Cosmic Paparazzi: Jupiter’s Great Red Spot

Approximate true-color image of Jupiter's great red spot

Approximate true-color image of Jupiter’s Great Red Spot – Credit: NASA/JPL-Caltech/SwRI/MSSS/Björn Jónsson

An approximately true color/contrast image processed from the image 61 raw framelets. This image should give a fairly good idea of what the Great Red Spot and surrounding areas would look like to human eyes from Juno’s position.

The data used to create the above image come from the Juno spacecraft’s JunoCam. After the recent end to Cassini’s mission, Juno is currently the only orbiter exploring a planet in our outer solar system.

Cassini Week: Goodbye Cassini

On September 15, 2017, Cassini’s extraordinary, decades-long mission ended. The discovery machine sent back its final transmissions before vaporizing within Saturn’s atmosphere. Its atoms now a part of the planet that it put into such sharp focus for us. It marked the end of an era.

The past week has been bittersweet. I’ve spent many hours remembering and sharing some of my favorite Cassini images. I’ve only posted a small fraction of my favorites, and every time I hit the publish button I’d remember another image that I wish I had included. I could devote this entire blog to sharing images and discoveries that we owe to Cassini and never run out of content. The robot was truly remarkable.

I’ve saved my favorite image for today’s post, as I wrap up Cassini Week.

The ringed beauty, Saturn.

The ringed beauty, Saturn – Credit: NASA/JPL/Space Science Institute

This image blew me away the first time I saw it. It’s an image seared into my mind and one I’ll never forget. But there’s more to it than just what you see at first glance. There’s a deeper meaning to be uncovered upon closer inspection.

Look closer at the image above. Click on it; look at it in full screen. On the left side, between Saturn’s brighter main rings and the G ring is a pale blue dot. It’s the same pale blue dot that Carl Sagan waxed poetically about nearly 30 years ago, when we first saw our home planet from a similar perspective.

“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.

The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there…

There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”

Sagan’s words have never rang more true.

Cassini, along with all of the other instruments of science, do more than just teach us about the subjects of their attention. They teach us about ourselves. They put our infinitesimally small corner of the Universe in perspective. Cassini showed us worlds we could have hardly imagined. Each discovery making the Universe a little larger, a little more dynamic.

For some, that might make you feel small. Personally, I don’t think that’s a bad thing. It puts our more minor inconveniences and frustrations in perspective. It’s a reminder of how far we’ve come as a species, how fortunate we are to live our lives at such an exciting time.

And, it gives us the tiniest glimpse of the potential of our future.

 

Cassini Week: Artistic Imagery

We’ve all marveled over Cassini’s images of the Saturn system for more than a decade. Saturn is a truly dynamic place, surrounded by equally dynamic worlds. But Cassini’s images did more than just capture images of these distant places; it created art. Breathtaking ‘landscapes’, magnificent portraits, and photographs perfectly timed and framed. Cassini has all of the skill and talent of a master photographer, with special thanks to its imaging team back on Earth. Below are just a few of my favorite Cassini photos.

Dione, Saturn, Rings, and Enceladus

Dione, Saturn, Rings, and Enceladus – Credit: NASA/JPL-Caltech/SSI

Quintet of Moons

Quintet of Moons – Credit: NASA/JPL-Caltech/Space Science Institute

Janus (179 kilometers, or 111 miles across) is on the far left. Pandora (81 kilometers, or 50 miles across) orbits between the A ring and the thin F ring near the middle of the image. Brightly reflective Enceladus (504 kilometers, or 313 miles across) appears above the center of the image. Saturn’s second largest moon, Rhea (1,528 kilometers, or 949 miles across), is bisected by the right edge of the image. The smaller moon Mimas (396 kilometers, or 246 miles across) can be seen beyond Rhea also on the right side of the image.

Dione, Epimetheus, and Rings

Dione, Epimetheus, and Rings – Credit: NASA/JPL-Caltech/Space Science Institute

Just one more day until Cassini’s Grand Finale. Stay tuned for more Cassini Week celebration.

