Progress M-16M completed flight

ROSCOSMOS - Russian Vehicles patch.

09/02/2013

 

 Progress M-16M undocking from ISS

9 February at 21:05 MSK (Moscow time) in a predetermined area of ​​the South Pacific was flooding incombustible residue cargo vehicle (THC) Progress M-16M.

 Russian Cargo Ship Departs from ISS

At 20:19 MSK in accordance with the program laid down in the ship's on-board computer specialists Mission Control Center (MCC) FSUE TsNIImash, the "space truck" was added to the main engine braking, followed by the controlled reduction of the THC from orbit.

Progress M reentry profile

THC Progress M-16M was launched to the International Space Station from the Baikonur Cosmodrome August 1, 2012, to deliver the cargo of food, fuel, water and equipment.

Progress M plasma during the reentry in hi-atmosphere, seen by ISS crew

Original text in Russian: http://www.federalspace.ru/main.php?id=2&nid=19883

Images, Video, Text, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / NASA / NASA TV / Roscosmos TV / G. De Chiara / Translation: Orbiter.ch Aerospace.

Cheers, Orbiter.ch

NASA Curiosity Rover Collects First Martian Bedrock Sample

NASA - Mars Science Laboratory (MSL) patch.

Feb. 9, 2013

Image above: At the center of this image from NASA's Curiosity rover is the hole in a rock called "John Klein" where the rover conducted its first sample drilling on Mars. Image credit: NASA/JPL-Caltech/MSSS.

NASA's Curiosity rover has, for the first time, used a drill carried at the end of its robotic arm to bore into a flat, veiny rock on Mars and collect a sample from its interior. This is the first time any robot has drilled into a rock to collect a sample on Mars.

The fresh hole, about 0.63 inch (1.6 centimeters) wide and 2.5 inches (6.4 centimeters) deep in a patch of fine-grained sedimentary bedrock, can be seen in images and other data Curiosity beamed to Earth Saturday. The rock is believed to hold evidence about long-gone wet environments. In pursuit of that evidence, the rover will use its laboratory instruments to analyze rock powder collected by the drill.

Animation above: An animated set of three images from NASA's Curiosity rover shows the rover's drill in action on Feb. 8, 2013, or Sol 182, Curiosity's 182nd Martian day of operations. Image credit: NASA/JPL-Caltech/MSSS.

"The most advanced planetary robot ever designed is now a fully operating analytical laboratory on Mars," said John Grunsfeld, NASA associate administrator for the agency's Science Mission Directorate. "This is the biggest milestone accomplishment for the Curiosity team since the sky-crane landing last August, another proud day for America."

For the next several days, ground controllers will command the rover's arm to carry out a series of steps to process the sample, ultimately delivering portions to the instruments inside.

"We commanded the first full-depth drilling, and we believe we have collected sufficient material from the rock to meet our objectives of hardware cleaning and sample drop-off," said Avi Okon, drill cognizant engineer at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Rock powder generated during drilling travels up flutes on the bit. The bit assembly has chambers to hold the powder until it can be transferred to the sample-handling mechanisms of the rover's Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) device.

Before the rock powder is analyzed, some will be used to scour traces of material that may have been deposited onto the hardware while the rover was still on Earth, despite thorough cleaning before launch.

"We'll take the powder we acquired and swish it around to scrub the internal surfaces of the drill bit assembly," said JPL's Scott McCloskey, drill systems engineer. "Then we'll use the arm to transfer the powder out of the drill into the scoop, which will be our first chance to see the acquired sample."

Image above: NASA's Mars rover Curiosity used its Mast Camera (Mastcam) to take the images combined into this mosaic of the drill area, called "John Klein." Image credit: NASA/JPL-Caltech/MSSS.

 "Building a tool to interact forcefully with unpredictable rocks on Mars required an ambitious development and testing program," said JPL's Louise Jandura, chief engineer for Curiosity's sample system. "To get to the point of making this hole in a rock on Mars, we made eight drills and bored more than 1,200 holes in 20 types of rock on Earth."

Inside the sample-handling device, the powder will be vibrated once or twice over a sieve that screens out any particles larger than six-thousandths of an inch (150 microns) across. Small portions of the sieved sample will fall through ports on the rover deck into the Chemistry and Mineralogy (CheMin) instrument and the Sample Analysis at Mars (SAM) instrument. These instruments then will begin the much-anticipated detailed analysis.

Simulation of Martian Bedrock Drilling

The rock Curiosity drilled is called "John Klein" in memory of a Mars Science Laboratory deputy project manager who died in 2011. Drilling for a sample is the last new activity for NASA's Mars Science Laboratory Project, which is using the car-size Curiosity rover to investigate whether an area within Mars' Gale Crater has ever offered an environment favorable for life.

JPL manages the project for NASA's Science Mission Directorate in Washington.

For images and more information about the mission, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ .

You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity

Image (mentioned), Video, Text, Credits: NASA / Dwayne Brown / JPL / Guy Webster.

Greetings, Orbiter.ch

NASA's Successful Robotic Refueling Demo Points To a Bright Satellite - Servicing Future

ISS - International Space Station patch.

Feb. 09, 2013

Following six historic days of operations aboard the International Space Station, NASA's Robotic Refueling Mission, or RRM, demonstrated remotely controlled robots using current-day technology could refuel satellites not designed to be serviced.

RRM tests from January 14-25 culminated in a first-of-its-kind robotic fluid transfer, a demonstration that could be a catalyst to expanded robotic satellite-servicing capabilities and lead to a greener, more sustainable space. NASA also hopes that RRM technologies may help boost the commercial satellite-servicing industry.

Image above: The Robotic Refueling Mission, or RRM, investigation (center, on platform) uses the International Space Station's Canadarm2 and the Canadian Dextre robot (right) to demonstrate satellite-servicing tasks. (NASA).

