Biggest Black Hole Blast Discovered

ESO - European Southern Observatory logo.

28 November 2012

New ESO observations reveal most powerful quasar outflow ever found

Artist’s impression of the huge outflow ejected from the quasar SDSS J1106+1939

Astronomers using ESO’s Very Large Telescope (VLT) have discovered a quasar with the most energetic outflow ever seen, at least five times more powerful than any that have been observed to date. Quasars are extremely bright galactic centres powered by supermassive black holes. Many blast huge amounts of material out into their host galaxies, and these outflows play a key role in the evolution of galaxies. But, until now, observed quasar outflows weren’t as powerful as predicted by theorists.

Quasars are the intensely luminous centres of distant galaxies that are powered by huge black holes. This new study has looked at one of these energetic objects — known as SDSS J1106+1939 — in great detail, using the X-shooter instrument on ESO’s VLT at the Paranal Observatory in Chile [1]. Although black holes are noted for pulling material in, most quasars also accelerate some of the material around them and eject it at high speed.

“We have discovered the most energetic quasar outflow known to date. The rate that energy is carried away by this huge mass of material ejected at high speed from SDSS J1106+1939 is at least equivalent to two million million times the power output of the Sun. This is about 100 times higher than the total power output of the Milky Way galaxy — it’s a real monster of an outflow,” says team leader Nahum Arav (Virginia Tech, USA). “This is the first time that a quasar outflow has been measured to have the sort of very high energies that are predicted by theory.”

Many theoretical simulations suggest that the impact of these outflows on the galaxies around them may resolve several enigmas in modern cosmology, including how the mass of a galaxy is linked to its central black hole mass, and why there are so few large galaxies in the Universe. However, whether or not quasars were capable of producing outflows powerful enough to produce these phenomena has remained unclear until now [2].

The newly discovered outflow lies about a thousand light-years away from the supermassive black hole at the heart of the quasar SDSS J1106+1939. This outflow is at least five times more powerful than the previous record holder [3]. The team’s analysis shows that a mass of approximately 400 times that of the Sun is streaming away from this quasar per year, moving at a speed of 8000 kilometres per second.

“We couldn’t have got the high-quality data to make this discovery without the VLT’s X-shooter spectrograph,” says Benoit Borguet (Virginia Tech, USA), lead author of the new paper. “We were able to explore the region around the quasar in great detail for the first time.”

As well as SDSS J1106+1939, the team also observed one other quasar and found that both of these objects have powerful outflows. As these are typical examples of a common, but previously little studied, type of quasars [4], these results should be widely applicable to luminous quasars across the Universe. Borguet and colleagues are currently exploring a dozen more similar quasars to see if this is the case.

“I’ve been looking for something like this for a decade,” says Nahum Arav, “so it’s thrilling to finally find one of the monster outflows that have been predicted!”

ESO’s Very Large Telescope (VLT)

Notes:

[1] The team observed SDSS J1106+1939 and J1512+1119 in April 2011 and March 2012 using the X-shooter spectrograph instrument attached to ESO’s VLT. By splitting the light up into its component colours and studying in detail the resultant spectrum the astronomers could deduce the velocity and other properties of the material close to the quasar.

[2] The powerful outflow observed in SDSS J1106+1939 carries enough kinetic energy to play a major role in active galaxy feedback processes, which typically require a mechanical power input of roughly 5% of the luminosity of the quasar. The rate at which kinetic energy is being transferred by the outflow is described as its kinetic luminosity.

[3] SDSS J1106+1939 has an outflow with a kinetic luminosity of at least 1046 ergs s−1. The distances of the outflows from the central quasar (300–8000 light-years) was greater than expected suggesting that we observe the outflows far from the region in which we assume them to initially accelerated (0.03–0.4 light-years).

[4] A class known as Broad Absorption Line (BAL) quasars.

More information:

This research was presented in a paper, “Major contributor to AGN feedback: VLT X-shooter observations of SIV BAL QSO outflows”, to appear in The Astrophysical Journal.

The team is composed of B. C. J. Borguet (Virginia Tech, USA), N. Arav (Virginia Tech, USA), D. Edmonds (Virginia Tech, USA), C. Chamberlain (Virginia Tech, USA), C. Benn (Isaac Newton Group of Telescopes, Spain).

