November 1, 2007, 8:29 PM CT

Missing Black Hole Report

Astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away.

The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there were hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance.

"Active, supermassive black holes were everywhere in the early universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself." Dickinson is a co-author of two new papers appearing in the Nov. 10 issue of the Astrophysical Journal. Emanuele Daddi of the Commissariat a l'Energie Atomique in France led the research.

The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores.

For decades, a large population of active black holes has been considered missing. These highly energetic structures belong to a class of black holes called quasars. A quasar consists of a doughnut-shaped cloud of gas and dust that surrounds and feeds a budding supermassive black hole. As the gas and dust are devoured by the black hole, they heat up and shoot out X-rays. Those X-rays can be detected as a general glow in space, but often the quasars themselves can't be seen directly because dust and gas blocks them from our view......... Posted by: Sean      Read more         Source

November 1, 2007, 8:20 PM CT

Mars Express Probes Red Planet's Unusual Deposits

The radar system on the European Space Agency's Mars Express orbiter has uncovered new details about some of the most mysterious deposits on Mars: the Medusae Fossae Formation. It has provided the first direct measurement of the depth and electrical properties of these materials, providing new clues about their origin.

The Medusae Fossae Formation consists of enigmatic deposits. Found near the Martian equator along a divide between highlands and lowlands, they may represent some of the youngest deposits on the surface of the planet. This is implied because there is a marked lack of impact craters dotting these deposits.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages NASA's roles in the Mars Express mission. Mars Express has been collecting data on the Medusae Fossae Formation deposits using its Mars Advanced Radar for Subsurface and Ionospheric Sounding (Marsis). Between March 2006 and April 2007, Mars Express flew over the Medusae Fossae Formation deposits a number of times, taking radar soundings as it went.

"This is the first direct measurement of the depth of these deposits," said Thomas Watters of the Smithsonian Institution, Washington, D.C., lead author of a new report on the findings in the journal Science. "We didn't know whether they were just a thin veneer or much thicker." The radar observations found the Medusae Fossae Formation to be massive deposits more than 2.5 kilometers (1.4 miles) thick in places. The instrument reveals the depth based on the time it takes for the radar beam to pass through the layers and bounce off the plains material underneath......... Posted by: Sean      Read more         Source

November 1, 2007, 8:13 PM CT

A Mighty Duo

Black holes announce the death of a massive star. When such a gas balloon exhausts its hydrogen fuel, it can no longer create any energy. Within seconds, the core of the star collapses under its own weight, while its temperature rises. With the core of the star collapsing in upon itself, a shock wave is generated that speeds outward and sweeps away the outer gas layers. The star flares up as a supernova. What is left is an extremely dense and massive stellar corpse; whose gravitational pull is so strong that even light cannot escape it: a black hole.

Such black holes are frequently part of a binary stellar system: together with another star they orbit around a common centre of gravity. The object M33 X-7 in the galaxy M33, about 3 million light years from Earth, in the constellation Triangulum, has such a companion sun. It orbits around the "monster" mass every three and half days, eclipsing its X-ray emissions. The black hole is located in the centre of a so-called accretion disc, in which gas matter swirls around like water running down the plug hole of a bathtub. As it heats up in the process, it radiates in x-ray wavelengths.

"Based on the length of the eclipse of the x-ray source and the scale of the companion's star motion as inferred from observations, we were able to make precise calculations of the masses of the two components of the binary star system," explains Wolfgang Pietsch from the Max Planck Institute for Extraterrestrial Physics in Garching, near Munich. The astronomers based their observations on data gleaned by NASA's Chandra X-Ray Observatory as well as the Gemini telescope on Mauna Kea in Hawaii. What they discovered in terms of the two cosmic partners' respective masses took them by surprise: the black hole has 15.7 times the mass of our sun, and its companion star is even 70 times heavier than the Sun. This is the mightiest pairing of a black hole and a star that scientists have come across. And they are quite stumped for explanations......... Posted by: Sean      Read more         Source

Fri, 02 Nov 2007 00:53:28 GMT

If We Had No Moon

The Earth has a large moon, making it unique in the inner solar system. The father of the SMART-1 lunar mission, Bernard Foing of the European Space Agency, looks at the effect the Moon has had on the Earth, and explores how different our world would be if we had no planetary companion.

