Northern lights, in history and now


This video says about itself:

Night of the Northern Lights

On 25th February 2014 Sun produced X4.9 flare which on 27th February caused G2 (KP 6) geomagnetic storm on Earth. It was the brightest aurora display so far during this solar maximum which I could witness with auroral displays overhead in the far north of Scotland. This short movie illustrates what has been seen from latitude 58.3 degrees north.

By Peter Frost in Britain:

Heavenly treat

Friday 27th March 2015

As natural phenomena go few come more spectacular or mysterious than the northern lights. PETER FROST dons his astronomer’s hat to reveal their provenance

They saw them in Scotland, in Northumberland, on the Isle of Man and as far south as north Norfolk. It was some of the best British sightings of the aurora borealis, the famous northern lights, in living memory.

Hundreds of people all over Britain braved the freezing late night and early mornings but declared the experience one well worth getting frozen for.

Those lucky enough to see them described spectacular waves, streaks or curtains of pale green and pink, but shades of red, yellow, blue and violet were also spotted.

It’s rare for northern lights to be seen from anywhere in Britain and when they are visible it is usually from Shetland, Orkney or the north of Scotland.

Last week however, good sightings could be had from all over the country as far south as Norfolk. These amazing multicoloured ethereal light displays are caused by collisions between electrically charged particles from the sun that enter into the earth’s atmosphere.

They are more common much further north and British tourists normally need to take cruises or air holidays to northern latitudes if they want to see the amazing spectacle.

Polar lights — the aurora polaris — are a natural phenomenon found in both the northern and southern hemispheres. The northern versions are called aurora borealis while the southern lights aurora australis.

They were first named by two great early astronomers Pierre Gassendi and Galileo Galilei both of whom witnessed a spectacular display in September 1621. They jointly named the phenomena aurora borealis — the northern dawn.

Much earlier, a thousand years ago, Gregory of Tours, Gallo-Roman historian, scientist and later saint looked into the night sky over France and saw a light “… so bright that you might have thought that day was about to dawn.”

We now know the origin of the aurora starts on the surface of the sun when solar activity ejects a cloud of gas. If one of these reaches Earth it collides with its magnetic field two or three days after leaving the sun.

Our planet’s magnetic field is invisible but if it could be seen it would make Earth look like a comet with a long magnetic tail stretching a million miles behind us away from the sun.

When a coronal mass ejection — as the stream of cloud of gas from the sun’s surface is more properly named — collides with the magnetic field it causes complex changes to happen to the magnetic tail region.

These changes generate currents of charged particles, which then flow along lines of magnetic force towards the Earth’s poles.

The particles are boosted in energy in Earth’s upper atmosphere and when they collide with oxygen and nitrogen atoms they produce the dazzling light shows that are the aurora.

Beautiful they may be but the invisible flows of particles and magnetism can damage electrical power grids and also affect satellites operating in space.

The lights can be in place day and night but are not bright enough to be visible in daylight. For the same reason in cities or towns with lots of light pollution you are unlikely to get good viewing.

Auroras tend to be more frequent and spectacular during high solar sunspot activity and these cycle over periods of approximately 11 years. That is what is happening now.

Some displays are particularly spectacular and make the headlines. This happened in August-September 1859, in February 1958, which I remember seeing as a London schoolboy, and in March 1989 the last time really good sightings were possible in southern England.

Last February produced spectacular solar activity and a few relatively clear nights again gave some lucky stargazers a chance to see the spectacular and colourful light show.

This year has been even better and there is a good chance that the shows aren’t over. Keep your eyes on those northern skies.

Lunar eclipse, 4 April


This video says about itself:

Total Lunar Eclipse on April 4 – Shortest Eclipse of Century

4 March 2015

The total eclipse of the full moon on April 4, 2015 will last less than five minutes, making it the shortest total lunar eclipse of the 21st century.

The total lunar eclipse will be visible from western North America, eastern Asia, the Pacific, Australia and New Zealand. At North American time zones, that means the greatest eclipse happens before sunrise on April 4 – the morning of April 4, not the evening.