The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). 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:

Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1247/eso1247a.pdf

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

Images, Text, Credits: ESO / L. Calçada / Richard Hook/ Virginia Tech / Nahum Arav / Benoît Borguet.

Greetings, Orbiter.ch

Why Study Plants in Space?

ISS - International Space Station patch.

Nov. 27, 2012

Why is NASA conducting plant research aboard the International Space Station? Because during future long-duration missions, life in space may depend on it.

The ability of plants to provide a source of food and recycle carbon dioxide into breathable oxygen may prove critical for astronauts who will live in space for months at a time. In addition, plants provide a sense of well-being. At the McMurdo Station for research in Antarctica -- a site that in the dead of winter resembles the space station in its isolation, cramped quarters, and hostile environment -- the most sought after section of the habitat is the greenhouse.

NASA and the European Space Agency, or ESA, are studying how plants adapt to micro- and low-gravity environments in a series of experiments designed to determine the ability of vegetation to provide a complete, sustainable, dependable and economical means for human life support in space. As researchers continue to gain new knowledge of how plants grow and develop at a molecular level, this insight also may lead to significant advances in agriculture production on Earth.

Image above: Samples from the Seedling Growth investigation aboard the International Space Station help researchers study the impact of the microgravity environment on plant growth. (NASA).

Plant biology experiments on the space station using the European Modular Cultivation System, or EMCS, allow scientists to investigate plant growth and the processes within their cells to understand how plant life responds to conditions in space. Researchers currently are planning three new plant growth investigations specifically designed to examine the growth of seedlings in microgravity using this facility.

Combining the proposals of NASA Principal Investigator John Z. Kiss, and ESA Principal Investigator Javier Medina, the Seedling Growth investigation will continue at the space station for a series of experiments: Seedling Growth 1, 2 and 3 in 2013, 2014 and 2015 respectively. The results of these experiments will help researchers understand how plants sense and respond to the space environment.

Once aboard the space station, astronauts will conduct experiments to examine the seedlings' cultivation and stimulation under controlled temperature, atmosphere composition, limited water supply, illumination and acceleration conditions using centrifuges. Because the station crew is key to the success of the experiments, crew members will receive significant training, including on-board computer video instruction.

Thus far, NASA's Ames Research Center, Moffett Field, Calif., has completed three experiments using the EMCS. The 2006 study called Root Phototropism, or Tropi, used Thale cress (Arabidopsis thaliana) seeds from the mustard family to investigate how plant roots respond to varying levels of light and gravity. Using a rotating centrifuge, Kiss designed the experiment to expose the plants to different gravity conditions.

In 2010, the Tropi-2 experiment expanded on the knowledge gained from the first Tropi investigation. Collectively, the two studies demonstrated how red and blue light affects plant growth differently at varied levels of gravity. With this information, researchers now know that they can optimize plant root and shoot growth in space by fine-tuning the plants' exposure to light.

Image above: View of the TROPI seedling cassette for the European Modular Cultivation System, or EMCS, aboard the International Space Station Destiny laboratory module during Expedition 14. (NASA).

Most recently, the Plant Signaling space experiment, led by Principal Investigator Imara Perera, research associate professor at North Carolina State University, Raleigh, N. C., studied the roots and shoots of wild type and genetically modified Thale cress plant seedlings in microgravity and 1g -- a simulation of Earth's gravity. Images of the seedlings were sent to Earth before astronauts harvested and preserved the seedlings for post-flight analysis. The frozen plants are scheduled to return to Earth in 2013 aboard a SpaceX Dragon capsule.

The analysis of these data will lead to an understanding of the molecular mechanisms plants use to sense and respond to changes in their environment. Insights gained from this study will help scientists identify plants that are better able to withstand long duration spaceflight and microgravity conditions.

Description of the International Space Station's, U.S. Destiny laboratory location on ISS

Unique Environments Demand Specialized Equipment

Provided by ESA, the EMCS consists of a holding structure filling four station lockers and includes an incubator with two centrifuges. Two to four Ames-developed Experiment Containers, or ECs, can mount to each of the two centrifuge rotors to allow scientists to perform experiments at various g-levels up to twice Earth's gravity, or 2g.