So, would life have evolved differently, or even appeared on
Earth without the Moon? Posted by: Gerard      Read more     Source

October 31, 2007, 7:24 PM CT

Supermassive Black Holes Produce Powerful Galaxy-Shaping Winds

Supermassive black holes can produce powerful winds that shape a galaxy and determine their own growth, confirms a group of researchers from Rochester Institute of Technology.

The RIT team has, for the first time, observed the vertical launch of rotating winds from glowing disks of gas, known as accretion disks, surrounding supermassive black holes in the centers of galaxies. The findings are published in the Nov. 1 issue of Nature.

Gas flowing into a supermassive black hole first accumulates in a rapidly spinning accretion disk, which forms the engine of a quasar, a type of active galactic nucleus found in some galaxies and an extremely powerful source of radiation.

"Gas flowing in from the galaxy 'fuels' the quasar," says Andrew Robinson, associate professor of physics at RIT and an author of the study. "Gas flowing out from the quasar regulates black hole growth and galaxy formation".

The RIT team, consisting of Stuart Young, David Axon and Robinson, together with colleagues James Hough and James Smith from the University of Hertfordshire in England, studied the winds of gas coming off the quasar PG 1700+518, located in a galaxy at a distance of approximately 3 billion light-years from Earth. Robinson and Smith obtained the data using the William Herschel Telescope on the Canary Islands......... Posted by: Sean      Read more         Source

October 28, 2007, 4:10 PM CT

Crew set for first spacewalk

Two astronauts will step out of the International Space Station later today to take part in a six and a half hour spacewalk (Extra Vehicular Activity, EVA) to install the Italian-built Node 2 module, also known as Harmony.

Follow the spacewalk live on NASA TV.

Dressed in American EVA suits, two members of the STS-120 crew, Scott Parazynski and Douglas Wheelock, will start to make their way out of the hatch on the Station's Quest airlock at 12:28 CEST (10:28 UT).

The spacewalkers will be assisted by other crew members inside the ISS. ESA astronaut Paolo Nespoli will act as Intra Vehicular (IV) astronaut, overseeing and coordinating activities. Whilst other crew members will use the Station's robotic arm to lift Harmony out of Space Shuttle Discovery's cargo bay.

The astronauts' main task during the EVA is to attach the Italian-built Node 2 connecting module to a temporary position on the port side of Unity (Node 1). At the end of the STS-120 mission, once Discovery has undocked, the Expedition 16 crew will relocate Harmony to its permanent location at the forward end of the US Destiny lab.

Other tasks during the mission's first spacewalk include the retrieval of an antenna from the Station's Z1 truss for return to Earth, and preparations for the relocation of the P6 truss......... Posted by: Sean      Read more         Source

October 25, 2007, 10:00 PM CT

Hubble spies shells of sparkling stars

New images taken with NASAs Hubble Space Telescope part of a research project led by UC Riversides Gabriela Canalizo have revealed the wild side of an elliptical galaxy, nearly two billion light-years away, that previously had been considered mild-mannered.

The Hubble photos show shells of stars around a bright quasar, known as MC2 1635+119, which dominates the center of the galaxy. The presence of the shells is an indication of a titanic clash with another galaxy in the relatively recent past.

The collision, which is funneling gas into the galaxys center, is feeding a supermassive black hole. The accretion onto the black hole is the quasars energy-source.

This observation supports the idea that some quasars are born from interactions between galaxies, said Canalizo, an assistant professor of astrophysics in the Department of Physics and Astronomy, and a member of the Institute of Geophysics and Planetary Physics. It also provides more evidence that mergers are crucial for triggering quasars. Most quasars were active in the early universe, which was smaller, so galaxies collided more frequently.

Astronomers have long speculated that quasars are fueled by interactions that bring an inflow of gas to the black holes in the centers of galaxies. Since this quasar is relatively nearby, it is a great laboratory for studying how more distant quasars are turned on......... Posted by: Sean      Read more         Source

October 24, 2007, 7:22 PM CT

Ancient Salt Deposits in a Martian Crater

The ancient cratered highlands of the southern hemisphere of Mars has an intriguing and complex history as it has been riddled with impact craters and modified by volcanic processes and by the wind.

