The Astronomy Discussion Thread

[Loniat]

Originally Posted by Muir Woods

I'll lay my bias out, I'm not much of an expert on telescope products. My interest in astronomy lies more in the quirkiest and most bizzare entities of the universe (eg. neutron stars/pulsars, black holes, quasars, gamma ray bursts...etc), and thus more theoretical. I've only owned one telescope in my life, and that is the crappy Simmon's model 6330 60mm telescope I had since 4th grade. I think your question would be best presented and answered in an astronomy focused site, such as this forum. Look into their forum and search for "buying telescope" or "beginner telescope" and you'll quickly find tons of topics on it. This thread may address that issue between a reflector vs refractor. Or this site has descriptions of recommended beginner's telescope. I'm sorry I couldn't help you more directly.

Thanks!

I decided to spend a little more than what I thought and will get a ETX-90AT: http://shopping.discovery.com/product-57068.html

Let’s see what I can learn with this!

[Catgirls]

An interesting story I originally pulled off Digg.com:

Biggest Lightning Storm Ever Recorded on Saturn


Space.com

Scientists are tracking the strongest lighting storm ever detected at Saturn. The storm is larger than the continental United States, with electrical activity 1,000 times stronger than the lightning on Earth.

Radio outbursts were first detected by NASA's Cassini spacecraft Jan. 23.

The storm is about 2,175 miles wide (3,500 kilometers). "It's really the only large storm on the whole planet," said Andrew Ingersoll, a member of the Cassini imaging team.

Earth-based amateur astronomers were able view Saturn's dayside with their telescopes when Cassini could not. The amateurs' images of Saturn provided the first visual confirmation of the storm.

NASA has produced audio files of the storm. Now, these are crazy. Realizing that Saturn is huge and that storm is probably not that huge (for the size of the planet) ... still ... a lightning storm larger than the United States is awesome. I’ve always wondered if some day one large lightning storm could consume all or most of the US at one time (one continuous storm of the same weather cell).

[Catgirls]

There's a report coming out today (09 March 06) that "NASA's Cassini spacecraft may have found evidence of liquid water reservoirs" on Saturn's moon Enceladus. Digg.com & Drudge Report are pushing this.

http://www.drudgereport.com/flash8na.htm

[Press release set for 2 PM ET release]

NASA's Cassini spacecraft may have found evidence of liquid water reservoirs that erupt in Yellowstone-like geysers on Saturn's moon Enceladus. The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon.

"We realize that this is a radical conclusion - that we may have evidence for liquid water within a body so small and so cold," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute, Boulder, Colo. "However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms."

High-resolution Cassini images show icy jets and towering plumes ejecting huge quantities of particles at high speed. Scientists examined several models to explain the process. They ruled out the idea the particles are produced or blown off the moon's surface by vapor created when warm water ice converts to a gas. Instead, scientists have found evidence for a much more exciting possibility. The jets might be erupting from near-surface pockets of liquid water above 0 degrees Celsius (32 degrees Fahrenheit), like cold versions of the Old Faithful geyser in Yellowstone.

If true, this would be very interesting to say the least.

[JanthraX^]

Welcome to Celestia
Unlike most planetarium software, Celestia doesn't confine you to the surface of the Earth. You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy.
All movement in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across. A 'point-and-goto' interface makes it simple to navigate through the universe to the object you want to visit.
Celestia is expandable. Celestia comes with a large catalog of stars, galaxies, planets, moons, asteroids, comets, and spacecraft. If that's not enough, you can download dozens of easy to install add-ons with more objects.
-------

I have only recently found this and it has kept me amazed for many hours and im still going, thats that the intro from the website, i recommend any person who likes the stars and wants to explore to get this immediatley, completely free and easy to use! (im not trying to promo it, just what i think of this cool program)
http://www.shatters.net/celestia/


Also, a small question, realitvely close to our solar system there is a large very unstable star that is constantly pulling itself apart and back together again, does anybody know about this star, its name or have any pics of it? lol a bit vague, i know =D

[Kamui4356]

Originally Posted by Catgirls

There's a report coming out today (09 March 06) that "NASA's Cassini spacecraft may have found evidence of liquid water reservoirs" on Saturn's moon Enceladus. Digg.com & Drudge Report are pushing this. If true, this would be very interesting to say the least.

