Monthly Archives: December 2009

Jet Setter

Enceladus proudly displays its plumage

The icy Enceladus shows off its southern geysers, stately hovering in orbit around Saturn in this raw image from the Cassini spacecraft, taken on Christmas day.

It is impressive to get such a clear view of the geysers with the low phase angle of the sunlight. Typically the geysers are only seen when the sun is shining through them from the opposite side of the moon.

Image: NASA/JPL/SSI

A Visit to Prometheus

Closeup of Prometheus

This raw image, taken by the Cassini spacecraft on December 26, 2009 (on a certain space blogger’s birthday, by the way) shows an amazing view of Prometheus, one of Saturn’s many shepherd moons.

This is the closest yet that Cassini has come to the 96-mile-long oblong moon. Details of its cratered surface are visible, as is the shadow it casts into the material it pulls from the inner edge of the F ring (part of which can be seen at upper left.) This action is a defining characteristic of the little moon as its tumbling orbit causes it to dip in and out of the bright, icy ring, disturbing the material and pulling out long streamers with its passing.

During the springtime on Saturn, Prometheus’ shadow is often cast directly into the F ring with dramatic effect.

Cassini was approximately 36,000 miles from Prometheus when this image was taken. I rotated the original 90º and adjusted levels slightly to emphasize the moon’s shadow a bit, but otherwise this is the raw image straight from the spacecraft as posted on the CICLOPS site.

Image: NASA/JPL/Space Science Institute

Reflecting on Titan

Sunlight reflects off a Titanic lake

This soon-to-be historic image, released today, shows a glint of sunlight reflecting off the surface of a lake on Titan.

Taken by the Cassini spacecraft’s Visual and Infrared Mapping Spectrometer (VIMS) in July 2009, the image has been extensively researched by scientists to make sure it was in fact a reflection off of a liquid surface and not from another source, like lightning or a volcanic eruption. Eventually it was determined that this is, in fact, the effect of sunlight hitting the surface of a large lake on Titan’s northern hemisphere known as Kraken Mare.

“This one image communicates so much about Titan — thick atmosphere, surface lakes and an otherworldliness.”

– Bob Pappalardo, Cassini project scientist

At over 150,000 square miles, Kraken Mare is larger than the Caspian Sea and is filled with extremely frigid liquid methane. Although not water like we have here on Earth, the existence of stable surface liquid of any sort is an important find for planetary scientists. In our solar system only Earth – and now Titan – are known to have surface liquids.

Liquid was found in a lake near Titan’s south pole in 2008 but hasn’t been confirmed in the northern hemisphere until now, when the sun’s light was able to pierce the moon’s thick atmosphere during the advance of the spring equinox.

This iconic image will be presented today at the American Geophysical Union meeting in San Francisco.

Read the official mission release here, and even more background on The Planetary Society’s blog.

Image credit: NASA/JPL/University of Arizona/DLR

Back in Action

“I know everything hasn’t been quite right with me.

But I can assure you now, very confidently, that it’s going to be all right again.”

This mesmerizing video montage showing beautiful high-resolution views of Martian landscapes opens with the fortunate foreshadowing of today’s news that the Mars Reconnaissance Orbiter has resumed full operations since being on suspension since August 26. Various computer resets by the orbiter had prompted engineers to go on standby until a full diagnostic could be made.

While the cause of the resets has not been determined, they have installed some protections in the orbiter’s software systems.

“This has been a long stand-down. Now we’re ready to resume our science and relay mission.”

– Dan Johnston, MRO Mission Manager

The MRO is not only a valuable tool for observing Mars in high-resolution but also serves as an important data relay device for the Spirit and Opportunity rovers on the surface.

The video above was released by the HiRISE team at the University of Arizona’s Department of Planetary Sciences on December 11.

Credit: NASA/JPL/University of Arizona

Off to Marquette

 

Opportunity checks out "Marquette Island"

The rover Opportunity took this false-color photo of another possible stony meteorite dubbed “Marquette Island” on Monday December 7. These objects stand out on the barren sandy plain that Opportunity is currently traveling across on its way to Endeavour Crater and provide interesting targets for investigation. The rover has already used its Rock Abrasion Tool (RAT) to peek beneath the surface of Marquette.

The circular scar of the RAT can be seen above on the upward-facing left side of the rock.

First called “Sore Thumb” by mission scientists because of how it sticks out on the plain like…..well, a sore thumb, it has since been renamed according to the recently-established trend of naming such objects after islands here on Earth.

Opportunity’s tire tracks can be seen in the top left of this image as well.

Image: NASA/JPL-Caltech

Fear and Dread

The European Space Agency’s Mars Express has captured footage of Mars’ two tiny moons, Phobos and Deimos, passing each other in what is known as a “mutual event”. Although the moons themselves are in no special positions the images are noteworthy, being the first time the moons have been photographed passing each other.

Mars Express’ High Resolution Stereo Camera (HRSC) took 130 images of the moons on November 5 over a time period of 1.5 minutes. The images were then combined to make this animation.

The moons are separated by a distance of 8,948 miles in these images.

14-mile-wide Phobos is named after the Greek word for fear, 8-mile-wide Deimos is named after the word for dread. Small and irregularly-shaped, they are most likely captured asteroids. Both were discovered in 1877 by American astronomer Asaph Hall.

Read more about these images on the ESA site or on The Planetary Society’s blog.

Credit: ESA / DLR / FU Berlin (G. Neukum)

Details of Rembrandt

Inside Mercury's Rembrandt crater

Within the 440-mile-wide Rembrandt impact basin on Mercury we find radiating fractures extending across a central plain and a younger sharp-edged crater, the tip of its central peak peeking into the sunlight.

This impact basin was discovered by the MESSENGER spacecraft in October of 2008. It is one of the youngest impact basins on Mercury, although that may still mean it is over 4 billion years old.

The angle of the sunlight in the image above helps accentuate the topographic features of the basin floor. The photo was taken on September 29, 2009. I rotated it 90º…north on Mercury is to the right.

Image: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Follow

Get every new post delivered to your Inbox.

Join 14,557 other followers

%d bloggers like this: