The birth of planets has been revealed in astonishing detail by a telescope with 10 times the resolution of Hubble.
The Atacama Large Millimetre Array (ALMA) is a new radio telescope in northern Chile that became fully operational in 2013. Costing $1.4 billion, it is the most expensive ground-based telescope in the world, and the most sensitive at millimetre and submillimetre wavelengths. A cluster of 66 high-precision antennas work in unison to achieve phenomenal resolution.
ALMA was designed to open an entirely new "window" on the universe. Its capabilities have been demonstrated once again with a stunning image released by astronomers this week, showing extraordinarily fine detail in the planet-forming disk around a young star. These new results are a major step forward in the understanding of protoplanetary disks and the formation of planets.
HL Tau is a million-year-old Sun-like star, located 450 light-years from Earth in the constellation of Taurus. The photo seen here exceeds all expectations and reveals a series of concentric and bright rings, separated by gaps. These new substructures have never been seen before and are believed to show the possible positions of planets forming in the dark patches – similar to how our own Solar System would have looked more than 4 billion years ago.
ALMA Deputy Director, Stuart Corder: "These features are almost certainly the result of young planet-like bodies forming in the disk. This is surprising, since such young stars are not expected to have large planetary bodies capable of producing the structures we see in this image."
Catherine Vlahakis, Deputy Program Scientist: "When we first saw this image, we were astounded at the spectacular level of detail. HL Tauri is no more than a million years old, yet already its disk appears to be full of forming planets. This one image alone will revolutionise theories of planet formation."
ALMA's new high-resolution capabilities were achieved by spacing the antennas up to 15 kilometres apart. This baseline at millimetre wavelengths enabled a resolution of 35 milliarcseconds – equivalent to a penny seen from over 110 kilometres away. An even larger cluster of telescopes known as the Square Kilometre Array is planned for operation in 2024. This will have 50 times the resolution of ALMA and 500 times that of Hubble.
In August, the European Space Agency (ESA) achieved a major success when its Rosetta probe rendezvoused with comet 67P. The spacecraft has been returning spectacular images of this strange little world, located midway between the orbits of Mars and Jupiter. Among its latest photographs is the image below showing what appear to be dunes like those found on the deserts and beaches of Earth. Seen from a distance of about 8.8 km (5.5 miles), the scale here is 92 cm/pixel, meaning the dunes are roughly the width of a jumbo jet (as shown in this helpful illustration from Reddit).
The comet is already becoming more active as it approaches the Sun, with jets of dust shooting outward in slowly increasing quantities. Data from the mass spectrometers on Rosetta show that its coma (or atmosphere) contains a surprisingly rich variety of chemicals. Although low density, this would smell terrible, were humans able to experience it.
A surface lander is due to touch down on 12th November. Philae will take seven hours to land and is equipped with a 1024 x 1024 pixel CCD. If all goes according to plan, this will take images both during its final descent phase and on the surface, when the camera will be 30 cm above the ground. Its field of view will be roughly 30 x 30 cm, giving a resolution of 0.3 mm/pixel. You can follow the latest developments on the ESA blog (where many more images can be found) and via Twitter @ ESA_Rosetta.
Astronomers have detected what appears to be a signature of "axions" – dark matter particle candidates. If confirmed, this would be the first direct detection and identification of the elusive substance, which has been a mystery in physics for over 30 years.
XMM-Newton observatory. Credit: ESA
A landmark paper by Professor George Fraser – who tragically died earlier this year – and colleagues from the University of Leicester offers what is potentially the first direct detection of dark matter. This hypothetical form of matter comprises 85% of the Universe, but neither emits nor absorbs light or other electromagnetic radiation in any significant way. Its existence is only known because of the gravitational pull it has on objects. In other words, it is what holds everything together, and without it, galaxies would unravel and fly apart.
The study – to be published on 20th October in the Monthly Notices of the Royal Astronomical Society – looked at 15 years of measurements taken by the European Space Agency's orbiting XMM-Newton observatory; almost its entire archive of data. A curious signal was seen in the X-ray sky which had no conventional explanation, but is now believed to have been the result of axions. Previous searches for these particles, notably at CERN, and with other spacecraft in Earth orbit, have so far proved unsuccessful.
“The X-ray background – the sky, after the bright X-ray sources are removed – appears to be unchanged whenever you look at it,” says Dr. Andy Read from the University of Leicester's Department of Physics and Astronomy and now leading the paper. “However, we have discovered a seasonal signal in this X-ray background, which has no conventional explanation, but is consistent with the discovery of axions.”
