Ring Shadows

Ring Shadows on Saturn. Image Credit: NASA/JPL-Caltech/Space Science Institute

Ring Shadows on Saturn. Image Credit: NASA/JPL-Caltech/Space Science Institute

The Cassini – Saturn – Sun angles were just right for Cassini to capture this unusual picture. The rings of Saturn are edge on and their shadows are projected onto the planet.

From the NASA caption:

This view looks toward the sunlit side of the rings from slightly above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Aug. 14, 2014.

The view was obtained at a distance of approximately 1.1 million miles (1.7 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 23 degrees. Image scale is 63 miles (102 kilometers) per pixel.

There are two moons in the image: the most obvious one is Tethys, seen at the lower right below the rings. The other is Mimas. Can you spot it? You may need to click the image to see the large version. Funny how it sticks right out once you find it. Give it a try.

If you give up ckck the “More” link below to narrow you search.
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Bollide Map

Bolide map 1994 - 2013.  Image credit: Planetary Science via NASA

Bolide map 1994 – 2013. Image credit: Planetary Science via NASA

Here’s a great map especially if you like fireballs as much as I do. As you will read below it is a map of small asteroid strikes. I find the distribution of daytime/nighttime remarkable. Sure it’s about 50/50 as you would expect but I’d think the daytime ones would be more difficult to detect – apparently not.

Check out the links at the end of the article.

From NASA’s Near Earth Object (NEO) Program:

A map released today by NASA’s Near Earth Object (NEO) Program reveals that small asteroids frequently enter and disintegrate in the Earth’s atmosphere with random distribution around the globe. Released to the scientific community, the map visualizes data gathered by U.S. government sensors from 1994 to 2013. The data indicate that Earth’s atmosphere was impacted by small asteroids, resulting in a bolide (or fireball), on 556 separate occasions in a 20-year period. Almost all asteroids of this size disintegrate in the atmosphere and are usually harmless. The notable exception was the Chelyabinsk event which was the largest asteroid to hit Earth in this period. The new data could help scientists better refine estimates of the distribution of the sizes of NEOs including larger ones that could pose a danger to Earth.

 

Finding and characterizing hazardous asteroids to protect our home planet is a high priority for NASA. It is one of the reasons NASA has increased by a factor of 10 investments in asteroid detection, characterization and mitigation activities over the last five years. In addition, NASA has aggressively developed strategies and plans with its partners in the U.S. and abroad to detect, track and characterize NEOs. These activities also will help identify NEOs that might pose a risk of Earth impact, and further help inform developing options for planetary defense.

 

The public can help participate in the hunt for potentially hazardous Near Earth Objects through the Asteroid Grand Challenge, which aims to create a plan to find all asteroid threats to human populations and know what to do about them. NASA is also pursuing an Asteroid Redirect Mission (ARM) which will identify, redirect and send astronauts to explore an asteroid. Among its many exploration goals, the mission could demonstrate basic planetary defense techniques for asteroid deflection.

 

For more information about the map and data, go to: http://neo.jpl.nasa.gov

For details about ARM, and the Asteroid Grand Challenge, visit: www.nasa.gov/asteroidinitiative

The Egg Nebula

A Hubble look at the Egg Nebula. Copyright Credit: NASA/ESA/Hubble Heritage Team (STScI/AURA). Acknowledgment: W. Sparks (STScI) & R. Sahai (JPL)

A Hubble look at the Egg Nebula. Copyright Credit: NASA/ESA/Hubble Heritage Team (STScI/AURA). Acknowledgment: W. Sparks (STScI) & R. Sahai (JPL)

Not a new image but always fun to look at is the Egg Nebula. I always think of ripples in a pond produced by tossing a pebble in and in a way it is. ars

Planetary nebulas have nothing much to do with planets, rather they are how stars like our own sun will end their active life cycles. Planetary nebulas are varied in how they present themselves but all are beautiful sights to see.

Treat yourself to a Planetary Nebula sampler.

From ESA Space in Images:

This colourful image shows a cosmic lighthouse known as the Egg Nebula, which lies around 3000 light-years from Earth. The image, taken with the NASA/ESA Hubble Space Telescope, has captured a brief but dramatic phase in the life of a Sun-like star.

The Egg Nebula is a ‘preplanetary nebula’. These objects occur as a dying star’s hot remains briefly illuminates material it has expelled, lighting up the gas and dust that surrounds it.

These objects will one day develop into planetary nebulas which, despite the name, have nothing at all to do with planets. They gained their rather misleading title because when they were discovered in the 18th century they resembled planets in our Solar System when viewed through a telescope.

Although the dying star is hidden behind the thick dust lane that streaks down the centre of this image, it is revealed by the four lighthouse-like beams clearly visible through the veil of dust that lies beyond the central lane.

The light beams were able to penetrate the central dust lane due to paths carved out of the thick cloud by powerful jets of material expelled from the star, although the cause of these jets is not yet known.

