RSSArchive for December, 2010

Square Kilometre Array is coming

THE SQUARE KILOMETRE ARRAY (SKA) will be a huge network of radio telescope antennae, all working in concert to provide unprecedentedly precise and sensitive views of the universe.

Able to see from the present day almost all the way to the Big Bang, and everything in between, it will answer fundamental questions about the origin of stars, galaxies and planetary systems.

Comprising thousands of separate antennae, connected electronically to form one large antenna thousands of kilometres wide, the SKA will have to be built on a large patch of real estate. Two regions are competing for the “hosting” rights—a joint Australia–New Zealand bid, and a bid comprising a number of southern African countries.

It is expected the decision about where the SKA is to be built will be made in 2012.

Related stories:

The Square Kilometre Array

Aussies and Kiwis forge cosmic connection

World’s biggest telescope – the Aussie bid

Video animation produced by Swinburne Astronomy Productions.

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Total lunar eclipse today

A TOTAL LUNAR ECLIPSE will happen today, December 21, visible from certain parts of the world. (Shown above is an amateur video of a similar eclipse from 2007.)

The whole of the eclipse will be seen from the North American continent, Iceland and Greenland. (For observers in the western parts of Canada and the USA, the eclipse will actually begin before midnight on December 20.)

For the UK, the eclipse will begin just before sunrise and moonset, so observers there will see only the initial stages of the eclipse before the sky becomes too bright and the Moon dips below the horizon.

For observers in Australia and New Zealand, the eclipse will already be in progress by the time the Moon rises above the horizon…which will be at different times depending upon location.

A lunar eclipse occurs when the Moon goes “behind” the Earth (with respect to the Sun) and moves through the Earth’s shadow. So the Sun, the Earth and the Moon have to be in a line, with Earth in the middle. Here’s a video that demonstrates it:

You don’t need a telescope to watch a lunar eclipse (although you’re welcome to do so if you have one.) Just go outside in the mid-evening (for Australian observers) after the Moon has risen and look to the east.

The times of moonrise vary depending on where you are in Australia. The times of moonrise—in local times, with daylight saving included—are:

Sydney — 8:05pm

Melbourne — 8:42pm

Brisbane — 6:40pm

Canberra — 8:17pm

Hobart — 8:49pm

Adelaide — 8:30pm

Darwin — 7:11pm

Alice Springs — 7:21pm

Perth — 7:26pm

There are usually a couple of lunar eclipses each year, but they’re not always visible from the same spots. For any particular location on Earth, you might get one or two lunar eclipses per year.

Some are better than others, depending upon how much of Earth’s shadow the Moon moves through.

From start to finish, they can be up to a couple of hours long.

For Australian observers, the next lunar eclipse after this one, will be on June 15, 2011, when again about half of it will be visible. After that, the following one will be on December 10, 2011, when we’ll see the whole total eclipse.

For more details on how, when and where to see the eclipse, please refer to these web pages:


New Zealand

North America


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Airborne observatory reaches milestone

SOFIA observatory

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a modified Boeing 747SP, equipped with a 2.5-metre-diameter telescope.

NASA’s STRATOSPHERIC OBSERVATORY for Infrared Astronomy, or SOFIA, has completed the first of three science flights to demonstrate the aircraft’s potential to make discoveries about the universe.

SOFIA is a heavily modified Boeing 747SP that cruises at altitudes between 39,000 and 45,000 feet. At that altitude, it is above most of the atmosphere that interferes with astronomical observations.

In particular, it is above most of the water vapour that inhibits observations at infrared wavelengths.

It will enable researchers to better understand a wide range of astronomical phenomena including how stars and planets are born, how organic substances form in interstellar space, and how supermassive black holes feed and grow.

“These initial science flights mark a significant milestone in SOFIA’s development and ability to conduct peer-reviewed science observations,” said NASA Astrophysics Division Director Jon Morse.

