Astronomy

[Ivo]

BBC News website reported that the 11 metre diameter asteroid called BX34 actually passed within 60,000km of the earth yesterday at 1600 GMT, which is quite close.

Quite close? That's six times closer than the Moon! The equivalent of perhaps London to Edinburgh in a straight line and back 50 times!

How much damage would an 11-metre asteroid cause if landed on Earth? I would guess enough to potentially wipe out London?

 

[LE Greys]

Quite close? That's six times closer than the Moon! The equivalent of perhaps London to Edinburgh in a straight line and back 50 times!

How much damage would an 11-metre asteroid cause if landed on Earth? I would guess enough to potentially wipe out London?

Surely most of it would burn up in the atmosphere.

Had a chance for a bit of impromptu astronomy last night from an HST stranded right next to the ECML 200 Miles to London board for three hours. Three planets and a crescent Moon, plus another two planets out of view and possibly four more moons. No aurora, unfortunately.

 

[Class172]

Surely most of it would burn up in the atmosphere.

I would have thought so.

 

[Xenophon PCDGS]

I would have thought so.

if this happens, what would be the visual image of an 11 metre diameter object being subjected to this, at such a distance of 60,000km, that was reported on the BBC News website.

 

[Class172]

Depending on the composition of the meteorite I would expect at least [SUP]3[/SUP]/4 to burn up in the atmosphere.

 

[LE Greys]

if this happens, what would be the visual image of an 11 metre diameter object being subjected to this, at such a distance of 60,000km, that was reported on the BBC News website.

http://apod.nasa.gov/apod/ap081011.html

It might look like this if it got a lot closer, say about 60 km. 60,000 km is right up at the top of the exosphere, so essentially airless. To put it into perspective, geostationary communications satellites orbit at 36,000 km and the Moon is around 375,000 km away. All you would see is a tiny, moving dot (depending on how reflective the surface is) and that would need quite a powerful telescope. Resolving one of the big communications or GPS satellites is hard enough, and they are far bigger with very reflective structures.

 

[Peter Mugridge]

Had a chance for a bit of impromptu astronomy last night from an HST stranded right next to the ECML 200 Miles to London board for three hours. Three planets and a crescent Moon, plus another two planets out of view and possibly four more moons. No aurora, unfortunately.

From west to east that would be Venus, Crescent Moon, Jupiter plus Mars very low in the east?

By four moons, I am guessing you had binoculars with you and had a look at the Galilean Moons of Jupiter?

 

[LE Greys]

From west to east that would be Venus, Crescent Moon, Jupiter plus Mars very low in the east?

By four moons, I am guessing you had binoculars with you and had a look at the Galilean Moons of Jupiter?

You're forgetting the planet you look down to see. Apparently, Uranus and Neptune were on almost the same axis as Jupiter as well, but I couldn't find them.

 

[Eagle]

Apparently, Uranus and Neptune were on almost the same axis as Jupiter as well, but I couldn't find them.

Neither are visible to the naked eye.

 

[Peter Mugridge]

Somehow I think it's a little bit sneaky to count Earth as an astronomical observation.....
--- old post above --- --- new post below ---
.
.
.

Neither are visible to the naked eye.

I think he was using binoculars through the droplight in a door since he was seeing the Jovian moons; it should certainly be possible to see Uranus ( magnitude 5.9 ) and Neptune ( magnitude +8.0 ) with binoculars, although you would need to know exactly where you were looking.

Technically Uranus is within naked eye visibility, being just above 6th magnitude, but I agree it would be virtually impossible to identify it amongst the mass of similarly faint stars.

 

[Class172]

Anyone had a good view of Mars yet? With the street lamp in front of my house, all I could make out was a salmon-pink blob.

 

[STEVIEBOY1]

Anyone had a good view of Mars yet? With the street lamp in front of my house, all I could make out was a salmon-pink blob.

Which direction will that be, north , south , east or west and is it better seen in the evening or early morning when still dark? Likewise for Mercury when that appears in the next week?

 

[Zoe]

Which direction will that be, north , south , east or west and is it better seen in the evening or early morning when still dark? Likewise for Mercury when that appears in the next week?

Mars rises in the east after sunset and is visible for the rest of the night. Mercury is visible in the west after sunset but sets within 2 hours.

 

[Peter Mugridge]

I have made a number of visual observations, but not yet had an opportunity to turn my telescope on it this apparition. Ditto with Saturn a little further to the east.

 

[LE Greys]

I have made a number of visual observations, but not yet had an opportunity to turn my telescope on it this apparition. Ditto with Saturn a little further to the east.

