Tailless comet discovery


This video says about itself:

28 April 2016

Observations with ESO’s Very Large Telescope, and the Canada France Hawai`i Telescope, show that C/2014 S3 (PANSTARRS) is the first object to be discovered that is on a long-period cometary orbit, but that has the characteristics of a pristine inner Solar System asteroid. It may provide important clues about how the Solar System formed.

This video shows the probable history of this object in both the inner and outer Solar System over a period of more than four billion years.

From the European Southern Observatory:

Unique Fragment from Earth’s Formation Returns after Billions of Years in Cold Storage

Tailless Manx comet from Oort Cloud brings clues about the origin of the Solar System

29 April 2016

Astronomers have found a unique object that appears to be made of inner Solar System material from the time of Earth’s formation, which has been preserved in the Oort Cloud far from the Sun for billions of years. Observations with ESO’s Very Large Telescope, and the Canada France Hawai`i Telescope, show that C/2014 S3 (PANSTARRS) is the first object to be discovered on a long-period cometary orbit that has the characteristics of a pristine inner Solar System asteroid. It may provide important clues about how the Solar System formed.

In a paper to be published today in the journal Science Advances, lead author Karen Meech of the University of Hawai`i’s Institute for Astronomy and her colleagues conclude that C/2014 S3 (PANSTARRS) formed in the inner Solar System at the same time as the Earth itself, but was ejected at a very early stage.

Their observations indicate that it is an ancient rocky body, rather than a contemporary asteroid that strayed out. As such, it is one of the potential building blocks of the rocky planets, such as the Earth, that was expelled from the inner Solar System and preserved in the deep freeze of the Oort Cloud for billions of years [1].

Karen Meech explains the unexpected observation: “We already knew of many asteroids, but they have all been baked by billions of years near the Sun. This one is the first uncooked asteroid we could observe: it has been preserved in the best freezer there is.”

C/2014 S3 (PANSTARRS) was originally identified by the Pan-STARRS1 telescope as a weakly active comet a little over twice as far from the Sun as the Earth. Its current long orbital period (around 860 years) suggests that its source is in the Oort Cloud, and it was nudged comparatively recently into an orbit that brings it closer to the Sun.

The team immediately noticed that C/2014 S3 (PANSTARRS) was unusual, as it does not have the characteristic tail that most long-period comets have when they approach so close to the Sun. As a result, it has been dubbed a Manx comet, after the tailless cat. Within weeks of its discovery, the team obtained spectra of the very faint object with ESO’s Very Large Telescope in Chile.

Careful study of the light reflected by C/2014 S3 (PANSTARRS) indicates that it is typical of asteroids known as S-type, which are usually found in the inner asteroid main belt. It does not look like a typical comet, which are believed to form in the outer Solar System and are icy, rather than rocky. It appears that the material has undergone very little processing, indicating that it has been deep frozen for a very long time. The very weak comet-like activity associated with C/2014 S3 (PANSTARRS), which is consistent with the sublimation of water ice, is about a million times lower than active long-period comets at a similar distance from the Sun.

The authors conclude that this object is probably made of fresh inner Solar System material that has been stored in the Oort Cloud and is now making its way back into the inner Solar System.

A number of theoretical models are able to reproduce much of the structure we see in the Solar System. An important difference between these models is what they predict about the objects that make up the Oort Cloud. Different models predict significantly different ratios of icy to rocky objects. This first discovery of a rocky object from the Oort Cloud is therefore an important test of the different predictions of the models. The authors estimate that observations of 50–100 of these Manx comets are needed to distinguish between the current models, opening up another rich vein in the study of the origins of the Solar System.

Co-author Olivier Hainaut (ESO, Garching, Germany), concludes: “We’ve found the first rocky comet, and we are looking for others. Depending how many we find, we will know whether the giant planets danced across the Solar System when they were young, or if they grew up quietly without moving much.”

Notes

[1] The Oort cloud is a huge region surrounding the Sun like a giant, thick soap bubble. It is estimated that it contains trillions of tiny icy bodies. Occasionally, one of these bodies gets nudged and falls into the inner Solar System, where the heat of the sun turns it into a comet. These icy bodies are thought to have been ejected from the region of the giant planets as these were forming, in the early days of the Solar System.

