Nearer Ceres to Thee

Detail of 'xkcd' #1476, by Randall MunroeOh, yes. There is that.

What, you mean the mission where we chuck a metal box into space, fly it out to the asteroid belt, find a big rock, drop into orbit, survey the gravitational field and some other stuff, then kick out, maneuver through the storm of flying rocks, find another big rock, and do the whole orbit thing all over gain?

Yeah. That one.

Next stop, Ceres. ETA: 6 March 2015, SCET.

Say hello to Dawn.

No, really. This is already a great show. And it’s about to get even better.


Munroe, Randall. “Ceres”. xkcd. 21 January 2015.

NASA. “DAWN: A Journey to the Beginning of the Solar System”. Jet Propulsion Laboratory. 2015.

Mission: Mars—MAVEN Draws Nigh

NASA, via Facebook:

At 8 pm EDT today, MAVEN will be at a distance of 205,304,736 km (127,570,449 miles) from Earth with an Earth-centered velocity of 27.95 km/s (17.37 mi/s or 62,532 mph) and a Sun-centered velocity of 22.29 km/s (13.58 mi/s or 48,892 mph). We are now just 17 days from Mars orbit insertion on September 21st.

NASA's MAVEN satellite approaches Mars.Having traveled a total of 678,070,879 km (421,332,902 mi) in its heliocentric transfer orbit, the MAVEN spacecraft has now covered ~95% of its total journey from Earth to #Mars.

The spacecraft is currently at a distance of 4,705,429 km (2,923,818 mi) from Mars, and 215,446,454 km (133,872,220 mi) from the Sun. One-way light time to the #MAVEN spacecraft from Earth is 11 minutes and 24 seconds.

All navigation solutions continue to produce trajectory arrival predictions that ensure a successful transition to MAVEN’s required science orbit.

This is the sort of thing that we ought to be getting excited about. The MAVEN mission is awesome.

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Nothing to See Here: Titanian Clathrate Edition

NASA would like your attention long enough to explain a thing or two about how—

—absolutely cool the Cassini-Huygens mission really is.

The NASA and European Space Agency Cassini mission has revealed hundreds of lakes and seas spread across the north polar region of Saturn’s moon Titan. These lakes are filled not with water but with hydrocarbons, a form of organic compound that is also found naturally on Earth and includes methane. The vast majority of liquid in Titan’s lakes is thought to be replenished by rainfall from clouds in the moon’s atmosphere. But how liquids move and cycle through Titan’s crust and atmosphere is still relatively unknown.

A recent study led by Olivier Mousis, a Cassini research associate at the University of Franche-Comté, France, examined how Titan’s methane rainfall would interact with icy materials within underground reservoirs. They found that the formation of materials called clathrates changes the chemical composition of the rainfall runoff that charges these hydrocarbon “aquifers.” This process leads to the formation of reservoirs of propane and ethane that may feed into some rivers and lakes.

And it doesn’t stop there.

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A Distant Glimpse of Uranus

JPL PIA17178 (detail)Last month, Cassini got its first-ever glimpse of Uranus:

NASA’s Cassini spacecraft has captured its first-ever image of the pale blue ice-giant planet Uranus in the distance beyond Saturn’s rings.

The planets Uranus and Neptune are sometimes referred to as “ice giants” to distinguish them from their larger siblings, Jupiter and Saturn, the classic “gas giants.” The moniker derives from the fact that a comparatively large part of the planets’ composition consists of water, ammonia and methane, which are typically frozen as ices in the cold depths of the outer solar system. Jupiter and Saturn are made almost entirely of hydrogen and helium, with smaller percentages of these ices.

When this view was obtained, Uranus was nearly on the opposite side of the sun as seen from Saturn, at a distance of approximately 28.6 astronomical units from Cassini and Saturn. An astronomical unit is the average distance from Earth to the sun, equal to 93 million miles (150 million kilometers). At their closest, the two planets approach to within about 10 astronomical units of each other.

Just to be clear, all those AUs add up to just under 4.3 billion kilometers (2.66b miles).


Dyches, Preston and Steve Mullns. “Cassini Spies the Ice-Giant Planet Uranus”. Jet Propulsion Laboratory. May 1, 2014.

NASA/JPL-Caltech/Space Science Institute. “PIA17178: Blue Orb on the Horizon”. Photojournal. May 1, 2014.

Cassini: Cosmic Gestation?

File under, And we are so amazed ….

JPL explains:

Say hello to Peggy.NASA’s Cassini spacecraft has documented the formation of a small icy object within the rings of Saturn that may be a new moon, and may also provide clues to the formation of the planet’s known moons.

Images taken with Cassini’s narrow angle camera on April 15, 2013, show disturbances at the very edge of Saturn’s A ring — the outermost of the planet’s large, bright rings. One of these disturbances is an arc about 20 percent brighter than its surroundings, 750 miles (1,200 kilometers) long and 6 miles (10 kilometers) wide. Scientists also found unusual protuberances in the usually smooth profile at the ring’s edge. Scientists believe the arc and protuberances are caused by the gravitational effects of a nearby object. Details of the observations were published online today (April 14, 2014) by the journal Icarus.

