Winter solstice

Happy solstice at 15:11 UTC.

Miss H.

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Potentially Hazardous Objects

NASA Maps Dangerous Asteroids That May Threaten Earth

If you've seen films like "Armageddon," you know the potential threat asteroids can be for Earth. To meet that threat, NASA has built a map like no other: a plot of every dangerous asteroid that could potentially endanger our planet … at least the ones we know about.

NASA released the new map of "potentially hazardous asteroids" in a post to its online Planetary Photojournal overseen by the agency's Jet Propulsion Laboratory in Pasadena, Calif. The map shows the orbital paths of more than 1,400 asteroids known creep too close to Earth for comfort. None of the asteroids mapped pose an impact threat to Earth within the next 100 years, agency officials said.

"These are the asteroids considered hazardous because they are fairly large (at least 460 feet or 140 meters in size), and because they follow orbits that pass close to the Earth's orbit (within 4.7 million miles or 7.5 million kilometers)," NASA officials explained in the image description.

 

http://www.space.com/22369-nasa-asteroid-threat-map.html?cmpid=514630_20131201_15043144

We are all made of stars

"Education is the most powerful weapon which you can use to change the world." - RIP Nelson Mandela

Jupiter in the sights of Year 10 Astronomers

A keen Y10 student has produced her first stacked image of Jupiter. The equatorial belts are clearly visible. Well done.

Thanks HS.

Oi what's that?

What do you think? Tail, no nucleus...

Breaking up is hard to do

Perhaps one of the last images of Ison...

Observing Ison at perihelion

So far Comet ISON has spent November sinking ever lower in the east before sunrise as it heads toward the Sun. Ironically, the comet should brighten greatly as it disappears into the Sun's glare.

But you might have a long shot at seeing the comet at its very brightest, as it pulls a hairpin turn around the Sun on Thanksgiving Day, November 28th. Comet ISON will be physically closest to the Sun that day around 19^h Universal Time. It will appear within one Sun diameter of the Sun's edge from about 17^hto 20^h UT. 

Use the chart to determine where the comet is with respect to the Sun. The comet's position is indicated every 12 hours (in Universal Time; adjust to your time zone accordingly), and celestial north is up.

As the chart shows, during its perihelion the comet swings around the Sun in a counterclockwise direction. It's due south of the Sun at 17:30 UT, very close to its southeast at 18:30 UT, due east at 19:20 UT, and farther northeast for several hours thereafter.

From Comet ISON's point of view, the Sun will be

enormous during its closest approach, filling the comet's sky and broiling its surface to a temperature of about 2,700° C (4,900° F). That's almost hot enough to melt iron, not to mention ice! The comet should peak in brightness from around perihelion until perhaps a few hours after.

Will it be detectable then? If you block out the Sun's disk very cautiously and carefully with no momentary lapses — put the Sun behind a chimney or lamp post, not your wavering finger — you might possibly detect the comet's fuzzy pinpoint of a head with the unaided eye if the air is very clear. Do not attempt this with binoculars or a telescope!

 

Block the Sun's disk very cautiously using a chimney or lamp post (pictured here) — not your wavering finger — on November 28th, and you just might glimpse the comet's fuzzy-pinpoint head with the unaided eye. Do not attempt this with binoculars or a telescope!

S&T: Alan MacRobert

 

 

http://www.skyandtelescope.com/observing/highlights/Spot-Comet-ISON-at-Perihelion-233011581.html

Ison increasing in magnitude

Ison v NASA

Once in a lifetime galactic fireworks display due from Comet Ison

Comet Ison, first spotted a year ago, is now visible to the naked eye and will continue to brighten as it hurtles toward the Sun.

What Happened to Mars? A Planetary Mystery

Billions of years ago when the planets of our solar system were still young, Mars was a very different world.  Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm. In this cozy environment, living microbes might have found a home, starting Mars down the path toward becoming a second life-filled planet next door to our own.

But that's not how things turned out.

