The real explanation for the strange lunar colour change has its origins in the motions of the Moon and Earth around the Sun. We see the Moon because it reflects sunlight, turn the Sun off and the Moon would seem to vanish. During a lunar eclipse, as they are known, the Earth passes between the Moon and Sun, blocking sunlight from reaching the lunar surface. If it wasn’t for the atmosphere on Earth, the Moon would simply go dark but the scattering effects of our atmosphere bend or refract sunlight back to the Moon. Of all the colours of the spectrum, red is the one that makes it through to the Moon and so it turns a deep red colour. It is worth noting that the presence of cloud and dust in the atmosphere will determine just how red the Moon will actually go.

The eclipse will noticeably start (U1) at 12:45 GMT as the shadow of the Earth starts to creep across the face of the Moon until at 14:06 GMT the shadow covers the Moon entirely (U2), this is the start of the total phase of the eclipse. The eclipse reaches its mid point at 14:31 GMT and totality finally ends (U3) at 14:57 GMT. The shadow finally leaves the Moon (U4) at 16:17.

Checkout the image below to see how much of the eclipse you will be able to see from your location, using the references in brackets above U1, U2 etc.

Unfortunately, this years shower looks set to be one of the less impressive displays. Previous years have shown storm level activity with hundreds of meteors visible per hour at peak although we are only treated to this every 33 years (next due around 2028). Sadly we can only expect around 20 meteors per hour this year with the light of the Moon also blotting out some of the fainter ones.

Like all meteor showers they are named after the constellation they seem to come from and in the case of the Leonids, seem to come from the constellation Leo. That said, its best to look a little away from the constellation they come from to maximise your chances of seeing them. Its worth noting that meteor showers are notoriously hard to predict so its worth keeping your eye out overnight tonight (17th) and tomorrow night too to catch the peak. Don’t worry if you do miss it though as meteors from the Leonids can be seen for a few weeks either side of the peak.

Its always difficult to know just where to look to catch meteors which are a little bit like lightening displays, you never know when or where the next will be. Your best approach is to wrap up warm, get outside after your local midnight, make yourself comfortable, lay back on a sunbed and look skyward away from the Moon.

If you are lucky enough to have clear skies then you should be able to spot a few meteors. The meteor’s from the Leonids tend to be amongst the fastest of meteors, hitting the Earth’s atmosphere at around 72km per second so they will produce a pretty fast streak in the sky. Happy hunting.

Comet Giacobini-Zinner orbits the Sun once every 6 years and as it does, it leaves behind a trail of debris. Every year, during the month of October, the Earth passes through this cloud of debris and what we see here on Earth is a display of shooting stars or meteors to use their correct term. As the pieces hurtle through our atmosphere they can be seen as the charateristic streak of light in the sky.

If the Earth passes through the orbit just after the comet then we are in for a real treat as the cloud of debris will have been replenished, ergo a lot more meteors. Giacobini-Zinner is in the area and reaches its closest approach to the Sun in February 2012. Earth will reach the cloud 132 days before this so you would think that this year would be nothing special. Wrong! Recent forecasts predict the Earth will pass particularly close to an older cloud from a previous pass of the comet.

Remember though that meteor showers are unreliable so don’t be surprised if the predicted storm doesn’t appear. That said, its looking very likely at the moment and even NASA are considering the potential risk of damage to the International Space Station and other satellites due to meteroid impacts.

To observe the storm, get outside on the 8th October between 18:00 and 22:00 GMT and watch. Europe and Middle East are best placed but if its dark where you are during those hours, its worth a try. Its also worth keeping an eye out on the 7th and 9th just in case it happens earlier or later. No equipment is needed, just a comfortable chair, wrap up warm and wait. The Moon will be gibbous on the 8th so keep your gaze to the north to avoid its glare and if all goes as expected, it could be incredible and something NOT to be missed.

During the day, questions will be tweeted out by me with the #SpaceQuiz hashtag, you will need to keep an eye out for these, note down the answers and after the last question has been received, send in one tweet with all your answers. Be sure to include the #SpaceQuiz hashtag in your answer tweet otherwise it won’t count.

Question Format

Question 1 will include 5 separately tweeted sub-questions each with a numerical answer. You must add up all the answers and the total will be the answer you will need to send in.

Question 2 will be a general knowledge question (space related of course).

Question 3 is a ‘What or Who am I?’ round. There will be 4 separately tweeted out clues leading you to the answer.

Question 4 will be a picture question.

Question 5 will be another general knowledge question.

Question 6 will be another ‘What or Who am I?’ round. There will be 4 separately tweeted out clues leading you to the answer.

Question 7 will be another picture question.

Question 8 – Question 10 will be general knowledge questions.

At the end of that lot send in your tweet with your answers, don’t forget to include the #SpaceQuiz hashtag. The winners of the prizes will be drawn at random from the correct entries and announced on Wednesday at 10am.

Prizes

Prizes have been donated by some great organisations and include..

