solar orbit

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A ‘Ring of Fire’ solar eclipse is a rare phenomenon that occurs when the moon’s orbit is at its apogee: the part of its orbit farthest away from the Earth. Because the moon is so far away, it seems smaller than normal to the human eye. The result is that the moon doesn't entirely block out our view of the sun, but leaves an “annulus,” or ring of sunlight glowing around it. Hence the term  “annular” eclipse rather than a “total” eclipse.

Largest Batch of Earth-size, Habitable Zone Planets

Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.

Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.

All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.

In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.

For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.

The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.

 The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.

The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.

Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer. 

How Did the Spitzer Space Telescope Detect this System?

Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system. 

Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.

The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.

At 40 light-years away, humans won’t be visiting this system in person anytime soon…that said…this poster can help us imagine what it would be like: 

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Solar System: Things to Know This Week

Our solar system is a jewel box filled with a glittering variety of beautiful worlds–and not all of them are planets. This week, we present our solar system’s most marvelous moons.

1. Weird Weather: Titan

Saturn’s hazy moon Titan is larger than Mercury, but its size is not the only way it’s like a planet. Titan has a thick atmosphere, complete with its own “water cycle” – except that it’s way too cold on Titan for liquid water. Instead, rains of liquid hydrocarbons like ethane and methane fall onto icy mountains, run into rivers, and gather into great seas. Our Cassini spacecraft mapped the methane seas with radar, and its cameras even caught a glimpse of sunlight reflecting off the seas’ surface. Learn more about Titan: saturn.jpl.nasa.gov/science/titan/

2. Icy Giant: Ganymede

Jupiter’s moon Ganymede is the largest in the solar system. It’s bigger than Mercury and Pluto, and three-quarters the size of Mars. It’s also the only moon known to have its own magnetic field. Details: solarsystem.nasa.gov/planets/ganymede/indepth

3. Retrograde Rebel: Triton

Triton is Neptune’s largest moon, and the only one in the solar system to orbit in the opposite direction of its planet’s rotation, a retrograde orbit. It may have been captured from the Kuiper Belt, where Pluto orbits. Despite the frigid temperatures there, Triton has cryovolcanic activity – frozen nitrogen sometimes sublimates directly to gas and erupts from geysers on the surface. More on Triton: solarsystem.nasa.gov/planets/triton/indepth

4. Cold Faithful: Enceladus

The most famous geysers in our solar system (outside of those on Earth) belong to Saturn’s moon Enceladus. It’s a small, icy body, but Cassini revealed this world to be one of the solar system’s most scientifically interesting destinations. Geyser-like jets spew water vapor and ice particles from an underground ocean beneath the icy crust of Enceladus. With its global ocean, unique chemistry and internal heat, Enceladus has become a promising lead in our search for worlds where life could exist. Get the details: saturn.jpl.nasa.gov/science/enceladus/

5. Volcano World: Io

Jupiter’s moon Io is subjected to tremendous gravitational forces that cause its surface to bulge up and down by as much as 330 feet (100 m). The result? Io is the most volcanically active body in the Solar System, with hundreds of volcanoes, some erupting lava fountains dozens of miles high. More on Io’s volcanoes: solarsystem.nasa.gov/planets/io/indepth

6. Yin and Yang Moon: Iapetus

When Giovanni Cassini discovered Iapetus in 1671, he observed that one side of this moon of Saturn was bright and the other dark. He noted that he could only see Iapetus on the west side of Saturn, and correctly concluded that Iapetus had one side much darker than the other side. Why? Three centuries later, the Cassini spacecraft solved the puzzle. Dark, reddish dust in Iapetus’s orbital path is swept up and lands on the leading face of the moon. The dark areas absorb energy and become warmer, while uncontaminated areas remain cooler. Learn more: saturn.jpl.nasa.gov/news/2892/cassini-10-years-at-saturn-top-10-discoveries/#nine

7. A Double World: Charon and Pluto

At half the size of Pluto, Charon is the largest of Pluto’s moons and the largest known satellite relative to its parent body. The moon is so big compared to Pluto that Pluto and Charon are sometimes referred to as a double planet system. Charon’s orbit around Pluto takes 6.4 Earth days, and one Pluto rotation (a Pluto day) takes 6.4 Earth days. So from Pluto’s point of view Charon neither rises nor sets, but hovers over the same spot on Pluto’s surface, and the same side of Charon always faces Pluto. Get the details: www.nasa.gov/feature/pluto-and-charon-new-horizons-dynamic-duo

8. “Death Star” Moon: Mimas

Saturn’s moon Mimas has one feature that draws more attention than any other: the crater Herschel, which formed in an impact that nearly shattered the little world. Herschel gives Mimas a distinctive look that prompts an oft-repeated joke. But, yes, it’s a moon. More: olarsystem.nasa.gov/planets/mimas