Today, Mars is bitter cold and desiccated. The planet's thin, wispy atmosphere provides scant cover for a surface marked by dry riverbeds and empty lakes. If Martian microbes still exist, they're probably eking out a meager existence somewhere beneath the dusty Martian soil.
What happened? This haunting question has long puzzled scientists. To find the answer, NASA is sending a new orbiter to Mars called MAVEN (Mars Atmosphere and Volatile Evolution).

MAVEN will launch from Cape Canaveral, Florida, during a 20-day period that begins on November 18, 2013. The trip to Mars takes 10 months, and MAVEN will go into orbit around Mars in September 2014. It will take 5 weeks for the spacecraft to get into its final science-mapping orbit, test
the instruments, and test science mapping sequences. After this commissioning phase, MAVEN has a 1-Earth-year primary mission during which it will make its key measurements.

Check out the latest NASA ScienceCast... http://www.youtube.com/watch?v=etL2ZhqGNCs

The Milky Way

Y11 astronomers always look up to the stars. Two students happened to find themselves in South Africa, with little light pollution and a great view of the Milky Way.

Good work girls. Keep watching...

Horizon: 40 years on the Moon

Did you miss the repeat of Brian Cox? Horizon reviewed 40 years on the Moon. Our Y10 students reviewed the documentary. One budding journalist, may take over when Brian retires. See what you think...

 

In this documentary, Professor Brian Cox tells his audience in detail about the Apollo Missions to the Moon, including the near tragedy of Apollo 13. Not only this, but he also talks about the Moon itself, giving us many useful statistics, along with the history itself.

He starts by giving us an introduction to what life was like before the Apollo missions eve existed – during the Cold War. It created a climate of fear and insecurity. Not only this, but there was a huge amount of international competition; particularly between Russia and America. The Russian soviets then launched Sputnik in 1957, which was the first artificial satellite to orbit the Earth. This was a challenge to America’s pride; they had failed to dominate.

They then managed to launch another satellite, but this one was carrying a dog. There was no hope of getting the dog back down; they hid from the public that the dog had died. Then, a few years later the first space chimp, Ham, was to be launched into space by the Americans. He returned, completely healthy and unharmed.

In 1961, the Russians again took control, as they successfully launched the first man in space – Major Yuri Gagarin, of the Soviet Union. Many people, even a few Americans, agreed that it was the “greatest achievement in history”. There was a live televisions broadcast about it – “here is a man who has done and seen things that no other living human has done and seen.”

The Americans then decided that if a Russian could go into space, then so could they. However, they were more focused on the Moon and wanted desperately to overtake the Russians in getting there. President Kennedy decided to make a motivational speech on the matter, which inspired many. “I believe this nation should commit itself to achieving the goal before this decade is out: of landing a man on the moon and returning him safely to the earth.” This set a new goal for NASA, but they had a very short time period. They were still raring to go, because they wanted to go to the moon, not because it was easy, but because it was hard.

In 1958, they decided to start recruiting astronauts, following very strict criteria. Of the 508 that had applied, after all the medical tests known to man, as well as exhaustive interviews, only 31 remained. These 31 people then had “stress tests” – the doctors tried to make sure that whoever they selected were “immune to anything”, because they did not know what space was like. Finally, they selected Gus Grissom, Ed White, and Roger Chaffee.

Now the problem was getting them to the moon and back. The idea of an orbit came around – if the speed of the rocket were to keep boosting, then they would be able to orbit around earth. If they managed to intercept the speeds, then they would be able to orbit around the moon; after a few touches on the brake pedal, they would be able to land. They just needed to build a safe and accurate rocket.

However, because of the mad rush to get man to the moon before the decade ended, there were many problems with the spacecraft – some parts were not even functioning properly; they were not examined, because they had a tight schedule to follow, and everyone’s main focus was to beat the Russians. 10 minutes before they were about to launch, there was a problem with the oxygen tanks; a fire broke out, and the three astronauts were killed. After the space spacecraft was removed from the launch pad, the air was filled with pure oxygen – very immune to fire. Apollo 1 was a failed mission.

