The Astronomy Thread

[Lord Rahl]

Here's an article that no doubt Nibiru conspiracy theorists will go nuts over.

http://www.space.com/13584-extra-gia...ar-system.html

[Magicman2051]

Yeah but those models are being constantly revised and furthermore most of them are, the ones that are being published anyway, considered "clean" or "ordered" models which make tons of presumptions about the way things occur without actually modelling each individual variation. Named such because of their tendency to completely ignore trojans, extra-solar captures and even the effect of other large celestial bodies on formation.

Cool though.

[Lord Rahl]

My fellow space lovers, today marks the 50th anniversary of Scott Glenn's flight aboard Friendship 7, the first manned orbital mission by the USA.



I don't know about you guys, but the early days of NASA, I'm not so sure about the Soviet space program since I know little about it, are very interesting because basically everyone involved with the space programs knew very little about what to do. You have all of these physicists and engineers and other scientists working to make something work they have little idea that it will actually work. Take, for example, one thing mentioned in the video above. They say one theory was that Glenn wouldn't be able to see because they thought in zero G the eyes would not be able to focus. And then there's Glenn himself. He was just a fighter pilot and literally rode an ICBM rocket into space with the hope that he'd make it back to Earth alive. It was a time of so much will, determination, cooperation, and outright mystery. Very exciting!

Also, there's some recent news about the Moon that has intrigued me. NASA thinks the Moon is going through some geographic activity because of its cooling. Speaking of geological activity, here's an article explaining why the Moon does not have volcanoes...but one might.

[mAIOR]

Here's an article that no doubt Nibiru conspiracy theorists will go nuts over.

http://www.space.com/13584-extra-gia...ar-system.html

either that or you factor in the amount of gunk from kuiper's belt and Oort's cloud where over 700 planetoids with similar dimensions to Pluto lurk. One of the two...



Cheers...

[Macedon1an]

Meteor witnessed across Britain

Police forces say they have received a number of calls reporting what is believed to have been a meteor.

A "huge fireball" was reported travelling from northern Scotland to southern England at about 21:40 GMT, amid fears a plane had crashed.

Police received reports of a "bright light" and "orange glow", but aircraft-related incidents were ruled out.

The Met Office tweeted......(read more)

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I once witnessed a meteor fall, some 5-6 years ago, I was sitting in my living room and then saw this big ball of light through the window... the next day I found out that it fell somewhere near Skopje... It was pretty cool

[Lord Rahl]

I've seen plenty of meteorites but not one large meteor.

[Gen. Chris]

I suppose this thread would be appropriate for what I wish to discuss.

It may be stupid to ask in this thread, but has anyone ever really considered just how large the universe could be? I mean look at our own galaxy: current estimates are our own Milky Way is 100,000 to 120,000 light-years across at its widest. To put it in perspective, Pluto at its farthest isn't even one-tenth of a light-year away from our Sun.

Now consider this: Our "Local Group" consists of over 50 galaxies, with an estimated diameter of ~10,000,000 light years. That means that if our pre-human ancestors had set out across the local group from one end to another, at light speed, they would only be perhaps half way across. That alone is an incredibly distance, especially when one considers that a light-year is "only" about 6 trillion miles...Now add 10 million of them.

Next up is the Virgo Supercluster, which is estimated to contain 100+ groups and clusters of galaxies in its 110,000,000 light year diameter, including our own Local Group. Going at light speed, it would take a little less than double the time that has passed between now and the extinction of the dinosaurs to travel across it. To make it worse, the Virgo supercluster is just one of estimated millions of superclusters.

Finally, there's the universe itself. Currently, we can only ever see objects as far away as the universe is old due to the speed of light, which means, given the age of the universe at ~13.75-14 billion years old, that we can only see objects at a maximum 13.75-14 billion light years away. But of course, those objects are only appearing to us as they were when the light that we are currently seeing was "created" (sorry if that is awkwardly worded, but I believe you know what I mean). Now, those objects are millions upon millions of light-years, if not more, away from that location that we currently observe them at. Taking into account that many are moving farther away rather than closer (depending on which direction they are going), the observable universe is growing every day. And this is all of what we can SEE...Imagine what is beyond.


We will likely never get beyond our own galaxy (simply no way to conceivably do it unless we somehow break the light-speed barrier), and yet there are likely billions of galaxies out there. What's out there we will probably never know...

(Sorry if some of that is tough to read...I'm not very good at writing. And sorry for the quite longwinded post )

[Lord Rahl]

Do you mean the observable universe? Wikipedia says from Earth, the universe is 14 billion parsecs (46 billion, or 4.6 × 1010, light years) in any direction.

[Gen. Chris]

Do you mean the observable universe? Wikipedia says from Earth, the universe is 14 billion parsecs (46 billion, or 4.6 × 1010, light years) in any direction.

