Blog Archives

Just Another Hazy Day on Titan

Color-composite of Titan made from raw images acquired by Cassini on April 7, 2014. (NASA/JPL-Caltech/SSI/J. Major)

Color-composite of Titan made from raw images acquired by Cassini on April 7, 2014. (NASA/JPL-Caltech/SSI/J. Major)

The weather forecast for Titan? Cloudy, hazy, and cold — just like every other day! The image here is a color-composite made from raw data captured by Cassini during a flyby on April 7, 2014, and it shows a look at the two main features of Titan’s atmosphere: a thick orange “smog” made of organic compounds created by the breakdown of nitrogen and methane by UV light, and a wispy blue upper-level haze composed of complex hydrocarbons.

Cassini was approximately 19,076 miles (30,700 km) from Titan when these particular images were captured.

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What Is Pluto? A New Video from New Horizons

Is Pluto a planet? A dwarf planet? A Kuiper Belt Object? All — or none — of the above?

Pluto has been a topic of scientific fascination since Clyde Tombaugh discovered it in February 1930, and then a topic of controversy after the IAU reclassified it as a dwarf planet in 2006. While conversations continue over Pluto’s planetary identity, at least one theme carried through the talks at the Pluto Science Conference in July 2013. See if you can figure out what it is in the video above! (Hint: it’s not difficult.)

NASA’s New Horizons mission will help us understand worlds at the planetary frontier by making the first reconnaissance of Pluto in July 2015. Read more about the mission here.



Watch a Full Year of the Moon (in Five Minutes)

This is pretty neat — it’s a visualization of the Moon’s phases and libration all throughout 2014, made by NASA’s Goddard Space Flight Center Visualization Studio. They’ve done these several times in the past, and this is the latest one.

For accuracy you just can’t beat it: the global terrain map you see in the rendering was made with actual images and measurements of the lunar surface obtained by the Lunar Reconnaissance Orbiter’s LROC camera and laser altimeter. It’s the most detailed imaging of the Moon’s surface available!

So you know about the phases, but why is the Moon rocking back and forth like that? That’s the libration effect I mentioned — read more below:
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Voyager’s Long-Distance Valentine

This is from a post I originally published in 2010. I’ll keep trotting it out until it’s not cool anymore. (Which I don’t think will ever happen.)

Venus, Earth, Jupiter, Saturn, Uranus and Neptune as seen by Voyager 1 in 1990 (Credit: NASA)

On February 14, 1990, after nearly 13 years of traveling the solar system, the Voyager 1 spacecraft passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.

From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space. And Voyager was still a long ways off from reaching the “edge” of our solar system, the bubble of energy emitted by the Sun in which all of the planets, moons, and asteroids reside. In fact, Voyager 1 still has an expected five years to go before it crosses that boundary and truly enters interstellar space.*

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

– Carl Sagan

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Ganymede Gets a Little Geologic Love

The first geologic map (left) of Jupiter's moon Ganymede

The first geologic map of Jupiter’s moon Ganymede (left) and a composite surface map made from the best Voyager and Galileo images (right)

We don’t get to hear a lot about Ganymede these days, what with everyone paying so much attention to Titan and Enceladus and Europa and several other moons out there. Which is too bad because 1. Ganymede is plenty fascinating in its own right; and 2. it’s the LARGEST MOON IN THE SOLAR SYSTEM (and we shouldn’t forget it!) That’s why I was so happy to see this news come out today: geologists have created the first map of Ganymede that focuses exclusively on its complex geology, as observed close-up by the Voyager and Galileo spacecraft during their respective flybys. The resulting global map — which reminds me of some of the ornate illustrations that Giovanni Schiaparelli made of Mars in the 1880s — is a colorful layout of the many different terrains found across icy Ganymede, providing evidence of its complex history and a guide to future exploration missions.

Read more in my Discovery News article here.

Image credit: USGS Astrogeology Science Ctr/Wheaton/ASU/NASA/JPL-Caltech

A Visual Demonstration of Gravity, Courtesy of Cassini

Prometheus passes inside Saturn's F ring on Feb. 5 (NASA/JPL-Caltech/SSI. Animation by J. Major)

Prometheus passes inside Saturn’s F ring on Feb. 5 (NASA/JPL-Caltech/SSI. Animation by J. Major)

Prometheus is at it again! On Feb. 5, Cassini acquired a series of images with its narrow-angle camera of Saturn’s reflective and ropy F ring, around the inside of which travels the shepherd moon Prometheus. As it orbits Saturn it regularly arcs outwards toward the inner edge of the F ring and tumbles back inwards again, a scalloping orbit by a potato-shaped moon that yanks at the fine icy particles of the ring with its gravitational tug. However faint they might be, these tidal forces are enough to pull the wispy ring particles into long strands, gaps, and clumps that follow Prometheus’ passage before eventually settling back down again.

The animation above shows a brief segment of this neverending process in play. Click here to read more, and see more images of Prometheus here.

Mars Gets a Brand New Crater

HiRISE image of a bright rayed crater on Mars (NASA/JPL-Caltech/Univ. of Arizona)

HiRISE image of a bright rayed crater on Mars (NASA/JPL-Caltech/Univ. of Arizona)

If you count at least slightly over two years old as “brand new” then yes, this one is certainly that!

Seen above in an image taken by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter on Nov. 19, 2013, a 100-foot-wide (30-meter) crater is surrounded by bright rays of ejected material and blown-clear surface. Since HiRISE calibrates color to surface textures, the less-dusty cleared surface at the crater site appears blue. (See a true-color calibrated scan here.)

By narrowing down when this particular spot was last seen to be crater-free, scientists have determined that the impact event that caused this occurred between July 2010 and May 2012.

Ejected material from this cratering event was thrown outward over 9 miles (15 km). It’s estimated that impacts producing craters at least 12.8 feet (3.9 meters) in diameter occur on Mars at a rate of over 200 per year.

Source: NASA/JPL (And download this on a HiFlyer here!)


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