A few days before Christmas in 1968, Apollo 8 was launched into space. The aircraft passed to the far side of the moon, which was very exciting for all of the crew; the astronauts completely lost sight of Earth. It took 3 days to travel into lunar orbit. Apollo 8 sent  a message to earth; they read an extract from the Bible, and wished everybody a merry Christmas. The largest ever television audience, even today, stayed up to watch the success.

Apollo 11 almost turned out to be a huge disaster. The computers misinterpreted the speed of the spacecraft; Armstrong and Aldrin expected to see a clear, flat landing site. All they saw was rocks and craters; back and mission control, they watched Armstrong’s heart rate increase from 77, to 156 bpm. The Eagle had limited fuel – it would have been difficult to clear away rock. They eventually found another landing site, but only had 30 seconds before having to abort. They finally managed. Upon their return, the crew was placed in quarantine, for fear of “lunar germs”!

Apollo 12 was also very successful. However, everybody became very nervous as to what would happen to the 3 astronauts of Apollo 13. One of the oxygen tanks had exploded, and one was leaking. The landing was cancelled, but they were not sure if they would have enough air to make it back to earth. They escaped into an attached lunar module, with a separate lunar supply. They would need to spend the 4 day journey back to Earth with as little oxygen as possible. For the first time in the history of American space flight, there was no back-up to save them if anything went wrong – they would only be able to return to Earth alive if there were no faults at all in the system, and if there was enough oxygen. They would have to fire the only engine they had left; the decent engine. They managed to survive and safely arrive at earth – much to the happiness of everyone.

Many Americans found it offensive that they were fighting for basic human rights, whilst the government was spending most of their money on exploring space and the moon.

America are currently trying to discover more about the moon. Other countries around the world are also very ambitious around the moon. China is talking about launching another mission in about 2025. More countries that are trying include India, Russia, and many places around Europe. “I’m delighted that we’re going back to the moon. And I’d like to see it as the first step to the exploration of a new frontier; out into the solar system and beyond.”

But how were the Van Allen Belt negotiated on the journey to the Moon? There are many theories that answer this, but only one seems to be correct: The Apollo spacecraft passed through the belt quickly, so that in the short time that they were exposed, the astronauts did not receive a dose of radiation that would be considered “dangerous” compared to the other risks in the mission.

 

Thanks to YY, Y10 astronomy, Nonsuch High School for Girls

My First Telescope

A keen y10 astronomer has been testing her new equipment. Look at the excellent images achieved in the first week.

 

A wonderful view of the contrast and depth of craters appreciated, near the terminator.



An image of the sun using a homemade sun filter using a purpose made safety film. Two sun spots are visible in the top left hand corner.

 What type of telescope should I buy?

 A good all-round beginner’s telescope is a Newtonian reflector. It’s a simple design and is relatively cheap for the size of mirror you’ll get for your money – ideal if you’re just starting out.

A Newtonian reflector with a 6-inch (150mm) mirror will give you good views of the brighter galaxies and nebulae, and should also perform well when you train it on the Moon and planets. 

But what about the other types of telescope? Well, refractors are perhaps the most recognisable of all designs. They use a series of lenses to bring what you’re looking at to focus at the eyepiece end of the tube, and are great for observing the Moon or rich star clusters. 

There’s also the Dobsonian, which is a type of reflector that has a simple mount and because of that, often has a much larger mirror for its price. As this collects more light it will let you see dimmer objects, so it’s a great choice if you want to see faint galaxies and nebulae. 

Finally, there are the catadioptric telescopes that use a combination of corrector lenses and mirrors. Their compact size makes them relatively portable and their high focal ratios mean that they’re ideal for lunar and planetary observing.

Thanks to the Sky At Night.
 

Higgs boson scientists win Nobel prize

Peter Higgs, from the UK, and Francois Englert from Belgium, share the prize.

