Strange Skies
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Cassiopaea

Supernova could cause mass extinction on Earth

Cassiopeia A
© NASASupernova remnant Cassiopeia A. A supernova might have occurred around the right time and at the right distance from Earth to contribute to a minor mass extinction several million years ago.
An exploding star hundreds of light-years from Earth may have played a role in a minor mass extinction that happened 2.59 million years ago, new research indicates. Scientists modeled the light and radiation that would have reached Earth from relatively close exploding stars, or supernovae.

The impacts on Earth and its lifeforms could help explain the die-off that happened as the Pliocene Epoch wrapped up and the Pleistocene began, they say.

It's generally accepted that several stars have gone supernova about 300 light years from Earth within the past few million years. Recent evidence for these supernovae comes from two studies published in April. In one, researchers traced the amount of iron-60, a radioactive form of iron, in deep-sea crusts.

Iron-60 is catapulted into space by supernovae or in winds from massive stars; its presence can reveal when a star exploded nearby. Scientists found two influxes of iron-60, one about 1.5 to 3.2 million years ago, another at 6.5 to 8.7 million years ago.

Another group calculated the likely trajectories of recent supernovae, and found that the stars were probably nine times the size of our own sun, and exploded about 300 light years from Earth.

In the new study, scientists were curious about how these recent supernovae might have affected life on Earth, as well as our planet's atmosphere. To cause a truly catastrophic extinction, you'd need a supernova within about 26 light-years from Earth.

"This event is not close enough to have precipitated a major mass extinction, but may have had noticeable effects," wrote the researchers, who recently published the findings in Astrophysical Journal Letters.

Bizarro Earth

Incredible nighttime thunderstorm photo captured by pilot over the Pacific Ocean

Thunderstorm
© Santiago BorjaA developing thunderstorm climbs high into the atmosphere over the Pacific Ocean south of Panama.
This is one of the most striking thunderstorm photos we've seen.

Taken from a plane at the moment of a lightning flash, it illustrates both the ferocity of a turbulent atmosphere and the beauty of Mother Nature. A strong, roiling updraft; a smooth, flat anvil; and the overshooting top — all features of intense developing thunderstorms.

The photo was taken over the Pacific Ocean from the cockpit of an airplane. The photographer and pilot, Santiago Borja, says he was circling around it at 37,000 feet altitude en route to South America when he captured this spectacular view.

Borja said it was difficult to get the shot in near-darkness and during a bumpy ride. "Storms are tricky because the lightning is so fast, there is no tripod and there is a lot of reflection from inside lights," Borja told The Washington Post in an email.

"I like this photo so much because you can feel the amazing size of the storm and its power," Borja said. "But at the same time it's wonderful how peacefully you can fly around it in still air without touching it."

The photo was taken with his Nikon D750 camera south of Panama on a Boeing 767-300.

"I primarily enjoy nature, landscape and cityscape photography," Borja said. "Since I carry my camera everywhere, I started trying to capture storms and in-flight experiences some time ago combining my two greatest passions: flying and photography."

Info

New dwarf planet 2015 RR245, discovered beyond Neptune

2015 RR245
© OSSOS/Alex Parker2015 RR245's orbit takes it 120 times further from the Sun than the Earth is.
A new dwarf planet has been discovered beyond Neptune, in the disk of small icy worlds that resides there. The planet was discovered by an international team of astronomers as part of the Outer Solar Systems Origins Survey (OSSOS). The instrument that found it was the Canada-France Hawaii Telescope at Maunakea, Hawaii.

The planet is about 700 km in size, and has been given the name 2015 RR245. It was first sighted by Dr. JJ Kavelaars, of the National Research Council of Canada, in images taken in 2015. Dwarf planets are notoriously difficult to spot, but they're important pieces of the puzzle in tracing the evolution of our Solar System.

Dr. Michele Bannister, of the University of Victoria in British Columbia, describes the moment when the planet was discovered: "There it was on the screen— this dot of light moving so slowly that it had to be at least twice as far as Neptune from the Sun."

"The icy worlds beyond Neptune trace how the giant planets formed and then moved out from the Sun. They let us piece together the history of our Solar System. But almost all of these icy worlds are painfully small and faint: it's really exciting to find one that's large and bright enough that we can study it in detail." said Bannister.

Sun

Stunning solar effect captured above Redcar, UK

Solar halo Teesside, UK
© Tom LoweSun halo and smaller halo over Redcar.
There was an optical phenomenon over the skies of the Redcar the other day.

No, little green men weren't spotted over Teesside , but there was something looking rather other-worldly...A sun Halo.

A Sun halo is formed when light is refracted in millions of hexagonal ice crystals which are suspended in the atmosphere and can be formed at different degrees.