"RRM gives NASA and the emerging commercial satellite servicing industry the confidence to robotically refuel, repair and maintain satellites in both near and distant orbits -- well beyond the reach of where humans can go today," said Frank Cepollina, associate director of the Satellite Servicing Capabilities Office, or SSCO at NASA's Goddard Space Flight Center in Greenbelt, Md.

New Technologies for a New Industry

Since 2009, SSCO has aggressively advanced robotic technologies for a notional, free-flying, servicer spacecraft that could access, repair and refuel satellites in geosynchronous Earth orbit, or GEO. RRM is a critical part of this technology development campaign.

"RRM allows us to take a major step into the future -- a future where humans and machines can together take on greatly expanded roles in space capability, research and exploration," Cepollina said.

Image above: Stray drops of ethanol remain on the RRM Nozzle Tool after it withdraws from the fuel valve and the newly attached "quick disconnect" fitting. (NASA).

Veterans of five manned servicing missions to NASA's Hubble Space Telescope, Cepollina and the SSCO team conceived the idea of RRM and saw it through its rapid 18-month development to its July 2011 launch on STS-135, the last space shuttle mission. A joint effort with the Canadian Space Agency, RRM uses the space station as test bed for the research and development of robotic satellite-servicing capabilities.

The cutting-edge technologies RRM demonstrates could extend the lives of many of the hundreds of satellites currently in GEO. These assets deliver such essential services as weather reports, cell phone communications, television broadcasts, government communications and air traffic management.

Image above: Stephen Roderick supports an autonomous rendezvous and capture test in Goddard's Satellite Servicing Center, an incubator for cutting-edge satellite-servicing technologies. (NASA).

Servicing capabilities could greatly expand options for government and commercial fleet operators in the future, potentially delivering stakeholders significant savings in spacecraft replacement and launch costs.

RRM: A First-of-Its-Kind Refueling

The January RRM activities employed the teleoperated Canadian Dextre robot, four sophisticated RRM tools and the washing-machine-sized RRM module to execute an end-to-end refueling demonstration on orbit. Unlike other demos, RRM is the first to test the robotic refueling of satellite interfaces not designed to be accessed or serviced.

This artist's concept shows a servicing spacecraft, left, approaching a client satellite. NASA is developing technology needed to bring a high-technology "gas pump, robotic mechanic and tow truck" to satellites in orbit. (NASA).

Robot controllers at NASA's Johnson Space Center in Houston first commanded an RRM tool -- working at the end of more than 70 feet (21.34 meters) of combined Dextre and Canadarm2 robotics -- to cut a pair of twisted wires each 0.02 inches in diameter, the thickness of four sheets of paper. Additional exacting tasks followed, with RRM tools cutting more wire -- used to secure satellite parts during launch -- and unscrewing and stowing two protective caps before finally exposing the representative fuel valve.

After the Johnson team threaded the RRM Nozzle tool with its attached hose onto the valve, operators at NASA's Marshall Space Flight Center in Huntsville, Ala., sent a precise sequence of commands to activate the RRM Fluid Transfer System. Liquid ethanol flowed from the Fluid Transfer System into the Nozzle Tool and through the attached fuel valve, ultimately pulsing back into the module's reservoir. Once the fluid transfer was complete, the Nozzle Tool used a novel technique to withdraw from the valve, leaving behind a clever "quick disconnect" fitting that would allow for a simpler and more efficient future refueling connection.

Future RRM tasks scheduled for 2013 include thermal blanket cutting, and fastener and electronic termination cap removals: all firsts of their kinds. A new round of servicing task boards, tools and activities are slated to continue its investigations through 2015.

RRM: Mission to the Future Delivers

Results Straight from Space

Results of RRM operations show that current-day robotic technology can refuel the common, triple-sealed satellite fuel valves of orbiting satellites. "The RRM tools, technologies and techniques passed their tests with flying colors," said SSCO deputy project manager Benjamin Reed. "We are immensely pleased with its success and very grateful to our partner the Canadian Space Agency."

The team's excitement in completing the task was heightened by the treasury of experience and insight gained from the exercise.

"Nothing compares to seeing how your hardware and procedures work in a real space environment," said Reed. "This is the beauty of being able to test new, game-changing technologies on the International Space Station."

"We were very excited to see the RRM refueling task validated the ground development work that our dedicated SSCO team performs every day," Reed said. "It is direct evidence that we are not working blindly in the proverbial vacuum, but rather that our carefully planned work at Goddard accurately simulates the real environment of space."

SSCO plans to present RRM results to date at the upcoming Satellite 2013 conference, as well as during space station panels and other events.

What's Next?

NASA continues to test capabilities for a new robotic servicing frontier. In conjunction with RRM, the SSCO team has been studying a conceptual servicing mission and building technologies to address uncharted territory. They include an autonomous rendezvous and capture system, a propellant transfer system for zero gravity and specialized algorithms to orchestrate and synchronize satellite-servicing operations.

On Jan. 15, NASA released a Request for Information to seek input on a potential public-private partnership to effect the full utilization of NASA-developed technology through an end-to-end technology demonstration of a satellite-servicing capability for client satellites located in GEO. The conceptual Restore Mission would potentially perform servicing operations in orbit in the 2018-2023 timeframe. RRM is proving the technology to achieve such a future mission.

"RRM is a harbinger of the next era in satellite fleet operations," Reed said. "It disrupts the accepted paradigm that a GEO satellite must be decommissioned at the end of its propellant reserves. Nearly 50 years of common practice is challenged with the options that RRM proves and foreshadows."

For information, updates and videos about RRM and NASA's satellite servicing activities, visit: http://ssco.gsfc.nasa.gov

For more information about the International Space Station and its crew, visit:
http://www.nasa.gov/station

Related links:

Canadian Space Agency (CSA-ASC): http://www.asc-csa.gc.ca/eng/default.asp

Satellite Servicing Capabilities Office (SSCO): http://ssco.gsfc.nasa.gov/index.html

Robotic Refueling Mission (RRM): http://ssco.gsfc.nasa.gov/rrm_refueling_task.html

Images (mentioned), Video, Text, Credit: NASA's Goddard Space Flight Center / Adrienne Alessandro.