From the world’s Eastern Hemisphere – eastern Asia, Indonesia, New Zealand and Australia – the greatest eclipse takes place after sunset April 4.

Read more here.

From ZeeNews in India:

Total lunar eclipse on April 4, to be visible in North East of India

Last Updated: Wednesday, March 25, 2015 – 17:11

Indore: Star gazers can gear up for another celestial treat – a total lunar eclipse, next weekend.

The total lunar eclipse will take place from 3:45:04 PM to 7:15:2 PM (IST), will be visible in the North East of India on April 4.

According to Dr Rajendraprakash Gupt, Superintendent of Ujjain Jiwaji Observatory, the celestial event will last for about three and a half hours.

The astronomical event will be at its peak at 5:30:30 PM when the earth’s shadow will block the moon completely.

A magnificent viewing of the event is expected in the North East where dusk falls early in India, the superintendent of the two-century-old observatory said.

A total lunar eclipse takes place when the Earth comes between the Sun and Moon and forms a straight line. The Earth blocks any direct sunlight from reaching the Moon, he added.

Unlike a solar eclipse which lasts for a few minutes at any given place due to the smaller size of the Moon’s shadow, a lunar eclipse lasts for a few hours.

Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions, as they are dimmer than the full Moon.

Solar eclipse on Faroe islands, video


This video says about itself:

Timelapse captures eclipse over Faroes

20 March 2015

Thousands of solar eclipse followers watch the skies above the Faroe Islands turn dark. Rough cut (no reporter narration).

To the birds of northern Finland


This video is called The Amazing Northern Lights (Aurora borealis) – FINLAND.

On 10 March 2015, first by train to the airport. Tufted ducks swimming not far from the railway.

Then, our plane flew to Helsinki in southern Finland. Many coniferous trees around the airport. Small patches of snow.

Then, another plane flew us to Oulu in northern Finland; just south of the Arctic circle.

Will we see northern lights, and beautiful birds, here?

Spacecraft arriving at dwarf planet Ceres


This video from the USA says about itself:

Dawn Nears Ceres – Approach Images, Movies and Animations

2 March 2015

NASA’s Dawn mission will arrive at Ceres on March 6, 2015, and will be the first spacecraft to explore a dwarf planet. Ceres is the largest body in the main asteroid belt. At the time of its discovery in 1801 it was considered a planet and later demoted.

From Associated Press:

Mysterious dwarf planet Ceres gets ready for the spotlight

By ALICIA CHANG

AP Science Writer

March 5, 2015 Updated 4 hours ago

LOS ANGELES — The mysterious dwarf planet Ceres is ready for its close-up.

Located in the asteroid belt between Mars and Jupiter, Ceres is the largest unexplored space rock in the inner solar system. But that distinction ends Friday, when NASA’s Dawn spacecraft arrives after nearly an eight-year journey, which included a stopover at the asteroid Vesta.

Dawn has already beamed back images of Ceres from its approach.

Five things to know about Ceres:

THE DISCOVERY

Ceres was spotted on New Year’s Day in 1801 by Italian monk and astronomer Giuseppe Piazzi who was searching for a star. It was the first object discovered in the asteroid belt, a zone littered with rocky debris left over from the formation of the sun and planets 4½ billion years ago.

THE NAME

Piazzi named the object “Ceres Ferdinandea” after the Roman goddess of harvest and in honor of King Ferdinand IV of Naples and Sicily. Other astronomers shortened it to Ceres. The word cereal also has its origins in Ceres. The chemical element cerium, discovered in 1803, was named after Ceres.

THE IDENTITY CRISIS

Located about 250 million miles from the sun, Ceres was deemed a comet when it was first discovered. Then it was promoted to a planet and later downgraded to an asteroid. Since 2006, it has been classified as a dwarf planet like Pluto, the one-time ninth planet. Dwarf planets are spherical in shape like planets, but they share the same celestial neighborhood with other similar-sized objects.

