The detection of the heavy metals iron (Fe) and nickel (Ni) in the fuzzy atmosphere of a comet are illustrated in this image, which features the spectrum of light of C/2016 R2 (PANSTARRS) on the top left superimposed to a real image of the comet taken with the SPECULOOS telescope at ESO’s Paranal Observatory. Each white peak in the spectrum represents a different element, with those for iron and nickel indicated by blue and orange dashes, respectively. Spectra like these are possible thanks to the UVES instrument on ESO’s VLT, a high-resolution spectrograph that spreads the line so much they can be individually identified. In addition, UVES remains sensitive down to wavelengths of 300nm. Most of the important iron and nickel lines appear at wavelengths of around 350nm, meaning that the capabilities of UVES were essential in making this discovery. Credit:ESO/L. Calçada, SPECULOOS Team/E. Jehin, Manfroid et al.
“It was a big surprise to detect iron and nickel atoms in the atmosphere of all the comets we have observed in the last two decades, about 20 of them, and even in ones far from the Sun in the cold space environment,” says Jean Manfroid from the University of Liège, Belgium, who lead the new study on Solar System comets published today in Nature.
Astronomers know that heavy metals exist in comets’ dusty and rocky interiors. But, because solid metals don’t usually sublimate (become gaseous) at low temperatures, they did not expect to find them in the atmospheres of cold comets that travel far from the Sun. Nickel and iron vapors have now even been detected in comets observed at more than 480 million kilometers from the Sun, more than three times the Earth-Sun distance.
The Belgian team found iron and nickel in comets’ atmospheres in approximately equal amounts. Material in our Solar System, for example that found in the Sun and in meteorites, usually contains about 10 times more iron than nickel. This new result therefore has implications for astronomers’ understanding of the early Solar System, though the team is still decoding what these are.
“Comets formed around 4.6 billion years ago, in the very young Solar System, and haven’t changed since that time. In that sense, they’re like fossils for astronomers,” says study co-author Emmanuel Jehin, also from the University of Liège. While the Belgian team has been studying these “fossil” objects with ESO’s VLT for nearly 20 years, they had not spotted the presence of nickel and iron in their atmospheres until now. “This discovery went under the radar for many years,” Jehin says.
The May 10, 2021 membership meeting of the Cuyahoga Astronomical Association (CAA) will take place via the Zoom online service beginning at 7:30 p.m.
The evening’s speaker will be Kelly Beatty, Senior Editor of Sky & Telescope magazine, whose talk is entitled “Darkness in Distress”
Light pollution, simply put, is any unnecessary or excessive outdoor illumination. Sadly, it has become a pervasive and ugly consequence of modern 24/7 society. Light pollution robs us of the night sky’s beauty, negatively affects the ecosystem, and creates an in-your-face waste of energy. But a new mindset and new technology are poised to slow — and perhaps reverse — this bane of modern life. Learn how you can safely light up your home, business, and community without wasting energy, disturbing your neighbors, or creating an unhealthy environment for humans and wildlife.
Beatty has been explaining the science and wonder of astronomy to the public since 1974. An award-winning writer and communicator, he is a Senior Editor for Cambridge-based Sky & Telescope magazine. He enjoys sharing his passion for astronomy with a wide spectrum of audiences, from children to professional astronomers, and you’ll occasionally hear his interviews and guest commentaries on National Public Radio and The Weather Channel. He served for a decade on the Board of Directors for the International Dark-Sky Association.
The new Test-Bed Telescope 2, a European Space Agency telescope, is housed inside the shiny white dome shown in this picture, at ESO’s La Silla Observatory in Chile. The telescope has now started operations and will assist its northern-hemisphere twin in protecting us from potentially hazardous, near-Earth objects. The domes of ESO’s 0.5 m and the Danish 0.5 m telescopes are visible in the background of this image. Credit: I. Saviane/ESO
Part of the world-wide effort to scan and identify near-Earth objects, the European Space Agency’s Test-Bed Telescope 2 (TBT2), a technology demonstrator hosted at ESO’s La Silla Observatory in Chile, has now started operating. Working alongside its northern-hemisphere partner telescope, TBT2 will keep a close eye on the sky for asteroids that could pose a risk to Earth, testing hardware and software for a future telescope network.
“To be able to calculate the risk posed by potentially hazardous objects in the Solar System, we first need a census of these objects. The TBT project is a step in that direction,” says Ivo Saviane, the site manager for ESO’s La Silla Observatory in Chile.
The project, which is a collaboration between the European Southern Observatory (ESO) and the European Space Agency (ESA), “is a test-bed to demonstrate the capabilities needed to detect and follow-up near-Earth objects with the same telescope system,” says ESA’s Head of the Optical Technologies Section Clemens Heese, who is leading this project.
An engineer guides the telescope structure of the Test-Bed Telescope 2 carefully into place as it is lowered into its sheltering dome at ESO’s La Silla Observatory. Credit: P. Sinclaire/ESO
The 56-cm telescope at ESO’s La Silla and TBT1, its identical counterpart located at the ESA’s deep-space ground station at Cebreros in Spain, will act as precursors to the planned ‘Flyeye’ telescope network, a separate project that ESA is developing to survey and track fast-moving objects in the sky. This future network will be entirely robotic; software will perform real-time scheduling of observations and, at the end of the day, it will report the positions and other information about the objects detected. The TBT project is designed to show that the software and hardware work as expected.
“The start of observations of TBT2 at La Silla will enable the observing system to work in its intended two-telescope configuration, finally fulfilling the project’s objectives,” says Heese.
While seriously harmful asteroid impacts on Earth are extremely rare, they are not inconceivable. Earth has been periodically bombarded with both large and small asteroids for billions of years, and the 2013 Chelyabinsk meteor event, which caused some 1,600 injuries, most due to flying splinters and broken glass, further raised the public’s awareness of the threat posed by near-Earth objects. Larger objects do more damage, but are thankfully easier to spot and the orbits of known large asteroids are already thoroughly studied. However, it is estimated that there are large numbers of smaller, yet-undiscovered objects we are unaware of that could do serious damage if they were to hit a populated area.
That’s where TBT and the future planned network of Flyeye telescopes come in. Once fully operational the network’s design would allow it to survey the night sky to track fast-moving objects, a significant advancement in Europe’s capacity to spot potentially hazardous near-Earth objects.
Shown in this screen grab from a video, the small “Ingenuity” rotorcraft made history, hovering above Jezero Crater, demonstrating that powered, controlled flight on another planet is possible. The video including this image was captured by the Perseverance rover parked nearby. Image Credit: NASA/JPL
April 19, 2021 — NASA’s Ingenuity Mars Helicopter became the first aircraft in history to make a powered, controlled flight on another planet. The Ingenuity team at the agency’s Jet Propulsion Laboratory in Southern California confirmed the flight succeeded after receiving data from the helicopter via NASA’s Perseverance Mars rover at 6:46 a.m. EDT (3:46 a.m. PDT).
A tight crop from a video frame showing the Ingenuity Mars Helicopter during its historic first flight on Mars. The video including this image was captured by the Perseverance rover parked nearby. Image Credit: NASA/JPL
The solar-powered helicopter first became airborne at 3:34 a.m. EDT (12:34 a.m. PDT) – 12:33 Local Mean Solar Time (Mars time) – a time the Ingenuity team determined would have optimal energy and flight conditions. Altimeter data indicate Ingenuity climbed to its prescribed maximum altitude of 10 feet (3 meters) and maintained a stable hover for 30 seconds. It then descended, touching back down on the surface of Mars after logging a total of 39.1 seconds of flight.
CAA: Cuyahoga Astronomical Association 