Astronomy pics

I've been slacking on the pics recently. Here's a batch I've been saving for a while.

Pacman in space

(c) BBC news

The Cassini spacecraft in orbit around Saturn has caught an interesting new view of the tiny moon Mimas.

The probe measured temperature differences across the object's surface and produced a map that looks just like the 1980s Pac-Man video games icon.
Scientists are unsure why Mimas should display such variations but say it is probably related to the diversity of textures in the surface materials. Some textures may retain heat better than others, they explain.

Mimas is about 400km (250 miles) across. It has a distinctive scar called Herschel Crater which has led many to draw comparisons with the "Death Star" from the Star Wars movies.

The Cassini team says the creation of the crater itself might have played a key role in changing conditions across extensive regions of the moon's surface.
Cassini is a joint venture between the US space agency (Nasa), the European Space Agency (Esa) and the Italian Space Agency (ASI). Its mission was recently extended through to 2017.

Moon crash

This is the last footage from the Japanese probe Kaguya before it was purposefully crashed into the Moons surface.

Cool!

Monthly Moon Round-up: Ganymede

"Ganymede, one of the four Galilean moons of Jupiter, is the largest moon in the Solar System. With a diameter of 5,260 kilometers it is even larger than planets Mercury and Pluto and just over three quarters the size of Mars. Ganymede is locked in synchronous rotation with Jupiter. This detailed mosaic of images from the Galileo spacecraft shows the trailing hemisphere of this planet-sized moon. Speckled with bright young craters, Ganymede's surface shows a mixture of old, dark, cratered terrain and lighter regions laced with grooves and ridges. Ganymede's true colors tend toward subtle browns and grays, but this mosaic's colors have been enhanced to increase surface contrasts. The violet shades extending from the top and bottom are likely due to frost particles in Ganymede's polar regions."

"How hazy is Jupiter's upper atmosphere? To help find out, astronomers deployed the Hubble Space Telescope to watch Jupiter eclipse its moon Ganymede. Although Ganymede circles Jupiter once a week, a particularly useful occultation occurs more rarely. Such an occultation was captured in great visual detail in April 2007. When near Jupiter's limb, Ganymede reflects sunlight though Jupiter's upper atmosphere, allowing astronomers to search for haze by noting a slight dimming at different colors. One result of this investigation was the above spectacular image, where bands of clouds that circle Jupiter are clearly visible, as well as magnificent swirling storm systems such as the Great Red Spot. Ganymede, at the image bottom, also shows noticeable detail on its dark icy surface."

Enceladus from Cassini

What a cracking photo! After Europa, Enceladus is my next bet for life in this solar system. Water, water, everywhere.........

"What telling impurities taint the ice plumes of Enceladus? To help answer this question, the robotic Cassini spacecraft dove last week to within 30 kilometers of Saturn's ice-plume emitting moon. At this closest-ever approach, Cassini attempted to sniff and obtain chemical data on particles ejected from Enceladus' regular surface, while at other times Cassini flew right through -- and sampled -- ice geysers directly. Searches in the data for impurity clues in the water-ice dominated plumes and surface ejecta are progressing. Although the main purpose of this flyby was particle analysis, several interesting images are emerging. Visible in the above image, for example, is an unusual gray sheen running vertically up the image center that might be water vapor escaping from surface canyons. Other notable features visible above include vast plains of craterless icy grooves, the day-night terminator across the image left, and an area near the top comparatively rich in craters."

Bailey's Beads

"Just before the Sun blacks out, something strange occurs. As the Moon moves to completely cover the Sun in a total solar eclipse, beads of bright sunlight stream around the edge of the Moon. This effect, known as Baily's beads, is named after Francis Baily who called attention to the phenomenon in 1836. Although, the number and brightness of Baily's beads used to be unpredictable, today the Moon is so well mapped that general features regarding Baily's beads are expected. When a single bead dominates, it is called the diamond ring effect, and is typically seen just before totality. Pictured above, a series of images recorded Baily's beads at times surrounding the recent total solar eclipse visible from Novosibirsk, Russia. The complete series can be seen by scrolling right. At the end of totality, as the Sun again emerges from behind the moon, Baily's beads may again be visible -- but now on the other side of the Moon."

Astronomy Picture of the Day

You might occasionally wonder where I get all the cool photos from space and beyond. NASA have a daily website called (funnily enough) Astronomy Picture of the Day. http://apod.nasa.gov/apod/astropix.html. They have been busy in the last few days. Enjoy! :)



1. The Echus chasm on Mars
2. Jupiter over Hadrians temple in Ephesus
3. Rhea and Saturn
4. The moon over the temple of Posiedon in Greece
5. Soyuz docking with the International Space Station

Monthly moon round-up - Dione

Size: 1,120 kilometers - 4th largest moon of Saturn
Orbital radius: 377,400 kilometers - 6.26 Saturn radii - within the E ring
Orbital period: 2.737 days - about 1/6 of Titan's
Discovery: 1684 by Giovanni Domenico Cassini

Dione's globe is dominated by a star-like pattern of bright "wispy terrain" -- or so it appeared from the Voyagers' distant views. It was long speculated that the wispy terrain represented relatively fresh volcanic flows of icy material. Close views from Cassini have revealed that the wisps are not volcanic features at all. They are exposed cliff faces, a terrain created by the fracturing and faulting of Dione's surface. In fact, there are fractures to be seen everywhere on Dione, representing multiple generations of tectonic events. Some slice up craters, while others have craters superimposed on them.

