Dark Flow

Dark flow is an astrophysical term describing a peculiar velocity of galaxy clusters. The actual measured velocity is the sum of the velocity predicted by Hubble's Law plus a small and unexplained (or dark) velocity flowing in a common direction.

According to standard cosmological models, the motion of galaxy clusters with respect to the cosmic microwave background should be randomly distributed in all directions. However, analyzing the three-year WMAP data using the kinematic Sunyaev-Zel'dovich effect, the authors of the study found evidence of a "surprisingly coherent" 600–1000 km/s flow of clusters toward a 20-degree patch of sky between the constellations of Centaurus and Vela.

The authors (Alexander Kashlinsky, F. Atrio-Barandela, D. Kocevski, and H. Ebeling) suggest that the motion may be a remnant of the influence of no-longer-visible regions of the universe prior to inflation. Telescopes cannot see events earlier than about 380,000 years after the big bang, when the universe became transparent (the Cosmic Microwave Background); this corresponds to the particle horizon at a distance of about 46 billion (4.6×10^10) light years. Since the matter causing the net motion in this proposal is outside this range, it would in a certain sense be outside our visible universe; however, it would still be in our past light cone.

The results appeared in the October 20, 2008, issue of Astrophysical Journal Letters. Since then, the authors have extended their analysis to additional clusters and the recently released WMAP five-year data.

Location

The dark flow was determined to be flowing in the direction of the Centaurus and Hydra constellations. This corresponds with the direction of the Great Attractor, which was a previous gravitational mystery originally discovered in 1973. However, the source of the Great Attractor's attraction was thought to originate from a massive cluster of galaxies called the Norma cluster, situated merely between 150-250 million light-years away. This may reveal that the source of that attraction might lie even further away, and which the Great Attractor itself is heading towards.

In a study from March 2010, Kashlinsky extended his work from 2008, by using the 5-year WMAP results rather than the 3-year results, and doubling the number of galaxy clusters observed from 700. The team also sorted the cluster catalog into four "slices" representing different distance ranges. They then examined the preferred flow direction for the clusters within each slice. While the size and exact position of this direction display some variation, the overall trends among the slices exhibit remarkable agreement. "We detect motion along this axis, but right now our data cannot state as strongly as we'd like whether the clusters are coming or going," Kashlinsky said.

The team has so far catalogued the effect as far out as 2.5 billion light-years, and hope to expand their catalog out further still to twice the current distance.


Panoramic view of galaxies beyond Milky Way, with Norma cluster & Great Attractor shown by a long blue arrow at the bottom-right in image near the disk of the Milky Way.

NASA's Goddard Space Center confirmed this could be the effects of a sibling universe or a region of space-time fundamentally different from the observable universe. Data on more than 1,000 galaxy clusters have been measured, including some as distant as 3 billion light-years. Alexander Kashlinsky claims these measurements show the universe's steady flow is clearly not a statistical fluke. Said Kashlinsky: "At this point we don't have enough information to see what it is, or to constrain it. We can only say with certainty that somewhere very far away the world is very different than what we see locally. Whether it's 'another universe' or a different fabric of space-time we don't know."

Sloan Great Wall

The Sloan Great Wall is a giant wall of galaxies (a galactic filament) and to the present day is the largest known structure in the universe. Its discovery was announced on October 20, 2003 by J. Richard Gott III of Princeton University and Mario Jurić and their colleagues, based on data from the Sloan Digital Sky Survey.

The wall measures 1.37 billion light years (1.30×1025 m) in length, which is approximately 1/60 of the diameter of the observable universe, and is located approximately one billion light-years from Earth.

The Sloan Great Wall, classified as the supercluster SCl 126 in SIMBAD, is nearly three times longer than the CfA2 Great Wall of galaxies, the previous record-holder, which was discovered by Margaret Geller and John Huchra of Harvard in 1989.

Axial Precession

In astronomy, axial precession is a gravity-induced, slow and continuous change in the orientation of an astronomical body's rotational axis. In particular, it refers to the gradual shift in the orientation of Earth's axis of rotation, which, like a wobbling top, traces out a cone in a cycle of approximately 26,000 years (called a Great or Platonic Year in astrology). The term "precession" typically refers only to this largest secular motion; other changes in the alignment of Earth's axis — nutation and polar motion — are much smaller in magnitude.