Best regards; Orbiter.ch

Is the ozone layer on the road to recovery??

ESA - MetOp weather satellite logo.

8 February 2013

 Antarctic ozone hole 2011 and 2012

Satellites show that the recent ozone hole over Antarctica was the smallest seen in the past decade. Long-term observations also reveal that Earth’s ozone has been strengthening following international agreements to protect this vital layer of the atmosphere.

According to the ozone sensor on Europe’s MetOp weather satellite, the hole over Antarctica in 2012 was the smallest in the last 10 years.

The instrument continues the long-term monitoring of atmospheric ozone started by its predecessors on the ERS-2 and Envisat satellites.

Since the beginning of the 1980s, an ozone hole has developed over Antarctica during the southern spring – September to November – resulting in a decrease in ozone concentration of up to 70%.

South Pole ozone

Ozone depletion is more extreme in Antarctica than at the North Pole because high wind speeds cause a fast-rotating vortex of cold air, leading to extremely low temperatures. Under these conditions, human-made chlorofluorocarbons – CFCs – have a stronger effect on the ozone, depleting it and creating the infamous hole.

Over the Arctic, the effect is far less pronounced because the northern hemisphere’s irregular landmasses and mountains normally prevent the build-up of strong circumpolar winds.

Reduced ozone over the southern hemisphere means that people living there are more exposed to cancer-causing ultraviolet radiation.

International agreements on protecting the ozone layer – particularly the Montreal Protocol – have stopped the increase of CFC concentrations, and a drastic fall has been observed since the mid-1990s.

However, the long lifetimes of CFCs in the atmosphere mean it may take until the middle of this century for the stratosphere’s chlorine content to go back to values like those of the 1960s.

The evolution of the ozone layer is affected by the interplay between atmospheric chemistry and dynamics like wind and temperature.

If weather and atmospheric conditions show unusual behaviour, it can result in extreme ozone conditions – such as the record low observed in spring 2011 in the Arctic – or last year’s unusually small Antarctic ozone hole.

Total ozone

To understand these complex processes better, scientists rely on a long time series of data derived from observations and on results from numerical simulations based on complex atmospheric models.

Although ozone has been observed over several decades with multiple instruments, combining the existing observations from many different sensors to produce consistent and homogeneous data suitable for scientific analysis is a difficult task.

Within the ESA Climate Change Initiative, harmonised ozone climate data records are generated to document the variability of ozone changes better at different scales in space and time.

With this information, scientists can better estimate the timing of the ozone layer recovery, and in particular the closure of the ozone hole.

MetOp weather satellite

Chemistry climate models show that the ozone layer may be building up, and the hole over Antarctica will close in the next decades.

Related links:

ESA's CCI ozone project: http://www.esa-ozone-cci.org/

BIRA/IASB: http://www.aeronomie.be/

KNMI: http://www.knmi.nl/index_en.html

DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10002/

RT Solutions Inc.: http://www.rtslidort.com/

WMO ozone bulletin: http://www.wmo.int/pages/prog/arep/gaw/ozone/index.html

Graphics, Video, Text, Credits:  ESA / DLR / Eumetsat / NASA / WMO / GAW / KNMI / BIRA / IASB.

Cheers, Orbiter.ch

Hubble captures strobe flashes from a young star

ESA - Hubble Space Telescope logo.

Feb. 8, 2013

 Hubble image of LRLL 54361 and its surroundings

The NASA/ESA Hubble Space Telescope has produced a time-lapse movie of a mysterious protostar that behaves like a flashing light. Every 25.34 days, the object, designated LRLL 54361, unleashes a burst of light which propagates through the surrounding dust and gas. This is only the third time this phenomenon has been observed, and it is the most powerful such beacon seen to date. It is also the first to be seen associated with a light echo.

Hubble image of LRLL 54361

The cause of the fireworks seen in this Hubble image and video is hidden behind a dense disc and envelope of dust. However, astronomers think that the strobe effect is due to periodic interactions between two newly-formed stars that are gravitationally bound to each other.

These two stars drag material inwards from a surrounding disc of gas and dust. Astronomers propose that the light flashes seen in this video are due to this material suddenly being dumped onto the growing stars as they near one another in their orbits, unleashing a blast of radiation.

Light echo around LRLL 54361

“The protostar has such large brightness variations with a precise period that it is very difficult to explain,” says James Muzerolle of the Space Telescope Science Institute in Baltimore, USA, who has recently studied this fascinating object using Hubble and NASA’s Spitzer Space Telescope. Spitzer made repeated observations over seven years, before Hubble was pointed towards the object to make detailed observations over the period of one pulse event.

How LRLL 54361 flashes like a strobe light

The Hubble observations uncover a spectacular movement of light away from the centre of the system, an optical illusion known as a light echo. While it might look like eruptions of gas are coming out of the protostar, these pulses are actually flashes of light propagating through the surrounding dust and gas and reflecting towards the observer: there is no substantial physical motion within the cloud over these timescales.

Light echoes from LRLL 54361 (non-annotated)

Flashing double star systems like this one are rare, because close binaries account for only a few percent of our galaxy’s stellar population. Moreover, the pulsing light is likely to be a brief phenomenon in the early life of a star.

Light echoes from LRLL 54361 (annotated)

Notes:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

A press release from NASA, with more information about scientific research into LRLL 54361 is available here: http://hubblesite.org/news/2013/04

Images, Videos, Text,  Credit: NASA, ESA, J. Muzerolle (STScI) / E. Furlan (NOAO, Caltech), and R. Hurt (Caltech).

Greetings, Orbiter.ch

Arianespace orbits Amazonas-3 and Azerspace / Africasat-1a satellites

ARIANESPACE / ESA - Flight VA-212 poster.