Cassini Week: Rings

In the famous words of the 21st Century philosopher, Beyoncé, “if you like it then you shoulda put a ring on it”.

In that case, the Universe must have really liked Saturn.

While all of the gas giants in our solar system have rings, Saturn’s are by far the most prominent and celebrated. And while humans have been admiring Saturn’s rings for centuries (when Galileo first discovered them, he described them as Saturn’s ears), it was Cassini that brought them into razor-sharp focus.

Shadows cast on Saturn's A ring.

Shadows cast on Saturn’s A ring. – Credit: NASA/JPL/Space Science Institute

Several sets of shadows are cast onto the A ring in this image taken about a week after Saturn’s August 2009 equinox.

Near the middle of the image, shadows are cast by vertically extended clumps in the kinky, discontinuous ringlets of the Encke Gap in the A ring. These clumps are casting shadows approximately 275 kilometers (170 miles) long, implying a clump height about 600 meters (2,000 feet) above the ring plane.

In the middle left of the image, the waves created by Daphnis (8 kilometers, 5 miles across) on the edge of the Keeler Gap cast shadows on the A ring that are about 450 kilometers (280 miles) long, indicating waves that rise about one kilometer above the ring plane. The moon itself is not visible at this resolution, but it, too, orbits in the Keeler Gap of the A ring. Daphnis has an inclined orbit, and its gravitational pull perturbs the orbits of the particles of the A ring forming the Keeler Gap’s edge and sculpts the edge into waves having both horizontal (radial) and out-of-plane components. Material on the inner edge of the gap orbits faster than the moon so that the waves there lead the moon in its orbit. Material on the outer edge moves slower than the moon, so waves there trail the moon.

The Janus 2:1 spiral density wave

The Janus 2:1 spiral density wave – Credit: NASA/JPL-Caltech/SSI

This view from NASA’s Cassini spacecraft shows a wave structure in Saturn’s rings known as the Janus 2:1 spiral density wave. Resulting from the same process that creates spiral galaxies, spiral density waves in Saturn’s rings are much more tightly wound. In this case, every second wave crest is actually the same spiral arm which has encircled the entire planet multiple times.

Propeller in Saturn's A Ring

Propeller in Saturn’s A Ring – Credit: NASA/JPL-Caltech/Space Science Institute

NASA’s Cassini spacecraft captured these remarkable views of a propeller feature in Saturn’s A ring on Feb. 21, 2017. These are the sharpest images taken of a propeller so far, and show an unprecedented level of detail. The propeller is nicknamed “Santos-Dumont,” after the pioneering Brazilian-French aviator.

Have you heard of Saturn’s propellers before? They’re the result of a very small moon, unseen in the photo above, disturbing ring material. They offer a unique opportunity for researchers to track the orbits of unseen objects that are embedded within a disk of material.

Epimetheus and smog-enshrouded Titan, with Saturn's A and F rings stretching across the scene.

Epimetheus, Titan, and rings. – Credit: NASA/JPL/Space Science Institute

Cassini delivers this stunning vista showing small, battered Epimetheus and smog-enshrouded Titan, with Saturn’s A and F rings stretching across the scene.

Stay tuned for more, as we continue our Cassini Week celebration.

Cassini Week: Huygens Probe 

When Cassini launched in 1997, it carried with it a special payload: a probe named Huygens that would penetrate the permanent haze of Saturn’s largest moon Titan, and reveal to us the shrouded world below.

Huygens descent module and shield

Huygens descent module and shield – Credit: ESA

And what a world Titan is!

It’s larger than Mercury, approaching the diameter of Mars (Titan: 5,150 km / Mars: 6,780 km). It has an atmosphere with superrotating winds, composed of 95 nitrogen and 5% methane. And it has an abundance of massive liquid methane lakes and rivers, as well as water ice and rocks of all sizes. A truly dynamic place that can only be referred to as a world.

And we owe most of what we know about Titan thanks to Huygens and Cassini.