9. Don’t Be Afraid, It’s Just Phobos

In mythology, Mars is a the god of war, so it’s fitting that its two small moons are called Phobos, “fear,” and Deimos, “terror.” Our Mars Reconnaissance Orbiter caught this look at Phobos, which is roughly 17 miles (27 km) wide. In recent years, NASA scientists have come to think that Phobos will be torn apart by its host planet’s gravity. Details: www.nasa.gov/feature/goddard/phobos-is-falling-apart

Learn more about Phobos: solarsystem.nasa.gov/planets/phobos/indepth

10. The Moon We Know Best

Although decades have passed since astronauts last set foot on its surface, Earth’s moon is far from abandoned. Several robotic missions have continued the exploration. For example, this stunning view of the moon’s famous Tycho crater was captured by our Lunar Reconnaissance Orbiter, which continues to map the surface in fine detail today. More: www.lroc.asu.edu/posts/902

Discover more lists of 10 things to know about our solar system HERE.

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Solar System: Things to Know This Week

We’ve been up close and personal with Saturn for 13 years now, thanks to the Cassini mission

From a tour of Saturn’s many enthralling moons to an incredible view of Earth through its rings, the planet continues to captivate the imagination. This week, here are 10 things you need to know about our fascinating ringed neighbor.

1. Strange Sighting

When Galileo Galilei was observing Saturn in the 1600s, he noticed strange objects on each side of the planet. He drew in his notes a triple-bodied planet system with ears. These “ears” were later discovered to be the rings of Saturn.

2. Solar System Status

Saturn orbits our sun and is the sixth planet from the sun at an average distance of about 886 million miles or 9.5 AU.

3. Short Days

Time flies when you’re on Saturn. One day on Saturn takes just 10.7 hours (the time it takes for Saturn to rotate or spin once). The planet makes a complete orbit around the sun (a year in Saturnian time) in 29 Earth years, or 10,756 Earth days. saturn.jpl.nasa.gov/news/2955/measuring-a-day

4. No Shoes Necessary

That’s because you can’t stand on Saturn—it’s a gas-giant planet and doesn’t have a solid surface. But you might want a jacket. The planet’s temperatures can dip to -220 degrees F.

5. Few visitors

Only a handful of missions have made their way to Saturn: Pioneer 11, Voyager 1 and 2, and Cassini-Huygens, which is there now. Since 2004, Cassini has been exploring Saturn and its moons and rings—but will complete its journey on Sept. 15, 2017.

6. Saturn’s Close-Up

This month is a great time to observe Saturn from Earth. Check out June’s “What’s Up?” video for a how-to guide.

7. Daring Dives

Saturn’s spectacular ring system is made up of seven rings with several gaps and divisions between them. From now until September, the Cassini spacecraft is performing a set of daring dives every week between the planet and the rings. No other mission has ever explored this unique region before, and what we learn from these final orbits will help us understand of how giant planets—and planetary systems everywhere—form and evolve.

8. Many, Many Moons 

Saturn has a total of 62 moons: 53 known moons, with an additional nine moons awaiting confirmation.

9. Curious Shapes 

Saturn’s moon Atlas looks like a flying saucer. See for yourself.

10. Would You Live on a Moon? 

Saturn can’t support life as we know it, but some of its moons have conditions that might support life. Ocean worlds could be the answer to life in space and two of Saturn’s moons—Titan and Enceladus—are on that list.

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

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Some intriguing exoplanets

An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun. The first scientific detection of an exoplanet was in 1988. However, the first confirmed detection came in 1992; since then, and as of 1 April 2017, there have been 3,607 exoplanets discovered in 2,701 planetary systems and 610 multiple planetary systems confirmed.

1- Kepler-186f

was the first rocky planet to be found within the habitable zone – the region around the host star where the temperature is right for liquid water. This planet is also very close in size to Earth. Even though we may not find out what’s going on at the surface of this planet anytime soon, it’s a strong reminder of why new technologies are being developed that will enable scientists to get a closer look at distant worlds.

2- CoRoT 7b

The first super-Earth identified as a rocky exoplanet, this planet proved that worlds like the Earth were indeed possible and that the search for potentially habitable worlds (rocky planets in the habitable zone) might be fruitful.

3- Kepler-22b  

A planet in the habitable zone and a possible water-world planet unlike any seen in our solar system.

4- Kepler 10-b

Kepler’s first rocky planet discovery is a scorched, Earth-size world that scientists believe may have a lava ocean on its surface.

5- 55 Cancri e

55 Cancri e is a toasty world that rushes around its star every 18 hours. It orbits so closely – about 25 times closer than Mercury is to our sun – that it is tidally locked with one face forever blisters under the heat of its sun. The planet is proposed to have a rocky core surrounded by a layer of water in a “supercritical” state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam.

6- 51 Pegasi b

This giant planet, which is about half the mass of Jupiter and orbits its star every four days, was the first confirmed exoplanet around a sun-like star, a discovery that launched a whole new field of exploration.

7- Kepler-444 system

The oldest known planetary system has five terrestrial-sized planets, all in orbital resonance. This weird group showed that solar systems have formed and lived in our galaxy for nearly its entire existence.