Yup, it's interesting, but wasn't enceladus already believed to have liquid water beneath it's surface, much like europa?

As saturn's moons go, I'm more interested in mimas. It has a huge impact crater, relative to it's size, as well as 15 mile high cliffs. Both are believed to have been formed by the impact, which almost destroyed the moon. Of course, for NASA to get any funding to study something, they have to make people think there's a possibility of life either existing or having once existed there. It's really sad.

[Catgirls]

Originally Posted by Kamui4356

Yup, it's interesting, but wasn't enceladus already believed to have liquid water beneath it's surface, much like europa?

I believe you're right, but I haven't really been following this story that much. I'm more into the whole Mars exploration. BTW...here are some images of Enceladus:



Pretty...

[JanthraX^]

Originally Posted by Kamui4356

Yup, it's interesting, but wasn't enceladus already believed to have liquid water beneath it's surface, much like europa?

As saturn's moons go, I'm more interested in mimas. It has a huge impact crater, relative to it's size, as well as 15 mile high cliffs. Both are believed to have been formed by the impact, which almost destroyed the moon. Of course, for NASA to get any funding to study something, they have to make people think there's a possibility of life either existing or having once existed there. It's really sad.

it is actually water or methane, because i remember one of the moons having liquid methane lakes.

[Kensuke]

Originally Posted by JanthraX^

I have only recently found this and it has kept me amazed for many hours and im still going, thats that the intro from the website, i recommend any person who likes the stars and wants to explore to get this immediatley, completely free and easy to use! (im not trying to promo it, just what i think of this cool program)
http://www.shatters.net/celestia/


Also, a small question, realitvely close to our solar system there is a large very unstable star that is constantly pulling itself apart and back together again, does anybody know about this star, its name or have any pics of it? lol a bit vague, i know =D

I agree, Celestia is amazing, I have used it at least a couple of years, and I have spend hours exploring the solar system and also other star systems, especially those with planets. I'm regularly lurking the forum for updates and addons, Celestia is made for easy addons, so if something new is discovered,soon someone has posted a addon for it.

And that question, astronomy is just my hobby, but I can't remember that there is any star like that nearby. I'm afraid, you have to be more specific, or hope that someone more knowledgeable than me comes here.

[Muir Woods]

A little bit late, but regardless, The Hubble Space Telescope has released yet another ultra high resolution astronomical image. This time it is the Messier object 101 (M101), an immense spiral galaxy face on to us nearly twice the size of our Milky Way. It contains over one trillion stars and estimated about 100 billion of them are Sun-like (around spectral type G2V range). Apply Drake's equation, even with conservative subjective fractions, don't you think there just might be intelligent life on some planet orbiting around some Sun-like star? Anyways, this new extremely high resolution image is composed of over 50 individual Hubble exposures over a period of 10 years. For reasonably sized images and the full story here, or download the full size composition 15852 x 12392 pixels here and gaze in its wonder.

Originally Posted by JanthraX^

Also, a small question, realitvely close to our solar system there is a large very unstable star that is constantly pulling itself apart and back together again, does anybody know about this star, its name or have any pics of it? lol a bit vague, i know =D

Hmm, could you be describing rare super massive upper limit of main sequence stars? Stars above the theoretical stable limit of 90-100 solar masses would fuse and radiate energy so furiously that their luminosity pressure would exceed the force of gravity (the Eddington's Limit). Thus these stars, as predicted, would be unstable and expelling their own mass. Maybe it's the Pistol Star? A ~200 solar mass star 25,000 light years away. Or the "relatively" closer Eta Carinae? A 120-150 solar mass star about 8000 light years away? Or perhaps it some kind of different type of astronomical object altogether?

[Catgirls]

I'm sure you're all familiar with Google Maps ... well, they've applied the same technology to the surface of Mars to some extent. Give it a spin.