Feb. 7, 2013

Arianespace orbits Amazonas-3 and Azerspace/Africasat-1a satellites; First Ariane 5 ECA mission in 2013 a success

Ariane 5 ECA Flight VA212 lift-off

Thursday, February 7, 2013,  the launch occurred at 21:36 GMT (4:36 p.m. EST) Arianespace successfully carried out the 54th Ariane 5 launch in a row, orbiting two telecommunications satellites: Amazonas-3 for Spanish operator Hispasat, and Azerspace/Africasat-1a for the Azerbaijani operator Azercosmos 0JSC and the Azerbaijan Ministry of Communications and Information Technologies.

Launch of first 2013 Ariane 5 with Amazonas-3 / Azerspace-1

First Ariane 5 launch of 2013 and a new record

Today's successful mission, the 54th in a row for the European launcher, once again proves the reliability and availability of the Ariane 5 launch system. It also confirms that Arianespace continues to set the standard for independent access to space for all operators, including national and international space agencies, private industry and governments.

The 68th launch of Ariane 5 set a new record for weight injected into geostationary transfer orbit: the launcher on this mission carried a total payload of 10,317 kg, including 9,503 kg for the two satellites, Amazonas-3 and Azerspace/Africasat-1a.

This was the first Ariane 5 launch in 2013. Its success once again illustrated the operational capability of this launcher, the only one now on the market capable of simultaneously launching two payloads.

Processing Highlights of the Ariane 5, Amazonas-3 / Azerspace

Launching satellites for a long-standing customer and a new operator
Arianespace provides the launch services most clearly matches the requirements of all operators.

Amazonas-3 is the seventh Spanish satellite launched by Arianespace. The company first launched the Hispasat 1A and 1B satellites in 1992 and 1993, respectively, followed in 2005 and 2006 by the XTAR-Eur and Spainsat satellites for Hispasat and its subsidiary Hisdesat. Amazonas-2 was launched in 2009, followed by Hispasat 1E in 2010.

The Azerspace/Africasat-1a satellite is the first national satellite to be launched by Arianespace for the Azerbaijan Ministry of Communications and Information Technologies.

Azerspace/Africasat-1a satellite separation from Ariane 5 second stage

Arianespace has already launched the first satellites for 31 operators to date. 

Amazonas-3 – Azerspace/Africasat-1a mission at a glance

The mission was carried out by an Ariane 5 ECA launcher from Europe's Spaceport in Kourou, French Guiana. Liftoff was on Thursday, February 7, 2013 at 6:36 pm local time in Kourou (4:36 pm in Washington, D.C., 21:36 UT, 10:36 pm in Paris, and 1:36 am on Friday, February 8 in Baku).

Amazonas-3 was built by Space Systems/Loral using the SSL 1300 platform and  weighed 6,265 kg at launch. It has 33 Ku-band transponders, 19 C-band transponders, and 9 Ka-band spot beams. This high-power satellite provides a wide range of telecommunications and broadband connectivity services in Europe, the Americas and North Africa. It offers a design life of 15 years. Amazonas-3 is the 43rd satellite built by Space Systems/Loral to be launched by Arianespace.

Amazonas-3 separation from Ariane 5 second stage

The Azerspace/Africasat-1a satellite was built by Orbital Sciences Corporation using a Star-2 platform. Weighing 3,000 kg at launch, the satellite is equipped with 24 C-band transponders and 12 Ku-band transponders. It will provide a wide range of telecommunications services for Azerbaijan, Central Asia, Europe, the Middle East and Africa.

Amazonas-3 satellite

Azerspace/Africasat-1a is the 24th satellite built by Orbital Sciences Corporation to be launched by Arianespace.

 Azerspace/Africasat-1a satellite

For more information about Arianespace, visit: http://www.arianespace.com/index/index.asp

Images, Text, Videos, Credits: ARIANESPACE / ARIANESPA TV / Space Systems / Loral / Orbital Sciences Corporation / Orbiter.ch Aerospace.

Best regards, Orbiter.ch

Curiosity Completes "Drill-On-Rock Checkout"

NASA - Mars Science Laboratory (MSL) logo.

Feb. 6, 2013

Image above: The bit in the rotary-percussion drill of NASA's Mars rover Curiosity left its mark in a target patch of rock called "John Klein" during a test on the rover's 176th Martian day, or sol (Feb. 2, 2013), in preparation for the first drilling of a rock by the rover. Image credit: NASA/JPL-Caltech/MSSS.

The bit of the rock-sampling drill on NASA's Mars rover Curiosity left its mark on a Martian rock this weekend during brief testing of the tool's percussive action.

The successful activity, called a "drill-on-rock checkout" by the rover team at NASA's Jet Propulsion Laboratory, Pasadena, is part of a series of tests to prepare for the first drilling in history to collect a sample of rock material on Mars.

NASA's Mars rover Curiosity (MSL). Image credit: NASA/JPL-Caltech

An image of the bit mark on the rock target called "John Klein" is available online at http://www.nasa.gov/mission_pages/msl/multimedia/pia16717.html .

Another preparatory test, called "mini drill," will precede the full drilling. The mini drill test will use both the rotary and percussive actions of the drill to generate a ring of rock powder around a hole. This will allow for evaluation of the material to see if it behaves as a dry powder suitable for processing by the rover's sample handling mechanisms.

During a two-year prime mission, researchers are using Curiosity's 10 science instruments to assess whether the study area in Gale Crater on Mars ever has offered environmental conditions favorable for microbial life.

More information about Curiosity is online at: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ .

You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at http://www.twitter.com/marscuriosity .

Images (mentioned), Text, Credits: NASA / JPL / Guy Webster.

Greetings, Orbiter.ch

Kepler Data Suggest Earth-size Planets May Be Next Door

NASA - Kepler "Search for Earth-Size Planets" patch.

Feb. 6, 2013

Red Dwarf Planet: The artist's conception shows a hypothetical planet with two moons orbiting in the habitable zone of a red dwarf star. Click image for full caption and larger size. Credit: D. Aguilar/Harvard-Smithsonian Center for Astrophysics.

