NATIONAL GEOGRAPHIC'S SPACE PICTURES THIS WEEK L

Space Pictures This Week: Alien Invader, Framing Venus
By National Geographic News, 8 March 2013.

Hubble spies an alien invader and Dragon docks with the ISS in this week's best space pictures.

1. Circular Sky

Photograph by Tamas Ladanyi, TWAN

Taken on Earth or up in space, photos can be fascinating when they look outward. From nearby stars to distant galaxies, we look weekly at our favourite portraits of the universe.

Here, in a field near the small village of Sikonda in Hungary, a long exposure shows the motion of the celestial sky over an expansive field of straw. At the centre of rotation is the north star - also known as the pole star - that is approximately aligned with the earth's axis and retains its position as the planet moves. (Related: "North Star Closer to Earth Than Thought.")

2. Visible Orion

Taken in Iran and submitted to National Geographic's Your Shot on March 1, this image shows the Orion Nebula, the brightest part of the entire Orion constellation. An estimated 1,300 light-years from Earth, the nebula is one of few that's visible with the naked eye.

3. Space Delivery

As the SpaceX Dragon approached the International Space Station (ISS) this month for its second docking with the orbiting station, a crew member inside the ISS took this photo (released March 3) moments before the two connected. The Dragon is unmanned, but carried more than 1,200 pounds (544 kilograms) of supplies for the crew, including materials for experiments.

In October 2012, SpaceX became the first private company to make an official resupply delivery to the ISS, which is run by a consortium of national governments. The Dragon had completed a successful first dock with the ISS in May 2012. (Related: "SpaceX's Dragon Docks With Space Station-A First.")

4. Crowd of Galaxies

In an image from the Hubble Space Telescope released March 5, this photo shows the Abell 68 galaxy cluster, captured here in infrared light. The collection of luminescent blobs in the centre and upper left, according to NASA, is a series of individual galaxies, each including hundreds of billions of individual stars - and presumably, exponentially more orbiting planets.

The cartoonish alien invader in the upper right corner of the picture is due to the gravitational field of a galaxy cluster distorting the background images of more distant galaxies.

5. Developing Imagery

A new set of cameras aboard the International Space Station, known as ISERV Pathfinder, offers new views of Earth, including the Rio San Pablo river in Panama as it meets the Pacific Ocean in an image released March 1.

Installed in the ISS in January, Pathfinder was designed to provide geographic imagery, especially for developing countries hoping to monitor the incremental impacts of natural disasters and other environmental changes. The area around the San Pablo river has been considered a wetland of international importance by international governing bodies.

6. Venus In Frame

In an image released March 4, the Cassini spacecraft was able to snap this picture while in Saturn's shadow. By pointing itself toward the back-lit planet, Cassini captured Earth's twin Venus (white dot among Saturn's rings) shining brightly in the background. This particular viewing position around Saturn is known as "high solar phase." Cassini has been orbiting the ringed planet since it arrived in 2004. (See more photos of Saturn.)

7. Salty Seas

Using data on from the W. M. Keck Observatory in Hawaii, this artistic conception (released March 5) shows what astronomers from NASA and the Jet Propulsion Laboratory believe is occurring on one of Jupiter's moons, Europa. The scientists hypothesize that chemicals bubble up to Europa's frozen surface from the moon's liquid ocean, where they are bombarded with sulphur streaming from atmospheric eruptions on the nearby moon Io.  (Related: "New Jupiter Mission to Target Alien Oceans.")

[Source: National Geographic News. Edited.]