“We anticipate a number of important discoveries from this unique observatory, as well as extended investigations of discoveries by other space telescopes.”

SOFIA is fitted with a 2.5-metre-diameter telescope that views the sky through a hatch toward the back of the aircraft.

The telescope’s instruments can analyse light from a wide range of celestial objects, including warm interstellar gas and dust of bright star forming regions, by observing wavelengths between 0.3 and 1,600 microns. (A micron equals one millionth of a metre.) For comparison, the human eye sees light with wavelengths between 0.4 and 0.7 microns.

The airborne observatory is an international collaboration between NASA and the German Aerospace Centre, Deutsches Zentrum fur Luft und Raumfahrt (DLR).

Adapted from information issued by NASA.

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Night light is bad for you

Artificial lighting on Earth at Night

Poor lighting standards mean that much of Earth's nighttime artificial lighting shines straight up and is lost into space. This not only affects astronomers' views of the universe, but research has shown that it interferes with natural processes that purge the air of pollution.

  • Light pollution is the unintended spread of artificial light
  • It ruins astronomers’ views of the universe
  • And now it has been shown to increase air pollution too

Excess light at night can contribute to air pollution, according to a study by scientists at the US National Oceanic and Atmospheric Administration (NOAA) and the Co-operative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado.

Findings presented at the American Geophysical Union meeting in San Francisco indicate that upwardly directed light from outdoor lighting that contributes to sky glow over cities, also interferes with chemical reactions that naturally clean the air during nighttime hours.

Every night, chemicals from vehicle exhaust and other human created sources are broken down and prevented from becoming smog, ozone, or other irritants by a form of nitrogen oxide called the nitrate radical.

Sunlight destroys the naturally occurring nitrate radical, so this process occurs only in hours of darkness.

Measurements taken over Los Angeles by aircraft show that light pollution from cities is suppressing the radical.

Though the lights are 10,000 times dimmer than the Sun, the study’s first results indicate that city lights can slow down the nighttime cleansing by up to 7% and they can increase the starting chemicals for ozone pollution the next day by up to 5%.

As many cities are close to their limits of allowable ozone levels, this news is expected to generate immediate interest in light pollution reduction as a way to improve air quality among city, state and federal bodies.

Las Vegas at night

Light pollution from Las Vegas at night. All that light shining straight up is wasted energy.

“[This effect] is more important up in the air than it is directly on the ground so if you manage to keep the light pointing downward and not reflected back up into sky, into the higher parts of the air, then you would certainly have a much smaller effect of this,” NOAA investigator Harald Stark told BBC News.

International Dark-Sky Association (IDA) Executive Director Bob Parks is hopeful that results of this study will encourage cities to adopt environmentally responsible dark sky lighting practices that include using fully shielded fixtures, minimum lighting levels, and lighting only when necessary.

“The impending transition to LED outdoor lighting will also allow cities to utilise adaptive lighting controls to dim or turn off lights when not needed,” says Parks.

“Not only will this vastly reduce energy consumption, based on this new research, it could also improve air quality,” he adds. “This reinforces IDA’s long term goal to reduce total lumens in the environment.”

Starting in 2008, IDA has held yearly educational briefings for both houses of US Congress to raise federal awareness of light pollution. After the 2008 event, eleven members of Congress signed a letter to Environmental Protection Agency (EPA) Administrator Johnson requesting support for research and education on the environmental, health, and safety effects artificial light at night.

On 9 October 2008 EPA was petitioned to review light pollution to monitor and reduce atmospheric discoloration of the night sky under the Clean Air Act. The EPA has made no formal response to the petition.

Adapted from information issued by IDA. Image credits – Earth at night: C. Mayhew & R. Simmon (NASA/GSFC), NOAA/ NGDC, DMSP Digital Archive; Las Vegas: ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, NASA Johnson Space Centre.

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Join the hunt for alien planets!

Artist's impression of exoplanets

Artist's impression of exoplanets. Planet Hunters will let members of the public join the hunt for alien worlds.