As the late Professor Fraser explains in the paper: “It appears plausible that axions – dark matter particle candidates – are indeed produced in the core of the Sun and do indeed convert to X-rays in the magnetic field of the Earth.”
A sketch (not to scale) showing axions (blue) streaming out from the Sun, converting in the Earth's magnetic field (red) into X-rays (orange), which are then detected by the XMM-Newton observatory. Credit: University of Leicester
It is predicted that the X-ray signal due to axions will be greatest when looking through the sunward side of the magnetic field, because this is where the field is strongest. Each of these ghostly particles is extraordinarily light, with a vanishingly small mass just 1/100 billionth that of an electron or a million times less than a neutrino.
Dr. Read concludes: “These exciting discoveries, in George's final paper, could be truly ground-breaking, potentially opening a window to new physics, and could have huge implications, not only for our understanding of the true X-ray sky, but also for identifying the dark matter that dominates the mass content of the cosmos.”
President of the Royal Astronomical Society, Professor Martin Barstow: “This is an amazing result. If confirmed, it will be first direct detection and identification of the elusive dark matter particles and will have a fundamental impact on our theories of the Universe.”
We may know a lot more about dark matter in the coming years – thanks to a string of new observatories including the Euclid Space Telescope (2020), the European Extremely Large Telescope (2022) and the Advanced Technology Large-Aperture Space Telescope (2025). Dr. Read's team also plans to double the dataset from XMM-Newton and look at the results with more precision over the next few years.
NASA has announced finding several Kuiper Belt Objects that may be targeted by the New Horizons spacecraft, following its flyby of the Pluto system in July 2015.
Peering into the dim, outer reaches of our Solar System, NASA's Hubble Space Telescope has uncovered three Kuiper Belt Objects (KBOs) that the agency's New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015. The KBOs were detected by a search team who were awarded telescope time for this purpose, following a committee recommendation earlier this year.
"This has been a very challenging search, and it's great that in the end Hubble could accomplish a detection — one NASA mission helping another," said Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado, principal investigator of the New Horizons mission.
The Kuiper Belt is a vast rim of primordial debris encircling our Solar System. KBOs belong to a unique class of Solar System objects that has never been visited by spacecraft and which contain clues to the origin of our Solar System.
The KBOs that Hubble found are each about 10 times larger than typical comets, but only about 1-2 percent of the size of Pluto. Unlike asteroids, KBOs have not been heated by the Sun, and are thought to represent a pristine, well preserved, deep-freeze sample of what the outer Solar System was like following its birth 4.6 billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto.
The New Horizons team started to look for suitable KBOs in 2011 using some of the largest ground-based telescopes on Earth. They found several dozen KBOs, but none were reachable within the fuel supply available aboard the New Horizons spacecraft.
"We started to get worried that we could not find anything suitable – even with Hubble – but in the end, the space telescope came to the rescue," said team member John Spencer of SwRI. "There was a huge sigh of relief when we found suitable KBOs; we are 'over the moon' about this detection."
Following an initial proof of concept of the Hubble pilot observing program in June, the New Horizons team was awarded telescope time by the Space Telescope Science Institute for a wider survey in July. When the search was completed in early September, the team identified one KBO that is "definitely reachable" and two other potentially accessible KBOs that will require more tracking over several months to know whether they too are accessible by the New Horizons spacecraft.
This was a needle-in-a-haystack search for the New Horizons team, because the elusive KBOs are extremely small, faint, and difficult to pick out against myriad background stars in the constellation Sagittarius, which is in the present direction of Pluto. The three KBOs identified are each 1 billion miles beyond Pluto. Two of the KBOs are estimated to be as large as 34 miles (55 km) across, and the third is perhaps as small as 15 miles (25 km).
The New Horizons spacecraft, launched in 2006 from Florida, is the first mission in NASA's New Frontiers Program. Once a NASA mission completes its prime mission, the agency conducts an extensive science and technical review to determine whether extended operations are warranted.
The New Horizons team expects to submit such a proposal to NASA in late 2016 for an extended mission to fly by one of the newly identified KBOs. Hurtling across the Solar System, the New Horizons spacecraft would reach the distance of 4 billion miles from the Sun roughly three to four years after its July 2015 Pluto encounter. Accomplishing such a KBO flyby would substantially increase the science return from the New Horizons mission.
New measurements reveal there is half as much dark matter in our galaxy as previously thought, solving the 15-year-old "missing satellite galaxy" problem.