-> http://www.google.com/mars/

Cheers.

[Kensuke]

That is pretty cool, plus I hope in a year or so we have high-resolution maps of Mars, Mars Reconnaissance Orbiter that just reached Mars will be able to take pictures with a resolution down to 0,3 meters from 300 km altitude (altohught it has to go throught several months of aerobraking to get it in the right orbit). It is for future manned missions.
Wikipedia: http://en.wikipedia.org/wiki/Mars_Re...ssance_Orbiter

I find it amazing that probes main computer is "only" 133 MHz, of course it has to be reliable and able to endure radiation from sun unprotected.


And enjoy this 6572 x 8293 pixel picture of Enceladus.
http://antwrp.gsfc.nasa.gov/apod/ap060310.html

[Caliban]

I don't know if you guys/gals are interested in having a 3D representation of cosmic bodies but in case you do just click this link: http://www.crystalnebulae.co.uk/index.html

Pretty cool, eh?

[USB500]

Originally Posted by Catgirls

I believe you're right, but I haven't really been following this story that much. I'm more into the whole Mars exploration. BTW...here are some images of Enceladus:



Pretty...

Holy Zen! I almost crapped my pants! Those pics are pretty!

I think I'm going to dig in astronomy again after this and i'll put pic of my favourite astronomy subject: comet

Mmm... Hale-Bopp... :"D

[Kensuke]

I have always been fascinated about planets and I was delighted that Venus Express has succesfully reached its target.

Official site

Wikipedia

Unlike Mars Reconnaissance Orbiter, that using aerobraking to reach its orbit. Venus Express carried as much fuel as it could, and required 50-minute burn to slow the probe for orbit.

[Catgirls]

An Erupting Solar Prominence from SOHO
Credit: SOHO-EIT Consortium, ESA, NASA

Explanation: Our Sun is still very active. In the year 2000, our Sun went though Solar Maximum, the time in its 11-year cycle where the most sunspots and explosive activities occur. Sunspots, the Solar Cycle, and solar prominences are all caused by the Sun's changing magnetic field. Pictured above is a solar prominence that erupted in 2002 July, throwing electrons and ions out into the Solar System.

The above image was taken in the ultraviolet light emitted by a specific type of ionized helium, a common element on the Sun. Particularly hot areas appear in white, while relatively cool areas appear in red. Our Sun should gradually quiet down until Solar Minimum occurs, and the Sun is most quiet. No one can precisely predict when Solar Minimum will occur, although some signs indicate that it has started already!

» Link to actual web-site
» Link to HUGE version of the above picture

[Kamui4356]

That's an impressive pic. A truely massive prominence... I don't think I've seen one that big before. It's amazing how things like that can happen on our own sun. Though isn't the earth a bit too large there? Well it says approx. size...

[raikage]

Saw this on another forum:

[Jinto]

I can hardly get a feeling of the enourmous size of our sun. I can somehow imagine it, its just very hard to not shrinken it in my mind. But there is no way for me to ever imagine the size of stars like Antares right. I see these graphics, but can I feel/imagine the dimensions? No. Its just too huge to see my imaginary self in the right size next to it. With such big objects, I totally loose imagination.
If you are confused now... what I meant is the following. Imagine you fly to the imaginary sun. Lets assume the sun is just a holographic object just a 3-dimensional image. You'ld imagine its size right, if you feel you are on the sun's surface when you actually are on the holographic surface. You'ld imagine its size wrong, if you think you are on the surface but you are actually either far away from it or have already passed it.
I can imagine such a virtual flight for sun-sized objects, but with Antares-sized objects I totally loose correlations.

[USB500]

Wow, just looking at those pic scare the hell out of me I can't imagine how a solar system would like with a star with that humongous size

[Kamui4356]

Originally Posted by USB500

Wow, just looking at those pic scare the hell out of me I can't imagine how a solar system would like with a star with that humongous size

Well, according to one site I found, Antares has a radius of 3 AU. That would mean all the inner planets would be well inside the star.