  • Citizen scientists being asked to help identify alien Earths
  • Planet Hunters uses a simple Web-based tool to analyse data
  • Number of planets expected to quadruple in the next few years

WEB USERS AROUND THE GLOBE will be able to help professional astronomers in their search for Earth-like planets thanks to a new online citizen science project called Planet Hunters.

Planet Hunters, which is the latest in the Zooniverse citizen science project collection, will ask users to help analyse data taken by NASA’s Kepler mission. The space telescope has been searching for planets beyond our own Solar System—called exoplanets—since its launch in March 2009.

“The Kepler mission has given us another mountain of data to sort through,” said Kevin Schawinski, a Yale University astronomer and Planet Hunters co-founder.

Schawinski also helped create the Galaxy Zoo citizen science project several years ago, which enlisted hundreds of thousands of Web users around the world to help sort through and classify a million images of galaxies taken by a robotic telescope.

The Kepler space telescope is continually monitoring nearly 150,000 stars, recording their brightness over time. Astronomers analyse these images, looking for any stars that show a slight dimming of their brightness. This dimming could represent a planet passing in front of its host star, blocking a tiny fraction of its light as seen from Kepler’s vantage point in space.

Those stars that periodically dim are the best candidates for hosting relatively small planets that tightly orbit their stars, similar to Earth.

Screenshot from Planet Hunters

Screenshot from the Planet Hunters web site. Citizen scientists have to spot out-of-the-ordinary data in the plots of light intensity from a star. Such data could indicate the presence of a planet.

“The Kepler mission will likely quadruple the number of planets that have been found in the last 15 years, and it’s terrific that NASA is releasing this amazing data into the public domain,” said Debra Fischer, a Yale astronomer and leading exoplanet hunter.

Human brain better than machines

Although Planet Hunters is not tied directly to the Kepler mission, the website will serve as a complement to the work being done by the Kepler team to analyse the data.

Because of the huge amount of data being made available by Kepler, astronomers rely on computers to help them sort through the data and search for possible planet candidates.

“But computers are only good at finding what they’ve been taught to look for,” said Meg Schwamb, another Yale astronomer and Planet Hunters co-founder, “whereas the human brain has the uncanny ability to recognise patterns and immediately pick out what is strange or unique, far beyond what we can teach machines to do.”

After the success of the Galaxy Zoo project, the Yale team decided to enlist Web users once again to create what they hope will become a global network of human computing power.

When users log on to the Planet Hunters website, they’ll be asked to answer a series of simple questions about one of the stars’ light curves—a graph displaying the amount of light emitted by the star over time—to help the astronomers determine whether it displays a repetitive dimming of light, identifying it as an exoplanet candidate.

“The great thing about this project is that it gives the public a front row seat to participate in frontier scientific research,” Schwamb said.

Artist's impression of exoplanets

"The search for planets is the search for life": Debra Fisher, astronomer.

Hunt for alien life

The possibility of Earth-like planets beyond our own Solar System has captured the collective human imagination for centuries.

Today, astronomers have discovered more than 500 planets orbiting stars other than the Sun—yet almost all of these so-called exoplanets are large gas giants, similar to Jupiter, which bear little resemblance to Earth.

Ever since the first exoplanet was discovered in 1995, astronomers have raced to find ever smaller planets closer to our own world.

The search for planets is the search for life,” Fischer said. “And at least for life as we know it, that means finding a planet similar to Earth.”

Scientists believe Earth-like planets are the best place to look for life because they are the right size and orbit their host stars at the right distance to support liquid water, an essential ingredient for every form of life found on Earth.

Yet Fischer is quick to caution that, even with the exceptional data from the Kepler telescope, it will be extremely difficult to pick out the weak signal created by such a small planet as it dims its host star.

Planet Hunters is an experiment—we’re looking for the needle in the haystack,” she said.