"Over the past few years I have become increasingly interested in observing and photographing atmospheric optical phenomena," Said Tom Lowe who took the picture in Redcar.

"So when the sky is full of hazy high cirrus cloud as it was over Redcar, I regularly glance towards (never at) the sun.

"This is because these clouds are formed of tiny hexagonal ice crystals which reflect and refract sunlight in predictable ways, forming impressive and sometimes spectacular halos and arcs in the sky."

And while the large halo is actually quite common - we just end up missing them due to cleverly not staring at the Sun - the smaller halo is very rare. "The 9-degree halo is a much rarer sight, and this was the first I have seen. An aircraft contrail bisects the halos, itself casting a thin dark shadow on the cirrus, and to the left of this is a patch of much lower cloud, probably altocumulus.
Sun halo and smaller halo
© Tom Lowe

Camera

Shining silver-blue clouds captured over Denmark in night sky photo

noctilucent clouds
© Ruslan Merzlyakov/RMS photographyElectric-blue "night-shining" clouds can be seen swirling over the skyline of Nykøbing Mors in Denmark on July 1, 2016.
Bright blue-white noctilucent clouds danced over the town of Nykøbing Mors in Denmark just before dawn, just when this spectacular photo was taken.

Night sky photographer Ruslan Merzlyakov captured a series of nightscape images in the early morning of July 1, 2016. With electric-blue clouds swirling overhead, the small town is illuminated and the twinkling lights of the quaint skyline are reflected in the calm waters below.

"The whole horizon over Nykøbing Mors from west to east was filled with silver light and it was very bright!" Merzlyakov wrote in an email to Space.com.

Comment: The fact that the author calls noctilucent clouds common and rare in the same paragraph isn't the strangest thing about their article.

Space.com has previously published an article on the actual cause of these clouds which the author ignores, and it's an ominous cause that those of you who read our 'Fire in the Sky' section will be well aware of:

  • Increased meteor smoke: Noctilucent clouds brightening and spreading south



Cloud Grey

Rare undulatus asperatus clouds form over Dorset, UK

Undulatus asperatus clouds over Dorset, UK
© CloudySkiesPhotography/BNPSThese extraordinary images show a series of wavelike clouds looming over the south coast. The unique formation, known as Undulatus asperatus, develops when undulation in the atmosphere causes air to move up and down
These extraordinary images show a series of wavelike clouds looming over the south coast.

The unique formation, known as Undulatus asperatus, develops when undulation in the atmosphere causes air to move up and down.

When wind makes contact with the base of low-lying clouds, a striking wavy motion then appears.

Although they appear dark and gloomy, they usually dissipate without a storm following.

The incredible shots, taken on an iPhone, were captured by amateur cloud photographer, Simon Hammond, in locations across Dorset.

The 48-year-old said: 'When I first saw them I thought, 'this is something quite special. It was pure luck that I stumbled across them as I hadn't headed out to take pictures.

'I have seen some examples of this formation but never ones as impressive as these.

'They are rare and in the event that they do appear they tend to be short lived, but these hung around for about five hours.'

The Cloud Appreciation Society are clamouring for the cloud shape to be recognised as an official cloud type by the International Cloud Atlas.

If accepted Undulatus asperatus, which translates to 'roughened wave', would be the first new classification in 65 years.

Comment: Further evidence of our changing atmosphere? See also:


Cloud Grey

'Rare' noctilucent clouds put on sunrise show over Whitley Bay, UK

Whitley Bay noctilucent clouds
© Owen Humphreys/PA
Early-morning risers were treated to a rare and stunning show in the skies north of Newcastle.

Rare noctilucent clouds, which can only be seen when the sun is below the horizon, illuminated the dawn and provided the perfect opportunity for these snaps that will make you want to drop everything and drive up the A1.
Noctilucent clouds
© Owen Humphreys/PA

Info

Planet with 3 suns discovered

HD 131399
© ESO/L. Calçada This artist's impression shows a view of the triple star system HD 131399 from close to the giant planet orbiting in the system. The planet is known as HD 131399Ab and appears at the lower-left of the picture.Located about 340 light years from Earth in the constellation of Centaurus (The Centaur), HD 131399Ab is about 16 million years old, making it also one of the youngest exoplanets discovered to date, and one of very few directly imaged planets. With a temperature of around 580 degrees Celsius and having an estimated mass of four Jupiter masses, it is also one of the coldest and least massive directly imaged exoplanets.
If you thought Luke Skywalker's home planet, Tatooine, was a strange world with its two suns in the sky, imagine this: a planet where you'd either experience constant daylight or enjoy triple sunrises and sunsets each day, depending on the seasons, which happen to last longer than human lifetimes.

Such a world has been discovered by a team of astronomers led by the University of Arizona in Tucson, Arizona, using direct imaging. The planet, HD 131399Ab, is unlike any other known world - on by far the widest known orbit within a multi-star system. The discovery will be published online by the journal Science on Thursday, 7 July, 2016.