Earth's precession was historically called precession of the equinoxes because the equinoxes moved westward along the ecliptic relative to the fixed stars, opposite to the motion of the Sun along the ecliptic. This term is still used in non-technical discussions, that is, when detailed mathematics are absent. Historically, Hipparchus is credited with discovering precession of the equinoxes. The exact dates of his life are not known, but astronomical observations attributed to him by Ptolemy date from 147 BC to 127 BC.

With improvements in the ability to calculate the gravitational force between planets during the first half of the 19th century, it was recognized that the ecliptic itself moved slightly, which was named planetary precession as early as 1863, while the dominant component was named lunisolar precession. Their combination was named general precession instead of precession of the equinoxes. Lunisolar precession is caused by the gravitational forces of the Moon and Sun on Earth's equatorial bulge, causing Earth's axis to move with respect to inertial space. Planetary precession (actually an advance) is due to the small angle between the gravitational force of the other planets on Earth and its orbital plane (the ecliptic), causing the plane of the ecliptic to shift slightly relative to inertial space. Lunisolar precession is about 500 times larger than planetary precession. In addition to the Moon and Sun, the other planets also cause a small movement of Earth's axis in inertial space, making the contrast in the terms lunisolar versus planetary misleading, so in 2006 the International Astronomical Union recommended that the dominant component be renamed the precession of the equator and the minor component be renamed precession of the ecliptic, but their combination is still named general precession.

Effects

The precession of the Earth's axis has a number of observable effects. First, the positions of the south and north celestial poles appear to move in circles against the space-fixed backdrop of stars, completing one circuit in 25,771.5 years (2000 rate). Thus, while today the star Polaris lies approximately at the north celestial pole, this will change over time, and other stars will become the "north star". As the celestial poles shift, there is a corresponding gradual shift in the apparent orientation of the whole star field, as viewed from a particular position on Earth.

Secondly, the position of the Earth in its orbit around the Sun at the solstices, equinoxes, or other time defined relative to the seasons, slowly changes. For example, suppose that the Earth's orbital position is marked at the summer solstice, when the Earth's axial tilt is pointing directly towards the Sun. One full orbit later, when the Sun has returned to the same apparent position relative to the background stars, the Earth's axial tilt is not now directly towards the Sun: because of the effects of precession, it is a little way "beyond" this. In other words, the solstice occurred a little earlier in the orbit. Thus, the tropical year, measuring the cycle of seasons (for example, the time from solstice to solstice, or equinox to equinox), is about 20 minutes shorter than the sidereal year, which is measured by the Sun's apparent position relative to the stars. Note that 20 minutes per year is approximately equivalent to one year per 25,771.5 years, so after one full cycle of 25,771.5 years the positions of the seasons relative to the orbit are "back where they started". (In actuality, other effects also slowly change the shape and orientation of the Earth's orbit, and these, in combination with precession, create various cycles of differing periods; see also Milankovitch cycles. The magnitude of the Earth's tilt, as opposed to merely its orientation, also changes slowly over time, but this effect is not attributed directly to precession.)

For identical reasons, the apparent position of the Sun relative to the backdrop of the stars at some seasonally fixed time, say the vernal equinox, slowly regresses a full 360° through all twelve traditional constellations of the zodiac, at the rate of about 50.3 seconds of arc per year (approximately 360 degrees divided by 25,771.5), or 1 degree every 71.6 years.

GFAJ-1

GFAJ-1 is a strain of rod-shaped bacterium in the family Halomonadaceae. The extremophile was isolated from the hypersaline and alkaline Mono Lake in eastern California, and reported as new to science by a research team led by NASA astrobiologist Felisa Wolfe-Simon in a 2010 Science journal publication. According to the authors, the microbe, when starved of phosphorus, is capable of substituting arsenic for a small percentage of its phosphorus and sustain its growth. Immediately after publication, other microbiologists and biochemists expressed doubt about this hypothesis, and the claim that this bacterium uses arsenic instead of phosphorus in its metabolism is robustly debated in the scientific community.