Still, Galaxy Zoo proved that ordinary people can make extraordinary discoveries. Several Galaxy Zoo users were listed as co-authors on more than 20 published scientific papers that resulted from the citizen science project, most of whom had no prior knowledge of astronomy.

“The point of citizen science is to actively involve people in real research,” Schawinski said. “When you join Planet Hunters, you’re contributing to actual science—and you might just make a real discovery.”


Adapted from information issued by Yale University. Image credits: NASA / ESA / G. Bacon (STScI) / Planet Hunters.

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Qatar-led team finds its first alien world

Artist's impression of Qatar-1b

Artist's impression of the newly discovered alien world Qatar-1b. The planet is a gas giant 20 percent larger than Jupiter in diameter and 10 percent more massive. It circles its star once every 1.4 days, meaning that its "year" is just 34 Earth hours long.

  • Planet found orbiting star 550 light-years from Earth
  • Discovered by team led by Qatari scientist
  • International effort involving Qatar, USA and UK

A QATARI ASTRONOMER has teamed with scientists at the Harvard-Smithsonian Centre for Astrophysics (CfA) in the USA and other institutions to discover a new alien world.

This “hot Jupiter” adds to the growing list of “exoplanets” orbiting distant stars. Its discovery demonstrates the power of science to transcend political boundaries and increase ties between nations.

The planet, now called Qatar-1b, orbits an orange Type K star 550 light-years away.

Qatar-1b is a gas giant 20 percent larger than Jupiter in diameter and 10 percent more massive. It belongs to the “hot Jupiter” family because it orbits just 3.5 million kilometres from its star—only six times the radius of the star—which means it is very hot.

The planet roasts at a temperature of around 1,000 degrees Celsius.

Qatar-1b circles its star once every 1.4 days, meaning that its “year” is just 34 Earth hours long. It’s expected to be tidally locked with the star, so that one side of the planet always faces the star.

As a result, the planet spins on its axis once every 34 hours—three times slower than Jupiter, which rotates once in 10 hours.

International teamwork

“The discovery of Qatar-1b is a great achievement—one that further demonstrates Qatar’s commitment to becoming a leader in innovative science and research,” said Dr Khalid Al Subai, leader of the Qatar exoplanet survey and a research director of the Qatar Foundation for Education, Science and Community Development.

The Qatar exoplanet survey hunts for stars that “wink,” dimming slightly every time an orbiting planet creates a “mini-eclipse” by crossing in front of the star as seen from Earth.

Transit searches like this must sift through thousands of stars to find the small fraction with detectable planets. The complex observations and analysis create perfect opportunities for teamwork.

To find the new world, Qatar’s wide-angle cameras (located in New Mexico) took images of the sky every clear night beginning in early 2010. The photographs then were transmitted to the UK for analysis by collaborating astronomers at St. Andrews and Leicester Universities and Qatar. That analysis narrowed the field to a few hundred candidate stars.

The Harvard-Smithsonian team, with Dr Al Subai, followed up on the most promising candidates, making spectroscopic observations with the 1.5-metre-diameter telescope at the Smithsonian’s Whipple Observatory in Arizona. They also measured the stars’ dimming more accurately with Whipple’s 1.2-metre telescope.

Adapted from information issued by Harvard-Smithsonian Centre for Astrophysics / David A. Aguilar (CfA).

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Hubble’s cosmic bauble

Hubble image of SNR B0509-67.5

This delicate shell formed as the expanding blast wave and ejected material from a supernova (an exploding star) tore through the surrounding interstellar gas. It is located in the Large Magellanic Cloud (LMC), a small galaxy about 160 000 light-years from Earth.

  • Expanding shell of gas from an exploded star
  • Explosion occurred about 400 years ago
  • Image made from combined Hubble images

Hubble has spotted a festive bauble of gas in our neighbouring galaxy, the Large Magellanic Cloud. Formed in the aftermath of a supernova explosion that took place four centuries ago, this sphere of gas has been snapped in a series of observations made between 2006 and 2010.