Located about 340 light years from Earth in the constellation Centaurus, HD 131399Ab is believed to be about 16 million years old, making it one of the youngest exoplanets discovered to date, and one of very few directly imaged planets. With a temperature of 850 Kelvin (about 1,070 degrees Fahrenheit or 580 degrees Celsius) and weighing in at an estimated four Jupiter masses, it is also one of the coldest and least massive directly imaged exoplanets.

"HD 131399Ab is one of the few exoplanets that have been directly imaged, and it's the first one in such an interesting dynamical configuration," said Daniel Apai, an assistant professor of Astronomy and Planetary Sciences who leads a research group dedicated to finding and observing exoplanets at the UA.

Question

Frederick Valentich disappearance - Inspiration for new TV drama in Australia

Front page of The Australian with headline about Valentich Mystery
© The AustralianFrederick Valentich reported seeing some sort of aircraft just before he disappeared.
A pilot who disappeared nearly 40 years ago after reporting a UFO is one of the inspirations for the plot of the new television drama series The Kettering Incident. While the show revolves around fictional mysterious disappearances in the Tasmanian bush, the disappearance of Frederick Valentich was very real. Valentich was a 20-year-old pilot who went missing over Bass Strait in 1978, leaving nothing behind except a mysterious radio transmission.

Historian Reg Watson has been researching the disappearance for many years. "I've looked at it for gosh, three decades," he told Leon Compton on 936 ABC Hobart.

"I have to say, in my opinion, he had an encounter with a UFO — and I don't say that lightly."

'It's not an aircraft'

Valentich went missing on the night of October 21, 1978. Mr Watson said Valentich wanted to increase his flying hours and planned to fly from Moorabbin in Victoria to King Island. He left Moorabbin at 6:19pm and made radio contact with air traffic control in Melbourne at 7:06pm.

"He asked if there was any sort of aircraft in the area," Mr Watson said.

Valentich was told there was "no known traffic". He went on to report a large unknown aircraft had flown over the top of him and added: "It seems to be playing some sort of game. He's flying over me." Valentich then said:
"It's not an aircraft."
The pilot continued to speak with air traffic control in Melbourne about the craft until 7:12pm and that was the last anyone heard from him. Mr Watson said authorities searched for Valentich for four days but nothing was ever found.

Comment:
U.F.O. The Frederick Valentich Disappearance

UFO suspicions still cloud disappearance of Frederick Valentich

Frederick Valentich - 'Truth' Was Out There After All

Kidnapped by aliens: The pilot who vanished during close encounter

Farmer may hold clue to 36-year Frederick Valentich plane mystery

Australia: 30 years on: UFO mystery still vivid


Mars

Mars once had 3 moons besides Phobos and Deimos

Mars, Phobos, and Deimos
© Tokyo Institute of TechnologyMars, Phobos, and Deimos.
International collaboration finds that two small satellites (Phobos and Deimos) orbiting Mars can also be formed by a giant impact like the origin of our Moon. The research is reported in Nature Geoscience, July 2016.

An international team of researchers from Royal Observatory of Belgium, Institut de Physique du Globe, Universite de Rennes 1, Kobe University, and Tokyo Institute of Technology (Earth-Life Science Institute: ELSI) investigated the formation process of a disk produced by a potential giant impact on Mars, and satellites' formation process from this disk.

A huge satellite is quickly formed from this disk first, and it enhances the accretion of Phobos and Deimos in the outer region. After their formation, the huge satellite falls into Mars due to the strong tidal interaction with Mars, and eventually disappears. Only two tiny satellites, that is, Phobos and Deimos were left behind.

Researchers also found that about a half of the disk produced by a giant impact originally come from Mars, so that Phobos and Deimos should contain Martian materials. Recently, Japan Aerospace Exploration Agency (JAXA) has just started to plan a sample return mission from Martian satellite(s). Returned samples from Martian satellites are expected to have Martian materials.

Enigmatic origin of Martian satellites

Phobos and Deimos are orbiting on the Martian equatorial plane with very circular orbits. They are very small satellites and their masses are less than 10-7 of Mars mass. Because of their irregular shapes and spectral features, many researchers have thought that they were captured objects by Mars coming from the asteroid belt. However, the capture origin cannot easily explain their current circular and coplaner orbits, because captured satellites should have eccentric and randomly oriented orbits like many captured satellites found around Jovian planets.

On the other hand, Mars has the largest crater in our solar system on its northern hemisphere, which is called Borealis. A huge impact can create this crater and also eject a lot of materials around Mars, which may form a disk around Mars. Although formation of Martian satellites from this disk was proposed, little is known about the detailed process of disk formation and satellites' formation.