Peter Higgs

In the 1960s, they were among several physicists who proposed a mechanism to explain why the most basic building blocks of the Universe have mass.

The mechanism predicts a particle - the Higgs boson - which was finally discovered in 2012 at the Large Hadron Collider (LHC) at Cern, in Switzerland.

The boson explains why other elementary particles - the basic building blocks of the Universe - have mass.

"This year's prize is about something small that makes all the difference," said Staffan Normark, permanent secretary of the Royal Swedish Academy of Sciences.

More at http://www.bbc.co.uk/news/science-environment-24436781



Meteor Alert

Nasa plans 3D printer space launch

3D printer

US space agency Nasa is planning to launch a 3D printer into space next year to help astronauts manufacture spare parts and tools in zero gravity.

It will be the first time a 3D printer has been used in space and could help reduce the costs of future missions.

The device will have to withstand lift-off vibrations and operate safely in an enclosed space station environment.

Nasa has chosen technology start-up Made in Space to make the microwave oven-sized printer.

 

Apollo 13 improvised carbon dioxide scrub

"Imagine an astronaut needing to make a life-or-death repair on the International Space Station," said Aaron Kemmer, the company's chief executive.

"Rather than hoping that the necessary parts and tools are on the station already, what if the parts could be 3D printed when they needed them?"

In 1970, Apollo 13 astronauts had to cobble together a home-made carbon dioxide filter using a plastic bag, a manual cover and gaffer tape. A 3D printer might have solved the problem in minutes.

Thanks to the BBC at http://www.bbc.co.uk/news/technology-24329296

Happy Birthday NASA

Space Design Competition 2014

After reaching the national finals in the competition in 2013, Nonsuch girls are preparing to submit their latest proposal. All students are welcome to join.

View the winning 2013 entry: http://youtu.be/0Rhlf1rZ_fs

Introducing the Karen Baldwyn-Fishwick Tropy for Astronomy

The inaugural presentation of the Karen Baldwyn-Fishwick Tropy for Astronomy will be awarded for outstanding contribution in GCSE Astronomy at Nonsuch High School for girls.

The trophy will be presented on Thursday 14th November 2013 at Epsom Racecourse.

UK team designs human mission to Mars

Scientists at Imperial College London have designed a concept mission to land astronauts on Mars.

 

 

The plan envisages a three-person crew journeying to Mars aboard a small two-part craft.  The craft would rotate to generate artificial gravity and use a heat shield to protect itself against solar flares.

The crew would then return to Martian orbit in a pre-sent craft fuelled using ice from beneath the planet's surface.

The concept, developed in conjunction with the BBC, is intended to spark further debate about the technical obstacles and risks that would have to be overcome in order to put humans on Mars.

 

Find out more at the link below:

 

http://www.bbc.co.uk/news/science-environment-23349496

Black hole-bound gas cloud 'stretched like spaghetti'

The giant gas cloud heading for the black hole at the centre of our galaxy has begun its death spiral.

The cloud, known as G2 is now being stretched out like a piece of spaghetti by the black hole's extreme gravity.

This gravitational field has caused the head of the cloud to accelerate around the black hole and to speed back towards us.

Astronomers have been closely observing G2, hoping to catch it being ripped apart and eaten by the black hole.

Details of the latest observations are outlined in the Astrophysical Journal.



The gas cloud is being stretched out by the gravity of our galaxy's central black hole

Thanks to the BBC

Pluto's Newly Discovered Moons Receive Names

Pluto's newly discovered moons now have names. Known previously as P4 and P5, the International Astronomical Union has now given the fourth and fifth discovered moons of Pluto the names Kerberos and Styx. The small moons were discovered in 2011 and 2012 by the Hubble Space Telescope in preparation for the close passing of the New Horizons spacecraft by Pluto in 2015. Keberos is named for the many headed dog in Greek mythology that guards the entrance to the underworld, while Styx is named for the goddess who overlooks the mythological river that runs between the Earth and the underworld. Both monikers are related to the name of Pluto, who rules the mythical nether region. Because their reflectively is unknown, the size of each moon is quite uncertain -- but each is crudely estimated to be about 20 kilometers in diameter. The robotic New Horizons spacecraft is on schedule to pass by Pluto in 2015 and provide the first clear images of the dwarf planet and its companions.