The GFAJ-1 bacterium was discovered by geomicrobiologist Felisa Wolfe-Simon, a NASA astrobiology fellow in residence at the US Geological Survey in Menlo Park, California. GFAJ stands for "Give Felisa a Job". The organism was isolated and cultured beginning in 2009 from samples she and her colleagues collected from sediments at the bottom of Mono Lake, California, U.S.A. Mono Lake is hypersaline (about 90 grams/liter) and highly alkaline (pH 9.8). It also has one of the highest natural concentrations of arsenic in the world (200 μM). The discovery was widely publicized on 2 December 2010.



Biochemistry

A phosphorus-free growth medium (which actually contained 3.1 ± 0.3 μM of residual phosphate, from impurities in reagents) was used to culture the bacteria in a regime of increasing exposure to arsenate; the initial level of 0.1 mM was eventually ramped up to 40 mM. Alternative media used for comparative experiments contained either high levels of phosphate (1.5 mM) with no arsenate, or had neither added phosphate nor added arsenate. It was observed that GFAJ-1 could grow through many doublings in cell numbers when cultured in either phosphate or arsenate media, but could not grow when placed in a medium of a similar composition to which neither phosphate nor arsenate was added. The phosphorus content of the arsenic-fed, phosphorus-starved bacteria (as measured by ICP-MS) was only 0.019 (± 0.001) % by dry weight, one thirtieth of that when grown in phosphate, and about one hundredth that of most bacteria. This phosphorus content was also only about one tenth of the cells' arsenic content (0.19 ± 0.25 % by dry weight). Other data from the same study obtained with nano-SIMS does however suggest a ~75-fold excess of phosphate (P) over arsenic (As) when expressed as P:C and As:C ratios, even in cells grown with arsenate and no added phosphate. When cultured in the arsenate solution, GFAJ-1 only grew 60% as fast as it did in phosphate solution. The phosphate-starved bacteria had an intracellular volume 1.5 times normal; the greater volume appeared to be associated with the appearance of large "vacuole-like regions".

When the researchers added isotope-labeled arsenate to the solution to track its distribution, they found that arsenic was present in the cellular fractions containing the bacteria's proteins, lipids and metabolites such as ATP, as well as its DNA and RNA. Nucleic acids from stationary phase cells starved of phosphorus were concentrated via five extractions (one with phenol, three with phenol-chloroform and one with chloroform extraction solvent), followed by ethanol precipitation. Although direct evidence of the incorporation of arsenic into biomolecules is still lacking, radioactivity measurements suggested that approximately one-tenth (11.0 ± 0.1 %) of the arsenic absorbed by these bacteria ended up in the fraction that contained the nucleic acids (DNA and RNA) and all other co-precipitated compounds not extracted by the previous treatments. A comparable control experiment with isotope-labeled phosphate was not performed.

Eris

Eris, formal designation 136199 Eris, is the largest known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly. It is approximately 2,500 kilometres in diameter and 27% more massive than Pluto.

Eris was first identified in January 2005 by a Palomar Observatory-based team led by Mike Brown, and its identity verified later that year. It is a trans-Neptunian object (TNO) native to a region of space beyond the Kuiper belt known as the scattered disc. Eris has one moon, Dysnomia; recent observations have found no evidence of further satellites. The current distance from the Sun is 96.7 AU, roughly three times that of Pluto. With the exception of some comets the pair are the most distant known natural objects in the Solar System.

Because Eris is larger than Pluto, its discoverers and NASA initially described it as the Solar System’s tenth planet. This, along with the prospect of other similarly sized objects being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet for the first time. Under a then-new IAU definition approved on August 24, 2006, Eris is a "dwarf planet" along with Pluto, Ceres, Haumea and Makemake.

Eris is named after the Greek goddess Eris, a personification of strife and discord. The name was assigned on September 13, 2006 following an unusually long period in which it was known by the provisional designation 2003 UB313, which was granted automatically by the IAU under their naming protocols for minor planets. The regular adjectival form of Eris is Eridian.