Credit: ESO/L. Calçada
New measurements of dark matter in our own Milky Way galaxy reveal there is half as much of the mysterious substance as previously thought. Astronomers from the International Centre for Radio Astronomy Research (ICRAR) used a method developed almost 100 years ago to discover that the weight of dark matter in our galaxy is 800 billion (or 8 x 1011) times the mass of the Sun. They probed the edge of the Milky Way, looking closely, for the first time, at the fringes about 5 million trillion kilometres from Earth.
Astrophysicist Dr Prajwal Kafle said we have known for a while that most of the Universe is hidden:“Stars, dust, you and me, all the things that we see, only make up about 4 per cent of the entire Universe. About 25 per cent is dark matter and the rest is dark energy.”
Dr Kafle was able to measure the mass of the dark matter in the Milky Way by studying the speed of stars throughout the galaxy, including the edges, which had never been studied in this detail before. He used a robust technique developed by British astronomer James Jeans in 1915 – decades before the discovery of dark matter. This new calculation helps to solve a mystery that has been haunting theorists for almost two decades.
“The current idea of galaxy formation and evolution – called the Lambda Cold Dark Matter theory – predicts that there should be a handful of big satellite galaxies around the Milky Way that are visible with the naked eye, but we don’t see that,” Dr Kafle said. “When you use our measurement of the mass of dark matter, the theory predicts that there should only be three satellite galaxies out there, which is exactly what we see; the Large Magellanic Cloud, the Small Magellanic Cloud and the Sagittarius Dwarf Galaxy.”
University of Sydney astrophysicist Prof. Geraint Lewis, who was also involved in the research, said the missing satellite problem had been “a thorn in the cosmological side for almost 15 years.”
“Dr Kafle’s work has shown that it might not be as bad as everyone thought, although there are still problems to overcome," he said.
The study also presented a holistic model of the Milky Way, which allowed the scientists to calculate several interesting factors, such as the speed required to leave the galaxy.
“Be prepared to hit 550 kilometres per second if you want to escape the gravitational clutches of our galaxy,” Dr Kafle said. “A rocket launched from Earth needs just 11 kilometres per second to leave its surface.”
In a star-forming cloud near the galactic core, chemicals have been discovered that are more similar to amino acids – the building blocks of life – than any previous finding. Furthermore, these are present in abundant quantities.
For the first time, astronomers have detected a carbon-bearing molecule with a "branched" structure in interstellar space. Iso-propyl cyanide (i-C3H7CN) was discovered in a giant gas cloud known as Sagittarius B2, a dense region of star formation measuring 150 light years across, located 390 light years from the centre of the Milky Way.
An international team from the Max Planck Institute for Radio Astronomy (Germany), University of Cologne (Germany) and Cornell University (USA) made the discovery using the Atacama Large Millimeter Array (ALMA) in Chile, which became operational in March 2013. Twenty of the observatory's 12m radio telescopes were aligned towards the galactic core – about 27,000 light years from Earth.
"Thanks to the new capabilities offered by ALMA, we were able to perform a full spectral survey toward Sagittarius B2 at wavelengths between 2.7 and 3.6 mm, with sensitivity and spatial resolution ten times greater than our previous survey," says Arnaud Belloche, lead author of the study. "But this took only a tenth of the time."
The carbon atoms in the molecule feature a branched structure that is unlike the straight-chain backbone of other molecules detected so far. This opens a new frontier in the complexity of molecules found within star-forming regions, and bodes well for the presence of amino acids, for which this branched structure is a key characteristic. While various types of molecules have been detected in space, the hydrogen-rich and carbon-bearing (organic) molecules that are most similar to the ones necessary for life on Earth seem to be most common in the gas clouds where new stars are formed.
"Understanding the production of organic material at the early stages of star formation is critical to piecing together the gradual progression from simple molecules to potentially life-bearing chemistry," says Belloche.
The search for organic molecules in space began in the 1960s, and 180 different molecular species have been discovered so far. Each type of molecule emits light at particular wavelengths, in its own characteristic pattern, acting like a fingerprint that allows it to be detected using radio telescopes.
Until now, the organic molecules discovered in star-forming regions have shared one major structural characteristic: they each consist of a "backbone" of carbon atoms that are arranged in a single and more or less straight chain. The new molecule discovered by the team, iso-propyl cyanide, is unique in that its underlying carbon structure branches off in a separate strand.
"This is the first ever interstellar detection of a molecule with a branched carbon backbone," says co-author Holger Müller, University of Cologne.