Using publicly available data from NASA’s Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) estimate that six percent of red dwarf stars in the galaxy have Earth-size planets in the "habitable zone," the range of distances from a star where the surface temperature of an orbiting planet might be suitable for liquid water.

The majority of the sun's closest stellar neighbors are red dwarfs. Researchers now believe that an Earth-size planet with a moderate temperature may be just 13 light-years away.

"We don't know if life could exist on a planet orbiting a red dwarf, but the findings pique my curiosity and leave me wondering if the cosmic cradles of life are more diverse than we humans have imagined," said Natalie Batalha, Kepler mission scientist, NASA's Ames Research Center in Moffett Field, Calif.

The research team analyzed 95 planet candidates in the Kepler catalog orbiting 64 red dwarf stars. Most of these candidates aren't the right size or temperature to be considered Earth-like, as defined by the size relative to Earth and the distance from the host star. However, three candidates are both temperate and smaller than twice the size of Earth.

Red dwarf stars are smaller, cooler, and fainter than the sun. An average red dwarf is only one-third as large and one-thousandth as bright as the sun. Consequently, the not too hot or not too cold habitable zone would be much closer to a cooler star than it is to the sun.

NASA’s Kepler space telescope, for Search for Earth-Size Planets. Image Credit: NASA.

"This close-in habitable zone around cooler stars makes planets more vulnerable to the effects of stellar flares and gravitational interactions, complicating our understanding of their likely habitability,” said Victoria Meadows, professor at the University of Washington and principal investigator with the NASA Astrobiology Institute. "But, if the planets predicted by this study are indeed found very nearby, then it will make it easier for us to make the challenging observations needed to learn more about them, including whether or not they can or do support life."

The three planetary candidates highlighted in this study are Kepler Object of Interest (KOI) 1422.02, which is 90 percent the size of Earth in a 20-day orbit; KOI-2626.01, 1.4 times the size of Earth in a 38-day orbit; and KOI-854.01, 1.7 times the size of Earth in a 56-day orbit.

Located between 300 to 600 light-years away, the three candidates orbit stars with temperatures ranging from 3,400 to 3,500 degrees Kelvin. By comparison, the temperature of the sun is nearly 5,800 degrees Kelvin.

Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zone. Kepler is detecting planets and possible candidates with a wide range of sizes and orbital distances to help scientists better understand our place in the galaxy.

Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with JPL at the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters.

For more information about the discovery, see the CfA press release: http://www.cfa.harvard.edu/news/2013/pr201305.html

For information about the Kepler Mission: http://www.nasa.gov/kepler

Images (mentioned), Text, Credits: NASA / Ames Research Center / Michele Johnson.

Cheers, Orbiter.ch

Performed from Baikonur launch vehicle Soyuz-2.1a with the spacecraft Globalstar-2

ROSCOSMOS & ARIANESPACE logos.

02/06/2013

 Soyuz on ST-26 with Globalstar-2 launch

February 6 in 20 hours 04 minutes MSK (16:04 GMT - 11:04 a.m. EST) from Launch Complex 31 area Baikonur calculations of rocket-space industry Russia produced launch space (ILV) Soyuz-2.1a Arianespace-Starsem Flight ST-26 with the upper stage (RB) Frigate designed to the orbit of a cluster of six spacecraft systems mobile telecommunications services Globalstar-2.

Launch of Soyuz on ST-26 with Globalstar-2 Satellites Onboard

After the regular flight head unit from the third stage of the launch vehicle RB Frigate the mission ends with deployment of the payloads into a 572-mile-high orbit.

 Globalstar-2 spacecrafts constellation in orbit

Original text in Russian: http://www.federalspace.ru/main.php?id=2&nid=19870

For more information about Arianespace, visit: http://www.arianespace.com/index/index.asp

Images, Video, Text, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / Arianespace / Arianespace TV / Starsem / Globalstar / Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

The Wings of the Seagull Nebula

ESO - European Southern Observatory logo.

6 February 2013

 The glowing cloud Sharpless 2-296, part of the Seagull Nebula

This new image from ESO shows a section of a cloud of dust and glowing gas called the Seagull Nebula. These wispy red clouds form part of the “wings” of the celestial bird and this picture reveals an intriguing mix of dark and glowing red clouds, weaving between bright stars. This new view was captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.

Running along the border between the constellations of Canis Major (The Great Dog) and Monoceros (The Unicorn) in the southern sky, the Seagull Nebula is a huge cloud mostly made of hydrogen gas. It’s an example of what astronomers refer to as an HII region. Hot new stars form within these clouds and their intense ultraviolet radiation causes the surrounding gas to glow brightly.

The Seagull Nebula on the borders of the constellations of Monoceros and Canis Major

The reddish hue in this image is a telltale sign of the presence of ionised hydrogen [1]. The Seagull Nebula, known more formally as IC 2177, is a complex object with a bird-like shape that is made up of three large clouds of gas — Sharpless 2-292 (eso1237) forms the “head”, this new image shows part of Sharpless 2-296, which comprises the large “wings”, and Sharpless 2-297 is a small, knotty addition to the tip of the gull’s right “wing” [2].

These objects are all entries in the Sharpless nebula catalogue, a list of over 300 glowing clouds of gas compiled by American astronomer Stewart Sharpless in the 1950s. Before he published this catalogue Sharpless was a graduate student at the Yerkes Observatory near Chicago, USA, where he and his colleagues published observational work that helped to show that the Milky Way is a spiral galaxy with vast, curved arms.

Wide-field view of the entire Seagull Nebula (IC 2177)

Spiral galaxies can contain thousands of HII regions, almost all of which are concentrated along their spiral arms. The Seagull Nebula lies in one of the spiral arms of the Milky Way. But this is not the case for all galaxies; while irregular galaxies do contain HII regions, these are jumbled up throughout the galaxy, and elliptical galaxies are different yet again — appearing to lack these regions altogether. The presence of HII regions indicates that active star formation is still in progress in a galaxy.

