Here's a piccy of all known asteroids. The red ones are all near-earth asteroids. That we know of.



"It is estimated that there a likely to be bet. 100,000 to 1,000,000 similar asteroids as yet undiscovered with Earth-crossing orbits".

So all that pious hand wringing a few years ago about leaving all sorts of man-made cr@p floating around in space would be the equivalent of dropping one chewing gum wrapper at your local rubbish tip and worrying that it made the place look untidy ?

Yes and no, it's a different problem. Practically none of the known asteroids pose a threat whereas practically every piece of spce junk does simply because it is in or close to the orbits of satellites, the ISS and of course the occasional manned craft.

There are estimated to be tens of millions of bits of space debris, including about 600,000 objects larger than 1 cm orbiting Earth, and at least 16,000 larger than 10 cm. The problem is they don't need to be that big. This is the damage caused by a paint fleck that collided with a Space Shuttle window:

About a week ago the crew of the ISS actually hid in the Soyuz escape vehicle as one known piece of junk approached. Luckily it missed. But it's a huge problem.

Take a look at spaceweather.com www.spaceweather.com/ As well as giving updates on potential aurora sightings, it has a list of PHA's (Potentially Hazardous Asteroids) that are known to come close to, or cross, the Earth's orbit, and also shows a plot of their orbits. However, the worrying word is "Known"

Take a look at spaceweather.com www.spaceweather.com/ As well as giving updates on potential aurora sightings, it has a list of PHA's (Potentially Hazardous Asteroids) that are known to come close to, or cross, the Earth's orbit, and also shows a plot of their orbits. However, the worrying word is "Known"

Awe-inspiring image of the jets streaming from galaxy Hercules A, an object which is 2 billion light years* away.



Hercules A, the yellowy blob at centre of the image, is one BIG galaxy. For comparison, our own Milky Way galaxy is about 100,000 light years in diameter and it contains about 200 billion stars. Hercules A, is roughly 1,000 times more massive than the Milky Way and has at the centre a 2.5-billion-solar-mass central black hole, which spews out the jets at near-light speed.

The jets, which are only visible to a radio telescope, are about one-and-a-half million light-years long.



* 1 light-year = the distance light travels in 1 year at 186,000 miles per second.

I can't even begin to get my head around those figures.

a lightyear is about 9480000000000000 metres, that should make it a bit clearer for you

Next time you are thinking of complaining about the weather, it could be worse - you could be in the giant hurricane over Saturn's north pole

Best not to try, I just go 'wow' these days.

Active sunspot region has produced a series of X-class (i.e. fookin BIG) flares in the past few days, luckily none in our direction. But the Sun is rotating the region towards us, so there's a good chance one may blow off with Earth's number on it. Tin hats on, please.

The power of the Sun:

[urlhttp://www.bbc.co.uk/news/science-environment-22556750[/url

Time for everyone to make a Faraday box