The EMCS design enables control of temperature, humidity, oxygen and carbon dioxide. Equipped with white and infrared lights, EMCS also can control g-level simulation and water to perform experiments with biological samples. Video observation, imaging, data handling and command systems allow for control of the experiments inside the ECs. The ECs have specialized systems to study cell biology, small aquatic animals, roundworms, fruit flies and plants.

NASA's Ames Research Center worked closely with ESA to develop specific experimental units designed to grow plant seedlings, particularly Thale Cress, as well as other plant species. The hardware has performed flawlessly in supporting the Tropi-1, Tropi-2 and Plant Signaling experiments and will be used in the upcoming Seedling Growth study.

European Modular Cultivation System (EMCS): http://www.nasa.gov/mission_pages/station/research/experiments/EMCS.html

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images, Text, Credits: NASA / Ames Research Center / Barbara Patterson /  ESA.

Best regards, Orbiter.ch

Successful 18th launch of 2012 for China’s Long March 3B with ChinaSat-12

CNSA - China National Space Administration logo.

Nov. 27, 2012

 Long March 3B rocket

The Chinese have launched the ChinaSat-12 (Zhongxing-12) communications satellite into orbit via a Long March 3B/E (Chang Zheng-3B/E) on Tuesday – their 18th orbital launch of the year. The launch took place at 10:13 UTC from the LC2 launch pad at the Xichang Satellite Launch Center.

 ChinaSat-12 lifted off on a Long March 3B rocket (in Chinese)

This satellite was originally called Apstar-7B, a Spacebus-4000C2 platform geostationary communications satellite, with 24 C-band and 23 Ku-band high power beams. It was contracted to Thales Alenia Space of France for construction, on behalf of APT Satellites, in April of 2010.

Image above: Chinasat-12 lifted off on a Long March 3B rocket at 6:13 p.m. Beijing time on Tuesday. Credit: Xinhua.

Apstar-7B was a back up satellite, in event Apstar-7 failed to make it to orbit. However, the launch – carried out on March 31, 2012 – was a success, allowing Apstar 7B to be transferred to a secondary agreement between APT Satellites and the China Great Wall Industry Corporation (CGWIC).

With the secondary agreement in place, the satellite was taken by China Satcom – a state-owned satellite operator in Beijing – and renamed Zhongxing-12 (or ChinaSat-12). Zhongxing-12′s role is to replace Zhongxing-5A (ChinaSat-5A) at 87.5 degrees East.

ChinaSat-12 communications satellite

ChinaSat-12 had a lift-off mass of 5,054 kg and a design lifetime over 15 years. It uses a S400 propulsion system and is equipped with two deployable solar arrays.

For more information about CNSA, visit: http://www.cnsa.gov.cn/n615709/cindex.html

Images, Video, Text, Credits: CNSA / Xinhua / Thales Alenia / CNTV / Orbiter.ch Aerospace.

Greetings, Orbiter.ch

Do missing Jupiters mean massive comet belts?

ESA - Herschel Mission patch.

27 November 2012

Using ESA’s Herschel space observatory, astronomers have discovered vast comet belts surrounding two nearby planetary systems known to host only Earth-to-Neptune-mass worlds. The comet reservoirs could have delivered life-giving oceans to the innermost planets.

In a previous Herschel study, scientists found that the dusty belt surrounding nearby star Fomalhaut must be maintained by collisions between comets.

Debris disc around GJ 581

In the new Herschel study, two more nearby planetary systems – GJ 581 and 61 Vir – have been found to host vast amounts of cometary debris.

Herschel detected the signatures of cold dust at 200ºC below freezing, in quantities that mean these systems must have at least 10 times more comets than in our own Solar System’s Kuiper Belt.

GJ 581, or Gliese 581, is a low-mass M dwarf star, the most common type of star in the Galaxy. Earlier studies have shown that it hosts at least four planets, including one that resides in the ‘Goldilocks Zone’ – the distance from the central sun where liquid surface water could exist.

 Two planets are confirmed around G-type star 61 Vir, which is just a little less massive than our Sun.

The planets in both systems are known as ‘super-Earths’, covering a range of masses between 2 and 18 times that of Earth.