The delicate shell, photographed by the NASA/ESA Hubble Space Telescope, appears to float serenely in the depths of space, but this apparent calm hides an inner turmoil. The gaseous envelope formed as the expanding blast wave and ejected material from a supernova tore through the nearby interstellar medium.

Called SNR B0509-67.5 (or SNR 0509 for short), the bubble is the visible remnant of a powerful stellar explosion in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light-years from Earth.

Ripples seen in the shell’s surface may be caused either by subtle variations in the density of the ambient interstellar gas, or possibly be driven from the interior by fragments from the initial explosion.

The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.

Hubble and Chandra image of SNR B0509-67.5

The Hubble images overlaid with data (green) from NASA’s Chandra X-ray Observatory that show where the gas is so hot that it emits high-powered X-rays. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.

Astronomers have concluded that the explosion was an example of an especially energetic and bright variety of supernova. Known as Type Ia, such supernova events are thought to result when a white dwarf star in a binary system robs its partner of gas, taking on more mass than it is able to handle, so that it eventually explodes.

Hubble’s Advanced Camera for Surveys observed the supernova remnant on 28 October 2006 with a filter that isolates light from the glowing hydrogen seen in the expanding shell. These observations were then combined with visible-light images of the surrounding star field that were imaged with Hubble’s Wide Field Camera 3 on 4 November 2010.

With an age of about 400 years, the supernova might have been visible to Southern Hemisphere observers around the year 1600, although there are no known records of a “new star” in the direction of the LMC near that time.

A much more recent supernova in the LMC, SN 1987A, did catch the eye of Earth viewers and continues to be studied with ground- and space-based telescopes, including Hubble.

Adapted from information issued by the ESA–Hubble Information Centre. Image credit: NASA / ESA / Hubble Heritage Team (STScI/AURA) / CXC / SAO. Acknowledgement: J. Hughes (Rutgers University).

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Voyager sees solar wind run out of puff

Artist's impression of the heliosphere

Artist's impression of the bubble—the heliosphere—blown in interstellar space by the solar wind. The Voyager 1 spacecraft is soon to cross the boundary into interstellar space.

  • Voyager 1 launched on September 5, 1977
  • The most distant spacecraft from Earth – 17.4 billion km
  • Now exploring the boundary between Solar System and interstellar space

The 33-year-long odyssey of NASA’s Voyager 1 spacecraft has reached a new milestone…a distant point at the edge of our Solar System where there is no outward motion of solar wind.

The solar wind is a stream of hot ionised gas, or plasma, emanating directly outward from the Sun. It forms a bubble—known as the heliosphere—around our Solar System. The solar wind travels at supersonic speed until it crosses a shockwave called the termination shock. At this point, the wind dramatically slows down and heats up in the heliosheath.

Outside the bubble lies true interstellar space, through which blows a gentle “interstellar wind”.

Now hurtling toward that interstellar space some 17.4 billion kilometres from the Sun, Voyager 1 has crossed into an area where the solar wind speed has slowed to zero.

Scientists suspect the solar wind has been turned sideways by the pressure from the interstellar wind.

The event is a major landmark in Voyager 1’s passage through the heliosheath, the turbulent outer shell of the Sun’s sphere of influence, and the spacecraft’s upcoming departure from our Solar System.

Voyager spacecraft

The twin Voyager spacecraft were launched in 1977 to investigate the outer planets of the Solar System.

“The solar wind has turned the corner,” said Ed Stone, Voyager project scientist based at the California Institute of Technology. “Voyager 1 is getting close to interstellar space.”

Voyager shows us something new

Launched on September 5, 1977, Voyager 1 crossed a region called the termination shock in December 2004 into the heliosheath. Scientists have used data from Voyager 1’s Low-Energy Charged Particle Instrument to deduce the solar wind’s velocity.