In addition to its structure, the researchers were also surprised by its abundance in this region – it was found to be plentiful, at almost half the concentration of its straight-chain sister molecule (normal-propyl cyanide), which the team had already detected a few years ago.
Robin Garrod, an astrochemist at Cornell University: "The enormous abundance of iso-propyl cyanide suggests that branched molecules may in fact be the rule, rather than the exception, in the interstellar medium."
"Amino acids identified in meteorites have a composition that suggests they originate in the interstellar medium," adds Belloche. “Although no interstellar amino acids have yet been found, interstellar chemistry may be responsible for the production of a wide range of important complex molecules that eventually find their way to planetary surfaces."
"The detection of iso-propyl cyanide tells us that amino acids could indeed be present in the interstellar medium, because the side-chain structure is a key characteristic of these molecules", says Karl Menten, director at Max Planck. "Amino acids have already been identified in meteorites and we hope to detect them in the interstellar medium in the future."
India's first probe to Mars – Mangalyaan – successfully entered orbit at 02:00 UTC this morning.
By Nesnad (Own work), CC-BY-SA-3.0 via Wikimedia Commons
Just three days after NASA's MAVEN mission, the Indian Space Research Organisation (ISRO) has successfully delivered its first unmanned craft to Mars, becoming only the fourth agency to do so. Launched in November 2013, the Mars Orbiter Mission (MOM), also called Mangalyaan ("Mars-craft") was developed at a cost of only $74 million, nine times less than the $671 million spent on NASA's effort. This morning, after a journey of 422 million miles (680 million km), MOM fired its main motors along with eight smaller engines to reduce its velocity as it approached the Red Planet, before entering into a highly elliptical orbit of 261 x 48,000 miles (421 x 77,000 km).
In the coming weeks, the spacecraft will be thoroughly tested to ensure it is fully functional, before commencing observations of the planet using a suite of five scientific instruments: a Lyman-alpha photometer, methane sensor, exospheric neutral composition analyser, thermal infrared imaging and a colour camera providing images in the visual spectrum. With a mission duration of six months, it will study Mars' surface features, morphology, mineralogy, atmosphere and weather systems. It has autonomous features to handle contingency situations.
Including MOM, a total of five satellites are now actively orbiting Mars. The others are MAVEN (US), Mars Odyssey (US), Mars Reconnaissance Orbiter (US) and Mars Express (Europe). In addition, two rovers are operational on the surface – Opportunity and Curiosity.
The Prime Minister of India, Narendra Modi, applauded those who achieved the historic rendezvous: "Today, all of India should celebrate our scientists. Schools, colleges should applaud this. If our cricket team wins a tournament, the nation celebrates. Our scientists' achievement is greater."
Mars missions have been notorious for their high failure rate. India has now become the first country to make it to Mars on its first attempt: "The odds were stacked against us," added Modi. "Of the 51 missions attempted across the world so far, a mere 21 had succeeded. But we have prevailed."
ISRO plans to send a follow-up mission with a greater scientific payload in the 2017-2020 timeframe; this will include an orbiter and a stationary lander. Several other missions are planned by NASA and Europe. Another country with ambitions to reach Mars is the United Arab Emirates (UAE), which plans to send a spacecraft in 2021.
You can follow India's Mars mission on Twitter @ MarsOrbiter.
The latest mission to Mars will attempt to uncover new clues about why the planet lost its atmosphere and surface water billions of years ago.
Another entry on our timeline is becoming a reality, as the Mars Atmosphere and Volatile EvolutioN (MAVEN) probe has successfully entered Mars' orbit. Launched by an Atlas V rocket in November 2013, the spacecraft travelled 442 million miles (711 million km) to reach its destination. As it approached the Martian north pole last night, MAVEN performed a 33-minute burn to reduce its speed, a manoeuvre that consumed over half its fuel. This allowed it to be captured by the planet's gravity and inserted into an elliptical orbit, with arrival confirmed shortly before 0230 GMT (2230 EDT Sunday; 0330 BST).
Using a total of eight instruments, MAVEN will now begin studying the Red Planet’s upper atmosphere and its interactions with the solar wind. There is strong evidence that Mars once possessed a denser atmosphere and higher temperatures, allowing vast amounts of liquid water on the surface – possibly including a large ocean that covered one-third of the planet. These conditions may even have been suitable for life to emerge. At some point in the distant past, however, Mars lost 99% of its atmosphere to space. It is theorised that over millions of years, the planet's core began to cool and its magnetic field decayed, allowing the solar wind to sweep away most of the water and volatile compounds that the atmosphere once contained.
