The Astronomy Thread

[BustinDustin]

Watch your heads, it's Skylab all over again.

http://www.heraldsun.com.au/technology/danger-of-a-toxic-space-invader-as-failed-russian-mars-probe-phobos-grunt-could-crash-land-in-australia/story-fn7celvh-1226230955728

I hope people have insurance cover for space probes falling out of the sky and smashing into your home. :hihi


Anyone get up early to see Comet Lovejoy? There are some fascinating photos floating round on the web. Here is a preview http://rudiphoto.net/christmas-comet/h29752bea#h29752bea

 

[pahoffm]

Space Weather News for Jan. 3, 2012
http://spaceweather.com

FIRST METEOR SHOWER OF 2012: The annual Quadrantid meteor shower peaks on Wednesday morning, Jan. 4th, when Earth passes through a narrow stream of debris from a comet thought to have broken apart some 500 years ago. The shower is expected to be strong (as many as 100 meteors per hour), but elusive, with a peak that lasts no longer than a couple of hours. The shower's radiant near Polaris favors observers in the northern hemisphere. Images, live audio from a meteor radar, and more information are available on today's edition of http://spaceweather.com.

 

[pahoffm]

Space Weather News for Jan. 5, 2012
http://spaceweather.com

MARS PROBE PHOTOGRAPHED: Phobos-Grunt, a Russian Mars probe stuck in Earth orbit since November, is sinking back into the atmosphere. Best estimates suggest re-entry will occur on Jan. 15th or 16th.

Meanwhile, citizen scientists can see the probe moving through the night sky sometimes shining as brightly as a first-magnitude star. French astrophotographer Thierry Legault recently photographed Phobos-Grunt through a 14-inch telescope, revealing its outlines and perhaps a clue as to why the probe has had difficulty communicating with Earth. His images and video are highlighted on today's edition of http://spaceweather.com .

 

[Panthera tigris FC]

Another strange question I always thought of since I was a kid, was why only 1 out of 9 planets has oxygen/human beings on it??

A bit off topic, but:

The early Earth had no oxygen in its atmosphere. Our current relatively oxygen-rich atmosphere is a consequence of early photosynthetic bacteria producing the molecule. Without the availability of plentiful oxygen to allow the production of comparatively huge amounts of energy by aerobic organisms it is unlikely that life would have seen the emergence of significant multicellularity (including us).

So to answer your question, Earth happens to sit in a position in space relative to its star that allowed the emergence of life (the so-called Goldilocks zone - it's 'just right'). Life evolved to produce countless metabolites including free oxygen that altered the Earth in numerous ways including large changes to the atmosphere, causing further evolution and diversification - one such result was the evolution of humans.

 

[evo]

So to answer your question, Earth happens to sit in a position in space relative to its star that allowed the emergence of life (the so-called Goldilocks zone - it's 'just right'). Life evolved to produce countless metabolites including free oxygen that altered the Earth in numerous ways including large changes to the atmosphere, causing further evolution and diversification - one such result was the evolution of humans.

Given that the moon and Mars are also in the goldilocks zone I always wonder why science futurists nearly always talk of man-made pods/ green house type arrangments to live under if we were to inhabit those planets/moons. Wouldn't it make more sense to concentrate resources into trying to artificially kick start the type of early bacteria that established our atmosphere? Is the reason they don't focus on this the belief that this process would take too long?

 

[LeeToRainesToRoach]

Given that the moon and Mars are also in the goldilocks zone I always wonder why science futurists nearly always talk of man-made pods/ green house type arrangments to live under if we were to inhabit those planets/moons. Wouldn't it make more sense to concentrate resources into trying to artificially kick start the type of early bacteria that established our atmosphere? Is the reason they don't focus on this the belief that this process would take too long?

The Moon's too small to hold onto an atmosphere - insufficient gravitational pull.

I'm not up to date with science fiction scenarios like terraforming (making other planets resemble Earth) but yeah, I think the decades and expenditure needed re Mars are stumbling blocks.

 

[evo]

The Moon's too small to hold onto an atmosphere - insufficient gravitational pull.

Good point. Maybe we could drag heaps of space debris into its gravitational pull to increase its mass? It would also tidy up space a bit. ;D

 

[BustinDustin]

Space Weather News for Jan. 5, 2012
http://spaceweather.com

MARS PROBE PHOTOGRAPHED: Phobos-Grunt, a Russian Mars probe stuck in Earth orbit since November, is sinking back into the atmosphere. Best estimates suggest re-entry will occur on Jan. 15th or 16th.

Meanwhile, citizen scientists can see the probe moving through the night sky sometimes shining as brightly as a first-magnitude star. http://spaceweather.com .