More information

This research was presented in a paper entitled “Inner Solar System Material Discovered in the Oort Cloud”, by Karen Meech et al., in the journal Science Advances.

The team is composed of Karen J. Meech (Institute for Astronomy, University of Hawai`i, USA), Bin Yang (ESO, Santiago, Chile), Jan Kleyna (Institute for Astronomy, University of Hawai`i, USA), Olivier R. Hainaut (ESO, Garching, Germany), Svetlana Berdyugina (Institute for Astronomy, University of Hawai’i, USA; Kiepenheuer Institut für Sonnenphysik, Freiburg, Germany), Jacqueline V. Keane (Institute for Astronomy, University of Hawai`i, USA), Marco Micheli (ESA, Frascati, Italy), Alessandro Morbidelli (Laboratoire Lagrange/Observatoire de la Côte d’Azur/CNRS/Université Nice Sophia Antipolis, France) and Richard J. Wainscoat (Institute for Astronomy, University of Hawai`i, USA).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links

See also here.

Tailless comet C/2014 S3, artist's impression

Planet Mercury transit, 9 May


This video says about itself:

7 April 2016

A transit of Mercury is taking place on 9th May 2016. This is a relatively a rare event: there will be another on 11th November 2019 but, after that, you’ll have to wait until 2032! Learn more here. …

Planets and the Sun on the animation are not to scale.

Dwarf planet Makemake’s moon discovery


This video from the USA says about itself:

NASA’s Hubble Discovers Moon Orbiting Dwarf Planet Makemake

26 April 2016

Astronomers using the Hubble Space Telescope discovered a moon orbiting dwarf planet Makemake — the third largest known object past the orbit of Neptune, about two thirds the size of Pluto. Further observations of this moon may allow astronomers to calculate Makemake’s mass, which will give them a better idea of its density and thus its bulk composition. The Hubble Space Telescope has been instrumental in studying our outer solar system; it also discovered four of the five moons orbiting Pluto.

See also here. And here.

‘Dinosaur decline already before mass extinction’


This video from Britain says about itself:

Dinosaurs in decline BEFORE asteroid apocalypse

18 April 2016

Dinosaurs were already in an evolutionary decline tens of millions of years before the asteroid impact that finally wiped them out, scientists from the University of Reading and University of Bristol have found. Read more here.

Dr Manabu Sakamoto and Dr Chris Venditti, University of Reading, explain more.

This research was published on 18 April 2016 in the journal PNAS.

Filming took place in the Cole Museum of Zoology, University of Reading.

Asteroid animation courtesy of NASA.

See also here.

Unusual exoplanet discovery


This video says about itself:

30 March 2016

Artist’s impression of 55 Cancri e orbiting its parent star. Credit: NASA/JPL-Caltech.

By Ed Mazza in the USA:

Half Lava & Half Rock, 5 Cancri E Might Be The Weirdest Exoplanet Ever Discovered

Strange world is just 40 light years away.

03/31/2016 03:41 am ET

Nearly 2,000 planets have been discovered outside our solar system, but this just might be the strangest one yet.

A lava-loaded “super earth” called 55 Cancri e is twice the size of our own planet but eight times as dense. And it’s so close to its star that a year lasts only 18 hours.

Just 40 light years away, 55 Cancri e may also be tidally locked to its sun the way the moon is to Earth. One side would be a blazing hot eternal night with temperatures of 2,000 degrees Fahrenheit, and the other an even hotter permanent day, according to a heat map of the planet published in the journal Nature that used data from NASA’s Spitzer Space Telescope.

“The day side could possibly have rivers of lava and big pools of extremely hot magma, but we think the night side would have solidified lava flows like those found in Hawaii,” Michael Gillon of the University of Liège in Belgium said in a news release.

Thanks to radiation and solar winds, 55 Cancri e may leave a trail of dust behind it — like a planetary Pigpen — as it races around its sun.

The planet may even resemble Mustafar, the molten world in the “Star Wars” universe where Obi-Wan Kenobi fought Anakin Skywalker.