Features on Dione are named for people and places from Virgil's Aeneid, which complements similar Tethys' naming scheme (the Odyssey).

Like Tethys, Dione has little rocks keeping it company in its Lagrange points: Helene occupies the same orbit as Dione, 60 degrees ahead, while Polydeuces occupies the same orbit, 60 degrees behind.

Monthly moon round-up - Phobos

"This moon is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These martian moons may well be captured asteroids originating in the main asteroid belt between Mars and Jupiter or perhaps from even more distant reaches of the Solar System. The larger moon, Phobos, is indeed seen to be a cratered, asteroid-like object in this stunning color image from the Mars Reconnaissance Orbiter, recorded at a resolution of about seven meters per pixel. But Phobos orbits so close to Mars - about 5,800 kilometers above the surface compared to 400,000 kilometers for our Moon - that gravitational tidal forces are dragging it down. In 100 million years or so Phobos will likely be shattered by stress caused by the relentless tidal forces, the debris forming a decaying ring around Mars."

"Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877. Over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself, so large that the impact that blasted out the crater likely came close to shattering the tiny moon. This stunning, enhanced-color image of Stickney and surroundings was recorded by the HiRISE camera onboard the Mars Reconnaissance Orbiter as it passed within some six thousand kilometers of Phobos last month. Even though the surface gravity of asteroid-like Phobos is less than 1/1000th Earth's gravity, streaks suggest loose material has slid down inside the crater walls over time. Light bluish regions near the crater's rim could indicate a relatively freshly exposed surface. The origin of the curious grooves along the surface is mysterious but may be related to the crater-forming impact."

Uranus

Its one of the big gas giants, but we never hear much about it, apart from the favourite schoolboy joke about it. A joke even JK Rowling used, to perfection I might add, in one of the Harry Potter book. Notice I've refrained from making any jokes myself about Uranus. I shall leave it up to my readerships foul and twisted minds to do that for me.

But we have some stunning photos now about the Uranian system. Voyager and Hubble have both capture some beauties, both in real light and a mix of infrared and spectrograph.

So here's some photos of the Uranian system. Enjoy.

PS. I love the fact that the moons are named from A Midsummers Nights Dream, and other Shakespeare characters.

Monthly moon round-up - Titan

Titan is doing its best to become my favourite moon, although my heart will always belong to Europa ;)

Since the marvelous Huygens probe was dropped onto the surface last year, the main Cassini space craft is orbiting the Saturn system and has been taking un precidented pictures of the surface using radiowaves. Titans atmosphere normally makes surface pictures impossible, but the new equipment on Cassini gives a window on the surface we've never had before.

And there they are!! Lakes and rivers of Methane!! With drainage channels and other features associated with a free-flowing liquid. Cool as!

Ah Titan :)

Know thy neighbours

As always, click on the image to enlarge.

Space, above and beyond

There's been some fantastic astronomy pictures published in my absence. Here's just a few of them. (Please) click to enlarge.

1. My favourite moon Europa

2. The International Space Station

3. Alborz Mountains in Moonlight

4. Comet McNaught at dawn

5. Saturns rings and its moon Tethys.

Something for the weekend

There were a bunch of quality photos available today, so I thought I would put some up for you.

I keep intending not to publish anymore photos of Auroras, yet I keep coming across fantastic photos of them; and each one better than the last! lol

There is another fantastic close-up of Comet Holmes. And a wonderful shot of Earthrise! Taken my a Japanese probe that is orbitting the Moon right now. Beautiful :)

Have a nice weekend!

Iapetus

Its your monthly moon round-up.

This is Saturns moon, Iapetus. And it is half covered in black stuff. We're not too sure what this stuff is, but we are guessing its Carbon. Quite how it got there, we dont know - it could be volcanic but we dont inderstand the process.

The close up is from a fly-by by the probe Cassini. Incredible details! :)

Wanna go, now!

Io

I told you moons was where its at. Mars is geologically inert (no volcanic activity), Venus is too hot to visit, Mercury is a cinder, and rest are gas giants (because Pluto is no longer a planet!).
Its the vast array of moons that we have where the most spectacular things are happening.


Io, Jupiters moon is a hotbed of activity. Jupiter is playing Io like an accordian. The surface is being pulled upto 250km upwards to Jupiter at its closest orbit, and back down at its furthest orbit. This constant back and forth creates incredible friction inside Io, and as a result it constantly spews sulphur volcanoes. Mapping Io is impossible as the surface never remains the same, due to constant eruptions.

We even caught a volcano on camera. It is estimated that this eruption of sulphur and methane is 500km high.

Cool.

Moons and Rings

You know I like moons. These fantastic photos show just some of the many, many moons of Saturn and Jupiter.


1. I love this photo! This shows Saturns moon Enceladus creating one of Saturns rings. Like a comet, when the Sun hits the moon, the ice evaporates and creates a tail. Due to Saturns immense gravity the ice vapour follows Enceladus in orbit around the planet. We have never seen this view before because the Sun was behind us. It was only when the Cassini probe flew to the other side of Saturn and looked back, and Enceladus was silloutted could we see this ring creation in action.

2. Saturns moon Epimetheus against the rings.

3. My favourite moon Europa (still the best hope for extra terrestrial life, IMHO) rising over Jupiter.


Niiiice!