Purine Nucleoside Phosphorylase

Computer-generated Model of Purine Nucleoside Phosphorylase (PNP)Purine Nucleoside Phosphorylase (PNP) is an important target enzyme for the design of anti-cancer and immunosuppressive drugs. Bacterial PNP, which is slightly different from the human enzyme, is used to synthesize chemotherapuautic agents. Knowledge of the three-dimensional structure of the bacterial PNP molecule is useful in efforts to engineer different types of PNP enzymes, that can be used to produce new chemotherapeutic agents.

This picture shows a computer model of bacterial PNP, which looks a lot like a display of colorful ribbons. Principal Investigator was Charles Bugg.

the engraved hourglass nebula

The Engraved Hourglass Nebula (also known as MyCn 18) is a young planetary nebula situated in the southern constellation Musca about 8,000 light-years away from Earth. It was discovered by Annie Jump Cannon and Margaret W. Mayall during their work on an extended Henry Draper Catalogue. At the time it was designated simply as a small faint planetary nebula. Much improved telescopes and imaging techniques allowed the hourglass shape of the nebula to be discovered by Raghvendra Sahai and John Trauger of the Jet Propulsion Laboratory on July 30, 1995. It is conjectured that MyCn 18's hourglass shape is produced by the expansion of a fast stellar wind within a slowly expanding cloud which is denser near its equator than its poles.

The Hourglass Nebula was photographed by the Wide Field and Planetary Camera 2 of the Hubble Space Telescope.
It should be noted there is another nebula which shares the designation of hourglass nebula it can be found in the Lagoon Nebula.

Observation data

Right ascension: 13h 39m 35.116s
Declination: -67° 22′ 51.45″
Distance: 8 kly (2.5 kpc)
Apparent magnitude: 13.0
Constellation: Musca

earth lights

(click for full detail)

sr-71 blackbird

The SR-71 remained the world's fastest and highest-flying operational manned aircraft throughout its career. From an altitude of 80,000 ft (24 km) it could survey 100,000 square miles per hour (72 square kilometers per second) of the Earth's surface. On 28 July 1976, an SR-71 broke the world record for its class: an absolute speed record of 2,193.1669 mph (3,529.56 km/h), and a US "absolute altitude record" of 85,068.997 feet (25,929 m). Several planes exceeded this altitude in zoom climbs but not in sustained flight. When the SR-71 was retired in 1990, one was flown from its birthplace at United States Air Force Plant 42 in Palmdale, California to go on exhibit at what is now the Smithsonian Institution's Steven F. Udvar-Hazy Center (an annex of the National Air & Space Museum) in Chantilly, Virginia. The Blackbird, piloted by Colonel Ed Yielding and Lt. Col. J.T. Vida, set a coast-to-coast speed record at an average 2,124 mph (3,418 km/h). The entire trip was reported as 68 minutes and 17 seconds. Three additional records were set within segments of the flight, including a new absolute top speed of 2,242 mph measured between the radar gates set up in St. Louis and Cincinnati. These were accepted by the National Aeronautic Association (NAA), the recognized body for aviation records in the United States. An enthusiast site devoted to the Blackbird lists a record time of 64 minutes. The SR-71 also holds the record for flying from New York to London: 1 hour 54 minutes and 56.4 seconds, set on 1 September 1974. This is only Mach 2.68, well below the declassified figure of 3.0+. (For comparison, commercial Concorde flights took around 3 hours 20 minutes, and the Boeing 747 averages 6 hours.)