This image of Sharpless 2-296 was captured by the Wide Field Imager (WFI), a large camera mounted on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. It shows only a small section of the nebula, a large cloud that is furiously forming hot stars in its interior. The frame shows Sharpless 2-296 lit up by several particularly bright young stars — there are many other stars scattered across the region, including one so bright that stands out as the gull’s “eye” in pictures of the entire complex.

Zooming in on the wings of the Seagull Nebula

Wide-field images of this region of the sky show a multitude of interesting astronomical objects. The young bright stars within the nebula are part of the nearby star-forming region of CMa R1 in the constellation of Canis Major, which is filled with bright stars and clusters. Also lying close to the Seagull Nebula is the Thor’s Helmet Nebula, an object that was imaged using ESO’s Very Large Telescope (VLT) on ESO’s 50th Anniversary, 5 October 2012, with the help of Brigitte Bailleul — winner of the Tweet Your Way to the VLT! competition (eso1238a): http://www.eso.org/public/images/eso1238a/

Panning across part of the Seagull Nebula

Notes:

[1] Astronomers use the term HII to mean ionised hydrogen and HI for atomic hydrogen. A hydrogen atom consists of an electron bound to a proton but in an ionised gas atoms are split into freely moving electrons and positive ions, in this case just single protons.

[2] These objects are officially designated Sh 2-292, Sh 2-296, and Sh 2-297 respectively in the SIMBAD astronomical database.

More information:

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Photos of the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=mpg

Other photos taken with the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=15

Photos of La Silla: http://www.eso.org/public/images/archive/category/lasilla/

Images, Text, Credits: ESO / IAU and Sky & Telescope / Digitized Sky Survey 2. Acknowledgement: Davide De Martin / Videos: ESO/Digitized Sky Survey 2/Nick Risinger (skysurvey.org). Music: Disasterpeace.

Best regards, Orbiter.ch

A spiral galaxy with a secret

ESA - Hubble Space Telescope logo.

5 February 2013

 Hubble view of M 106

The NASA/ESA Hubble Space Telescope – with a little help from an amateur astronomer – has produced one of the best views yet of nearby spiral galaxy Messier 106. Located a little over 20 million light-years away, practically a neighbour by cosmic standards, Messier 106 is one of the brightest and nearest spiral galaxies to our own.

Despite its appearance, which looks much like countless other galaxies, Messier 106 hides a number of secrets. Thanks to this image, which combines data from Hubble with observations by amateur astronomers Robert Gendler and Jay GaBany, they are revealed as never before.

At its heart, as in most spiral galaxies, is a supermassive black hole, but this one is particularly active. Unlike the black hole at the centre of the Milky Way, which pulls in wisps of gas only occasionally, Messier 106’s black hole is actively gobbling up material. As the gas spirals towards the black hole, it heats up and emits powerful radiation. Part of the emission from the centre of Messier 106 is produced by a process that is somewhat similar to that in a laser - although here the process produces bright microwave radiation [1].

The anomalous arms of M 106

As well as this microwave emission from Messier 106’s heart, the galaxy has another startling feature - instead of two spiral arms, it appears to have four. Although the second pair of arms can be seen in visible light images as ghostly wisps of gas, as in this image, they are even more prominent in observations made outside of the visible spectrum, such as those using X-ray or radio waves.

Unlike the normal arms, these two extra arms are made up of hot gas rather than stars, and their origin remained unexplained until recently. Astronomers think that these, like the microwave emission from the galactic centre, are caused by the black hole at Messier 106’s heart, and so are a totally different phenomenon from the galaxy’s normal, star-filled arms.

The extra arms appear to be an indirect result of jets of material produced by the violent churning of matter around the black hole. As these jets travel through the galactic matter they disrupt and heat up the surrounding gas, which in turn excites the denser gas in the galactic plane and causes it to glow brightly. This denser gas closer to the centre of the galaxy is tightly-bound, and so the arms appear to be straight. However, the looser disc gas further out is blown above or below the disc in the opposite direction from the jet, so that the gas curves out of the disc — producing the arching red arms seen here.

Despite carrying his name, Messier 106 was neither discovered nor catalogued by the renowned 18th century astronomer Charles Messier. Discovered by his assistant, Pierre Méchain, the galaxy was never added to the catalogue in his lifetime. Along with six other objects discovered but not logged by the pair, Messier 106 was posthumously added to the Messier catalogue in the 20th century.

Zoom on M 106

Amateur astronomer Robert Gendler retrieved archival Hubble images of M 106 to assemble a mosaic of the centre of the galaxy. He then used his own and fellow astrophotographer Jay GaBany’s observations of M 106 to combine with the Hubble data in areas where there was less coverage, and finally, to fill in the holes and gaps where no Hubble data existed.

The centre of the galaxy is composed almost entirely of Hubble data taken by the Advanced Camera for Surveys, Wide Field Camera 3, and Wide Field and Planetary Camera 2 detectors. The outer spiral arms are predominantly HST data colourised with ground-based data taken by Gendler’s and GaBany’s 12.5-inch and 20-inch telescopes, located at very dark remote sites in New Mexico, USA.

Gendler was a prizewinner in the recent Hubble’s Hidden Treasures image processing competition. Another prizewinner, André van der Hoeven, entered a different version of Messier 106, combining Hubble and NOAO data.

Hubblecast 62: A spiral galaxy with a secret: http://www.spacetelescope.org/videos/heic1302a/

Notes:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

[1] Lasers work when light stimulates emission of more light from a cloud of excited gas, with the original light in effect being amplified (the word laser is an acronym for light amplification by the stimulated emission of radiation). The centre of M106 harbours a similar phenomenon called a maser (short for microwave amplification by the stimulated emission of radiation), in which microwave radiation, which is at longer wavelengths than visible light, is emitted. Note that unlike man-made lasers, which are designed to produce a narrow beam, astronomical masers shine in all directions.

