NEAS Awarded Lottery Funding

We have just received news from out Treasurer John Green (who headed up the proposal submission) that the Society has received a sum of over £4000 from the National Lottery Awards For All scheme.

This grant will allow the Society to further improve the telescope facilities at the observatory.

KABOOM! - 100 years on

On the 30th June 2008 - 100 years ago today - a chunk of rock & ice was casually making its way across the solar system when a planet called Earth rudely decided to get in its way.

It entered the atmosphere travelling approximately towards the west, at a speed of thousands of miles per hour. Beaten by massive forces, the object reached a few miles from the surface before exploding like a megaton bomb. The air blast - the shock wave produced by a large explosion - flattened trees for roughly 800 square miles around ground zero.

Witnesses reported that the ground immediately shook, followed by a wind of heat - felt miles away. The shock wave propagated around the world. The “impact” happened in the remote Siberian Krasnoyarsk Krai region - an area of swampland and the Podkamennaya Tunguska River. Had it happened over a populated area such as Moscow or St Petersburg, around a million people could have been killed.

It is now known as the Tunguska Event and is a relatively comtemporary example of how much of a cosmic shooting range the Earth sits in.

The event has been studied comprehensively since then. After the immediate impact, little interest was taken due to the remote nature of the region. (it is thought a expedition may have taken place soon after but any record of it was lost in the subsequent turbulant times of post World War One Russia).

In the 1920s the first recorded expeditions took place. Leonid Kulik, a mineralogist and geologist of the Soviet Academy, travelled to Tunguska to the region. He took accounts from locals and deduced the explosion had been caused by a meteorite impact.

However his studies revealed no crater, only a 30 miles region of scorched and flattened trees, stripped of bark. These were the first clues that it was an air blast. He continued to receive funding for his expeditions as he had persuaded the Soviet government based on the prospects of finding a valuable iron source from the impacted object.

No debris, or crater, has ever been conclusively identified at Tunguska, leading to debates over the nature of the object - was it a rocky asteroid or an icy comet? Recent spacecraft surveys of asteroids have shown that some resemble fragile piles of rubble, which may more easily explode in such an event.

Later expeditions found microscopic glass spheres soil samples. Chemical analysis showed that the spheres contained high proportions of nickel and iridium. These elements are found in high concentrations in meteorites, hinting that they could likely be of extraterrestrial origin - part of the

The Earth has come a long, long way in the hundred years since that morning in Northern Russia. But if another similar object was incoming, we likely wouldn’t know about until we, like the Siberian locals, saw a flash of light in our sky, felt the waves of hot air, and were knocked down by the ground shaking.

The odds of it happening again soon are quite low. But this anniversary should remind us that it can and will happen again.

Noctilucent Clouds

Noctilucent cloud activity is intensifying.

During the past couple of the weeks these silvery blue waves have been observed in the skies over the UK, mainland Europe, the Baltic and Russia. Northern latitudes between roughly 50° and 55°  have been shown to be favourable with particularly bright displays.

To try and see them you need to be looking west, about half to one hour after sunset - when the Sun has dipped a few degrees below the horizon. If you see luminous blue-white tendrils spreading across the sky, you’ve probably spotted a noctilucent cloud. In the northern hemisphere, the best time to look is between mid-May and the end of August.

NEAS Facebook group

There is now a group for society members who use Facebook, located here.

NASA Phoenix Update - Martian Ice!

You may recall that, not long after landing, NASA’s Phoenix Mars lander found a white material not far under the dust and soil. It wasn’t entirely expected to find ice that quickly and that close to the surface, but this new animated image has proven to be quite revealing:

The white material sublimated (changed from solid to gas). This means it can’t be salt and pretty much must be ice. Well done to whoever on the team picked this landing site!

This animation is made of images taken by the “Surface Stereo Imager” over the course of four days. They show sublimation of ice in a trench (informally called “Dodo-Goldilocks”) made by the probe’s soil scoop. In the bottom-left corner, lumps of material disappear, similar to the process of evaporation.

http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080619.html

20th June Sky Note

Summer officially begins tonight at 23:59 p.m. GMT for the northern hemisphere. The Sun is at its most northerly point along the ecliptic marking the Solstice - when the Sun ascends to its highest latitude on the celestial sphere: 23.5^o. In the Northern Hemisphere, it’s the longest day and shortest night of the year.

Also:

• Mars and Saturn are 10° apart. Look for Mars and Saturn in the west at dusk.
• The Moon rises around midnight. The Moon is to the lower left of Jupiter.
• Pluto is at opposition in the constellation of Sagittarius, although extremely dim at 14th magnitude.

Registax Link

Following on from last night’s excellent talk by Ralph Bell, those of you that attended who want to try some of the processing techniques demonstrated can download the Registax program by clicking the image below and following the links to “Registax V4″.

June Public Meeting

Our guest speaker this month is Ralph Bell from Greenwitch, who will be giving a talk about high resolution astrophotography (including some equipment demonstration and examples of astro-imaging)

Doors open at 7:30pm for an 8pm start (for further details click the Events tab at the top of the page)

Just where are all the sunspots?

Universe Today is reporting something I’ve seen a lot of sources reporting on over the past week - the lack of sunspots.

It seems there is a “small concern” that something odd may be happening with the current lack of magnetic activity on the Sun, two years after the solar minimum.

“…just as we begin to get worried that the next solar maximum is going to unleash all sorts of havoc on Earth (i.e. NASA’s 2006 solar storm warning), scientists have begun to get concerned as to whether there is going to be a solar maximum at all…solar physicists discussed the possibility that the Sun could be facing a long period of calm, leading to the concern that there could be another Maunder Minimum.“

Forecast of space weather have been suggesting that ‘Solar Cycle 24′ is a historically active cycle… but so far very little has happened. Is the Sun in as sustained depression? Or is it waiting to surprise us with a big leap in activity - flares and CMEs - over the next few months?

New Society Merchandise

There are now NEAS car stickers (£2) and NEAS awareness wristbands (£2.50) available to purchase from the Society at either the monthly public meeting or at the Thursday observatory meetings. All proceeds go towards the Society. Further items may follow depending on how successfully these sell.