The goal of MAVEN is to determine the history of the Martian atmosphere and its climate evolution. By measuring the rate at which gases are currently escaping to space and gathering knowledge about the relevant processes, researchers will be able to infer how the atmosphere changed over time. During the next twelve months, a series of "deep dips" will occur at 77 miles (125 km) minimum altitude to sample the upper atmosphere. This data will provide information down to where the upper and lower atmospheres meet, giving scientists a full profile of the upper tier.
MAVEN is the first probe to study the tenuous upper atmosphere of Mars in such detail. It will also examine the Sun's influence, looking at how much energy it puts into the planet and its climate. By chance, a comet will pass extremely close to Mars next month, offering a rare opportunity to see how incoming water and other molecules affect the physical processes. You can follow the mission progress at nasa.gov/maven and Twitter/MAVEN2Mars.
Artist's impression of what ancient Mars may have looked like, based on geological data. Credit: Ittiz [CC-BY-SA-3.0]
Since the retirement of the Space Shuttle fleet in 2011, NASA has been reliant on Russia for delivering manned flights to low-Earth orbit. The agency has been charged upwards of $70 million per person for rides on Russian Soyuz capsules. Russia's monopoly on space transportation looks set to end, however, as two major contracts worth $6.8 billion have just been awarded to Boeing and SpaceX.
From 2017, SpaceX's Falcon 9 launch vehicle and Dragon spacecraft – alongside Boeing's Crew Space Transportation (CST)-100 – will deliver astronauts to the International Space Station (ISS). Prior to these services, the contracts will include at least one crewed test flight per company. Once the launch, manoeuvring and docking systems have been validated, as many as six crewed missions will be undertaken by each company. These spacecraft will also serve as lifeboats for astronauts aboard the ISS.
According to NASA Administrator Charlie Bolden, turning over low-Earth orbit transportation to private industry will allow NASA to focus on an even more ambitious mission – sending humans to Mars. The agency recently completed a review of its Space Launch System, the rocket intended to carry humans to the Red Planet, and has reaffirmed its commitment to achieving this goal during the 2030s.
Astronomers have discovered the first evidence of water ice clouds on an object outside our own Solar System.
W0855 is the fourth closest system to our Sun, at 7.3 light-years away. In this illustration, the Sun is the bright star directly to the right of the brown dwarf. The slightly shifted star field accurately reflects how the sky around the constellations of Aquila and Delphinus would appear from this vantage point.
Scientists at the Carnegie Institution of Washington report the first evidence of water ice clouds on a body outside of our own Solar System. Water ice clouds are present on the gas giants – Jupiter, Saturn, Uranus, and Neptune – but have never been seen outside the planets orbiting our Sun until now. This finding is published by The Astrophysical Journal Letters.
At the Las Campanas Observatory in Chile, a near-infrared camera was used to detect WISE 0855–0714 (also called W0855) a tiny sub-brown dwarf located approximately 7.3 light years from Earth. This was first seen by a NASA space telescope – Wide-Field Infrared Survey Explorer – and confirmed in April 2014. But it was not known if the object could be seen by ground-based facilities. The Carnegie researchers managed to obtain 151 images from Las Campanas over a period of three nights.
"This was a battle at the telescope to get the detection," said Jacqueline Faherty, who led the study.
Chris Tinney, co-author on the result, stated: "This is a great result. This object is so faint and it’s exciting to be the first people to detect it with a telescope on the ground."
Brown dwarfs are too small to be classified as stars, but too large to be considered planets. Because of their size, they are too small to sustain the hydrogen fusion process that fuels stars. Their temperatures can range from nearly as hot as a star to as cool as a planet, and their masses also range between star-like and giant planet-like. They are of particular interest to scientists because they offer clues to star-formation processes. They also overlap with the temperatures of planets, but are much easier to study since they are commonly found in isolation.
W0855 is the fourth closest system to our own, practically next door in terms of astronomical distances. It is also the coldest object of its type found in interstellar space, having a temperature between 225 to 260 K (−48 to −13°C; −55 to 8°F). A comparison of near-infrared images of W0855 with models for predicting the atmospheric content of brown dwarfs showed evidence of frozen clouds of sulfide and water.
"Ice clouds are predicted to be very important in the atmospheres of planets beyond our Solar System, but they've never been observed outside of it before now," Faherty said.
The next generation of telescopes – such as the E-ELT (2022), PLATO observatory (2024-2030) and the ATLAST project (2025-2035) – will provide more detailed views of planets' and brown dwarfs' atmospheres.