General characteristics
Crew: 2
Payload: 3,500 lb (1,600 kg) of sensors
Length: 107 ft 5 in (32.74 m)
Wingspan: 55 ft 7 in (16.94 m)
Height: 18 ft 6 in (5.64 m)
Wing area: 1,800 ft2 (170 m2)
Empty weight: 67,500 lb (30 600 kg)
Loaded weight: 170,000 lb (77 000 kg)
Max takeoff weight: 172,000 lb (78 000 kg)
Powerplant: 2× Pratt & Whitney J58-1 continuous-bleed afterburning turbojets, 32,500 lbf (145 kN) each
Wheel track: 16 ft 8 in (5.08 m)
Wheel base: 37 ft 10 in (11.53 m)
Aspect ratio: 1.7
Performance
Maximum speed: Mach 3.3+ (2,200+ mph, 3530+ km/h) at 80,000 ft (24,000m)
Range:
Combat: 2,900 nm (5400 km)
Ferry: 3,200 nm (5,925 km)
Service ceiling: 85,000 ft (25,900m, 16 miles)
Rate of climb: 11,810 ft/min (60 m/s)
Wing loading: 94 lb/ft2 (460 kg/m2)
Thrust/weight: 0.382

more info here: http://en.wikipedia.org/wiki/SR-71_Blackbird

photo session: saturn

Four million miles (6,400,000 kilometers) from Saturn in late 2004, the Cassini spacecraft snapped a series of 126 natural-color photographs—the most detailed portrait of the planet ever made. Cassini, which began its voyage in 1997, is one of the most ambitious missions to another planet.

Hyperion

Despite its bathtub-ready appearance, Hyperion—Saturn's largest irregularly shaped moon—is anything but spongy.
High-resolution images taken by NASA's Cassini spacecraft—including the picture above taken in 2005—suggest the satellite's cuplike craters are reservoirs for hydrocarbons. The finding could mean that the ingredients needed for life as we know it may be more common in our solar system than previously thought, according to NASA.
Dark material spotted at the bottoms of some of the moon's craters has the same chemical signature as hydrocarbons, NASA scientists said. These organic molecules—made of hydrogen and carbon—are also found in comets, meteorites, and galactic dust.

orion rising

Orion always comes up sideways ... and was caught in the act earlier this month by astronomer Jimmy Westlake, stargazing eastward over the Rocky Mountains north of Leadville, Colorado, USA. To make this gorgeous image, Westlake placed his camera on a tripod for two exposures. The first lasted for 18 minutes allowing the stars to trail as they rose above the mountain range. After a minute long pause, the second exposure began and lasted only 25 seconds decorating the end of each trail with a celestial point of light. The three bright stars in Orion's belt stand in a nearly vertical line above the mountain peak right of center. Hanging from his belt, the stars and nebulae of the Hunter's sword follow the slope down and to the right. A festive yellow-orange Betelgeuse is the brightest star above the peak just left of center, but brighter still, planet Saturn shines near the upper left corner. In the foreground on planet Earth, a frozen lake and snowy mountains are lit by a four day old crescent Moon.

Credit & Copyright: Jimmy Westlake (Colorado Mountain College)

giant planet candidate companion

ESO PR Photo 26a/04 is a composite image of the brown dwarf object 2M1207 (centre) and the fainter object seen near it, at an angular distance of 778 milliarcsec. Designated "Giant Planet Candidate Companion" by the discoverers, it may represent the first image of an exoplanet. Further observations, in particular of its motion in the sky relative to 2M1207 are needed to ascertain its true nature. The photo is based on three near-infrared exposures (in the H, K and L' wavebands) with the NACO adaptive-optics facility at the 8.2-m VLT Yepun telescope at the ESO Paranal Observatory.

note: here is the comparison with other know planets.

credit: European Organisation for Astronomical Research in the Southern Hemisphere

neptune and triton

Voyager 2 is the first -- and as of 2002, only -- spacecraft to observe Neptune.

Twelve years after leaving Earth, Voyager 2 makes its closest approach to any planet since starting its journey, flying about 4,950 kilometers (3,000 miles) above Neptune's north pole. It discovers that Neptune has the strongest winds of any planet encountered, even though it receives the least solar energy.Voyager 2 also passes about 40,000 kilometers (25,000 miles) from Neptune's largest moon, Triton, the last solid body the spacecraft will have an opportunity to study. With a temperature around -235 degrees Celsius (-390 degrees Fahrenheit), it is the coldest body ever visited. Even so, geysers erupt on the moon's polar cap of frozen nitrogen and methane.After Triton, Voyager 2 heads downward out of the plane of the planets. Like Voyager 1, it begins a journey to the edge of the solar system and beyond. As of 2002, it continues to send back data from its location well past Pluto.

