Astronomy Day, 25 April


This video from the USA is called 365 Days of Astronomy.

From the California Academy of Sciences in the USA:

We’re teaming up with NASA to celebrate Astronomy Day this Saturday, April 25! Touch a meteorite, learn about telescopes, observe the 3D nature of constellations, and more.

Explore Your Universe at the Academy

April 25 is Astronomy Day—an international celebration of space. This year, the Academy will explore the past, present, and future of space observation. Discover the wonders of the cosmos with special programing all day long.

Event highlights:

• Join us for PLUTO-PALOOZA, an epic celebration of space exploration with partners from NASA and SETI.

• Celebrate the 25th anniversary of the Hubble Space Telescope with Hubble-themed Hohfeld Hall shows.

• Test your space smarts with a Cosmic Quiz Show.

• Catch our newest award-winning show, Habitat Earth, in Morrison Planetarium, our 75-foot digital immersive dome and gain new perspective about our own planet.

Click for More Astronomy Day Events here.

Glaciers on Mars, covered by dust, discovered


This 7 April 2015 video is called Glacial Belts of Water Ice Found On Mars.

From Astronomy Now:

Mars has belts of glaciers composed of water ice

8 April 2015

Mars has distinct polar ice caps, but Mars also has belts of glaciers at its central latitudes in both the southern and northern hemispheres. A thick layer of dust covers the glaciers, so they appear as surface of the ground, but radar measurements show that underneath the dust there are glaciers composed of frozen water. New studies have now calculated the size of the glaciers and thus the amount of water in the glaciers. It is the equivalent of all of Mars being covered by more than one metre of ice. The results are published in the scientific journal Geophysical Research Letters.

Several satellites orbit Mars and on satellite images, researchers have been able to observe the shape of glaciers just below the surface. For a long time scientists did not know if the ice was made of frozen water (H2O) or of carbon dioxide (CO2) or whether it was mud. Using radar measurements from the NASA satellite, Mars Reconnaissance Orbiter, researchers have been able to determine that it is water ice. But how thick is the ice and do the glaciers resemble glaciers on Earth? A group of researchers at the Niels Bohr Institute have now calculated this using radar observations combined with ice flow modelling.

Data Combined with Modelling

“We have looked at radar measurements spanning ten years back in time to see how thick the ice is and how it behaves. A glacier is after all a big chunk of ice and it flows and gets a form that tells us something about how soft it is. We then compared this with how glaciers on Earth behave and from that we have been able to make models for the ice flow,” explains Nanna Bjørnholt Karlsson, a postdoc at the Center for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

Nanna Bjørnholt Karlsson explains that earlier studies have identified thousands of glacier-like formations on the planet. The glaciers are located in belts around Mars between the latitudes 30° and 50° — equivalent to just south of Denmark’s location on Earth. The glaciers are found on both the northern and southern hemispheres.

From some locations on Mars they have good detailed high-resolution data, while they only have more sparse data from other areas. But by supplementing the sparse data with information about the flow and form of the glaciers from the very well studied areas, they have been able to calculate how thick and voluminous the ice is across the glacier belts.

Could Cover the Entire Planet

“We have calculated that the ice in the glaciers is equivalent to over 150 billion cubic metres of ice — that much ice could cover the entire surface of Mars with 1.1 metres of ice. The ice at the mid-latitudes is therefore an important part of Mars’ water reservoir,” explains Nanna Bjørnholt Karlsson.

That the ice has not evaporated out into space could actually mean that the thick layer of dust is protecting the ice. The atmospheric pressure on Mars is so low that water ice simply evaporates and becomes water vapour. But the glaciers are well protected under the thick layer of dust.

Nasa’s Curiosity rover finds water below surface of Mars. New measurements from the Gale crater contradict theories that the planet is too cold for liquid water to exist, but Mars still considered hostile to life: here.

Will extra-terrestrial life be discovered soon?


This video is from the film War Of The Worlds (2005)– The First Tripod.

The film is about an invasion of the USA by dangerous Martians. In the original book by H.G. Wells, the dangerous Martians invaded England.

Very probably, extra-terrestrial life, if any will be discovered soon, will be very unlike that.

From daily The Independent in Britain:

We will have definitive evidence of alien life in 20 years, Nasa chief scientist believes

Strong indications of life beyond Earth could be found within a decade

Christopher Hooton

Wednesday 08 April 2015

The discovery of extra-terrestrial life, probably the most exciting event in human history, may well take place within most of our lifetimes, a high-ranking Nasa scientist has predicted.

“I think we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years,” Nasa chief scientist Ellen Stofan said on Tuesday, during a panel discussion focusing on the space agency’s search for habitable environments outside of Earth.

“We know where to look. We know how to look,” Stofan added, “In most cases we have the technology, and we’re on a path to implementing it. And so I think we’re definitely on the road.”

Nasa believes such discoveries could happen so soon as they will not take place in deep space but in our own solar system and others in the Milky Way.

Sharing Stofan’s optimism, associate administrator for Nasa’s Science Mission Directorate John Grunsfeld said: “I think we’re one generation away in our solar system, whether it’s on an icy moon or on Mars, and one generation [away] on a planet around a nearby star.”

If life, in whatever form it takes, is found in orbit of the Sun, it could well be on Jupiter’s moons Europa and Ganymede or Saturn‘s satellite Enceladus, which hold seas beneath their icy surfaces.

The Milky Way is “a soggy place,” Paul Hertz, director of Nasa’s Astrophysics Division, explained.

“We can see water in the interstellar clouds from which planetary systems and stellar systems form.

“We can see water in the disks of debris that are going to become planetary systems around other stars, and we can even see comets being dissipated in other solar systems as [their] star evaporates them.”

These estimates don’t even take into account the fact that alien life may be able to prosper in conditions different to those required by humans, e.g without need for water.

NASA SUPER-TEAM TO LOOK FOR HABITABLE PLANETS, EXTRATERRESTRIAL LIFE The news comes a week after NASA’s chief said we’d have strong evidence of extraterrestrial life in a decade. [Ed Mazza, HuffPost]

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?