On this day...

http://earthsky.org/space/what-is-the-tunguska-explosion

On June 30, 1908, an explosion over Siberia killed reindeer and flattened trees. Scientists now believe it was a small comet or asteroid.

In a remote part of Russia, a fireball was seen streaking across the daytime sky. Within moments, something exploded in the atmosphere above Siberia’s Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia.

This event – now widely known as the Tunguska event – is believed to have been caused by an incoming meteor or comet, which never actually struck Earth but instead exploded in the atmosphere, causing what is known as an air burst, three to six miles (5–10 kilometers) above Earth’s surface.

The explosion released enough energy to kill reindeer and flatten trees for many kilometers around the blast site. But no crater was ever found.

Ten Thousandth Near-Earth Object Discovered

From NASA.

June 25, 2013: More than 10,000 asteroids and comets that can pass near Earth have now been discovered. The 10,000th near-Earth object, asteroid 2013 MZ5, was first detected on the night of June 18, 2013, by the Pan-STARRS-1 telescope, located on the summit of the Haleakala crater on Maui. Managed by the University of Hawaii, the PanSTARRS survey receives NASA funding.

Asteroid 2013 MZ5 as seen by the University of Hawaii's PanSTARR-1 telescope. In this animated gif, the asteroid moves relative to a fixed background of stars. Image credit: PS-1/UH

"Finding 10,000 near-Earth objects is a significant milestone," said Lindley Johnson, program executive for NASA's Near-Earth Object Observations (NEOO) Program at NASA Headquarters. "But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth."

Visions of the Universe

In a new exhibition - Visions of the Universe - at the National Maritime Museum in London, more than 100 awe-inspiring views of space are on show, exploring the development of telescopy, photography, and our understanding of our place in the Universe.

Star cluster Pismis 24
Photographed by the Hubble Space Telescope, 2006 (NASA)

More at the BBC.

First Woman In Space

50 years ago today Valentina Vladimirovna Tereshkova (Russian: Валенти́на Влади́мировна Терешко́ва; born 6 March 1937) was the first woman in space.

She is a retired Soviet cosmonaut and Engineer, and the first woman to have flown in space, having been selected from more than four hundred applicants and five finalists to pilot Vostok 6 on 16 June 1963. 

In order to join the Cosmonaut Corps, Tereshkova was only honorarily inducted into the Soviet Air Force and thus she also became the first civilian to fly in space. During her three-day mission, she performed various tests on herself to collect data on the female body's reaction to spaceflight.

Thanks to Wikipedia 

Explaining the Topography of Mars

June 11, 2013: NASA research indicates hunks of frozen carbon dioxide, dry ice, may glide down some Martian sand dunes on cushions of gas similar to miniature hovercraft, plowing furrows as they go.

"I have always dreamed of going to Mars," said Serina Diniega, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and lead author of a report published online by the journal Icarus. "Now I dream of snowboarding down a Martian sand dune on a block of dry ice."

Watch the experimental report at http://youtu.be/mNXBfz1iVzc

This image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter is an example of a type called "linear gullies," which may be explained by slabs of dry ice gliding down the slopes of sand dunes. Image credit: NASA/JPL-Caltech/Univ. of Arizona

Researchers deduced this process could explain one enigmatic class of gullies seen on Martian sand dunes by examining images from NASA's Mars Reconnaissance Orbiter (MRO) and performing experiments on sand dunes in Utah and California.
The hillside grooves on Mars, called linear gullies, show relatively constant width -- up to a few yards, or meters, across -- with raised banks or levees along the sides. Unlike gullies caused by water flows on Earth and possibly on Mars, they do not have aprons of debris at the downhill end of the gully. Instead, many have pits at the downhill end.

