Asteroid, companion of planet Earth, discovered


This NASA video says about itself:

Asteroid 2016 HO3Earth’s Constant Companion

15 Jun. 2016

A small asteroid has been discovered in an orbit around the sun that keeps it as a constant companion of Earth, and it will remain so for centuries to come. Full story here.

Pharaoh Tutankhamun’s meteorite dagger


Tutankhamun's dagger

From Meteoritics & Planetary Science:

The meteoritic origin of Tutankhamun’s iron dagger blade

20 MAY 2016

Abstract

Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations. The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age. Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron. Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis.

Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results. We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x-ray fluorescence spectrometry, strongly supports its meteoritic origin.

In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects. Moreover, the high manufacturing quality of Tutankhamun‘s dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun‘s time.

Tutankhamun's meteorite scarab in brooch

From Astronomy magazine, 1 June 2016:

The dagger was not the only relic in King Tut’s possession that was rare and unusual; he also possessed a scarab necklace made of silica glass that might have been created by the heat of a meteorite impacting the desert sand and melting it down.

Three ‘Earth-like’ planets discovered


This video says about itself:

Three New Earth-Like Planets orbiting Star TRAPPIST 1 Might Be Our Best Bet For Finding Life

2 May 2016

The three Earth-like planets around the Star TRAPPIST-1 were discovered using transit method, only detection method currently available to us.

The Transit method looks for dims in star light as planets pass in front of it, the amount of dimming determines the size of the planet and location of the planet.

Belgian astronomers discovered the three potentially habitable Earth-like planets orbiting an ultracool dwarf star, named TRAPPIST-1, about 40 light-years from Earth. These are some of the smallest exoplanets ever discovered, with a radius only slightly bigger than Earth’s, and they are the first planets discovered around an ultracool dwarf – a dim star not much bigger than Jupiter. Their results are published in Nature.

The most exciting thing about this discovery, made by the Belgian TRAPPIST telescope as the planets passed in front of the star, is that these planets are close enough for us to study. Many of the other potentially habitable worlds we’ve found are much further away and around much brighter stars, making them more difficult to observe.

“These are the first planets similar in size and temperature to Earth and Venus for which we can study the atmospheric composition in detail, and really constrain the surface conditions and habitability,” lead author Dr. Michaël Gillon from the University of Liège told IFLScience.

At first glance, the system might not seem that promising. Two of the planets, TRAPPIST- 1b and c, have years lasting about 1.5 and 2.4 Earth days respectively, meaning they orbit very closely, while TRAPPIST-1d has a less well determined period in the range of 4.5 to 73 days. However, the star has a surface temperature of only 2,550 Kelvins (2,277°C / 4,130 °F ), so they are unlikely to be inferno worlds. Instead, they could be quite the opposite.

The closest two planets receive no more than four times the amount of radiation received by Earth, while the furthest planet likely receives less. This puts the planets at the edges of the star’s habitable zone, the region in which liquid water can exist. It’s not certain if the planets are solid, but TRAPPIST-1 is rich in heavy elements, which indicates a suitable evironment for rocky planets to form.

The planets have a radius of 1.11, 1.05, and 1.16 times that of Earth, which combined with their locations strongly indicates that these objects possess some of the right conditions for life. The planets’ temperatures could range from slightly higher than water’s boiling point to well below freezing.

Tune used in this video is: Surfing Llama and artist name is Bird Creek.

By Michael McLaughlin in the USA:

Astronomers Find 3 ‘Temperate’ Planets That May Support Life

The Earth-like planets are the first ones found orbiting an ultracool dwarf star.

05/02/2016 06:30 pm ET

Astronomers say three recently discovered planets similar to Earth’s size and temperature may have conditions that could sustain life.

An international team observed the three planets orbiting a reddish, ultracool dwarf star, once thought too dim to anchor a solar system. Their research, published in the journal Nature on Monday, said these are the first planets ever seen orbiting an ultracool dwarf star.

“Systems around these tiny stars are the only places where we can detect life on an Earth-sized exoplanet with our current technology,” co-author Michael Gillon, of the University of Liege in Belgium, said in a statement. “So if we want to find life elsewhere in the universe, this is where we should start to look.”

Previously, scientists have only found exoplanets — planets that do not orbit our sun — with conditions unlike Earth’s. In November, for instance, a rocky, Earth-sized planet was found 39 light years away, but its temperature was estimated at 300 degrees to 600 degrees. The discovery of the three potentially habitable planets may encourage researchers to look more closely at the huge numbers of ultracool dwarf stars.

The three planets orbit a star in the Aquarius constellation named Trappist-1, which is about the size of Jupiter. But the planets are close enough to the star to have “temperate” conditions on their surface, MIT researcher Julien De Wit told NPR.

The planets are about 40 light years from Earth — making them nearby in galactic terms.

The nearness and their star’s dimness will make it easier for scientists to study the exoplanets, which are often tough to analyze when orbiting a distant, bright star.

Each of the planets has a side that’s perpetually in daylight and another side that’s completely dark. The most likely region to support life would be along the line separating day and night, where temperatures would be less extreme, according to Gizmodo.

The nearest two planets complete their revolutions around the star in 1.5 days and 2.4 days. Scientists haven’t completely charted the last planet’s orbit, but it could take from 4.5 to 72.8 days.

Astronomers don’t yet know what the planets are made of, and want to check for liquid water, the foundation for life.

Researchers may get further information about the atmospheric conditions after monitoring what happens to the star’s light when the planets pass in front of it, according to The Verge. The presence of different gases on the planets will cause the light to behave differently.

The team used the Trappist telescope in Chile to study 60 stars too dim to see with the naked eye, according to Gizmodo. NASA’s planned launch of the James Webb Space Telescope in 2018 could be useful, as one of its missions is to search for solar systems supporting life.

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.