Orbit



Eris has an orbital period of 557 years, and as of 2009 lies at 96.7 astronomical units from the Sun, almost its maximum possible distance. (Its aphelion is 97.5 AU.) Eris came to perihelion between 1698 and 1699, to aphelion around 1977, and will return to perihelion around 2256[34] to 2258. Eris and its moon are currently the most distant known objects in the Solar System apart from long-period comets and space probes. However, approximately forty known TNOs, most notably 2000 OO67 and Sedna, while currently closer to the Sun than Eris, have greater average orbital distances than Eris' semimajor axis of 67.7 AU.

The Eridian orbit is highly eccentric, and brings Eris to within 37.9 AU of the Sun, a typical perihelion for scattered objects. This is within the orbit of Pluto, but still safe from direct interaction with Neptune (29.8–30.4 AU). Pluto, on the other hand, like other plutinos, follows a less inclined and less eccentric orbit and, protected by orbital resonance, can cross Neptune’s orbit. (It is possible that Eris is in a 17:5 resonance with Neptune, though further observations will be required to know for sure.[37]) Unlike the eight planets, whose orbits all lie roughly in the same plane as the Earth's, Eris' orbit is highly inclined: It is tilted at an angle of about 44 degrees to the ecliptic. In about 800 years, Eris will be closer to the Sun than Pluto for some time.

Eris currently has an apparent magnitude of 18.7, making it bright enough to be detectable to some amateur telescopes. A 200 mm telescope with a CCD can detect Eris under favorable conditions. The reason it had not been noticed until now is because of its steep orbital inclination; most searches for large outer Solar System objects concentrate on the ecliptic plane, where most bodies are found.

Eris is now in the constellation Cetus. It was in Sculptor from 1876 until 1929 and Phoenix from roughly 1840 until 1875. In 2036 it will enter Pisces and stay there until 2065, when it will enter Aries. It will then move into the northern sky, entering Perseus in 2128 and Camelopardalis (where it will reach its northernmost declination) in 2173. Because the orbit of Eris is highly inclined, it only passes through a few constellations of the traditional Zodiac.

Size, mass, and density

The diameter of Eris has been measured to be 2,397 km, give or take 100 km, using images from the Hubble Space Telescope (HST).[38][39] The size of an object depends on its absolute magnitude and the albedo (the amount of light it reflects). At a distance of 97 AU, an object with a radius of 3,000 km would have an angular size of 40 milliarcseconds, which is directly measurable with the HST; although resolving such small objects is at the very limit of Hubble's capabilities, sophisticated image processing techniques such as deconvolution can be used to measure such angular sizes fairly accurately.)

This makes Eris only 0-8% larger than Pluto, which is about 2,306 km across. It also indicates an albedo of 0.86, higher than any other large body in the Solar System other than Enceladus. It is speculated that the high albedo is due to the surface ices being replenished due to temperature fluctuations as Eris' eccentric orbit takes it closer and farther from the Sun.

In 2007, a series of observations of the largest trans-Neptunian objects with the Spitzer Space Telescope gave an estimate of Eris's diameter of 2,600 (+400; -200) km.[8] The Spitzer and Hubble estimates overlap in the range of 2,400-2,500 km, 4-8% larger than Pluto.

The mass of Eris can be calculated with much greater precision. Based on the currently accepted value for Dysnomia's period, 15.774 days, Eris is 27 percent more massive than Pluto.

Phoenix

MRO (Mars Reconnaissance Orbiter) imaged Phoenix suspended from its parachute during descent through the Martian atmosphere.

phoenix.lpl.arizona.edu



Phoenix is a robotic spacecraft on a space exploration mission on Mars under the Mars Scout Program. The scientists conducting the mission are using instruments aboard the Phoenix lander to search for environments suitable for microbial life on Mars, and to research the history of water there. The multi-agency program is headed by the Lunar and Planetary Laboratory at the University of Arizona, under the direction of NASA's Jet Propulsion Laboratory. The program is a partnership of universities in the United States, Canada, Switzerland, Denmark, Germany, the United Kingdom, NASA, the Canadian Space Agency, the Finnish Meteorological Institute, Lockheed Martin Space Systems, MacDonald Dettwiler & Associates (MDA) and other aerospace companies.