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Robert Gendler: http://www.robgendlerastropics.com/

Image, Text, Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany, A van der Hoeven / Videos: NASA, ESA, L. Calçada / Digitzed Sky Survey 2, R. Gendler, J. GaBany, G. Bacon.

Greetings, Orbiter.ch

Massive stellar winds are made of tiny pieces‏

ESA - XMM-Newton Mission patch.

Feb. 5, 3013

 New view of stellar winds (click on the image for enlarge)

ESA’s XMM-Newton space observatory has completed the most detailed study ever of the fierce wind from a giant star, showing for the first time that it is not a uniform breeze but is fragmented into hundreds of thousands of pieces.

Massive stars are relatively rare, but play a very important role in recycling materials in the Universe. They burn their nuclear fuel much more rapidly than stars like the Sun, living only for millions of years before exploding as a supernova and returning most of their matter to space.

But even during their brief lives, they lose a significant fraction of their mass through fierce winds of gas driven off their surfaces by the intense light emitted from the star.

The winds from massive stars are at least a hundred million times stronger than the solar wind emitted by our own Sun and can significantly shape their surrounding environment.

They might trigger the collapse of surrounding clouds of gas and dust to form new stars or, conversely, blast the clouds away before they have the chance to get started.

Despite their important role, however, the detailed structure of the winds from massive stars remains poorly understood. Are they steady and uniform, or broken up and gusty?

Astronomers have now gained a detailed glimpse into this wind structure by taking observations with XMM-Newton spread over a decade to study variability in the X-ray emission from zeta Puppis. One of the nearest massive stars to Earth, it is bright enough to be seen with the naked eye in the constellation of Puppis, in the southern hemisphere.

The X-rays arise from collisions between slow- and fast-moving clumps in the wind, which heats them to a few million degrees. As individual colliding clumps in the wind are heated and cooled, the strength and energy of the emitted X-rays vary.

If only a small number of large fragments are present, variations in the combined emission could be large. Conversely, as the number of fragments grows, a change in the X-ray emission from any given fragment becomes less important, and the overall variability decreases.

In zeta Puppis, the X-ray emission was found to be remarkably stable over short timescales of just a few hours, pointing to a very large number of fragments. There must still be clumps in the wind to make X-rays in the first place, but there must be many of them to yield such low variability.

However, unexpected variation in the emission was seen on the order of several days, implying the presence of a few very large structures in the wind, possibly spiral-arm-like features superimposed on the highly fragmented wind co-rotating with the star.

“Studies at other wavelengths had already hinted that the winds from massive stars are not simply a uniform breeze, and the new XMM-Newton data confirm this, but also reveal hundreds of thousands of individual hot and cool pieces,” says Yaël Nazé, Université de Liège, Belgium, who led the study’s analysis.

XMM-Newton space observatory

“This is the first time constraints have been placed on the number of fragments in a stellar wind of an adult massive star, a number which far exceeds theoretical predictions.”

To fully understand these observations, improved models of stellar winds will be needed, taking into account both the large-scale emission structures and the highly fragmented wind, in order to understand how they affect mass-loss in stellar giants.

“Zeta Puppis also goes by the name Naos, which in antiquity was the name given to the innermost sanctuary of a temple, accessible to only a few people; thanks to XMM-Newton, scientists have been able to unlock the secrets of this mysterious stellar object,” adds Dr Nazé.

“This long-term XMM-Newton study of zeta Puppis has provided the first constraints on the number of fragments in a stellar wind from a massive star – there is no dataset with comparable sensitivity or time and or spectral coverage currently available for any other massive star,” says Norbert Schartel, ESA’s XMM-Newton project scientist.

More about:

XMM-Newton overview: http://www.esa.int/Our_Activities/Space_Science/XMM-Newton_overview

XMM-Newton in-depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=23

Images, Text, Credits: ESA / C. Carreau / Nazé et al.

Best regards, Orbiter.ch

Asteroid 2012 DA14 – Earth Flyby Reality Check

Asteroid Watch.

Feb. 4, 2013

 Artist's view of asteroids passing Earth

Small near-Earth asteroid 2012 DA14 will pass very close to Earth on February 15, so close that it will pass inside the ring of geosynchronous weather and communications satellites. NASA's Near-Earth Object Program Office can accurately predict the asteroid's path with the observations obtained, and it is therefore known that there is no chance that the asteroid might be on a collision course with Earth. Nevertheless, the flyby will provide a unique opportunity for researchers to study a near-Earth object up close. Here are the facts about the safe flyby of Earth of asteroid 2012 DA14 -- a record close approach for a known object of this size.

Record-Setting Asteroid Flyby

An overview of near-Earth objects with emphasis on the upcoming close approach of asteroid 2012 DA14.

Asteroid 2012 DA14 is a small near-Earth object – approximately 150 feet (45 meters) in diameter. On Feb. 15, 2013, the asteroid will pass by our planet at a remarkably close distance, but the asteroid’s path is understood well enough that there is no chance of a collision with the Earth.

Asteroid 2012 DA14 will be closest to Earth on Feb. 15 at approximately 19:24 UTC (2:24 p.m. EST/11:24 a.m. PST). This time may change by a minute or two as the asteroid is tracked on its approach and predictions are refined.

At the time of closest approach, the asteroid will be over the eastern Indian Ocean, off Sumatra -- approx. latitude: -6 deg South. / longitude: 97.5 deg East.

Graphic depicts the trajectory of asteroid 2012 DA14 on Feb 15, 2013. In this view, we are looking down from above Earth's north pole. Image credit: NASA/JPL-Caltech.

Asteroid 2012 DA14 will be only about 17,200 miles (27,700 kilometers) above Earth's surface at the time of closest approach on Feb 15, 2013. This distance is well outside Earth's atmosphere, but it is inside the belt of satellites in geostationary orbit, which is located 22,200 miles (35,800 kilometers) above Earth’s surface. The close-approach distance is only about one-tenth the distance between Earth and moon. Another way to express the distance between asteroid and Earth at time of closest approach is 4.4 Earth radii from Earth’s surface – or about twice the diameter of the Earth.