Interestingly, however, there is no evidence for giant Jupiter- or Saturn-mass planets in either system. 

The gravitational interplay between Jupiter and Saturn in our own Solar System is thought to have been responsible for disrupting a once highly populated Kuiper Belt, sending a deluge of comets towards the inner planets in a cataclysmic event that lasted several million years.

Debris disc around 61 Vir

“The new observations are giving us a clue: they’re saying that in the Solar System we have giant planets and a relatively sparse Kuiper Belt, but systems with only low-mass planets often have much denser Kuiper belts,” says Dr Mark Wyatt from the University of Cambridge, lead author of the paper focusing on the debris disc around 61 Vir.

“We think that may be because the absence of a Jupiter in the low-mass planet systems allows them to avoid a dramatic heavy bombardment event, and instead experience a gradual rain of comets over billions of years.”

“For an older star like GJ 581, which is at least two billion years old, enough time has elapsed for such a gradual rain of comets to deliver a sizable amount of water to the innermost planets, which is of particular importance for the planet residing in the star’s habitable zone,” adds Dr Jean-Francois Lestrade of the Observatoire de Paris who led the work on GJ 581.

However, in order to produce the vast amount of dust seen by Herschel, collisions between the comets are needed, which could be triggered by a Neptune-sized planet residing close to the disc.

“Simulations show us that the known close-in planets in each of these systems cannot do the job, but a similarly-sized planet located much further from the star – currently beyond the reach of current detection campaigns – would be able to stir the disc to make it dusty and observable,” says Dr Lestrade.

ESA’s Herschel space observatory

“Herschel is finding a correlation between the presence of massive debris discs and planetary systems with no Jupiter-class planets, which offers a clue to our understanding of how planetary systems form and evolve,” says Göran Pilbratt, ESA’s Herschel project scientist.

Related links:

61 Vir science paper: http://dx.doi.org/10.1111/j.1365-2966.2012.21298.x

GJ 581 science paper: http://dx.doi.org/10.1051/0004-6361/201220325

Herschel: ESA's giant infrared observatory: http://www.esa.int/SPECIALS/Herschel/index.html

Herschel overview: http://www.esa.int/SPECIALS/Herschel/index.html

Online Showcase of Herschel Images OSHI: http://oshi.esa.int/

Herschel in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16

Images, Text, Credits: ESA / AOES.

Best regards, Orbiter.ch

Cassini Finds a Video Gamers' Paradise at Saturn

NASA / ESA - Cassini Missionto Saturn patch.

Nov. 26, 2012

Scientists with NASA's Cassini mission have spotted two features shaped like the 1980s video game icon "Pac-Man" on moons of Saturn. One was observed on the moon Mimas in 2010 and the latest was observed on the moon Tethys. Image credit: NASA/JPL-Caltech/GSFC/SWRI.

ou could call this "Pac-Man, the Sequel." Scientists with NASA's Cassini mission have spotted a second feature shaped like the 1980s video game icon in the Saturn system, this time on the moon Tethys. (The first was found on Mimas in 2010). The pattern appears in thermal data obtained by Cassini's composite infrared spectrometer, with warmer areas making up the Pac-Man shape.

"Finding a second Pac-Man in the Saturn system tells us that the processes creating these Pac-Men are more widespread than previously thought," said Carly Howett, the lead author of a paper recently released online in the journal Icarus. "The Saturn system - and even the Jupiter system - could turn out to be a veritable arcade of these characters."

Scientists theorize that the Pac-Man thermal shape on the Saturnian moons occurs because of the way high-energy electrons bombard low latitudes on the side of the moon that faces forward as it orbits around Saturn. The bombardment turns that part of the fluffy surface into hard-packed ice. As a result, the altered surface does not heat as rapidly in the sunshine or cool down as quickly at night as the rest of the surface, similar to how a boardwalk at the beach feels cooler during the day but warmer at night than the nearby sand. Finding another Pac-Man on Tethys confirms that high-energy electrons can dramatically alter the surface of an icy moon. Also, because the altered region on Tethys, unlike on Mimas, is also bombarded by icy particles from Enceladus' plumes, it implies the surface alteration is occurring more quickly than its recoating by plume particles.