Top Prize One hour of telescope time in either Hawaii or Australia from Faulkes Telescope Project
Second Prize A years membership to The Society for Popular Astronomy
Third Prize Two eyepieces (15mm and 20mm) from Altair Astro
Fourth Prize Astronomy application for your iPhone/iPad from Vito Technology
Fifth Prize A goodie bag from the UK Space Agency

Entry available to UK residents only and my decision will be final.

Good luck

There are a couple of prominent stars in the constellation Gemini called Castor and Pollux which tonight, will be low in the west about an hour after sunset. Looking West you can see Castor on the right and Pollux to the left. Mercury then extends the line out to the left. You’ll need a good clear western horizon to spot it though.. Good luck.

Working from their base in New Mexico, the LINEAR team uses automated one-meter ground based telescopes to probe the skies for so-called near-Earth object (NEO) threats. The discovery of 2011 MD on Wednesday goes to show that we need to get better at identifying potential asteroid threats, investing more money and time into projects like LINEAR. The more time we have, the greater chance there is of us being able to do something about it.

Surprisingly, NEOs are more common than you think with around 8,000 known. This newly discovered interplanetary interloper is thought to measure no more than 20 meters wide, making it no real threat — but it’s a warning all the same.

If 2011 MD did hit us, then it would more than likely break up in the atmosphere and give us an amazing display of fireballs and meteors. As it turns out, it will sail harmlessly by at a butt-clenchingly close distance of only 12,000 kilometers (7,500 miles), 32 times closer than the moon, and closer than geosynchronous satellites.

The moment of closest approach will occur on Monday, June 27 at 17:00 UTC somewhere over the South Atlantic Ocean. Its visibility will be severely limited, but amateur astronomers in Australia and New Zealand should be able to track 2011 MD in the night sky just before closest approach.

I was lucky enough to have access to the Faulkes Telescope system which has two multi-million pound robotic telescopes available across the Internet. One is based in Hawaii and the other in Australia, perfect. After a frantic 30 minutes chasing the 2011MD across the sky I managed to grab this 10 second black and white image clearly showing its fast speed across the sky as it approached. At the time of the image, it was travelling across the sky at a rate of 1/20th of a degree per min (fast!) Later in the day at the moment of closest approach it was travelling at a staggering 1.1 degrees per min (a heck of a lot faster!)

I wanted to try a neat little trick and take a colour image of the fast moving asteroid next which I hoped would produce a rather curious affect. When astronomers take colour images of the sky, they don’t just use a colour camera, instead, we take a black and white picture through a red filter, another through a green filter and a third through a blue filter. These are then all recombined to produce the final colour image. We do this to maximise the resolution we get in the picture. When imaging the asteroid though, because of its fast speed it would be moving in between the 20 second exposures of each colour and, by the time the filter changed and the next exposure started, it would be in a completely different place! A great effect as you can see.

“Noctilucent clouds,” to use their correct name, gives a hint as to their origin and appearance. They are clouds often seen eerily illuminated at night, low on the north/western horizon. They seem to appear at their most intense after prolonged periods of low solar activity. For this reason, you might also hear them called “night-shining clouds.”

The sun is slowly waking up from an unexpectedly long period of quiet, so over the coming weeks we could be in for quite a spectacle. It’s possible, by some estimates, we could be in for the best show in a hundred years.

Browse the photos in this slide show to admire the magnificent beauty of these natural, and manmade, “night shining” clouds.

Noctilucent clouds are thought to be made of ice crystals high in the atmosphere, at altitudes of around 83km (in the mesosphere) where 99.99% of the atmosphere is below. They are on the edge of space, and mystery surrounds their formation as the mesosphere thought to be a million times drier than the Sahara desert!

For any cloud to form there must be water vapor and tiny microscopic particles for the vapor to condense around — a process called nucleation. Despite the dryness at these altitudes, convective activity could carry water vapor high into the mesosphere. However, the origin of dust particles remains a mystery.

Regardless of how they form, we can be sure, year after year, during late May and early June, they will honor us with some awesome displays. Strangely, this hasn’t always been the case!

The discovery of this phenomenon is attributed to Robert Leslie when he recorded a sighting in July 1885 from Southampton, UK — it’s curious there are no reports or records of noctilucent clouds before 1885.

Perhaps they are evidence of climate change, as the first observations coincided with the industrial revolution — since then, our pollutants may have been driven high into the upper reaches of the atmosphere to facilitate their formation.

Perhaps they are linked to volcanic activity, as they were first seen just two years after Krakatoa erupted. But while the effects of the eruption have died down, the clouds have persisted ever since and they seem to be spreading!

It’s also possible the airborne particles from which they form originate from meteoroids entering the atmosphere.

Their origins may remain a mystery for a few more years, but thankfully we can still enjoy them.

If your latitude is 40 degrees or more then you should be able to spot noctilucent clouds right now. They are easy to find and don’t require telescopes or binoculars. Just look north/west (the direction of the setting sun), about 30-60 minutes after sunset and if you see luminous blue or white tendrils stretching across the sky, then you may have spotted one of nature’s most beautiful sights, a sight we may have had some part in creating.