Cassini’s Shot of Spectacular Saturn, October, 2012.

17 October 2012
A glorious view of Saturn while the spacecraft was in its shadow.
The cameras were turned toward Saturn and the sun so that the planet and rings are backlit.
In addition to the visual splendour, this special, very-high-phase viewing geometry lets scientists study ring and atmosphere phenomena not easily seen at a lower phase.
The last time Cassini captured a view like this was in September 2006, when it captured ‘In Saturn’s Shadow’.
This image was taken using infrared, red and violet spectral filters which were combined to create this enhanced-colour view.
Image Credit: Photograph by Nasa/JPL-Caltech/Space Science Institute
Source: Spectacular Saturn: Cassini’s epic pictures using a one megapixel camera | Science | The Guardian

Did the Planet “Theia” hit Earth and create the Moon?


An artist’s rendering of the collision that created the moon (Paul Wootton/ /Science Photo Library/Corbis)
Scientists have announced that they had found evidence of the planetary body that slammed into the earth over four billion years ago, creating the moon.
In analyzing lunar rocks collected on the Apollo missions, they found that the moon rocks contained different ratios of oxygen isotopes 17 and 16 than their earthly counterparts, showing that some percentage of the moon likely had to come from somewhere else.
Daniel Herwartz, lead author of the study told
“The differences are small and difficult to detect, but they are there,” Herwartz said. “We now get an idea of the composition of Theia.”
That was the name given to the Mars-sized planet in 2000 by Alex Halliday.
Most scientists 14 years ago had started to accept the giant impact hypothesis, first proposed in the 1970s, and when Halliday proposed calling the planet Theia, the name caught on.
But what people couldn’t figure out was where all the evidence for Theia had gone.
The earth and moon have very similar chemical compositions. So similar, if fact, that it’s been a huge puzzle for scientists trying to prove the Giant Impact Theory.
With this new research there is finally some difference. Or is there?
There is still considerable scientific research looking in to moon formation, along with a lot of debate, so it’s no surprise really that not everyone in the scientific community agrees that the differing oxygen isotopes are conclusive enough evidence for Theia.
Read on via What Would the Planet That Smashed Into Earth and Created the Moon Have Been Like? | Smart News | Smithsonian.

Astronaut Chris Hadfield’s Snapshots from Space.


‘On a clear day you can see forever,’ says Hadfield. ‘Or at least from Havana to Washington DC …’
All photographs: Chris Hadfield/Macmillan
The guitar-strumming spaceman Chris Hadfield is releasing a new book – You Are Here: Around the World in 92 Minutes – featuring stunning images of the Earth captured while in orbit.
Here are some of his best snaps.
d4b3696a-0cc9-48be-8d2c-a57c3a78755c-2060x1236The Nile, draining into the Mediterranean. ‘The bright lights of Cairo announce the opening of the north-flowing river’s delta,’ says Hadfield. ‘Israel is to the north-east.
This 4,258 mile braid of human life is visible in a single glance from space.’
‘The Richat Structure in Mauritania, also known as the Eye of the Sahara, is a landmark for astronauts,’ says Hadfield. d52021d5-638c-43e3-887f-a8cd7c6d3695-2060x1236
‘If you’ve been busy doing experiments and haven’t looked out the window for a while, it’s hard to know where you are, especially if you’re over a vast 3,600,000-square-mile desert.
This bullseye orients you, instantly’ –
All photographs: Chris Hadfield/Macmillan
Read on via Astronaut Chris Hadfield’s amazing photos from space | Travel | The Guardian

View of Earth from Saturn.

While exploring Saturn, NASA’s Cassini spacecraft took the top image of Earth from a distance of about 1.45 billion kilometers (898 million miles) away.
NASA’s MESSENGER spacecraft was 98 million kilometers (61 million miles) from Earth, in orbit around Mercury, when it acquired the image.
The Cassini view is the third-ever image of Earth from the outer solar system.
Views of Earth from distant planets are rare because our planet is so close to the Sun.
Sunlight would damage the spacecraft’s sensitive imagers, so they are rarely pointed homeward.
However, Cassini was positioned so that Saturn blocked the Sun’s light while Earth was within the spacecraft’s field of view.
Sunlight glimmers around the giant planet’s limb and lights its icy, dusty rings.
The sunlit Earth is light blue.
via NASA Visible Earth: Views of a Distant Earth.

View of the Earth and Moon from planet Mars.

Photographic Image by NASA/JPL-Caltech/Univ. of Arizona
During a recent calibration exercise, NASA’s Mars Reconnaissance Orbiter captured a remarkable view of Earth and its moon from a distance of 127 million miles (205 million kilometers).
It’s so clear, you can even make out our planet’s continents.
To calibrate the HiRISE camera aboard the Mars Orbiter, NASA scientists needed to scan an object other than the Red Planet.
Seeing as Earth is right next door, that was an obvious choice.
The image is a combination of two separate exposures taken on November 20, 2016, and have been moderately adjusted to make both objects appear equally as bright (otherwise the Earth would have appeared too dark).
The combined view shows the correct positions and sizes of the two celestial bodies relative to each other.
Source: Incredible New Image Shows the Earth and Moon From Mars

Sunset over the Atlantic.

The Earth Science and Remote Sensing Unit at NASA’s Johnson Space Center picks this year’s top 16 photos of Earth from the International Space Station.
A sunset over the southern part of the Atlantic Ocean. Johnson Space Center/NASA
Source: See NASA’s Top 16 Earth Images of 2016 – The Washington Post