Mars is getting quite big. Do you think it might be possible to see some ice caps with only 60X magnification (really duff telescope)?

 

[Peter Mugridge]

Not sure.... it would depend a lot on the seeing conditions; you'd need a very crisp still night.

Just how bad is this telescope? What apperture is it? Refractor or reflector? I'm guessing you only have the one eyepiece? Whatever the answer to those factors..... give it a try and see what you can see.

 

[LE Greys]

Not sure.... it would depend a lot on the seeing conditions; you'd need a very crisp still night.

Just how bad is this telescope? What apperture is it? Refractor or reflector? I'm guessing you only have the one eyepiece? Whatever the answer to those factors..... give it a try and see what you can see.

Really duff three-inch refractor with an adjustable eyepiece. Everything always looks washed out, possibly something to do with the fact that it has a prism. I'll give it a try soon, but not this week, since I'm back in Aberdeen for it.

 

[Peter Mugridge]

That sounds like one of those very small ones with a tube only a couple of feet long ( if that ) and a very basic tripod - can you post up a photo of it?

 

[Zoe]

I saw Mercury this evening. It reaches greatest elongation east tomorrow so only a few more days left to have a good chance of observing it.

 

[Peter Mugridge]

I saw Mercury yesterday but unfortunately this evening it was pouring with rain!

Has anyone else managed a daylight sighting of Jupiter yet? I did that again yesterday.

 

[Class172]

Not a chance of observing where I am over the past few days — weather has been diabolical.

 

[Class172]

Just had my GCSE exam in Astronomy this afternoon, though I won't get the results until the 23rd August. :roll:

 

[Xenophon PCDGS]

Just had my GCSE exam in Astronomy this afternoon, though I won't get the results until the 23rd August. :roll:

When I saw this thread again, I wondered if this was what you were reporting. How did you feel the examination went for you ?

 

[LE Greys]

Don't know if this quite counts as astronomy. A polar orbit satellite went over two nights ago at about 23:25. Not sure what the light source for it was, but it was quite bright, about the same magnitude as Polaris. I was out looking for M-13, without much success.

 

[Peter Mugridge]

Going on the Heavens-Above website ( I think I detailed it earlier in this thread including how to save to your specific location ) will allow you to identify the specific satellite. the source of light for it would have been the Sun and it doesn't sound like it was particularly bright - try watching for an Iridium flare; they can be magnitude -8 or even -9 on rare occasions...

And while on the subject of astronomy, don't forget the forthcoming transit of Venus ( June 6th ), albeit only the last part is visible from the UK at sunrise. Usual warnings about the Sun apply... Get a proper filter.

 

[NY Yankee]

Does the British Museum or Science Museum have any interesting astronomy exhibits?

 

[LE Greys]

Does the British Museum or Science Museum have any interesting astronomy exhibits?

Strangely enough, I just went there. There's an entire section of the Science Museum devoted to space exploration, both by telescope and by people and probes. Apollo 10 command module Charlie Brown (fastest vehicle in history) takes pride of place, but there's all sorts of other stuff, including models of Prospero (the one and only British satellite) and the not-so-successful Beagle 2. Not quite so much about astronomy, doesn't excite the kids so much. The best place is actually the Greenwich Observatory, where they have all sorts of things, incuding the telescope that William Herschal first observed Uranus with. All the Harrison sea clocks as well, still working. If you ever pay a visit, it's very interesting.

 

[Zoe]

Anyone remember the London Planetarium? Not quite sure why they closed it, was there a lack of visitors?

 

[Peter Mugridge]

The planetarium at Grenwich is much better than the old Baker Street one anyway! The reason that one was closed was officially to provide more space for the waxworks.

 

[Eagle]

And while on the subject of astronomy, don't forget the forthcoming transit of Venus ( June 6th ), albeit only the last part is visible from the UK at sunrise. Usual warnings about the Sun apply... Get a proper filter.

The transit will start at 23.09 UK time (quite a while after sunset) but will continue until 05.49—time of sunrise on Wednesday will vary from 03.47 in Lerwick to 05.16 in Penzance.

Only problem, of course, is that the entire UK is forecast to be overcast that morning

There will be a wait of 105½ years for the next transit.
--- old post above --- --- new post below ---
Oh, and apparently there was a lunar eclipse today, but it wasn't visible in Europe because it happened at noon UK time. (It's normal for solar eclipses, like last month's one, to be flanked by two lunar eclipses two weeks either side.)