"Studies at infrared wavelengths give us a tremendous amount of information about the processes that shape planets and moons," said Mike Flasar, the spectrometer's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md. "A result like this underscores just how powerful these observations are."

Scientists saw the new Pac-Man on Tethys in data obtained on Sept. 14, 2011, where daytime temperatures inside the mouth of Pac-Man were seen to be cooler than their surroundings by 29 degrees Fahrenheit (15 kelvins). The warmest temperature recorded was a chilly minus 300 degrees Fahrenheit (90 kelvins), which is actually slightly cooler than the warmest temperature at Mimas (about minus 290 degrees Fahrenheit, or 95 kelvins). At Tethys, unlike Mimas, the Pac-Man pattern can also be seen subtly in visible-light images of the surface, as a dark lens-shaped region. This brightness variation was first noticed by NASA's Voyager spacecraft in 1980.

Cassini spacraft. Image credit: NASA/JPL-Caltech

"Finding a new Pac-Man demonstrates the diversity of processes at work in the Saturn system," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Future Cassini observations may reveal other new phenomena that will surprise us and help us better understand the evolution of moons in the Saturn system and beyond."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center in Greenbelt, Md., where the instrument was built.

More information about the Cassini-Huygens mission is at: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov and  http://www.esa.int/SPECIALS/Cassini-Huygens/

Images (mentioned), Text, Credits: NASA/Goddard Space Flight Center/Elizabeth Zubritsky/JPL/Jia-Rui Cook.

Greetings, Orbiter.ch

Fostering Curiosity: Mars Express relays rocky images

ESA - Mars Express Mission patch / NASA - Mars Science Laboratory (MSL) patch.

26 November 2012

 Rocknest3 relayed by Mars Express

For the first time, ESA’s Mars orbiter has relayed scientific data from NASA’s Curiosity rover on the Red Planet’s surface. The data included detailed images of ‘Rocknest3’ and were received by ESA’s deep-space antenna in Australia.

It was a small but significant step in interplanetary cooperation between space agencies.

Early on the morning of 6 October, ESA’s Mars Express looked down as it orbited the planet, lining up its lander communication antenna to point at Curiosity far below on the surface.

For 15 minutes, the NASA rover transmitted scientific data up to the ESA satellite. A few hours later, Mars Express slewed to point its high-gain antenna toward Earth and began downlinking the precious information to the European Space Operations Centre in Darmstadt, Germany, via the Agency’s 35 m-diameter antenna in New Norcia, Australia. 

The data were immediately made available to NASA’s Jet Propulsion Laboratory in California for processing and analysis, proving again that NASA’s amazing new rover can talk with Europe’s veteran Mars orbiter.

Curiosity’s ChemCam images Rocknest3

The information included a pair of tremendously interesting images acquired on 4 October by Curiosity’s ChemCam Remote Micro-Imager camera.

Mars Science Laboratory (MSL)

ChemCam comprises the camera together with a Laser-Induced Breakdown Spectrometer, which fires a laser at targets and analyses the chemical composition of the vaporised material.

The laser zaps areas smaller than 1 mm across on the surface of martian rocks and soils, and then the spectrometer provides information on the minerals and microstructures in the rocks.

Outstanding image quality

The first image (at top of article) was taken before a series of five ChemCam laser blasts and the second image (at right) was taken after. The image is centred on the fifth observation point.

Rocknest3 relayed by Mars Express

“The quality of these images from ChemCam is outstanding, and the mosaic image of the spectrometer analyses has been essential for scientific interpretation of the data,” says Sylvestre Maurice, Deputy Principal Investigator for ChemCam at France’s Research Institute in Astrophysics and Planetology (IRAP).

“This combination of imaging and analysis has demonstrated its potential for future missions.”

ChemCam laser targets

A third image, relayed separately by NASA, indicates the locations of the laser target points on Rocknest3, as seen by the RMI camera.

Laser targets on Rocknest3

‘Rocknest’ is the area where Curiosity stopped for a month to perform its first mobile laboratory analyses on soil scooped from a small sand dune. Rocknest3 was a convenient nearby target where ChemCam made more than 30 observations using 1500 laser shots.