8- PSR B1257+12 system

Discovered in 1992 and 1994, the planets that orbit pulsar PSR B1257+12 are not only the smallest planetary bodies known to exist outside our solar system, they also orbit a neutron star. These weird “pulsar planets” demonstrated that planets exist in all environments in the galaxy – even around the remnants of an exploded star.

9- HD 80606 b  

This world has the most eccentric orbit, and as one scientist put it, “wears its heart on its sleeve,” with storms, rotation, atmospheric heating, and a crazy orbit all plainly visible.

10- OGLE-2005-BLG-390

Considered to be the first cold super Earth, this exoplanet began to form a Jupiter-like core of rock and ice, but couldn’t grow fast enough in size. Its final mass is five times that of Earth. The planet’s nickname is Hoth, after a planet from Star War

Credits: NASA / JPL-Caltech

Solar System: Things to Know This Week

Get the latest on women making history at NASA, our Juno mission, the Curiosity rover and move!

1. Women at NASA Making History, Creating the Future

Throughout Women’s History Month, we’ve been presenting profiles of the women who are leading the way in deep space exploration.

+ Meet some of them

2. Juno and the Giant

Our Juno spacecraft made its fifth close flyby over giant Jupiter’s mysterious cloud tops.

+ See the latest from the King of Planets

3. When the Road Gets Rough, the Tough Keep Rolling

A routine check of the aluminum wheels on our Curiosity Mars rover has found two small breaks on the rover’s left middle wheel tread–the latest sign of wear and tear as the rover continues its journey, now approaching the 10-mile (16 kilometer) mark. But there’s no sign the robotic geologist won’t keep roving right through its ongoing mission.

+ Get the full report

4. What Do Mars and Dinosaurs Have in Common?

Our research reveals that volcanic activity at the giant Martian volcano Arsia Mons ceased about 50 million years ago, around the time of Earth’s Cretaceous-Paleogene extinction, when large numbers of plant and animal species (including dinosaurs) went extinct. However, there’s no reason to think the two events were more than a cosmic coincidence.

+ Learn how scientists pieced together the past

5. A Comet in Commotion

Images returned from the European Space Agency’s Rosetta mission indicate that during its most recent trip through the inner solar system, the surface of comet 67P/Churyumov-Gerasimenko was a very active place – full of growing fractures, collapsing cliffs and massive rolling boulders.

+ See the many faces of Comet #67P

6. Next Generation Space Robot is Ingenious, Versatile–and Cute

The next rovers to explore another planet might bring along a scout. The Pop-Up Flat Folding Explorer Robot (PUFFER) in development at the Jet Propulsion Laboratory was inspired by origami. Its lightweight design is capable of flattening itself, tucking in its wheels and crawling into places rovers can’t fit.

+ Meet PUFFER

7. Shadowy Dawn

According to data from our Dawn mission to Ceres, shadowed craters on the dwarf planet may be linked to the history of how the small world has been tilted over time by the gravity of planets like Jupiter.

+ Find out how understanding “cycles of obliquity” might solve solar system mysteries

8. On Orbit and Online

We’re developing a  long-term technology demonstration project of what could become the high-speed internet of the sky. The Laser Communications Relay Demonstration (LCRD) will help engineers understand the best ways to operate laser communications systems, which could enable much higher data rates for connections between spacecraft and Earth, such as scientific data downlink and astronaut communications.

+ See how it will work

9. A Big Role for Small Sats in Deep Space Exploration

We selected 10 studies to develop mission concepts using CubeSats and other kinds of very small satellites to investigate Venus, Earth’s moon, asteroids, Mars and the outer planets. “These small but mighty satellites have the potential to enable transformational science,” said Jim Green, director of NASA’s Planetary Science Division.

+ Get the small details

10. Rings Around the Red Planet?

It’s possible that one of our closest neighbors had rings at one point – and may have them again someday. At least, that’s the theory put forth by NASA-funded scientists at Purdue University.

+ See more details about the once and future rings of Mars

Discover more lists of 10 things to know about our solar system HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

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Yes, I’m still in orrery mode - a little one set in a pocket watch case.  The planets are solid metal - gold, silver and copper tones.  It was made to be a desk ornament but could be very carefully used as a fob or pendant.  It doesn’t move - no orbit or rotation - just an assemblage piece made to look like it might move.  

Available in my https://www.etsy.com/au/shop/steelhipdesign 

On July 11, the Juno spacecraft swung near to Jupiter’s turbulent cloud tops. About 11 minutes after the perijove, its closest approach to the Jovian giant, it passed directly above Jupiter’s Great Red Spot. During the much anticipated fly over, it captured this close-up image data from a distance of less than 10,000 kilometers. The raw JunoCam data was subsequently processed by citizen scientists. It is very long-lived but recently has found to be shrinking. In April, the Solar System’s largest storm system was measured to be 16,350 kilometers wide. That’s about 1.3 times the diameter of planet Earth! 

Image Credit: NASA, Juno, SwRI, MSSS, Gerald Eichstadt, Sean Doran