Hm, I thought I said observable in my post.

But yeah, from my wording I did mean to say observable...

Probably should have written it better, sorry

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For comparison's sake, if we condensed a light year (6 trillion miles) to inches, a light year would still be 94,696,969.696 mi...A wee bit longer than an AU. That is still such an astounding distance.

[Agent Miles]

The size of the whole universe has been calculated as well. The universe has three possible topologies. In a flat universe the angles in a triangle always add up to 180 degrees. In a negatively curved universe, the angles would add up to less than 180 degrees. In a positively curved universe, the angles would sum (you guessed it) to more than 180 degrees. In two dimensions, a flat universe would resemble a flat piece of paper, a negatively curved universe would be represented by a saddle shape and a positively curved universe would be a sphere. So the first two would ultimately be infinite in size and the last finite in size. We now know that the universe is almost totally flat from data collected with the WMAP, which agrees with the current theory of inflation. By measuring the size of the warmer and cooler spots in the Cosmic Microwave Background, scientists have determined the maximum amount of possible curving. If the whole universe is not infinite, then it must be at least 300 billion light years across.

[visser300]

How could it be 300 billion light years across? Our universe is just 14 billion ligh years old, right? so the longest distance should be more or less than 28 billion light years. But this bases on the assumption that material moves with light speed in these years which they can't.

So someone should englight me how the hell on earth our universe has 300 billion light years in size.

[Jack04]

How could it be 300 billion light years across? Our universe is just 14 billion ligh years old, right? so the longest distance should be more or less than 28 billion light years. But this bases on the assumption that material moves with light speed in these years which they can't.

So someone should englight me how the hell on earth our universe has 300 billion light years in size.

Space itself can expand faster than the speed of light, you just can't move through it faster.

[mrmouth]

So a couple of more NASA mars missions get the axe. Help me understand the tantrums from people like Bill Nye.

The global economy almost collapsed not that long ago, we are continuing to dig out of a recession and everyone is making tough decisions - and some of these people just dont seem to grasp that. Two more missions that would maybe, finally tell us if life ever existed there, or could.

Im typically a fan of stuff like this, but I just could care less at this point.

[Macedon1an]

Russia plans man on Moon and Mars landing by 2030

Russia's space agency is planning to send probes to visit Mars, Jupiter and Venus and also to put a man on the Moon, all by 2030.
RT reports that the country's space industry official blueprint - Space Development Strategies up to 2030 - was submitted to the government by the Russian Federal Space Agency (Roscosmos) last week. The report is apparently a fascinating read...[read more]

[Phier]

So a couple of more NASA mars missions get the axe. Help me understand the tantrums from people like Bill Nye.

The global economy almost collapsed not that long ago, we are continuing to dig out of a recession and everyone is making tough decisions - and some of these people just dont seem to grasp that. Two more missions that would maybe, finally tell us if life ever existed there, or could.

Im typically a fan of stuff like this, but I just could care less at this point.

Fubaring Nasa was pretty much a get go from the onset of this administration though. Why, I have no idea, I'd think it would be easy points.

Anyways when you consider the cost of government, the billions on stimulus, the NASA budget looks pretty paltry. As agencies go its kinda like fat guys telling the skinny guy we all have to make sacrifices while eating a cheeseburger.

[Gordon Freynman]

Russia plans man on Moon and Mars landing by 2030

Russia's space agency is planning to send probes to visit Mars, Jupiter and Venus and also to put a man on the Moon, all by 2030.

I'd be amazed to see them launch a probe to anywhere and have it not catastrophically fail in low Earth orbit by 2030

[Phier]

I'd be amazed to see them launch a probe to anywhere and have it not catastrophically fail in low Earth orbit by 2030

Lets not forget this isn't communist Russia. I think their reliability should improve.

[pchalk]

i remember attending a talk from the CEO of one of those private space flight companies. they use the russian soyuz rockets. its cheaper than the american equivalent and does the job they need. i have a feeling we dont need to worry about nasa's current issues. there are space programs popping up all over the world and nasa's program is still the best funded out there.

[Macedon1an]

Last Dance for Venus, Jupiter and the Moon This Weekend

During the past month we've been treated to a sort of "twilight tango" between the two brightest planets, Venus and Jupiter, in the western night sky. Like two ships passing in the night, they have spent the last several weeks first approaching each other, then passing each other on March 13.

Venus and Jupiter still adorn our evening sky at dusk, but they're now going their own separate ways after their spectacular mid-March tryst. But one last event is still to occur and will be spread across two nights, on Sunday (March 25) and Monday (March 26). Indeed, the twilight light tango will turn into a pas de trois as our nearest neighbor, the moon, gets involved in this eye-catching celestial scene. [read more]

[Godfrey I of Leuven]

Speaking of Venus, is anyone going to observe the transit later this year?