Yes, you read that correctly.

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Look Ahead: Cassini “Proximal” Mission

First, there was Equinox. And then came Solstice. Ever faithful, the Cassini probe continues to defy even the wildest expectations at its launch in 1997. And now, NASA is asking for public participation in preparing the spacecraft for its final mission:

Starting in late 2016, the Cassini spacecraft will repeatedly climb high above Saturn’s north pole, flying just outside its narrow F ring. Cassini will probe the water-rich plume of the active geysers on the planet’s intriguing moon Enceladus, and then will hop the rings and dive between the planet and innermost ring 22 times.

JPL-CassiniProximalMission-1Because the spacecraft will be very close to Saturn, the team has been calling this phase “the proximal orbits.” But they think someone out there can conjure up a cooler name. Here’s where you come in: you can choose your faves from a list already assembled, or you can submit your own ideas (up to three). The big reveal for the final name will be in May 2014.

This naming contest is part of the 10-year anniversary celebration. The mission will mark a decade of exploring Saturn, its rings and moons on June 30 PDT (July 1 EDT).

The name game is already underway. And they’ve already released an awesome trailer in advance of Cassini’s astounding swan song.

No, really, watch the trailer.

This is going to be so cool.

Cassini’s last mission could well be the inspiration of our next generation of scientists. It really is all that.

The Enceladus Deep

Our love affair with Enceladus grows deeper:

PIA18071A substantial ocean most likely exists beneath the icy surface of Saturn’s diminutive moon Enceladus, raising the possibility that primitive forms of extraterrestrial life exist in its briny depths.

The ocean lies between the moon’s rocky core and a layer of thick ice, and is estimated to be about the size of Lake Superior. That’s large for a moon that is only 310 miles (500 kilometers) in diameter and could fit within the borders of Arizona.

In our solar system, the only other moon known to have similar contact between liquid water and rock is Jupiter’s Europa. Both the rock and the water are considered to be essential for the chemistry that could, over eons, turn nonliving matter into living entities.

“The main implication of our work is that there are potentially habitable environments in our solar system that are entirely unexpected,” said Luciano Iess, an aerospace engineer at the Sapienza University of Rome and lead author on the study published Thursday in the journal Science.


The essential question is actually a matter of opinion, sort of: How important is this?

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Postcard From Cassini

PIA17157 detail
There is always this. Given the times, and the scale of science fiction, perhaps the idea of a holiday snap featuring four moons does not necessarily strike us as anything special. But then we stop to think about it:

Two pairs of moons make a rare joint appearance. The F ring’s shepherd moons, Prometheus and Pandora, appear just inside and outside of the F ring (the thin faint ring furthest from Saturn). Meanwhile, farther from Saturn the co-orbital moons Janus (near the bottom) and Epimetheus (about a third of the way down from the top) also are captured.

Prometheus (53 miles, or 86 kilometers across) and Pandora (50 miles, or 81 kilometers across) sculpt the F ring through their gravitational influences. Janus (111 miles, or 179 kilometers across) and Epimetheus (70 miles, or 113 kilometers across) are famous for their orbital dance, swapping places about every four years. They are also responsible for gravitationally shaping the outer edge of the A ring into seven scallops.


Just to go clockwise, that’s Epimetheus, Prometheus, Pandora, and Janus.

Seriously, though … anyone have a holiday snap to match? Didn’t think so.

Happy π Day

Happy π Day. Π? π? I go with π, since that’s what this is all about, anyway. right?

Well, you know, to our American friends. Never mind. Dumb joke. Predictable. Happy π Day to each and every one of you around the world and throughout the Universe.

On a related note, NASA proudly recalls the Pi Transfer:

π ManeuverOn Jan. 19, 2007, the Cassini spacecraft took this view of Saturn and its rings—the visible documentation of a technique called a “pi transfer” completed with a Titan flyby. A pi transfer uses the gravity of Saturn’s largest moon, Titan, to alter the orbit of the Cassini spacecraft so it can gain different perspectives on Saturn and achieve a wide variety of science objectives. During a pi transfer, Cassini flies by Titan at opposite sides of its orbit about Saturn (i.e., Titan’s orbital position differs by pi radians between the two flybys) and uses Titan’s gravity to change its orbital perspective on the ringed planet.

Taking in the rings in their entirety was the focus of this particular imaging sequence. Therefore, the camera exposure times were just right to capture the dark-side of its rings, but longer than that required to properly expose the globe of sunlit Saturn. Consequently, the sunlit half of the planet is overexposed.

Yeah. They can do this. Happy π Day.

Shine On, Cassini

Titan Layers (detail)

“Each flyby gives us a little more knowledge of Titan and its striking similarities to our world. Even with its cold surface temperatures of minus 290 degrees Fahrenheit (94 kelvins), Titan is like early Earth in a deep freeze.”


It’s a cosmic diamond jubilee, of sorts. The clock is running, with Cassini set to undertake it’s T-99 flyby of Titan tomorrow (March 6, 2014; 0725 PST). An additional flyby undertaken after the original schedule was settled makes this officially the spacecraft’s one-hundredth survey of Saturn’s largest moon.

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