sorce: http://www.jpl.nasa.gov/history/80s/Voyager2_1989.htm

video: http://realserver1.jpl.nasa.gov:8080/ramgen/timeline/Video-Voyager-2-Nep-020423.rm?mode=compact

Dr. von Braun Standing by Five F-1 Engines

A pioneer of America's space program, Dr. von Braun stands by the five F-1 engines of the Saturn V launch vehicle. This Saturn V vehicle is an actual test vehicle which has been displayed at the U.S. Space Rocket Center in Huntsville, Alabama. Designed and developed by Rocketdyne under the direction of the Marshall Space Flight Center, a cluster of five F-1 engines was mounted on the Saturn V S-IC (first) stage. The engines measured 19-feet tall by 12.5-feet at the nozzle exit and burned 15 tons of liquid oxygen and kerosene each second to produce 7,500,000 pounds of thrust. The S-IC stage is the first stage, or booster, of a 364-foot long rocket that ultimately took astronauts to the Moon.

Source: http://nix.larc.nasa.gov/info;jsessionid=5d5m4ql7dku94?id=MSFC-0201422&orgid=11

eclipsed saturn

Saturn eclipsing the sun, seen from behind from the Cassini orbiter. The image is a composite assembled from images taken by the Cassini spacecraft on 15 September, 2006.

Individual rings seen include (in order, starting from most distant):
- E ring
- Pallene ring (visible very faintly in an arc just below Saturn)
- G ring
- Janus/Epimetheus ring (faint)
- F ring (narrow brightest feature)
- Main rings (A,B,C)
- D ring (bluish, nearest Saturn)

For a detailed description, see http://photojournal.jpl.nasa.gov/catalog/PIA08329 and http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=698

military laser experiment

"A military scientist operates a laser in a test environment. The Directorate conducts research on a variety of solid-state and chemical lasers."

Prandtl-Glauert singularity

The Prandtl-Glauert singularity (sometimes referred to as a "vapor cone"), is the point at which a sudden drop in air pressure occurs, and is generally accepted as the cause of the visible condensation cloud that often surrounds an aircraft travelling at transonic speeds, though there remains some debate. It is an example of a mathematical singularity in aerodynamics.
One view of this phenomenon is that it exhibits the effect of compressibility and the so-called "N-wave". The N-wave is the time variant pressure profile seen by a static observer as a sonic compression wave passes. The overall three-dimensional shock wave is in the form of a cone with its apex at the supersonic aircraft. This wave follows the aircraft. The pressure profile of the wave is composed of a leading compression component (the initial upward stroke of the "N"), followed by a pressure descent forming a rarefaction of the air (the downward diagonal of the "N"), followed by a return to the normal ambient pressure (the final upward stroke of the "N"). The rarefaction may be thought of as the "rebounding" of the compression due to inertial effects. These condensation clouds, also known as "shock-collars" or "shock eggs," are frequently seen during space-shuttle launches around 25 to 33 seconds after launch when the vehicle passes through the area of maximum dynamic air-pressure, or max Q. These effects are also visible in archival footage of some nuclear tests. The condensation marks the approximate location of the shock wave.

Prandtl-Glauert singularity effects can be readily observed on a humid day by successfully cracking a whip. A visible cloud is produced at the point where the tip of the whip goes transonic.

largest known star

VY Canis Majoris (VY CMa) is a red hypergiant located in the constellation of Canis Major. This is the largest known star and one of the most luminous stars known.

Roberta M. Humphreys (2006) estimates the radius of VY CMa is between 1800 and 2100 solar radii. If our sun were replaced with such a star, its surface could extend to the orbit of Saturn. If we take its radius to be that higher figure of 2100 solar radii, it would take more than 8 hours for light to travel around its circumference. If it were possible for a human to walk on the surface of Canis Majoris, at 3 miles an hour for 8 hours a day, it would take him or her 650,000 years to walk the entire circumference (compared with 2 years 11 months to complete the same task on the Earth).