A wide-angle context image was acquired by Curiosity’s MastCam and shows Rocknest3 as targeted by ChemCam. Rocknest3 is about 10 x 40 cm, or roughly the size of a shoe box.

Fostering Curiosity – and others

ESA’s Mars orbiter has also relayed data for NASA’s other surface missions – Phoenix, Spirit and Opportunity – since 2004, and it relayed Curiosity’s radio signal during its arrival at Mars last August.

Rockenest3

During the Curiosity mission, Mars Express is set to provide additional relay slots, while maintaining its own scientific observation programme, under an ESA-NASA support agreement.

It can also rapidly provide relay services in case of unavailability of NASA’s own relay orbiter or if there is a problem on the rover itself.

Interplanetary cooperation

Mars Express Spacecraft

“ESA–NASA cooperation at Mars is a continuing success, and comes after both sides have worked diligently for a number of years to set technical and engineering standards to enable sharing data between spacecraft, networks and ground stations,” says Mars Express Spacecraft Operations Manager Michel Denis.

“Exploring Mars is a huge challenge, and space agencies are working to boost cooperation and mutual support for current and upcoming missions. It’s the way of the future.”

More information:

Mars Express: http://www.esa.int/SPECIALS/Mars_Express/index.html

Mars Science Laboratory: http://www.nasa.gov/mission_pages/msl/index.html

NASA MSL mission at JPL: http://marsprogram.jpl.nasa.gov/msl/

ChemCam team online: http://www.msl-chemcam.com/

Images, Text, Credits: ESA / NASA / JPL-Caltech / Malin Space Science Systems / LANL / CNES / IRAP / LPGN / CNRS.

Best regards, Orbiter.ch

Revisiting an old friend

ESA - Giotto Mission patch.

26 November 2012

Comet Halley, the originator of the Orionids meteor shower that lit up our skies last month – as they do every October – is seen here up close by ESA’s Giotto probe as it flew past the famous comet on 13–14 March 1986.

Comet Halley close up

Giotto was ESA’s first deep-space mission. It swept within 600 km of Halley, obtaining the first close-up images of a comet. This image was taken from a distance of about 2000 km from Comet Halley.

Comets are considered to be the primitive building blocks of the Solar System and likely helped to ‘seed’ Earth with water.

This milestone mission showed for the first time the nucleus of a comet and revealed jets of gas and dust streaming out into space.

The flyby also revealed the first evidence of organic material in a comet, boosting the idea that comets might have delivered some of the building blocks needed for life on Earth.

Comet Halley is visible to observers on Earth every 75–76 years and will not return to the inner Solar System until 2061. Its presence makes itself known every year, however, in the form of the Orionids meteor shower.

As the icy comet is warmed by the Sun, parts of it transform directly into a gas, dragging its dusty component along, which streams out in a long tail. These fragments continue along the trajectory of the comet, which Earth crosses on its yearly trip around the Sun.

Although only tiny grains of cometary debris, these fragments produce spectacular trails as they burn up in Earth’s atmosphere as ‘shooting stars’.

The Orionids are so-called because meteors appear to originate close to the constellation of Orion. Halley’s comet is also thought to be responsible for the Eta Aquariids meteor shower, which occurs every year in May.

Image above: The Giotto spacecraft, launched in 1985 on an Ariane 1 V14 launcher, brushed past the hidden nucleus of Comet Halley in 1986.

After visiting Comet Halley, Giotto went on to make a flyby of Comet 26P/Grigg-Skjellerup in July 1992.

Meanwhile, ESA’s new Rosetta comet-chasing spacecraft is en route to rendezvous with Comet 67P/Churyumov-Gerasimenko in 2014, where it will make the most detailed study of a comet ever attempted as it follows it on its journey around the Sun.

The mission will also be the first to land on a nucleus to ‘taste’ the surface ingredients, providing key details about the role of comets in the evolution of the Solar System. 

More about...

ESA's comet chaser: http://www.esa.int/SPECIALS/Rosetta/index.html

Giotto overview: http://www.esa.int/esaSC/120392_index_0_m.html

Rosetta Blog: http://webservices.esa.int/blog/blog/5/

Images, Text, Credits: ESA / MPS.

Cheers, Orbiter.ch