The orbit of asteroid 2012 DA14 is well understood – it will not come any closer than 17,150 miles (27,650 kilometers) above Earth's surface during its flyby on Feb 15, 2013.

The asteroid’s orbit around the sun is roughly similar to that of Earth, and it makes relatively close approaches to our planet’s orbit twice per orbit. But, the 2013 flyby is by far the closest the asteroid will approach our planet for many decades. The next notable close approach to Earth will be on February 16, 2046, when the asteroid will pass no closer than 620,000 miles (1,000,000,000 kilometers) from the center-point of Earth.

The flyby of asteroid 2012 DA14 is the closest ever predicted Earth approach for an object this large.

Graphic depicts the trajectory of asteroid 2012 DA14 during its close approach, as seen edge-on to Earth's equatorial plane. The graphic demonstrates why the asteroid is invisible to northern hemisphere observers until just before close approach: it is approaching from "underneath" our planet. On the other hand, after close approach it will be favorably placed for observers in the northern hemisphere. Image credit: NASA/JPL-Caltech.

Asteroid 2012 DA14's will be within the Earth/moon system for about 33 hours. Its orbit will bring it within the Earth/moon system (approach within one lunar distance, 237,000 miles of the Earth) on Feb. 15 at about 0300 UTC (7 p.m. PST on Thursday, Feb. 14). The asteroid will exit the Earth/moon system on Feb. 16 at about 1200 UTC (4 a.m. PST).

Asteroid 2012 DA14 is currently estimated to be about 150 feet (45 meters) across and has an estimated mass of about 130,000 metric tons. If radar observations of this asteroid are successful, we might have a more accurate estimate of the asteroid’s size after its close approach.

Asteroid 2012 DA 14 is traveling at about 17,450 miles per hour (28,100 kilometers per hour), or 4.8 miles per second (7.82 kilometers per second) relative to Earth. Scientists believe there are approximately 500,000 near-Earth asteroids the size of 2012 DA14. Of those, less than one percent have been discovered.

Scientists at NASA's Near-Earth Object Program Office in Pasadena, Calif. estimate that an asteroid the size of 2012 DA14 flies this close every 40 years on average and that one will impact Earth, on average, about once in every 1,200 years.

Asteroid 2012 DA14 to Safely Pass Earth

Asteroid 2012 DA14 to Safely Pass Earth. The flyby of asteroid 2012 DA14 on Feb. 15, 2013, will be the closest known approach to Earth for an object its size. Credit: NASA/JPL-Caltech.

Is there a chance that asteroid DA14 will collide with one or more satellites?

There is very little chance that asteroid 2012 DA14 will impact a satellite or spacecraft. Because the asteroid is approaching from below Earth, it will pass between the outer constellation of satellites located in geosynchronous orbit (22,245 miles/35,800 kilometers) and the large concentration of satellites orbiting much closer to Earth. (The International Space Station, for example, orbits at the close-in altitude of 240 miles/386 kilometers.). There are almost no satellites orbiting at the distance at which the asteroid will pass.

Asteroid 2012 DA14 will not impact Earth, but if another asteroid of a size similar to that of 2012 DA14 (about 150 feet across) were to impact Earth, it would release approximately 2.5 megatons of energy in the atmosphere and would be expected to cause regional devastation.

A comparison to the impact potential of an asteroid the size of 2012 DA14 could be made to the impact of a near-Earth object that occurred in 1908 in Tuguska, Siberia. Known in the asteroid community as the "Tunguska Event," this impact of an asteroid just slightly smaller than 2012 DA14 (approximately 100 – 130 feet/30-40 meters across) is believed to have flattened about 750 square miles (1,200 square kilometers) of forest in and around the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia.

Artist's view of the Podkamennaya Tunguska River asteroid impact

As there is no chance of impact, there is nothing that needs to be done about the asteroid. However, the flyby of 2012 DA14 is a great opportunity for science. NASA's Goldstone Solar System Radar, located in California's Mojave Desert, will observe the asteroid on Feb. 16, 18, 19 and 20. Due to the asteroid's small size, the radar images generated are expected to be no more than a few pixels across. It will also be observed by numerous optical observatories worldwide to attempt to determine its spin rate and composition.

During the closest approach, and dependant on local weather, the asteroid will be visible from parts of Europe, Africa and Asia. The asteroid will appear to be moving relatively quickly as it crosses the sky from the south to the north.

The NASA Near Earth Object Observation (NEOO) Program detects and tracks asteroids and comets passing close to Earth using both ground- and space-based telescopes. The network of projects supported by this program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them and plots their orbits to determine if any could be potentially hazardous to our planet.

Asteroid 2012 DA14 was discovered by the La Sagra Sky Survey operated by the Astronomical Observatory of Mallorca in Spain on Feb. 23, 2012. The asteroid was about 2.7 million miles (4.3 million kilometers) distant when it was detected. Their observations were reported to the NASA funded Minor Planet Center, operated by the Smithsonian Astrophysical Observatory for the International Astronomical Union, where all observations from observatories worldwide are combined to maintain the database on all known asteroids and comets in our solar system.

Additional information:

NASA's Science News - Record Setting Asteroid Flyby: http://science.nasa.gov/science-news/science-at-nasa/2013/28jan_2012da/

Asteroid Watch: For more information about asteroids and near-Earth objects, visit: http://www.jpl.nasa.gov/asteroidwatch and http://www.nasa.gov/asteroid . Updates about near-Earth objects are also available by following AsteroidWatch on Twitter at http://www.twitter.com/asteroidwatch .

Near-Earth Object Program Office: http://neo.jpl.nasa.gov/

Images, Videos, Text, Credits: NASA / JPL-Caltech.

Cheers, Orbiter.ch