Phoenix is the sixth successful landing on Mars, out of twelve total attempts (seven of which were American). It is the third successful static lander and the first since Viking 2, and as of 2008 the most recent spacecraft to land successfully on Mars. It is also the first successful landing on a polar region of Mars.

F-8 Crusader

The F-8 Crusader (originally F8U) was a single-engine aircraft carrier-based fighter aircraft built by Chance-Vought of Dallas, Texas, USA. It replaced the Vought F-7 Cutlass. The first F-8 prototype was ready for flight in February 1955, and was the last American fighter with guns as the primary weapon. The RF-8 Crusader was a photo-reconnaissance development and operated longer in U.S. service than any of the fighter versions. RF-8s played a crucial role in the Cuban Missile Crisis, providing essential low-level photographs impossible to acquire by other means. Naval Reserve units continued to operate the RF-8 until 1987.

In September 1952, United States Navy announced a requirement for a new fighter. It was to have a top speed of Mach 1.2 at 30,000 ft (9,150 m) with a climb rate of 25,000 ft/min (127 m/s), and a landing speed of no more than 100 mph (160 km/h). Korean War experience had demonstrated that 0.50 in (12.7 mm) machine guns were no longer sufficient and as the result the new fighter was to carry a 20 mm (0.8 in) cannon. In response, the Vought team led by John Russell Clark created the V-383. Unusual for a fighter, the aircraft had a high-mounted wing which allowed for short and light landing gear.


NASA's F-8C digital fly-by-wire testbed.

The most innovative aspect of the design was the variable-incidence wing which pivoted by 7° out of the fuselage on takeoff and landing. This afforded increased lift due to a greater angle of attack without compromising forward visibility because the fuselage stayed level. Simultaneously, the lift was augmented by leading-edge slats drooping by 25° and inboard flaps extending to 30°. The rest of the aircraft took advantage of contemporary aerodynamic innovations with area ruled fuselage, all-moving stabilators, dog-tooth notching at the wing folds for improved yaw stability, and liberal use of titanium in the airframe. Power came from the Pratt & Whitney J57 afterburning turbojet and the armament, as specified by the Navy, consisted of four 20 mm cannon, a retractable tray with 32 unguided Mighty Mouse FFARs, and cheek pylons for two AIM-9 Sidewinder air-to-air missiles. Vought also presented a tactical reconnaissance version of the aircraft called the V-382. The F-8 Crusader would be the last U.S. fighter designed with guns as its primary weapon.

Major competition came from Grumman with the F-11 Tiger, McDonnell with upgraded twin-engine F3H Demon (which would eventually become the F-4 Phantom II), and North American with their F-100 Super Sabre adopted for carrier use and dubbed the Super Fury.

In May 1953, the Vought design was declared a winner and in June, Vought received an order for three XF8U-1 prototypes (after adoption of the unified designation system in September 1962, the F8U became the F-8). The first prototype flew on 25 March 1955 with John Konrad at the controls. The aircraft exceeded the speed of sound during its maiden flight. The development was so trouble-free that the second prototype, along with the first production F8U-1, flew on the same day, 30 September 1955. On 4 April 1956, the F8U-1 performed its first catapult launch from USS Forrestal.

Project Constellation

NASA Project Constellation

Project Constellation is a NASA program to create a new generation of spacecraft for human spaceflight, consisting primarily of the Ares I and Ares V launch vehicles, the Orion crew capsule, the Earth Departure Stage and the Altair lunar lander. These spacecraft will be capable of performing a variety of missions, from Space Station resupply to lunar landings.

Most of the Constellation hardware is based on systems originally developed for the Space Shuttle, although Orion's two-part crew and service module system is heavily influenced by the earlier Apollo Spacecraft, and it uses engines derived from the Saturn V and Delta IV rockets. Proposed Constellation missions may employ both Earth Orbit Rendezvous and Lunar Orbit Rendezvous techniques.