Thanks and more at NASA.

Most “super” supermoon of 2013

Full moon falls on June 23, 2013 at 11:32 UTC. This full moon is not only the closest and largest full moon of the year. It also presents the moon’s closest encounter with Earth for all of 2013. The moon will not be so close again until August, 2014.

Astronomers call this sort of close full moon a perigee full moon. The word perigee describes the moon’s closest point to Earth for a given month. Two years ago, when the closest and largest full moon fell on March 19, 2011, many used a term we’d never heard before: supermoon. Last year, we heard this term again to describe the year’s closest full moon on May 6, 2012. Now the term supermoon is being used a lot. Last month’s full moon – May 24-25, 2013 – was also a supermoon. But the June full moon is even more super! In other words, the time of full moon falls even closer to the time of perigee, the moon’s closest point to Earth. The crest of the moon’s full phase in June 2013, and perigee, fall within an hour of each other.

 Did you know?

- the tides will be higher/lower at perigee

- an astrologer came up with the term supermoon

- each full moon has a name
- this month is know as Rose Moon, Flower Moon or Strawberry Moon in the Northern Hemisphere




More here. Thanks to EarthSky News.

Britain's first official astronaut

From the BBC:

It takes the "right stuff" to withstand cosmic bursts of camera light and meteoric bombardments of questions, but Tim Peake is orbit-ready and passed the test of facing the massed media this week.

As Britain's first official, government-backed astronaut, his selection for a mission in late 2015 marks a pivotal moment.

Countries as far afield as Belgium, Mexico and Vietnam have already had people in space, but so far the only Brits to make it have either had to change nationality (and become American) or win a Russian competition (as in the case of Helen Sharman in 1991).

The UK astronaut tells BBC science editor David Shukman that it is a "true privilege" to be assigned to a long duration mission.

The sensors that bring you those amazing pictures of the Sun, the rocket motors steering spacecraft, the harpoons that may help clear up space junk - many are designed and built in Britain. British space labs and companies have grown to become market leaders in key technologies and their business is valued at £9bn a year.

There are hopes that the space sector will grow - eventually to support as many as 100,000 jobs - and the figurehead of this renewed British effort in space is a former helicopter pilot from Chichester.
Science Minister David Willetts regards the £16m to secure Tim Peake's ticket as money well spent.
While Nasa wraps its astronauts in the rhetoric of fabled explorers - lots of "celestial destiny" and "bold endeavour" - the British take is far more mundane: the press release announcing Tim Peake's mission is mainly about British industry and jobs.



Awesome Power of the Sun

http://www.bbc.co.uk/news/science-environment-22556750

Thank you BBC and Pat for our alert.

Largest CME of the year

The flare on 13 May comes as the Sun is approaching "solar maximum"

The Sun has unleashed its most powerful eruption of 2013 so far.

The solar flare - a sudden release of radiation - peaked at 1705 BST on Monday, and was associated with a huge eruption of matter.

When these eruptions reach Earth, they can interfere with electronic systems in satellites and those on the ground.

Nasa said this solar explosion - known as a coronal mass ejection (CME) - was not directed at Earth, but it could pass several US spacecraft.

The event on Monday was classified as an "X-class" flare - the most intense type - with a designation of X2.8 (higher numbers denote a stronger flare). It surpassed an X1.7-class flare that occurred 14 hours earlier.

 

Space Oddity

International Space Station Commander Chris Hadfield has spent the last year charming the earthbound public with his tweets and Tumblr posts from the International Space Station. Now, it turns out he’s got pipes, too: to celebrate the end of his tenure on the I.S.S., he’s recorded a gorgeous and touching tribute to David Bowie’s “Space Oddity.”