55 Cancri e is so hot that the atmosphere may have completely evaporated, the researchers said. They believe it’s possible the planet still has an atmosphere, but only on the night side.

Because 55 Cancri e is so close, it has been extensively studied, yet researchers remain torn on the nature of the planet. At one point, it was believed to be a world covered in water. At another, researchers thought it might be made of diamond.

Now, they are leaning toward a blazing world of lava.

“We still don’t know exactly what this planet is made of — it’s still a riddle,” Brice-Olivier Demory of the University of Cambridge’s Cavendish Laboratory said in a news release. “These results are like adding another brick to the wall, but the exact nature of this planet is still not completely understood.”

Jupiter collision with comet or asteroid, video


This video, recorded in Ireland, says about itself:

Jupiter Collision! Impact Burst Captured By Amateur Astronomer

29 March 2016

John McKeon captured an impact on the gas giant on March 17th, 2016 (00:18:45 UT). The video was snapped using an 11″ SCT with an ASI120mm camera and Ir-pass 742nm filter. It was most likely an asteroid or comet colliding with Jupiter. — Full story here.

Credit: John McKeon / Edited by Space.com

See also here.

New telescope use improves astronomers’ quasar science


This video says about itself:

13 August 2015

The Spektr-R[6] (or RadioAstron) is a Russian scientific satellite with a 10 m (33 ft) radio telescope on board. It rivals the U.S Hubble space telescope. It was launched on the 18th of July 2011. Uses in astrophysics, cosmology, studies of black holes and exoplanets etc.

From Space Fellowship:

Earth-Space Telescope System Produces Hot Surprise

Published by Klaus Schmidt on Tue Mar 29, 2016 8:43 pm

Astronomers using an orbiting radio telescope in conjunction with four ground-based radio telescopes have achieved the highest resolution, or ability to discern fine detail, of any astronomical observation ever made. Their achievement produced a pair of scientific surprises that promise to advance the understanding of quasars, supermassive black holes at the cores of galaxies.

The scientists combined the Russian RadioAstron satellite with the ground-based telescopes to produce a virtual radio telescope more than 100,000 miles across. They pointed this system at a quasar called 3C 273, more than 2 billion light-years from Earth. Quasars like 3C 273 propel huge jets of material outward at speeds nearly that of light. These powerful jets emit radio waves.

Just how bright such emission could be, however, was thought to be limited by physical processes. That limit, scientists thought, was about 100 billion degrees. The researchers were surprised when their Earth-space system revealed a temperature hotter then 10 trillion degrees.

“Only this space-Earth system could reveal this temperature, and now we have to figure out how that environment can reach such temperatures,” said Yuri Kovalev, the RadioAstron project scientist. “This result is a significant challenge to our current understanding of quasar jets,” he added.

The observations also showed, for the first time, substructure caused by scattering of the radio waves by the tenuous interstellar material in our own Milky Way Galaxy.

“This is like looking through the hot, turbulent air above a candle flame,” said Michael Johnson, of the Harvard-Smithsonian Center for Astrophysics. “We had never been able to see such distortion of an extragalactic object before,” he added.

“The amazing resolution we get from RadioAstron working with the ground-based telescopes gives us a powerful new tool to explore not only the extreme physics near the distant supermassive black holes, but also the diffuse material in our home Galaxy,” Johnson said.

The RadioAstron satellite was combined with the Green Bank Telescope in West Virginia, The Very Large Array in New Mexico, the Effelsberg Telescope in Germany, and the Arecibo Observatory in Puerto Rico. Signals received by the orbiting radio telescope were transmitted to an antenna in Green Bank where they were recorded and then sent over the internet to Russia where they were combined with the data received by the ground-based radio telescopes to form the high resolution image of 3C 273.

The astronomers reported their results in the Astrophysical Journal Letters.

In 1963, astronomer Maarten Schmidt of Caltech recognized that a visible-light spectrum of 3C 273 indicated its great distance, resolving what had been a mystery about quasars. His discovery showed that the objects are emitting tremendous amounts of energy and led to the current model of powerful emission driven by the tremendous gravitational energy of a supermassive black hole.

The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in Russia and other countries. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

See also here.