Constellation Program

NASA has formed the Constellation Program to achieve the objectives of maintaining American presence in low Earth orbit, returning to the Moon for purposes of establishing an outpost, and laying the foundation to explore Mars and beyond in the first half of the 21st century. The Constellation Program's heritage rests on the successes and lessons learned from NASA’s previous human spaceflight programs: Mercury, Gemini, Apollo, Space Shuttle and the International Space Station (ISS).

Spacecraft

Orion will consist of two main parts, a Crew Module (CM) similar to the Apollo Command Module capable of holding four to six crew members, and a cylindrical Service Module (SM) containing the primary propulsion systems and consumable supplies. The Orion CM will be reusable for up to 10 flights, allowing NASA to construct a fleet of Orion CMs.

Current plans call for the phased introduction of Orion variants tailored for specific missions. The Block I Orion will be employed for ISS crew rotation and resupply and other Earth orbit missions, while the Block II and III variants will be designed for deep-space exploration.

Launch vehicles

As currently envisioned, the Orion spacecraft will be launched into a low earth orbit using the proposed Ares I rocket (the "Stick"). Formerly referred to as the Crew Launch Vehicle (CLV), the Ares I consists of a single Solid Rocket Booster (SRB) derived from the boosters used in the Space Shuttle system, connected at its upper end by an interstage support assembly to a new liquid-fueled second stage powered by an uprated Apollo-era J-2X rocket engine. The Orion spacecraft would be lifted into orbit atop this "stack", while a larger launch vehicle (the proposed Ares V) would be used to launch the heavier Earth Departure Stage and Altair.

In January 2007, NASA announced that a different launch vehicle design, the Ares IV, was actively under consideration for the program. If chosen, the Ares IV might replace both the Ares I and the Ares V launch vehicles for some Constellation launches at later dates, or all of them altogether.

Douglas Skyrocket D-558-2

NASA Dryden Douglas Skyrocket

The Douglas Skyrocket (the D-558-2; also found, D-558-II) was a rocket and jet-powered research aircraft built by the Douglas Aircraft Company for the U.S. Navy. On November 20, 1953, shortly before the 50th anniversary of powered flight, Scott Crossfield piloted the Douglas D-558-2 Skyrocket to Mach 2, or more than 2076 km/h, the first time an aircraft had exceeded twice the speed of sound.

All three of the Skyrockets had 35-degree swept wings.

Until configured for air launch, NACA 143 featured a Westinghouse J-34-40 turbojet engine rated at 3,000 pounds force (13 kN) static thrust. It carried 260 US gallons (980 L) of aviation gasoline and weighed 10,572 pounds (4,795 kg) at take-off.

NACA 144 (and NACA 143 after modification in 1955) was powered by an LR-8-RM-6 rocket engine rated at 6,000 pounds force (27 kN) static thrust. Its propellants were 345 US gallons (1,306 L) of liquid oxygen and 378 US gallons (1,431 L) of diluted ethyl alcohol. In its launch configuration, it weighed 15,787 pounds (7,161 kg).

NACA 145 had both an LR-8-RM-5 rocket engine rated at 6,000 pounds force (27 kN) static thrust and featured a Westinghouse J-34-40 turbojet engine rated at 3,000 pounds force (13 kN) static thrust. It carried 170 US gallons (644 L) of liquid oxygen, 192 US gallons (727 L) of diluted ethyl alcohol, and 260 US gallons (984 L) of aviation gasoline for a launch weight of 15,266 pounds (6,925 kg).

[edit] Aircraft serial numbers

* D-558-2 Skyrocket
o D-558-2 #1 - #37973 NACA-143, 123 flights
o D-558-2 #2 - #37974 NACA-144, 103 flights
o D-558-2 #3 - #37975 NACA-145, 87 flights

* Maximum speed: 720 mph, 1,250 mph when air-launched (1,160 km/h, 2,010 km/h when air-launched)
* Stall speed: 160.1 mph (257.7 km/h)
* Service ceiling: 16,500 ft (5,030 m)
* Rate of climb: 22,400 ft/min, 11,100 ft/min under rocket power only (6,830 m/min., 3,380 m/min under rocket power only)
* Wing loading: 87.2 lb/ft² (426 kg/m²)
* Thrust/weight (jet): 0.39

Charon

Charon NASA

Charon discovered in 1978, is, depending on the definition employed, either the largest moon of Pluto or one member of a double dwarf planet with Pluto being the other member. With the discovery in 2005 of two other moons of Pluto (Nix and Hydra), Charon is now also referred to as Pluto I. The New Horizons mission is scheduled to visit Charon and Pluto in July 2015.


