SATURN

Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. 

Named after the Roman god of agriculture, its astronomical symbol (♄) represents the god's sickle. Saturn is a gas giant with an average radius about nine times that of Earth. Although only one-eighth the average density of Earth, with its larger volume Saturn is just over 95 times more massive.

Saturn's interior is probably composed of a core consisting of iron–nickel and rock (silicon and oxygen compounds), surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium and an outer gaseous layer.

 

The planet exhibits a pale yellow hue due to ammonia crystals in its upper atmosphere.Electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is weaker than Earth's, but has a magnetic moment 580 times that of Earth due to Saturn's larger body radius. Saturn's magnetic field strength is around one-twentieth the strength of Jupiter's. 

The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h (500 m/s), faster than on Jupiter, but not as fast as those on Neptune.

Saturn has a prominent ring system that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and dust. Sixty-two known moons orbit the planet, of which fifty-three are officially named. 

This does not include the hundreds of "moonlets" comprising the rings. Titan, Saturn's largest and the Solar System's second largest moon, is larger than the planet Mercury and is the only moon in the Solar System to retain a substantial atmosphere.

See: http://en.wikipedia.org/wiki/Saturn

ROCKET STREAK AND STAR TRAILS - 2014 JANUARY 30

Fixed to a tripod and looking east across the Kennedy Space Center's Turn Basin, a camera captured these star trails as a series of short exposures over a three hour period on the evening of January 23rd. 

Positioned just a few miles from Space Launch Complex 41 at Cape Canaveral Air Force Station, it also captured a spectacular night launch of an Atlas V rocket carrying NASA's Tracking and Data Relay Satellite TDRS-L. 

Creating the trails, the apparent motion of the stars through the sky is just a reflection of the daily rotation of planet Earth on its axis. But that rotation is also the reason therocket streak follows a path arcing east across the Atlantic. 

Launching toward the east, in the direction of Earth's rotation, adds the rotation velocity to the rocket and reduces the fuel needed to reach orbit. 

A little ironically, TDRS-L is destined for a geostationary orbit. From there, 36,000 kilometers or so above the equator, its orbital period will match Earth's rotation and the satellite will hang motionless in planet Earth's sky.

See: http://apod.nasa.gov/apod/ap140130.html

OPPORTUNITY'S DECADE ON MARS - 2014 JANUARY 25

On January 25 (UT) 2004, the Opportunity rover fell to Mars, making today the 10th anniversary of its landing. After more than 3,500 sols (Mars solar days) the golf cart-sized robot from Earth is still actively exploring the Red Planet, though its original mission plan was for three months. 

This self-portrait was made with Opportunity's panoramic camera earlier this month. The camera's supporting mast has been edited out of the image mosaic but its shadow is visible on the dusty solar panels arrayed across the rover's deck. 

For comparison, a similar self-portrait from late 2004 is shown in the inset. Having driven some 39 kilometers (24 miles) from its landing site, Opportunity now rests at Solander Point at the rim of Endeavour Crater.

See: http://apod.nasa.gov/apod/ap140125.html

TRAPEZIUM CLUSTER

The Trapezium or Orion Trapezium Cluster, also known by its Bayer designation of Theta1 Orionis, is a tight open cluster of stars in the heart of the Orion Nebula, in the constellation of Orion. It was discovered by Galileo Galilei. 

On February 4, 1617 he sketched three of the stars (A, C, D), but missed the surrounding nebulosity. The fourth component (B) was identified by several observers in 1673, and several more components were discovered later, for a total of eight by 1888. Subsequently several of the stars were determined to be binaries. Telescopes of amateur astronomers from about 5 inch aperture can resolve six stars under good seeing conditions.

The Trapezium is a relatively young cluster that has formed directly out of the parent nebula. The five brightest stars are on the order of 15-30 solar masses in size. They are within a diameter of 1.5 light-years of each other and are responsible for much of the illumination of the surrounding nebula. The Trapezium may be a sub-component of the larger Orion Nebula Cluster, a grouping of about 2,000 stars within a diameter of 20 light-years.

See: http://en.wikipedia.org/wiki/Trapezium_Cluster

GREAT ORION NEBULAE - 2011 SEPTEMBER 13

The Great Nebula in Orion, also known as M42, is one of the most famous nebulas in the sky. 

The star forming region's glowing gas clouds and hot young stars are on the right in this sharp and colorful image that includes the smaller nebula M43 near center and dusty, bluish reflection nebulae NGC 1977 and friends on the left. 

Located at the edge of an otherwise invisible giant molecular cloud complex, these eye-catching nebulae represent only a small fraction of this galactic neighborhood's wealth of interstellar material. 

Within the well-studied stellar nursery, astronomers have also identified what appear to be numerous infant planetary systems. The gorgeous skyscape spans nearly two degrees or about 45 light-years at the Orion Nebula's estimated distance of 1,500 light-years.

