes are more focused in their abilities and have a fraction of the mass — and cost — of some past titans of space.

In May, engineers will be watching closely as NASA launches its first pair of CubeSats designed for deep space. The twin spacecraft are called Mars Cube One, or MarCO, and were built at NASA’s Jet Propulsion Laboratory in Pasadena, California.

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Newly Discovered Exoplanet May be Best Candidate in Search for Signs of Life

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Jason Dittmann
Harvard-Smithsonian Center for Astrophysics

Transiting rocky super-Earth found in habitable zone of quiet red dwarf star

This artist’s impression shows the exoplanet LHS 1140b, which orbits a red dwarf star 40 light-years from Earth and may be the new holder of the title “best place to look for signs of life beyond the Solar System”. Using ESO’s HARPS instrument at La Silla, and other telescopes around the world, an international team of astronomers discovered this super-Earth orbiting in the habitable zone around the faint star LHS 1140. This world is a little larger and much more massive than the Earth and has likely retained most of its atmosphere. Credit: ESO/spaceengine.org 


An exoplanet orbiting a red dwarf star 40 light-years from Earth may be the new holder of the title “best place to look for signs of life beyond the Solar System”. Using ESO’s HARPS instrument at La Silla, and other telescopes around the world, an international team of astronomers discovered a “super-Earth” orbiting in the habitable zone around the faint star LHS 1140. This world is a little larger and much more massive than the Earth and has likely retained most of its atmosphere. This, along with the fact that it passes in front of its parent stars as it orbits, makes it one of the most exciting future targets for atmospheric studies. The results will appear in the 20 April 2017 issue of the journal Nature.

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NASA News Briefing: Discoveries About Oceans Beyond Earth

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 NASA/JPL NEWS RELEASE | APRIL 10, 2017

NASA is exploring the ocean worlds in our solar system as part of our search for life outside of Earth. Credit: NASA

 

NASA will discuss new results about ocean worlds in our solar system from the agency’s Cassini spacecraft and the Hubble Space Telescope during a news briefing 11 a.m. PDT (2 p.m. EDT) on Thursday, April 13. The event, to be held at NASA Headquarters in Washington, will include remote participation from experts across the country. 

The briefing will be broadcast live on NASA Television and the agency’s website. 

These new discoveries will help inform future ocean world exploration — including NASA’s upcoming Europa Clipper mission planned for launch in the 2020s — and the broader search for life beyond Earth.

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NASA’s Juno Spacecraft Set for Fifth Jupiter Flyby

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DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown / Laurie Cantillo
NASA Headquarters, Washington

 

This enhanced-color image of a mysterious dark spot on Jupiter seems to reveal a Jovian “galaxy” of swirling storms. Credits: NASA/JPL-Caltech/SwRI/MSSS/Roman Tkachenko

 

NASA’s Juno spacecraft will make its fifth flyby over Jupiter’s mysterious cloud tops on Monday, March 27, at 1:52 a.m. PDT (4:52 a.m. EDT, 8:52 UTC).

At the time of closest approach (called perijove), Juno will be about 2,700 miles (4,400 kilometers) above the planet’s cloud tops, traveling at a speed of about 129,000 miles per hour (57.8 kilometers per second) relative to the gas-giant planet. All of Juno’s eight science instruments will be on and collecting data during the flyby.


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Experiments Show Titan Lakes May Fizz with Nitrogen

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Preston Dyches
Jet Propulsion Laboratory, Pasadena, Calif.

 

Radar images from Cassini showed a strange island-like feature in one of Titan’s hydrocarbon seas that appeared to change over time (series of images at left). One possible explanation for this “magic island” is bubbles. Image Credit: NASA/JPL-Caltech/Space Science Institute

 

A recent NASA-funded study has shown how the hydrocarbon lakes and seas of Saturn’s moon Titan might occasionally erupt with dramatic patches of bubbles.

For the study, researchers at NASA’s Jet Propulsion Laboratory in Pasadena, California, simulated the frigid surface conditions on Titan, finding that significant amounts of nitrogen can be dissolved in the extremely cold liquid methane that rains from the skies and collects in rivers, lakes and seas. They demonstrated that slight changes in temperature, air pressure or composition can cause the nitrogen to rapidly separate out of solution, like the fizz that results when opening a bottle of carbonated soda.

NASA’s Cassini spacecraft has found that the composition of Titan’s lakes and seas varies from place to place, with some reservoirs being richer in ethane than methane. “Our experiments showed that when methane-rich liquids mix with ethane-rich ones — for example from a heavy rain, or when runoff from a methane river mixes into an ethane-rich lake — the nitrogen is less able to stay in solution,” said Michael Malaska of JPL, who led the study.


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Ultracool Dwarf and the Seven Planets

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Dr. Paola Rebusco
MIT – Experimental Study Group
ESON USA
eson-usa@eso.org

This artist’s impression shows the view from the surface of one of the planets in the TRAPPIST-1 system. At least seven planets orbit this ultra cool dwarf star 40 light-years from Earth and they are all roughly the same size as the Earth. They are at the right distances from their star for liquid water to exist on the surfaces of several of them. This artist’s impression is based on the known physical parameters for the planets and stars seen, and uses a vast database of objects in the Universe. Credit: ESO/N. Bartmann/spaceengine.org

Astronomers using the TRAPPIST–South telescope at ESO’s La Silla Observatory, the Very Large Telescope (VLT) at Paranal and the NASA Spitzer Space Telescope, as well as other telescopes around the world [1], have now confirmed the existence of at least seven small planets orbiting the cool red dwarf star TRAPPIST-1 [2]. All the planets, labelled TRAPPIST-1b, c, d, e, f, g and h in order of increasing distance from their parent star, have sizes similar to Earth [3].

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