Distant Pluto and Charon (Hubble Space Telescope)

Charon appears to be covered by water ice, which differs from Pluto's surface of frozen nitrogen, methane, and carbon dioxide. One theory is that the materials that formed Charon were blasted out of Pluto in a collision. That's very similar to the way in which our own moon is thought to have been created.

Chandra X-ray Observatory

Chandra X-ray Observatory

NASA's Chandra X-ray Observatory, which was launched and deployed by Space Shuttle Columbia on July 23, 1999, is the most sophisticated X-ray observatory built to date.


M87 Core; about 50 million light years

The Instruments:

The Science Instrument Module (SIM) holds the two focal plane instruments, the Advanced CCD Imaging Spectrometer (ACIS) and the High Resolution Camera (HRC), moving whichever is called for into position during an observation.

ACIS consists of 10 CCD chips and provides images as well as spectral information of the object observed. It operates in the range of 0.2 - 10 keV. HRC has two micro-channel plate components and images over the range of 0.1 - 10 keV. It also has a time resolution of 16 microseconds. Both of these instruments can be used on their own or in conjunction with one of the observatory's two transmission gratings.

The transmission gratings, which swing into the optical path behind the mirrors, provide Chandra with high resolution spectroscopy. The High Energy Transmission Grating Spectrometer (HETGS) works over 0.4 - 10 keV and has a spectral resolution of 60-1000. The Low Energy Transmission Grating Spectrometer (LETGS) has a range of 0.09 - 3 keV and a resolution of 40-2000.


G292.0+1.8; about 20,000 light years; 142 hours of observation

Latest Discoveries:

# X-ray emissions from materials falling from a protoplanetary disc into a star.
# Hubble constant measured to be 76.9 km/s/Mpc using Sunyaev-Zel'dovich effect.
# 2006 Chandra found strong evidence that dark matter exists by observing supercluster collision
# 2006 X-ray emitting loops, rings and filaments discovered around a supermassive black hole within Messier 87 imply the presence of pressure waves, shock waves and sound waves. The evolution of Messier 87 may have been dramatically affected.
# Observations of the Bullet cluster put limits on the cross-section of the self-interaction of dark matter.

Triton

Nasa : Neptune : Triton

Triton is the largest moon of Neptune, with a diameter of 2,700 kilometers (1,680 miles). It was discovered by William Lassell, a British astronomer, in 1846 scarcely a month after Neptune was discovered. Triton is colder than any other measured object in the Solar System with a surface temperature of -235° C (-391° F). It has an extremely thin atmosphere. Nitrogen ice particles might form thin clouds a few kilometers above the surface. The atmospheric pressure at Triton's surface is about 14 microbars, 1/70,000th the surface pressure on Earth.



Triton is the only large satellite in the solar system to circle a planet in a retrograde direction - in a direction opposite to the rotation of the planet. It also has a density of about 2.066 grams per cubic centimeter. This means Triton contains more rock in its interior than the icy satellites of Saturn and Uranus do. The relatively high density and the retrograde orbit has led some scientists to suggest that Triton may have been captured by Neptune as it traveled through space several billion years ago. If that is the case, tidal heating could have melted Triton in its originally eccentric orbit, and the satellite might even have been liquid for as long as one billion years after its capture by Neptune.



It is one of only three objects in the Solar System known to have a nitrogen-dominated atmosphere (the others are Earth and Saturn's giant moon, Titan). Triton has the coldest surface known anywhere in the Solar System (38 K, about -391° Farenheit); it is so cold that most of Triton's nitrogen is condensed as frost, making it the only satellite in the Solar System known to have a surface made mainly of nitrogen ice. The pinkish deposits constitute a vast south polar cap believed to contain methane ice, which would have reacted under sunlight to form pink or red compounds. The dark streaks overlying these pink ices are believed to be an icy and perhaps carbonaceous dust deposited from huge geyser-like plumes, some of which were found to be active during the Voyager 2 flyby. The bluish-green band visible in this image extends all the way around Triton near the equator; it may consist of relatively fresh nitrogen frost deposits. The greenish areas includes what is called the cataloupe terrain, whose origin is unknown, and a set of 'cryovolcanic' landscapes apparently produced by icy-cold liquids (now frozen) erupted from Triton's interior.