When the speed of the charged particles hitting the outward face of Voyager 1 matched the spacecraft’s speed, researchers knew that the net outward speed of the solar wind was zero. This occurred in June, when Voyager 1 was about 17 billion kilometres from the Sun.

Because the velocities can fluctuate, scientists gathered four more monthly readings before they were convinced the solar wind’s outward speed actually had slowed to zero.

Analysis of the data shows the velocity of the solar wind has steadily slowed at a rate of about 72,400 kph each year since August 2007, when the solar wind was speeding outward at about 209,000 kph. The outward speed has remained at zero since June.

The results were presented at the American Geophysical Union meeting in San Francisco.

“When I realised that we were getting solid zeroes, I was amazed,” said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator and senior staff scientist at the Johns Hopkins University Applied Physics Laboratory.

“Here was Voyager, a spacecraft that has been a workhorse for 33 years, showing us something completely new again.”

Entering a new frontier

Scientists think Voyager 1 has not crossed the heliosheath into interstellar space. Crossing into interstellar space would mean a sudden drop in the density of hot particles and an increase in the density of cold particles.

Researchers are putting the data into their models of the heliosphere’s structure and should be able to better estimate when Voyager 1 will reach interstellar space.

They currently estimate Voyager 1 will cross that frontier in about four years.

Diagram of Voyager and Pioneer spacecraft positions

Where are they now? Positions of the two Voyager spacecraft, and Pioneers 10 and 11. Voyager 1 (bottom right corner) is the most distant.

“In science, there is nothing like a reality check to shake things up, and Voyager 1 provided that with hard facts,” said Tom Krimigis, principal investigator on the Low-Energy Charged Particle Instrument, who is based at the Applied Physics Laboratory and the Academy of Athens, Greece.

“Once again, we face the predicament of redoing our models.”

A sister spacecraft, Voyager 2, was launched in August 20, 1977 and has reached a position 14.2 billion kilometres from the Sun.

Both spacecraft have been travelling along different trajectories and at different speeds. Voyager 1 is travelling faster, at a speed of about 61,100 kph, compared to Voyager 2’s velocity of 56,300 kph.

In the next few years, scientists expect Voyager 2 to encounter the same kind of phenomenon as Voyager 1.

The Voyagers were built by NASA’s Jet Propulsion Laboratory, which continues to operate both spacecraft.

Adapted from information issued by NASA / JPL.

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Fourth planet found in Solar System look-alike

An artist's impression of one of the planets in the HR 8799 system.

An artist's impression of one of the planets in the HR 8799 system. Credit: NASA, ESA, and G. Bacon (STScI).

  • Fourth planet found in system with three previously known planets
  • The planetary system resembles a supersized version of our Solar System
  • Origin of the four giant planets remains a puzzle

An international team of astronomers has discovered and imaged a fourth giant planet outside our Solar System, a discovery that further strengthens the remarkable resemblances between a distant planetary system and our own.

In a new paper in the journal Nature, the astronomers say the planetary system resembles a supersized version of our Solar System.

“Besides having four giant planets, both systems also contain two ‘debris belts’ composed of small rocky or icy objects, along with lots of tiny dust particles,” said Benjamin Zuckerman, a UCLA professor of physics and astronomy and co-author of the Nature paper.

Our giant planets are Jupiter, Saturn, Uranus and Neptune, and our debris belts include the asteroid belt between the orbits of Mars and Jupiter and the Kuiper Belt, beyond Neptune’s orbit.

The newly discovered fourth planet (known as HR 8799e) orbits a bright star called HR 8799, which lies some 129 light years from Earth and is faintly visible to the naked eye. The mass of the HR 8799 planetary system is much greater than our own.

Astronomers estimate that the combined mass of the four giant planets may be 20 times greater than the mass of all the planets in our Solar System, and the debris belt counterparts also contain much more mass than our own.