Object Name:
VY Canis Majoris
Object Description:
Variable Star with Circumstellar Nebula
Position (J2000):
R.A. 07h 22m 58s.33Dec. -25° 46' 3".2
Constellation:
Canis Major
Distance:
Approximately 5,000 light-years (1.5 kiloparsecs)
Dimensions:
These images are roughly 35 arcseconds (0.85 light-years or 0.25 parsecs) across.

VY Canis Majoris Credit: NASA, ESA, and R. Humphreys (University of Minnesota)

journey to the center of the galaxy

In Jules Verne's science fiction classic A Journey to the Center of the Earth, Professor Hardwigg and his fellow explorers encounter many strange and exciting wonders. What wonders lie at the center of our Galaxy? Astronomers know of some of the bizarre objects which exist there, like vast cosmic dust clouds, bright star clusters, swirling rings of gas, and even a supermassive black hole. Much of the Galactic Center is shielded from our view in visible light by the intervening dust and gas, but it can be explored using other forms of electromagnetic radiation. This haunting wide angle image of the Galactic Center region in infrared light was constructed using data from the Midcourse Space Experiment (MSX) satellite. The image maps three mid-infrared bands, otherwise invisible to human eyes, into visible blue, green, and red colors revealing the thermal emission from dust clouds near the galactic center that have been heated by starlight. The galactic plane runs along the middle of this image while the galactic center itself is the bright spot at picture center. The field of view of this cropped picture is about 1.5 by 2.5 degrees.


Journey to the Center of the Galaxy Credit: MSX, IPAC, NASA

proteus

Picture: Proteus in flight in 2002 in the Department of Energy’s Atmospheric Radiation Measurement - Unmanned Aerial Vehicle (ARM-UAV)* Program.

The Scaled Composites Model 281 Proteus is a tandem-wing high-endurance aircraft designed by Burt Rutan to investigate the use of aircraft as high altitude telecommunications relays. The Proteus is actually a multi-mission vehicle, able to carry various payloads on a ventral pylon. An extremely high-efficiency design, the Proteus can orbit a point at over 65,000 feet (19,800 m) for more than 18 hours. It is currently owned by Northrop Grumman.

Proteus has an all-composite airframe with graphite-epoxy sandwich construction. Its wingspan of 77 feet 7 inches is expandable to 92 feet with removable wingtips installed. Proteus is an "optionally piloted" aircraft ordinarily flown by two pilots in a pressurized cabin. However, it also has the capability to perform its missions semi-autonomously or flown remotely from the ground. Under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, NASA's Dryden Flight Research Center assisted Scaled Composites in developing a sophisticated station-keeping autopilot system and a satellite communications (SATCOM)-based uplink-downlink data system for Proteus' performance and payload data. The Proteus wing was adapted for use on the Model 318 White Knight carrier aircraft, which is the launch system for Rutan's Tier One spacecraft and the DARPA X-37.

General characteristics

Crew: Two (pilot & co-pilot)
Length: 56 ft 4 in (17.17 m)
Wingspan: 77 ft 7 in (23.65 m)
Height: 17 ft 7 in (5.36 m)
Wing area: 487.7 ft² (including canards) (45.31 m²)
Empty weight: 5,900 lb (2,700 kg)
Loaded weight: 12,500 lb (5,700 kg)
Powerplant: 2× Williams International FJ44-2 , 2,300 lbf (10.2 kN) each

Performance

Maximum speed: 274 knots (315 mph, 507 km/h)
Range: 415 nm (480 miles, 770 km)
Service ceiling: 60,000 ft (18,300 m)
Rate of climb: 6,000 ft/min (30 m/s)
Wing loading: 26 lb/ft² (128 kg/m²)
Thrust/weight: 1.8 N/kg

*Proteus has been used in a number of deployments as a part of a project sponsored by the DOE's Atmospheric Radiation Measurement program and the Sandia National Laboratories to study cirrus clouds in the upper atmosphere. During these flights, the aircraft was equipped with over 20 sensors mounted on five different parts of the aircraft. In November 2002, Proteus participated in another phase of the project, flying from Ponca City. In October, 2004, Proteus operated out of Fairbanks, Alaska, and in February, 2006, the aircraft was deployed to Darwin, Australia.