Got my first observation of the Mars probe on December 24, 2011 @ approximately 9:30pm, viewing from Melbourne, the probe came from the SE and travelled NE at approximately 45-50 degrees. The magnitude of the probe was brighter than the ISS but was travelling slower than the ISS.

Good website spaceweather.

 

[BustinDustin]

MARS PROBE PHOTOGRAPHED: Phobos-Grunt, a Russian Mars probe stuck in Earth orbit since November, is sinking back into the atmosphere. Best estimates suggest re-entry will occur on Jan. 15th or 16th.

For those interested in tracking not only the Phobos-Grunt but other satellites this would be a useful tool, actually it's superb - http://www.n2yo.com/satellites/?c=most-popular , you'll like this Phantom.

 

[pahoffm]

For those interested in tracking not only the Phobos-Grunt but other satellites this would be a useful tool, actually it's superb - http://www.n2yo.com/satellites/?c=most-popular , you'll like this Phantom.

Thanks, I've saved it as a favourite.

 

[Panthera tigris FC]

The Moon's too small to hold onto an atmosphere - insufficient gravitational pull.

I'm not up to date with science fiction scenarios like terraforming (making other planets resemble Earth) but yeah, I think the decades and expenditure needed re Mars are stumbling blocks.

Yep, lots of issues with terraforming....water, heat, shielding of cosmic radiation etc. etc. We've got it pretty good here on earth (well a small fraction of the earth that is habitable by humans!).

Pods seem far more practical.

As an aside, Evo, do you know of Lawrence Krauss? He has a new book coming out this month entitled, A Universe From Nothing, that you might dig.

 

[evo]

Ah yeah I remember him from the early beyond belief lectures. Looks interesting.

 

[pahoffm]

For those interested in CMEs, massive bursts of solar winds arising from massive explosions of the Sun, after a minor one hitting Earth yesterday, there will be a larger one hitting tomorrow.

The effect of one hitting straight after the other usually means that conditions are just right to produce auroras (Northern and Southern Lights) at high latitudes, so observers in Tasmania and southern New Zealand, as well as those in northern Asia, Europe and America have a great opportunity.

Impact is expected to be around midday January 24th, mid-USA time. This would be about 3am January 25th, Australian east-coast time, if I have that correct.

 

[Rosy]

I don't know the first thing about telescopes. Would appreciate it if anyone could tell me it the following would be worthwhile as an introduction or is it just a bit of a toy? (Half price on special for $99)

Technical Specifications (Tasco 30-060402)
Accessories: Diagonal, Moon filter
Accessory Tray: Yes
Diagonal: Star Diagonal
Diameter: 60mm
Eyepiece (s): 4mm, 12.5mm, 25mm
Faintest Stellar Magnitude: 11
Finder-scope: Optical 6x24mm
Focal Length in mm: 780mm
Focal Ratio: f13
Highest Practical Power: 140X
Mount Type: Alt-azimuth
Optical Design: Refractor
Resolving Power (arc sec): 1.93
Tripod: Aluminium
Tube Weight: Metallic turquoise
Weight: 4535g (4.5Kg)

 

[LeeToRainesToRoach]

I don't know the first thing about telescopes. Would appreciate it if anyone could tell me it the following would be worthwhile as an introduction or is it just a bit of a toy? (Half price on special for $99)...

Definitely not an expert on telescopes, but this is similar to the one I borrowed off a mate as a teenager when I was getting interested in astronomy. Refractors are ideal for starting out and there's not much sense in spending a fortune in case the interest doesn't last. You'd be able to obtain decent views of the Moon and the more prominent star clusters; a star atlas as a companion would keep someone occupied for many hours (the maps in Norton's Star Atlas are less fancy than some, but the accompanying text is a fantastic read for novices). Just don't expect to see Saturn in anything like the detail implied by Tasco's product page!

http://www.tasco.com.au/Products/CategoryID/123/List/1/Level/a/ProductID/100.aspx

 

[TigerForce]

As for us Melburnians, let's hope it doesn't rain next Tuesday April 29 as a partial solar eclipse will occur at 5.07pm from WNW part of the sky.

It's a shame we won't see a Total Eclipse for 200 years over here.

 

[Chiang Mai Tiger]

It's a shame we won't see a Total Eclipse for 200 years over here.

...nor another Richmond premiership mate!

 

[TigerForce]

Partial solar eclipse will occur from WNW part of the sky today at 5.07pm.

Not much chance for us Vics with this rain and clouds everywhere.

 

[LeeToRainesToRoach]

Partial solar eclipse will occur from WNW part of the sky today at 5.07pm.

Not much chance for us Vics with this rain and clouds everywhere.

It's a Melbourne-style 'total eclipse'.

 

[TigerForce]

It's a Melbourne-style 'total eclipse'.

Suppose it'll be filmed and shown on the news. Oh well, look forward to 2018 now...