He’s also a veteran member of Max Q—an all-astronaut band that’s been playing with rotating lineups since 1987. When Hadfield’s on the ground, he covers bass and lead vocals. And he’s good—really good. As of this morning, the “Space Oddity” video had passed 1.5 million hits, and Bowie’s Facebook page lauded it as  “possibly the most poignant version of the song ever created.”

Large Meteor in the Sky Last Night

A large blue meteor was spotted last night (8th May) travelling across the night sky by people in many parts of England and Wales. Many observers suggested it was a fireball, a brighter-than-usual meteor. The International Astronomical Union defines a fireball as "a meteor brighter than any of the planets" (magnitude −4 or greater).

Watch amateur footage here.

Sightings of the celestial body were reported on Twitter in areas such as Cornwall, Hampshire, Lancashire, south Wales and Worcestershire.

Suzy Buttress, of Basingstoke, described witnessing the meteor as a "once in a lifetime thing".
Space scientist Dr Maggie Aderin-Pocock said the phenomenon was likely to have been debris from Halley's Comet.

Dr Aderin-Pocock explained what could have caused the spectacle.

"Unfortunately I didn't see this meteor myself, but I think what's unusual is the size of this one. With meteor showers people will see a number of meteors over an hour, so let's say six or 10 an hour.
"It seems that this one was particularly large and particularly bright, which is why it's caught so much attention.
"It's quite likely to be part of the Eta Aquarids, which is the debris left by Halley's Comet.
"And twice a year we pass through the debris left behind by the comet and when this happens we see more of these shooting stars but there must have been a large lump left behind which is what caused such a bright meteor to be seen."

Herschel finds hot gas on the menu for Milky Way’s black hole

ESA’s Herschel space observatory has made detailed observations of surprisingly hot molecular gas that may be orbiting or falling towards the supermassive black hole lurking at the centre of our Milky Way galaxy.

Our local black hole is located in a region known as Sagittarius A* – Sgr A* – after a nearby radio source. It has a mass about four million times that of our Sun and lies around 26 000 light-years away from the Solar System.
Even at that distance, it is a few hundred times closer to us than any other galaxy with an active black hole at its centre, making it the ideal natural laboratory to study the environment around these enigmatic objects.
Vast amounts of dust lie in the plane of the Milky Way between here and its centre, obscuring our view at visible wavelengths. But at far-infrared wavelengths, it is possible to peer through the dust, affording Herschel’s scientists the chance to study the turbulent innermost region of our Galaxy in great detail.

Molecules on the menu at the Milky Way’s black hole

Herschel has detected a great variety of simple molecules at the Milky Way’s heart, including carbon monoxide, water vapour and hydrogen cyanide. By analysing the signature from these molecules, astronomers have been able to probe some of the fundamental properties of the interstellar gas surrounding the black hole.
“Herschel has resolved the far-infrared emission within just 1 light-year of the black hole, making it possible for the first time at these wavelengths to separate emission due to the central cavity from that of the surrounding dense molecular disc,” says Javier Goicoechea of the Centro de Astrobiología, Spain, and lead author of the paper reporting the results.
The biggest surprise was quite how hot the molecular gas in the innermost central region of the Galaxy gets. At least some of it is around 1000ºC, much hotter than typical interstellar clouds, which are usually only a few tens of degrees above the –273ºC of absolute zero.
While some of the heating is down to the fierce ultraviolet radiation pouring from a cluster of massive stars that live very close to the Galactic Centre, they are not enough to explain the high temperatures alone.
In addition to the stellar radiation, Dr Goicoechea’s team hypothesise that emission from strong shocks in highly-magnetised gas in the region may be a significant contributor to the high temperatures. Such shocks can be generated in collisions between gas clouds, or in material flowing at high speed from stars and protostars.
“The observations are also consistent with streamers of hot gas speeding towards Sgr A*, falling towards the very centre of the Galaxy,” says Dr Goicoechea. “Our Galaxy’s black hole may be cooking its dinner right in front of Herschel’s eyes.”