The concentric rings seen in the less dense cloud surrounding the star are due to the star ejecting material at regular intervals – typically every hundred years – during a phase of the star’s evolution just prior to this preplanetary nebula phase. These dusty shells are not usually visible in these nebulas, but when they are it provides astronomers with a rare opportunity to study their formation and evolution.
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Dusty Rover

Dust buildup on Curiosity. Image Credit: NASA/JPL-Caltech/MSSS

Dust buildup on Curiosity. Image Credit: NASA/JPL-Caltech/MSSS

An image from Curiosity’s Mastcam (left cam) showing surface texture on Mars. A thin coating of dust is starting to accumulate on Curiosity, but so far it looks pretty good. I am not sure of the image scale.

The image was taken on 23 November 2014 in the Mount Sharp area where it has been driving around taking a look for good sites to examine.

Second Time Through, Mars Rover Examines Chosen Rocks.

Futura Launch Replay

Here is a replay of yesterday’s beautiful Futura launch as the Soyuz TMA-15M left from the Baikonur Cosmodrome in Kazakhstan to the International Space Station.

Terry Virts of NASA, Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos) and Samantha Cristoforetti of the European Space Agency join Expedition 42 Commander Barry “Butch” Wilmore of NASA and Alexander Samoukutyaev and Elena Serova of Roscosmos.

Among the investigations during the mission involves “Space Headaches” which are often caused by intracranial pressure change. The goal is to come up with effective counter measures. Scientists will use biologic samples to determine if immune system impairment increases the risk of infection or poses a health risk aboard the ISS and likely other long duration missions.

Video source

 

Futura Ready for Launch

The Futura mission launches in just hours as launch preparations draw to a close and ESA’s Samantha Cristoforetti, Roscosmos’ Anton Shkaplerov and NASA’S Terry Virts board the Soyuz TMA-15M for launch to the International Space Station. One launched, the 274 tonnes of rocket propellant will get the crew at the station in just six hours.

Launch site: Baikonur cosmodrome in Kazakhstan

Launch time: 21:01 GMT –  23 November 2014

A very nice launch and all is well upon reaching orbit.

Arrival: 24 November at 02:30

Watch this launch LIVE at ESA- coverage begins at 20:00 GMT

I have been following ESA’s Italian astronaut Samantha Cristoforetti and you can too: samanthacristoforetti.esa.int.

Saturn Swirls

Atmospheric swirls on Saturn. Credit: NASA/JPL-Caltech/Space Science Institute

Atmospheric swirls on Saturn. Credit: NASA/JPL-Caltech/Space Science Institute

Originally meant to publish yesterday: Cassini took this image of the Saturn swirling atmosphere. Planetary atmospheres (including our own) are a study in fluid dynamics and that is clearly evident here.

The image was taken on 23 August 2014 in red light from about 1.8 million km / 1.1 million miles with the narrow-angle camera.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

Sunburn on Jupiter?

Cassini gives us clues about the Great Red Spot's color.

Cassini gives us clues about the Great Red Spot’s color.

New research on the Great Red Spot of Jupiter based on Cassini’s flyby nearly 14 years ago (Dec 2000) suggests the red color is from the “sunburn” of particles and the variable color comes from cloud altitudes.

From NASA:

The ruddy color of Jupiter’s Great Red Spot is likely a product of simple chemicals being broken apart by sunlight in the planet’s upper atmosphere, according to a new analysis of data from NASA’s Cassini mission. The results contradict the other leading theory for the origin of the spot’s striking color — that the reddish chemicals come from beneath Jupiter’s clouds.

The results are being presented this week by Kevin Baines, a Cassini team scientist based at NASA’s Jet Propulsion Laboratory, Pasadena, California, at the American Astronomical Society’s Division for Planetary Science Meeting in Tucson, Arizona.

Baines and JPL colleagues Bob Carlson and Tom Momary arrived at their conclusions using a combination of data from Cassini’s December 2000 Jupiter flyby and laboratory experiments.

In the lab, the researchers blasted ammonia and acetylene gases — chemicals known to exist on Jupiter — with ultraviolet light, to simulate the sun’s effects on these materials at the extreme heights of clouds in the Great Red Spot. This produced a reddish material, which the team compared to the Great Red Spot as observed by Cassini’s Visible and Infrared Mapping Spectrometer (VIMS). They found that the light-scattering properties of their red concoction nicely matched a model of the Great Red Spot in which the red-colored material is confined to the uppermost reaches of the giant cyclone-like feature.

“Our models suggest most of the Great Red Spot is actually pretty bland in color, beneath the upper cloud layer of reddish material,” said Baines. “Under the reddish ‘sunburn’ the clouds are probably whitish or grayish.” A coloring agent confined to the top of the clouds would be inconsistent with the competing theory, which posits that the spot’s red color is due to upwelling chemicals formed deep beneath the visible cloud layers, he said. If red material were being transported from below, it should be present at other altitudes as well, which would make the red spot redder still.
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