Four images obtained at different altitudes during Titan's descent

Four images obtained at different altitudes during Titan’s descent – Credit: ESA/NASA/JPL/University of Arizona

The probe was named after the man who discovered Titan in 1655, the Dutch astronomer Christiaan Huygens.

Christiaan Huygens

Christiaan Huygens

After a seven year journey, Cassini entered Saturn’s orbit on July 1, 2004. On Christmas Day of that year (Spacecraft Event Time), the shelled Huygens probe separated from Cassini and began its three-week coast to Titan’s surface. Finally, on January 14, 2005, Huygens fell through Titan’s atmosphere, slowed by parachutes, for 2 hours and 27 minutes, before landing on the surface. On the way down, its suite of instruments and cameras captured priceless data about the mysterious world on which it would spend the rest of its life.

First color photo from Titan's surface

First color photo from Titan’s surface – Credit: NASA/JPL/ESA/University of Arizona

Huygens sent data back from the surface of Titan for 72 minutes, before Cassini–our relay station to the probe–dipped below the moon’s horizon. The amount of data collected and transmitted during that short time, however, was phenomenal. In addition to the breathtaking photos, Huygens provided us with unprecedented data about the alien moon, data that is still being analyzed for new discoveries to this day.

Stay tuned for more, as we continue our week of commemorating the Cassini mission on the eve of the spacecraft’s Grand Finale.

Cassini Week: Moons Mimas and Pan

This week we’re celebrating the accomplishments of the Cassini spacecraft which, in just a few days, will plunge into Saturn’s atmosphere in its Grand Finale. Today, we take a look at just two of Saturn’s more than 60 moons: Mimas and Pan.

Mimas:

When it comes to Saturn’s moon Mimas, Cassini kept delivering surprise after surprise. First, there was a fantastic image showing us, in great detail, Mimas’s remarkable Herschel crater (Voyager 1 was the first to give us images of Herschel crater, but they paled in comparison to what Cassini revealed).

Mimas, with prominent Herschel crater.

Mimas, with prominent Herschel crater. – Source: NASA/JPL-Caltech

Then again, maybe…
Obi-Wan Kenobi: "That's no moon. It's a space station."

But Cassini revealed another surprise on Mimas. When it took a look at its infrared profile and created a temperature map, we found Pac-Man.

Mimas Temperature Map

Mimas Temperature Map – Source: NASA/JPL/Goddard/SWRI/SSI

Pan:

While Mimas is quite a unique satellite of our beloved ringed planet, Pan certainly deserves some recognition as well.

Saturn's ravioli moon, Pan

Saturn’s ravioli moon, Pan – Source: NASA/JPL/Space Science Institute

The above image was captured in March of 2017, as Cassini zoomed within 15,300 miles (24,600 kilometers) of Pan.

I don’t know about you, but this moon makes me hungry for a pan of ravioli.
Will Riker rolling his eyes.

Stay tuned, more Cassini action to come as we prepare for the Grand Finale.

Sunday Matinee – NASA at Saturn: Cassini’s Grand Finale

The final chapter in a remarkable mission of exploration and discovery, Cassini’s Grand Finale is in many ways like a brand new mission. Twenty-two times, NASA’s Cassini spacecraft will dive through the unexplored space between Saturn and its rings. What we learn from these ultra-close passes over the planet could be some of the most exciting revelations ever returned by the long-lived spacecraft. This animated video tells the story of Cassini’s final, daring assignment and looks back at what the mission has accomplished.


Cassini’s Grand Finale

On September 15, one of the most fruitful space missions ever imagined will come to an end. After two decades in space, Cassini’s fuel supplies are close to being depleted. To avoid contaminating one of Saturn’s moons, including a pair that could harbor life–Enceladus and Titan–the decision was made to retire Cassini into Saturn’s atmosphere. Up until contact between the orbiter and Earth is lost, Cassini will continue to study our beloved ringed planet. New insight will be gleaned from this mission that’s only made possible by Cassini’s fatal approach to the gas giant. Among the data to be collected:

  • The spacecraft will make detailed maps of Saturn’s gravity and magnetic fields, revealing how the planet is arranged internally, and possibly helping to solve the irksome mystery of just how fast Saturn is rotating.
  • The final dives will vastly improve our knowledge of how much material is in the rings, bringing us closer to understanding their origins.
  • Cassini’s particle detectors will sample icy ring particles being funneled into the atmosphere by Saturn’s magnetic field.
  • Its cameras will take amazing, ultra-close images of Saturn’s rings and clouds.

Cassini launched on Oct. 15, 1997. After a seven-year journey the orbiter arrived at Saturn, carrying the European Space Agency’s Huygens probe. In 2005, the probe successfully landed on Saturn’s largest moon, Titan.


Quick facts about Titan:

  • Titan is the solar system’s second largest moon.
  • It’s the only moon in our solar system that has cloud systems and a dense, planet-like atmosphere.
  • Titan has liquid hydrocarbon lakes, mountains, and seasonal weather patterns.

For 13 years, Cassini has orbited Saturn and provided us with fascinating information about, not just the planet, but its intricate ring system and many moons.

Cassini mission overview infographic

Cassini mission overview infographic – Click for larger version – Source: NASA/JPL

In addition to the important scientific data that was collected by Cassini, are the breathtaking images that have been collected: storms and aurorae on Saturn, detailed views of the worlds that are Saturn moons, and remarkable visions of Saturn’s sensational rings.

For the next week, we celebrate Cassini’s achievements.

Still from the short film Cassini's Grand Finale, the spacecraft is shown diving between Saturn and the planet's innermost ring.

Still from the short film Cassini’s Grand Finale, the spacecraft is shown diving between Saturn and the planet’s innermost ring. – Credit: NASA/JPL-Caltech

The Google Lunar XPRIZE

Be the first team to land a spacecraft on the Moon, travel at least 500 meters, transmit HD images and video back to Earth, and you’ve won yourself $20 million. Oh, and you also have to do this 90%-funded by private investment and do it by the end of 2017. That’s the mission for the Google Lunar XPRIZE.

XPRIZE logo

The XPRIZE is the name of various competitions organized by the non-profit XPRIZE Foundation.

The XPRIZE mission is to bring about “radical breakthroughs for the benefit of humanity” through incentivized competition. We foster high‐profile competitions that motivate individuals, companies and organizations across all disciplines to develop innovative ideas and technologies that help solve the grand challenges that restrict humanity’s progress.

One of the most famous XPRIZE competitions was the Ansari XPrize. In 2004, Mojave Aerospace Ventures took that $10 million prize with their SpaceShipOne, after they became the first team to “build a reliable, reusable, privately financed, manned spaceship capable of carrying three people to 100 kilometers above the Earth’s surface twice within two weeks”. The prize was a major step forward for the development of a private space industry. A few other XPRIZEs have included developing super-efficient automobiles, solutions for cleaning the ocean after oil spills, improving sensor systems for health care services, and to improve our understanding of ocean acidification.

Google Lunar XPRIZE

The Google Lunar XPRIZE is the biggest competition yet, and sets-out to”ignite a new era of planetary exploration by lowering the cost to explore and capturing and inspiring the imagination of a new generation.” More than thirty teams initially registered for the lunar competition. Of those, sixteen participated in all of the required registration activities. But as of January 1st, 2017, the pool was reduced by another eleven. Five teams currently remain, all of which have active contracts to launch to the Moon this year. Those teams are:

SpaceIL (Israel)

SpaceIL was the first team to secure a launch contract. They plan to land their “hopper” craft on the Moon, then fly–in a single ‘hop’–the required 500 meters and land again to secure the prize.

Moon Express (United States)

Moon Express was the first country to secure their government’s authorization to operate on the lunar surface. They intend to launch their “hopper” craft from New Zealand in late 2017.

