Discussion in 'Community' started by jp-30, Jul 16, 2010.
Nice night here to watch them.
We had relatively clear skies again last night, and out balcony faces east, so braved the bitter cold (about -5°C) for about five minutes, caught 4 in that short time. Pretty amazing.
5(unconfirmed)planets just 12 ly away
Bit crowded. Point Webb at it!
We're caring about fully unconfirmed planets now?
I guess because they are so close and awaiting yay or nay so so it gets attention?
A comet to be brighter than the full Moon a year from now
Comet Ison has taken millions of years to reach us travelling from the so-called Oort cloud – a reservoir of trillions and trillions of chunks of rock and ice, leftovers from the birth of the planets. It reaches out more than a light-year – a quarter of the way to the nearest star. In the Oort cloud the Sun is but a distant point of light whose feeble gravity is just enough to hold onto the cloud. Every once in a while a tiny tug of gravity, perhaps from a nearby star or wandering object, disturbs the cloud sending some of its comets out into interstellar space to be lost forever and a few are scattered sunward. Comet Ison is making its first, and perhaps only visit to us. Its life has been cold, frozen hard and unchanging, but it is moving closer to the Sun, and getting warmer.
Ison's surface is very dark – darker than asphalt – pockmarked and dusty with ice beneath the surface. It's a small body, a few tens of miles across, with a tiny pull of gravity. If you stood upon it you could leap 20 miles into space taking over a week to come down again, watching as the comet rotated beneath you. You could walk to the equator, kneel down and gather up handfuls of comet material to make snowballs, throw them in a direction against the comet's spin and watch them hang motionless in front of you. But it will not remain quiet on Comet Ison for the Sun's heat will bring it to life.
By the end of summer it will become visible in small telescopes and binoculars. By October it will pass close to Mars and things will begin to stir. The surface will shift as the ice responds to the thermal shock, cracks will appear in the crust, tiny puffs of gas will rise from it as it is warmed. The comet's tail is forming.
Slowly at first but with increasing vigour, as it passes the orbit of Earth, the gas and dust geysers will gather force. The space around the comet becomes brilliant as the ice below the surface turns into gas and erupts, reflecting the light of the Sun. Now Ison is surrounded by a cloud of gas called the coma, hundreds of thousands of miles from side to side. The comet's rotation curves these jets into space as they trail into spirals behind it. As they move out the gas trails are stopped and blown backwards by the Solar Wind.
^ In Sept. What does "ISON" mean?
I really doubt it will be brighter than the full moon. I get forwarded emails about stuff like that all the time, and it never happens.
Lunar occulation of Jupiter
"The video is sped up by a factor of five to show the process. At the end he also got a shot of Jupiter reappearing, with its moon
Io popping up just ahead of the planet. You can see the shadow of
Io on Jupiter’s cloud tops, too. Bear in mind, the Moon was about 400,000 km (240,000 miles) away at the time, but Jupiter was over 600 million kilometers (360 million miles) farther out! It looks small here, but in reality Jupiter is over 40 times wider than our Moon."
We had a great clear sky for Christmas night, so I easily saw Jupiter next to the moon.
I saw Jupiter close to the moon on the night of the day after Christmas, but I didn't know what it was until I came inside and looked up online and referred to some star charts.
Astronomers estimate 100 billion planets in the galaxy
"To do that calculation, the Caltech team determined the probability that an M-dwarf system would provide Kepler-32's edge-on orientation. Combining that probability with the number of planetary systems Kepler is able to detect, the astronomers calculated that there is, on average, one planet for every one of the approximately 100 billion stars in the galaxy."
Ok, this bugs me. As a youngster I learned that there were 100 billion stars in our galaxy. The novel 2001 has a great line:
“Behind every man now alive stand thirty ghosts, for that is the ratio by which the dead outnumber the living. Since the dawn of time, roughly a hundred billion human beings have walked the planet Earth.
Now this is an interesting number, for by a curious coincidence there are approximately a hundred billion stars in our local universe, the Milky Way. So for every man who has ever lived, in this Universe there shines a star."
Then along came Sagan who kept saying there were 200 billion stars in the galaxy. Ok then. Then for just about the past decade astronomers started saying there are 400 billion stars in out galaxy. Alright. Now we are back to 100 billion?
Largest structure in universe discovered — it's mind-boggling
Large quasar group stretches 4 billion light-years, so big theory says it shouldn't exist
To put that mind-boggling size into perspective, the disk of the Milky Way galaxy — home of Earth's solar system — is about 100,000 light-years wide. And the Milky Way is separated from its nearest galactic neighbor, Andromeda, by about 2.5 million light-years.
Could this be the work of an alien civilization? It would be cool if it was.
(They'd need one big bad-*** gravity pump though.....)
I think they are saying there are 100 billion M-dwarf stars, not in total.
I like to look upon THIS PAGE and it's various maps when such items hit the headlines.
Earth may have been hit by an gamma-ray burst over 1200 years ago
Just around the time Medieval Europe was plagued by green rage monsters....
Earth buzzing asteroid would be worth almost 200 billion
I truly wish Gerard K. Oneill had been obeyed by NASA.
Commet will pass close to Mars in 2014
There is a 1 in 10,000 chance it will actually hit mars but right now it says the comet should miss by 65,000 miles. Honestly, I kinda want the impact.
Some pretty amazing images of Saturn from Cassini
Isn't a Comet supposed to get incredibly close to Earth soon?
Nope. We've got a couple good ones coming, but they won't be terribly close to us. One of them will get nice and close to Mars, though.
Comet Panstarrs should start showing up for the northern hemisphere soon, though. It's just not close by.
And that's not even all of them. There are half a million known.
It's like an astronomical lava lamp.
I have a question for the more experienced sky-watchers here: I bought a decent pair of binoculars last year as an interim step before getting a telescope a few years down the road, once my daughters are old enough to make good use of it.One thing I wanted to tart focusing on with the binoculars was the Galilean moons of Jupiter, I think I've spotted them several times, but I'm not certain. To help me, I found this online tool showing the position of the moons a specific times. BUT -- what it shows as "direct view2 has east to the left of North. I understand that#s the way star charts are usually made, so that if you're looking north and have north at the bottom of your chart, east would be where it's supposed to be. But if I'm standing in my yard looking up at Jupiter, won't the moons be aligned in the inverse of what the tool shows me?
The latest in the "Is there life on Europa?" puzzle.
Anybody see the comet yet?