2007 March 12


Watch Jupiter Rotate
 
Explanation:
What would it be like to coast by Jupiter and watch it rotate? This was just the experience of the New Horizons spacecraft as it approached and flew by Jupiter earlier this year. Clicking on the image will bring up a movie of what the robotic spacecraft saw. Visible above in the extensive atmosphere of the Solar System's largest planet are bands and belts of light and dark clouds, as well as giant rotating storm systems seen as ovals. Other movies compiled by New Horizons and other passing spacecraft have captured the clouds swirling and moving relative to themselves. Jupiter has a diameter of about eleven times that of our Earth, and rotates once in about 10 hours. The robotic New Horizons spacecraft continues to speed toward the outer Solar System where it is expected to approach Pluto in 2015.

2007 March 13


Attacking Mars 

Explanation: The Spirit rover attacked Mars again in 2005 September. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near the summit of Husband Hill. Spirit's Panoramic Camera captured the rover's Instrument Deployment Device above as moved to get a closer look at an outcrop of rocks named Hillary. The Spirit rover, and its twin rover Opportunity, have now been exploring the red planet for over three years. Both Spirit and Opportunity have found evidence that parts of Mars were once wet.

2007 March 14


Barred Spiral Galaxy M95   

Explanation:
Why do some spiral galaxies have a ring around the center? First and foremost, M95 is one of the closer examples of a big and beautiful barred spiral galaxy. Visible in the above recent image from the CFHT telescope in Hawaii, USA, are sprawling spiral arms delineate by open clusters of bright blue stars, lanes of dark dust, the diffuse glow of billions of faint stars, and a short bar across the galaxy center. What intrigues many astronomers, however, is the circumnuclear ring around the galaxy center visible just outside the central bar. Recent images by the Chandra X-ray Observatory have shown that X-ray light surrounding the ring is likely emission from recent supernovas. Although the long term stability of the ring remains a topic of research, recent observations indicate its present brightness is at least enhanced by transient bursts of star formation. M95, also known as NGC 3351, spans about 50,000 light-years and can be seen with a small telescope toward the constellation of the Lion (Leo).

2007 March 15


NGC 2442: Galaxy in Volans

Explanation:
Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish, (Piscis) Volans. Located about 50 million light-years away, the galaxy's two spiral arms extending from a pronounced central bar give it an ominous hook-shaped appearance. This striking color image also shows obscuring dust lanes, young blue star clusters and reddish star forming regions surrounding a core of yellowish light from an older population of stars. But the star forming regions seem more concentrated along the drawn-out northern (top) spiral arm. The distorted structure is likely the result of a close encounter with a smaller galaxy located just outside this telescopic field of view. The picture spans about 1/6 of a degree, or 150,000 light years at the estimated distance of NGC 2442.

2007 March 16


Eclipsing the Rings

Explanation:
The March 3rd total lunar eclipse was widely viewed by denizens of planet Earth. But only a day before, well placed observers could also watch a lunar occultation of Saturn as the planet passed behind the nearly Full Moon. From Selsey, UK, astronomer Pete Lawrence actually saw Saturn graze the lunar limb, the Moon's bright surface dramatically eclipsing a substantial part of the gas giant's spectacular rings. In this summary view of the grazing occultation, south is up and Saturn's position is shown every 90 seconds in a composite of images constructed from video frames. The frames were all recorded near the occultation event, then combined and adjusted to compensate for the large difference in brightness between Saturn and the lunar surface

2007 March 17


Eiffel Moon 

Explanation:
Celestial and terrestrial lights are featured in this stunning image that includes the Moon in phases of the total lunar eclipse of March 3rd. In the foreground, the distinctively-shaped Eiffel Tower, over 300 meters tall, is a well-known tourist destination and one of the most visited buildings in the world. Of course the Moon is even more recognizable, but harder to visit. The last lunar tour was undertaken nearly 35 years ago, during the Apollo 17 mission.

2007 March 19


Galaxy Group Hickson 44

Explanation:
Galaxies, like stars, frequently form groups. A group of galaxies is a system containing more than two galaxies but less than the tens or hundreds typically found in a cluster of galaxies. A most notable example is the Local Group of Galaxies, which houses over 30 galaxies including our Milky Way, Andromeda, and the Magellanic Clouds. Pictured above is nearby compact group Hickson 44. This group is located about 60 million light-years away toward the constellation of Leo. Also known as the NGC 3190 Group, Hickson 44 contains several bright spiral galaxies and one bright elliptical galaxy on the upper left. The bright source on the upper right is a foreground star. Many galaxies in Hickson 44 and other compact groups are either slowly merging or gravitationally pulling each other apart.

2007 March 20


A Blue Crescent Moon from Space

Explanation:
What's happening to the Moon? Drifting around the Earth in 2006 July, astronauts from the International Space Station (ISS) captured a crescent Moon floating far beyond the horizon. The captured above image is interesting because part of the Moon appears blue, and because part of the moon appears missing. Both effects are created by the Earth's atmosphere. Air molecules more efficiently scatter increasingly blue light, making the clear day sky blue for ground observers, and the horizon blue for astronauts. Besides reflecting sunlight, these atmospheric molecules also deflect moonlight, making the lower part of the moon appear to fade away. As one looks higher in the photograph, the increasingly thin atmosphere appears to fade to black.

2007 March 21


Molecular Cloud Barnard 163

Explanation:
It may look to some like a duck, but it lays stars instead of eggs. In the center of the above image lies Barnard 163, a nebula of molecular gas and dust so thick that visible light can't shine through it. With a wing span measured in light years, Barnard 163's insides are surely colder than its exterior, allowing conditions where gas can clump and eventually form stars. Barnard 163 lies about 3,000 light years from Earth toward the constellation of Cepheus the King. The red glow in the background results from IC 1396, a large emission nebula that houses the Elephant's Trunk Nebula. Finding Barnard 163 in an image of its greater emission nebula IC 1396 can be a challenge, but it's possible.

2007 March 22


Goa Silhouettes

Explanation:
On Moonday, March 19, shortly before the equinox, locations in Asia and the Arctic were favoured by the New Moon's shadow during a partial solar eclipse. Although the view from Goa, India found the eclipsed Sun near the horizon, photographer Joerg Schoppmeyer was still able to capture this lovely image, combining celestial with terrestrial silhouettes. The next eclipse season will begin in late August this year, featuring a total lunar eclipse on August 28, and another partial solar eclipse on September 11. Compared to the March 19th eclipse, the September 11th eclipse will be seen on the other side of our fair planet, from parts of South America and Antarctica.