Additionally, it is one of the most heavily dissected terrains on Mars exhibiting the densest population of valley networks: old dried up channels and valleys that may have been formed by surface runoff, the seepage of ground water, or both.

Recently, the Thermal Emission Imaging System (THEMIS) aboard Mars Odyssey (MO), in conjunction with spectral data from the Thermal Emission Spectrometer (TES) aboard the Mars Global Surveyor (MGS) have revealed the presence of a unique surface deposit that may be rich in chloride salts formed from the presence of liquid water. Three separate missions (MGS, MO and MRO) have come to reveal the composition and nature of these unique deposits, which, eventhough they occur as relatively small deposits (less than 25 square kilometers) are widely distributed in Noachian (most ancient) terrains with fewer occurrences in the Hesperian (middle geologic time) terrains.

This HiRISE infrared color sub-image (approximately 900 meters wide) shown here is part of one such deposit in an ancient partially buried unnamed crater in Terra Cimmeria, that shows this deposit in a light-toned almost fleshy color. The deposit appears to be relatively thin and occurs in low-lying areas. It is also heavily pockmarked and discontinuous, possibly from removal of the material by erosion. Both of these aspects suggest that the deposit is indeed very old......... Posted by: Sean      Read more         Source

October 23, 2007, 9:05 PM CT

Paolo Nespoli to the International Space Station

Paolo Nespoli set off on his way to the International Space Station earlier this evening on board NASA's Space Shuttle Discovery. Inside the Shuttle's cargo bay is the Node 2 module, the first European-built module to be permanently attached to the Station.

This evening, Space Shuttle Discovery lifted off from NASA's Kennedy Space Center in Cape Canaveral, Florida, at 11:38 local time (17:38 CEST) and successfully entered low Earth orbit after almost 8 minutes of powered flight. On this STS-120 mission, the third Shuttle flight this year, Discovery carries a crew of seven, including ESA astronaut Paolo Nespoli, from Italy.

The first day in space is devoted to a series of inflight inspections to ensure that Discovery did not suffer any damage during launch. The orbiter will then manoeuvre to rendezvous with the International Space Station (ISS). Docking is planned for 25 October at 14:33 CEST.

The purpose of the 14-day STS-120 mission is to deliver and install the Italian-built Node 2 module - the first addition to the Station's work and living space for six years. A second main task is to relocate the ISS P6 truss section and deploy its solar arrays and heat dispersal radiator.

The mission will also see the rotation of one of the ISS Expedition crew members. NASA astronaut Clayton Anderson, who has been a resident on the Station since arriving with the crew of STS-117 last June, will be replaced by NASA astronaut Daniel Tani......... Posted by: Sean      Read more         Source

October 22, 2007, 8:30 PM CT

Successful Ariane 5 upper stage engine re-ignition

A successful re-ignition of the Ariane 5 upper stage engine performed during the most recent mission has consolidated Ariane 5's readiness for the launch of the Jules Verne Automated Transfer Vehicle.

The launch of ESA's Automated Transfer Vehicle (ATV), which carries supplies to the International Space Station, will require multiple firings of the Ariane 5 ES upper stage engine. In this context, hundreds of re-ignition tests under various thermal conditions have been undertaken at the DLR Test Centre in Lampoldshausen to qualify the Aestus engine for several re-ignitions.

In order to consolidate this on ground qualification a re-ignition experiment waccording toformed during the last Ariane-5 launch - on the evening of 5 October - when an Ariane 5 GS launcher lifted off from Europe's Spaceport in French Guiana carrying two commercial telecommunications satellites into geostationary transfer orbit.

Once the commercial payloads were safely on their way, a successful experimental re-ignition of the Aestus engine took place - 54 minutes after the release of the second payload. The experiment was done to validate operational conditions (mainly temperatures and pressures) and procedures (propellant settling in tanks) of the launcher upper stage, which will be applied during the ATV orbital injection mission. It also verified the behaviour of the composite during the re-ignition phase......... Posted by: Sean      Read more         Source