THE BRIGHT SPOTS

Ceres — with a diameter of about 600 miles — is thought to have a rocky core surrounded by an icy mantle. Long ago it might have harbored an underground ocean. As Dawn approached Ceres, it spotted a pair of puzzling bright spots inside a crater. Scientists think the shiny dots may be exposed ice or salt.

THE MISSION

Launched in 2007 and powered by ion propulsion engines, Dawn will make the first close-ups of a dwarf planet. It will study Ceres for 16 months from varying altitudes, getting as close as 235 miles above Ceres’ surface, or the distance of the International Space Station above Earth.

The spacecraft will take sharper images of the mysterious spots and use its instruments to confirm whether Ceres’ surface is still active and spewing plumes of water vapor.

This summer, another NASA spacecraft dubbed New Horizons will make the first visit to the dwarf planet Pluto.

NASA’s Dawn spacecraft successfully entered orbit around Ceres on March 6. It is the first spacecraft to successfully orbit two extraterrestrial bodies, enabling it to provide data on two different primordial objects in the solar system: here.

Spaceship approaching dwarf planet Ceres


This video says about itself:

19 January 2015

NASA’s Dawn mission snapped imagery of Ceres at a distance of 238,000 miles (about the same distance between the Earth and the Moon) on Jan. 13th, 2015. The images show ‘hint of craters’ according to NASA’s Jet Propulsion Laboratory.

By Jacqueline Howard in the USA:

NASA Probe Gives Close-Up Look At Dwarf Planet Ceres, But What Are Those Weird White Spots?

Posted: 02/06/2015 5:53 pm EST Updated: 02/10/2015 8:59 am EST

What are those things?

Scientists have been puzzling over a set of weird white spots on Ceres ever since 2004, when the spots showed up in images captured by the Hubble Space Telescope, io9.com reported. Now NASA’s Dawn space probe, which is drawing ever closer to the dwarf planet, has obtained the best images yet of the spots–and still no one can explain them.

“We are at a phase in the mission where the curtain is slowly being pulled back on the nature of the [dwarf planet’s] surface,” Dr. Chris Russell, planetary scientist at the University of California, Los Angeles, and principal investigator for the $466-million mission, told NBC News. “But the surface is different from that of other planets, and at this stage the increasing resolution presents more mysteries rather than answers them.”

With a diameter of 590 miles (950 kilometers), Ceres is the largest object in the solar system’s main asteroid belt, located between Mars and Jupiter. Signs of water were detected on Ceres just last year, and some astronomers think the white spots may be ice at the bottoms of craters or subsurface ice that’s been pushed up from under the dwarf planet’s surface.

Scientists hope the Dawn mission will help us understand how Ceres and other large celestial objects formed.

Dawn is expected to arrive at Ceres on March 6, 2015.

Dawn on Ceres: Nasa probe to enter dwarf planet’s orbit. First-ever rendezvous with the largest object in the asteroid belt separating Mars from Jupiter will reveal what Ceres is made of: here.

Mysterious bright spot on dwarf planet Ceres is actually two bright spots: here.

Will four humans die on planet Mars?


This video says about itself:

9 February 2015

Meet the people who’ve volunteered to be on the first manned mission to Mars … and stay there.

Three volunteers are on the shortlist to be among four people on the Mars One programme, the first manned space flight to Mars – a one-way trip that’s effectively a suicide mission. A physics student in the UK, a young doctor from Mozambique and an Iraqi-American woman, all happy to sacrifice their futures for a place in history.

Why do they want to leave Earth, and who are they leaving behind? As the list of potential Mars explorers is whittled down further on 16 February, meet those competing to be the first to land on the Red Planet.

See also here.

MEET THE FINAL 100 PEOPLE COMPETING FOR A LIFE ON MARS Dutch nonprofit Mars One has narrowed the field to 100 applicants for a one-way trip to Mars. Ultimately, 24 will be chosen to train, and, organizers claim, four will go on the official mission. [WaPo]

An extremely high-altitude plume seen at Mars’ morning terminator: here.

Life on Mars: chemicals found on red planet indicate it once could have supported life: here.