YB49

The Northrop YB-49 was a prototype jet-powered flying wing medium bomber aircraft developed by Northrop for the United States Air Force shortly after World War II. It was a development of the piston-engined YB-35, and the two YB-49s actually built were both converted YB-35 test aircraft. The aircraft was never to enter production, however, being passed over in favor of the more conventional Convair B-36 in service.

General characteristics

Crew: 7
Length: 53 ft 1 in (16.20 m)
Wingspan: 172 ft 0 in (52.40 m)
Height: 20 ft 3 in (6.2 m)
Wing area: 4,000 ft² (371.6 m²)
Airfoil: NACA 65-019 root, NACA 65-018 tip
Empty weight: 88,442 lb (40,116 kg)
Loaded weight: 133,559 lb (60,581 kg)
Max takeoff weight: 193,938 lb (87,969 kg)
Powerplant: 8× Allison/General Electric J35-A-19 turbojets, 3,800 lbf (17 kN) each

Performance

Maximum speed: 493 mph (793 km/h)
Range:
Combat: 1,615 mi (2,599 km)
Ferry: 3,578 mi (5,758 km)
Service ceiling: 45,700 ft (13,900 m)
Rate of climb: 3,758 ft/min (19.1 m/s)
Wing loading: 33 lb/ft² (163 kg/m²)
Thrust/weight: 0.23

Armament

Guns: 4 x .50 in (12.7 mm) machine guns
Bombs: 32,000 lb (14,500 kg)

1919 negative eclipse

1919 eclipse (negative version)

From the report of Sir Arthur Eddington on the expedition to verify Albert Einstein's prediction of the bending of light around the sun.

In Plate 1 is given a half-tone reproduction of one of the negatives taken with the 4-inch lens at Sobral. This shows the position of the stars, and, as far as possible in a reproduction of this kind, the character of the images, as there has been no retouching. A number of photographic prints have been made and applications for these from astronomers, who wish to assure themselves of the quality of the photographs, will be considered as as far as possible acceded to.

Source: F. W. Dyson, A. S. Eddington, and C. Davidson, "A Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations Made at the Total Eclipse of May 29, 1919"

ps: the positive/normal version can be seen here.

Descent Panorama of Saturn's Titan

Credit: ESA, NASA, Descent Imager/Spectral Radiometer Team (LPL)

You're the first spacecraft ever to descend to Titan -- what do you see? Immediately after the Huygen's probe pierced the cloud deck of Saturn's moon Titan last January, it took a unique series of pictures of one of the Solar System's most mysterious moon's. Those pictures have recently been digitally stitched together to create spectacular panoramas and a dramatic descent movie. Pictured above is a panoramic fisheye view Huygen's obtained from about five kilometers above Titan's surface. The digital projection makes the local surface, mostly flat, appear as a ball, but allows one to see in all directions. Huygen's eventual landing site was in the large dark area below, just right of the center. This relatively featureless, dark, sandy basin appears to be surrounded by light colored hills to the right and a landscape fractured by streambeds and canyons above. Recent evidence indicates that Titan's lakebeds and streambeds are usually dry but sometimes filled with a flashflood of liquid methane from rare torrents of methane rain.

great mountain moonrise

Great Mountain Moonrise

Credit & Copyright: Tunc Tezel

On May 31st, a gorgeous Full Moon rose over Uludag Mountain in Bursa Province, Turkey. This alluring telephoto view of the twilight scene is a composite of images taken roughly every two minutes beginning shortly after Sunset, following the rising Moon as it moves up and to the right. Of course, as the Moon rises it gets brighter and changes color, becoming less reddened as the sight-line through the dense atmosphere is steadily reduced. Each of the final two exposures also captured a rising planet Jupiter. Like the Full Moon, the bright, wandering planet is nearly opposite the Sun in Earth's sky and was caught on the lefthand side of the picture in two places, just above a small peak in the mountain side. Intriguingly, some considered this Full Moon a Blue Moon.