Neptune and Triton three days after the flyby of Voyager 2.

MESSENGER (NASA)

MESSENGER NASA Official

The MErcury Surface, Space ENvironment, GEochemistry and Ranging (or MESSENGER for short) is a NASA mission, launched August 3, 2004, designed to study the characteristics and environment of Mercury from orbit. Specifically, the scientific objectives of the mission are to characterize the chemical composition of Mercury's surface, the geologic history, the nature of the magnetic field, the size and state of the core, the volatile inventory at the poles, and the nature of Mercury's exosphere and magnetosphere over a nominal orbital mission of one Earth year. The mission will be the first to return to Mercury in over 35 years — the only previous probe to visit Mercury was Mariner 10, which completed its mission in March, 1975. MESSENGER will offer several vast improvements in scanning ability, with cameras that can resolve surface features down to just 60 feet across (18 meters) compared to the one mile (1.61 kilometer) resolution offered by Mariner 10. MESSENGER will also be the first probe to image the entire planet; Mariner 10 was only able to observe one hemisphere that was lit during its flybys.



In addition to being an acronym, MESSENGER was chosen as the probe's name because Mercury was the messenger of the gods in Roman mythology.

Solar System Simulator

Solar System Simulator



See where the planets, spacecrafts are...

Io and Jupiter

Here Io is seen just passing in front of Jupiter, as seen from the Galileo spacecraft on the day of its arrival at Jupiter. Galileo has since flown by the other three Galilean satellites of Jupiter (Europa, Ganymede, and Callisto) during its orbital tour of the Jovian system.

Voyager - NASA

NASA Voyager

NASA's two venerable Voyager spacecraft are celebrating three decades of flight as they head toward interstellar space. Their ongoing odysseys mark an unprecedented and historic accomplishment.

Voyager 2 launched on Aug. 20, 1977, and Voyager 1 launched on Sept. 5, 1977. They continue to return information from distances more than three times farther away than Pluto.

The Voyagers call home via NASA's Deep Space Network, a system of antennas around the world. The spacecraft are so distant that commands from Earth, traveling at light speed, take 14 hours one-way to reach Voyager 1 and 12 hours to reach Voyager 2. Each Voyager logs approximately 1 million miles per day.

Each of the Voyagers carries a golden record that is a time capsule with greetings, images and sounds from Earth. The records also have directions on how to find Earth if the spacecraft is recovered by something or someone.

wikisky.org

wikisky.org

WIKISKY.ORG is an interactive information-management system which encompasses the entire outer space. The basic element of the system is a detailed map of the whole star sky that mirrors more than half a billion celestial objects. No additional instructions are necessary to browse the map or change its scale. The process is very easy. By using the smallest scale, the user can view the whole star sky at once. Using the largest scale, the user can view tiny areas with the most distant and weakest sky objects.

GRIN: Great Images In NASA

GRIN

GRIN is a collection of over a thousand images of significant historical interest scanned at high-resolution in several sizes. This collection is intended for the media, publishers, and the general public looking for high-quality photographs.

(The picture: HL-10 on Lakebed with B-52 flyby 1969)

Phoenix Spacecraft: Next Stop, Mars

Phoenix Spacecraft


A new space explorer is waiting in the wings and ready to take center stage: the Mars lander called Phoenix. Set for launch aboard a Delta II rocket, Phoenix's assignment is to dig through the Martian soil and ice in the arctic region and use its onboard scientific instruments to analyze the samples it retrieves.

Both rocket and spacecraft are undergoing final preparation at NASA's Kennedy Space Center in Florida.

Launch:
Date: Aug. 3
Time: 5:35 a.m. EDT