See: http://apod.nasa.gov/apod/ap110913.html

COSMIC FOUNTAIN OF CRYSTAL RAIN

NASA's Spitzer Space Telescope detected tiny green crystals, called olivine, thought to be raining down on a developing star. This graphic illustrates the process, beginning with a picture of the star and ending with an artist's concept of what the crystal "rain" might look like.

The top picture was taken in infrared light by NASA's Spitzer Space Telescope. An arrow points to the embryonic star, called HOPS-68. The middle panel illustrates how the olivine crystals are suspected to have been transported into the outer cloud around the developing star, or protostar. Jets shooting away from the protostar, where temperatures are hot enough to cook the crystals, are thought to have transported them to the outer cloud, where temperatures are much colder. Astronomers say the crystals are raining back down onto the swirling disk of planet-forming dust circling the star, as depicted in the final panel.

See: http://www.spitzer.caltech.edu/images/3632-ssc2011-06c-Cosmic-Fountain-of-Crystal-Rain

MOST EXTREME HUMAN SPACEFLIGHT RECORDS

Oldest Person in Space

John Glenn flew on space shuttle Discovery's STS-95 mission in October 1998, aged 77! Having been the first American to orbit the Earth back in February 1962, that second flight gave him another record, the longest time between trips to space - 36 years.

Youngest Person in Space

Fictional Wesley Crusher does not qualify as the youngest person in space; rather the title goes to cosmonaut Gherman Titov (at right), a month shy of 26 years old when he launched aboard the Soviet spacecraft Vostok 2 in August 1961.

Most Consecutive Days in Space

Russian cosmonaut Valery Polyakov spent nearly 438 consecutive days aboard the Mir space station, from January 1994 to March 1995.

Shortest Spaceflight Mission

Alan Shepard's May 5, 1961, spaceflight was the first for an American. Also, Shepard achieved a less-celebrated record on that day: briefest human spaceflight mission, of only 15-minutes' duration.

Farthest Trip from Earth

In April 1970, NASA's ill-fated Apollo 13 capsule swung around the far side of the moon at an altitude of 158 miles (254 km), putting the astronauts 248,655 miles (400,171 km) away from Earth. It's the farthest our species has ever been from our home planet.

Most Total Time Spent in Space

Soviet cosmonaut Sergei Krikalev holds this record, with a little more than 803 days accrued over six spaceflights. That's more than two years and two months spent zipping around the Earth.

Longest Continuously Inhabited Spacecraft

This record belongs to the International Space Station, and it grows every day. The $100 billion (see the Most Expensive Spaceship) orbiting lab has held occupants since Nov. 2, 2000.

Longest Space Shuttle Mission

The STS-80 mission of space shuttle Columbia began on Nov. 19, 1996, and owing to delays lasted nearly 17 days and 16 hours in space, the record for a shuttle mission.

Most Time on the Moon

In December 1972, Harrison Schmidt and Eugene Cernan of NASA's Apollo 17 mission spent just under 75 hours, more than three days, on the surface of the moon. Apollo 17 also marked the last time people traveled to the moon, or even went past low-Earth orbit.

Fastest Human Spaceflight

The crew of NASA's Apollo 10 moon mission reached a top speed of 24,791 mph (39,897 kph) relative to Earth as they rocketed back to our planet on May 26, 1969. That's the fastest any human beings have traveled.

Most Spaceflights by an Astronaut

Franklin Chang-Diaz (shown) and Jerry Ross both went to space seven times aboard NASA's space shuttles. Chang-Diaz made his flights between 1986 and 2002, while Ross made his between 1985 and 2002.

Biggest Space Gathering

During NASA's STS-127 shuttle mission aboard Endeavour in 2009, the shuttle's seven-person crew docked, then went aboard the International Space Station, joining the six spaceflyers already there. The 13-person party was the largest-ever gathering of people in space at the same time. The record has been matched since then. (Only nine of the spaceflyers are pictured here).

Longest Single Spacewalk

On March 11, 2001, NASA astronauts Jim Voss and Susan Helms spent 8 hours and 56 minutes outside the space shuttle Discovery and the International Space Station during the STS-102 mission, performing some maintenance work and preparing the orbiting lab for the arrival of another module.

Most Women in Space at Once

Four women sped around the world in space at the same time in April 2010. NASA astronaut Tracy Caldwell Dyson traveled to the International Space Station in a Russian Soyuz spaceship. She was soon joined on the orbiting lab by NASA astronauts Stephanie Wilson and Dorothy Metcalf-Lindenburger and Japan's Naoko Yamazaki, who made the trip aboard the space shuttle Discovery on its STS-131 mission.

Most Expensive Spaceship

The International Space Station has cost $100 billion to date, making the station not not only the most expensive spaceship, but also the most expensive single structure ever built.

Largest Spaceship

The International Space Station sets this record. The space station is so large that it can easily be seen by the unaided eye from the ground (under the right conditions). It measures about 357.5 feet (109 meters) across. There are huge solar arrays at each end of the truss, and they have a wingspan of 239.4 feet (73 m).

See: http://www.space.com/11638-space-records-countdown.html