Synergy Moon (International)

Synergy Moon isn’t contracting with a launch provider for their launch, they’re doing it themselves thanks to Interorbital Systems being a part of the team. Their launch is expected to take place from the Pacific Ocean, off of the coast of California, in the second half of 2017.

Team Indus (India)

Team Indus is planning on launching their adorable 5kg rover, ECA, on December 28 of this year. ECA will include science instruments and cameras from the French national space agency: CNES.

Team Indus's ECA rover

Team Indus’s ECA rover – Source: Team Indus

Hakuto (Japan)

Hakuto’s rover is hitching a ride on the same lander as Team Indus, and boasts some big “partnerships, including au by KDDI, Suzuki, rock band Sakanaction, and a longterm Moon-resources-exploration plan with the Japanese space agency JAXA“.

The Prize

The first team to pull this amazing feat off will earn themselves the $20 million grand prize. In addition to the grand prize, the second place finisher will receive a respectable $5 million. Also, Google has handed out over $5 million in Milestone Prizes for teams (former and current) that have accomplished various important steps to make the mission possible.

Thanks to the Google Lunar XPRIZE, 2017 is set to be an exciting year for private space exploration–The New Space Race is on.

If you’d like to learn more about the Google Lunar XPRIZE, check out the excellent documentary series: Moonshot.

Luna 9 – The First Lunar Soft-Landing

The Soviets claimed many firsts in their space race with the United States. First person in space (and orbit), first woman in space, first satellite in orbit. Most would agree, however, that the United States accomplished the biggest first by being the first (and to this day, only) to land humans on the Moon. But the Soviet space program did claim a important lunar firsts of their own: the first lunar fly-by, the first pictures of the far side of the Moon, and the first soft-landing of a probe on the Moon’s surface.

Luna 9 model

Luna 9 model – Source: NASA.gov

On February 3, 1966, the Soviet spacecraft, Luna 9, completed its 3-day journey to the Moon and landed safely on the lunar surface. This ‘soft-landing’ (as in: not a crash-landing) marked the first time a human-made craft survived a landing on any body other than Earth. The successful landing was accomplished by a number of systems that all had to work flawlessly: inflation of an airbag system to cushion the impact, the retrorocket burn to slow the craft, and the deployment of a contact sensor to determine the precise altitude above the Moon. At an altitude of 5 meters, the contact sensor was triggered: engines were shut off and the landing capsule was ejected. Though the craft’s speed was reduced significantly, it still impacted the Moon at a velocity of 22 km/hr (13.7 miles per hour). The airbags allowed the capsule to safely bounce several times before it came to rest.

Following landing and an approximately four-minute pause, four petals that served as the craft’s shell unfolded and stabilized the probe the ground. Antennas were deployed and the craft’s television camera began recording the lunar landscape, capturing the first views ever seen from the surface of the Moon. In addition to the images and radiation readings, the landing also disproved models that suggested that the Moon was covered in a thick layer of dust that would cause any craft (and eventually, persons) who landed there to sink.

One of the first images taken from the Moon's surface

One of the first images taken from the Moon’s surface – Source: Smithsonian National Air and Space Museum

Luna 9’s batteries lasted for three days after landing, during which the craft was able to record a number of panoramic images and beam them back to Earth.

Joddrell Bank, the British observatory located at the University of Manchester, had been paying close attention to the race between the Soviets and the United States. Scientists there not only tracked Luna 9’s progress, but they also recognized the type of signal that the craft was beaming back. They deployed the correct receiving equipment and were able to acquire the lunar images and publish them before the Soviets even managed to see them. There’s still debate as to whether the Soviet scientists let this happen on purpose or not.

While the Soviets soft-landed their craft first, the United States wasn’t far behind. Three months after Luna 9, the US landed Surveyor 1 on the Moon’s surface. Various robots continued to explore the Moon, paving the way for the humans that followed them. After the United States stopped sending astronauts to the Moon in 1972, the next soft-landing wouldn’t occur until 2013, when the Chinese lander Chang’e-3 brought the rover Yutu to explore our celestial neighbor.