Representation of HR 8799 planetary system and Solar System

A 3D representation of the HR 8799 planetary system (left) and our Solar System (right). All orbital diameters are greatly exaggerated in order to make them visible. (Background Milky Way image credit: Atlas image courtesy of 2MASS / Umass / IPAC-Caltech / NASA / NSF.)

Planets’ long-term fate uncertain

The new planet joins three previously discovered planets that were the subjects of a 2008 paper in the journal Science reporting the first-ever images of a planetary family orbiting a star other than our sun. Four of the co-authors of the new Nature paper, including Zuckerman, were also co-authors on that Science paper.

“This is the fourth imaged planet in this planetary system, and only a tiny percentage of known exoplanets (planets outside our Solar System) have been imaged; none has been imaged in multiple-planet systems other than those of HR 8799,” Zuckerman said.

All four planets orbiting HR 8799 are similar in size, likely between five and seven times the mass of Jupiter. The newly discovered planet orbits HR 8799 more closely than the other three. If it were in orbit around our Sun, astronomers say, it would lie between the orbits of Saturn and Uranus.

The astronomers used the Keck II telescope at Hawaii’s W.M. Keck Observatory to obtain images of the fourth planet. Zuckerman’s colleagues are from Canada’s National Research Council (NRC), Lawrence Livermore National Laboratory (LLNL) in California, and Lowell Observatory in Arizona.

“The images of this new inner planet are the culmination of 10 years’ worth of innovation, making steady progress to optimise every aspect of observation and analysis,” said Christian Marois, an NRC astronomer and lead author of the Nature paper. “This allows us to detect planets located ever closer to their stars and ever further from our own Solar System.”

HR 8799 planetary system

Actual image showing the three earlier planets (b, c, and d) and the newly discovered planet "e". Arrows show the next 10 years of motion. 20 AU is 20 times the distance from the Earth to the Sun. (Credit: NRC-HIA, C. Marois, and Keck Observatory)

“The four massive planets pull on each other gravitationally,” said co-author Quinn Konopacky, a postdoctoral researcher at LLNL. “We don’t yet know if the system will last for billions of years or fall apart in a few million more.”

“As astronomers carefully follow the HR 8799 planets during the coming decades, the question of the stability of their orbits could become much clearer.”

New instrument will help with future studies

The origin of these four giant planets remains a puzzle; neither of the two main models of planet formation can account for all four.

“There’s no simple model that can form all four planets at their current location,” said co-author Bruce Macintosh of LLNL. “It’s going to be a challenge for our theoretical colleagues.”

It is entirely plausible that this planetary system contains additional planets closer to the star than these four planets, quite possibly rocky, Earth-like planets, Zuckerman said. But such interior planets are far more difficult to detect, he added.

“Images like these bring the exoplanet field, which studies planets outside our Solar System, into an era of exoplanet characterisation,” said co-author Travis Barman, a Lowell Observatory exoplanet theorist.

“Astronomers can now directly examine the atmospheric properties of four giant exoplanets that are all the same young age and that formed from the same building materials.”

Detailed study of the properties of HR 8799e will be challenging due to the planet’s relative faintness and its proximity to its star. To overcome those limitations, Macintosh is leading an effort to build an advanced exoplanet imager, called the Gemini Planet Imager, for the Gemini Observatory.

This new instrument will physically block the starlight and allow quick detection and detailed characterisation of planets similar to HR 8799e. UCLA and the NRC are also contributing to Gemini Planet Imager.

Adapted from information issued by Stuart Wolpert, UCLA.

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Amazing shuttle launch video!

Watch this amazing 45-minute-long video of the “best of the best” imagery of NASA space shuttle launches.

NASA engineer Matt Melis is an expert in imagery analysis at the Glenn Research Centre, and in this documentary he shows us how photographic documentation of a space shuttle launch “plays a critical role in the engineering analysis and evaluation process that takes place during each and every mission.”

Adapted from information issued by NASA Glenn Research Centre / Matt Melis.

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