Search found 3078 matches
- Tue Jan 19, 2021 4:34 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Medulla Nebula Supernova Remnant (2021 Jan 18)
- Replies: 22
- Views: 10648
Re: APOD: The Medulla Nebula Supernova Remnant (2021 Jan 18)
https://scontent.fhel4-1.fna.fbcdn.net/v/t1.0-9/139785209_3598945906893161_7915779118917198360_o.jpg?_nc_cat=109&ccb=2&_nc_sid=dbeb18&_nc_eui2=AeHa2LsRpbY6jUi_OJwfEWUfQZ3BZdRPNwRBncFl1E83BJ-IvCPKpgdTTT_utIeJqzWzSC9feWgZy_ALWQJMA85G&_nc_ohc=WCfaE8bDliIAX8zXO7t&_nc_ht=scontent.fhe...
- Tue Jan 19, 2021 4:12 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Lunar Corona with Jupiter and Saturn (2021 Jan 19)
- Replies: 13
- Views: 5338
Re: APOD: A Lunar Corona with Jupiter and Saturn (2021 Jan 19)
https://apod.nasa.gov/apod/calendar/S_210119.jpg A Lunar Corona with Jupiter and Saturn Explanation: Why does a cloudy moon sometimes appear colorful? The effect , called a lunar corona , is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in ...
- Tue Jan 19, 2021 3:52 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Lunar Corona with Jupiter and Saturn (2021 Jan 19)
- Replies: 13
- Views: 5338
Re: APOD: A Lunar Corona with Jupiter and Saturn (2021 Jan 19)
You're right! Thanks for making me look.Sa Ji Tario wrote: ↑Tue Jan 19, 2021 2:11 pm More than one of Jupiter's moons can be seen
- Mon Jan 18, 2021 5:27 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Medulla Nebula Supernova Remnant (2021 Jan 18)
- Replies: 22
- Views: 10648
Re: APOD: The Medulla Nebula Supernova Remnant (2021 Jan 18)
In view of neufer's brain anatomy post, this nebula is much more aptly names the Cerebellum Nebula:
Or even the Mushroom Nebula:
Or even the Mushroom Nebula:
- Mon Jan 18, 2021 5:25 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Medulla Nebula Supernova Remnant (2021 Jan 18)
- Replies: 22
- Views: 10648
Re: APOD: The Medulla Nebula Supernova Remnant (2021 Jan 18)
Does anyone know why the oxygen (blue) is concentrated toward the lower left? We aren't necessarily seeing more oxygen in that region. We could simply be seeing it because that's where it is most strongly ionized, which would be a consequence of the distribution of hot stars that provide the ionizi...
- Mon Jan 18, 2021 3:41 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Jets from Unusual Galaxy Centaurus A (2021 Jan 17)
- Replies: 18
- Views: 5597
Re: APOD: Jets from Unusual Galaxy Centaurus A (2021 Jan 17)
The jet and the lobe are not directed straight at us, however. If they were, we wouldn't see a jet at all, just a very bright central light source. Ann For M87 the angle between our line of site and the axis of the jet and the counterjet: 17±3°. (using apparent component speeds in the jet, 0.21±0.0...
- Mon Jan 18, 2021 3:38 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Jets from Unusual Galaxy Centaurus A (2021 Jan 17)
- Replies: 18
- Views: 5597
Re: APOD: Jets from Unusual Galaxy Centaurus A (2021 Jan 17)
https://apod.nasa.gov/apod/calendar/S_210117.jpg Jets from Unusual Galaxy Centaurus A https://upload.wikimedia.org/wikipedia/commons/e/e6/Centauros_a-spc.png It's easy to guess disk's plane angle to our line of sight. But what about the pair of jets? The visible one must be toward us. But exactly h...
- Sun Jan 17, 2021 5:02 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Jets from Unusual Galaxy Centaurus A (2021 Jan 17)
- Replies: 18
- Views: 5597
Re: APOD: Jets from Unusual Galaxy Centaurus A (2021 Jan 17)
Nasty looking image! I don't think it would be a good place to live! :shock: It looks as though the whole galaxy is in chaos!! Beautiful though; isn't it? It's not at all clear to me how deadly this black hole activity and consequent plasma jets and x-ray emission and bubbles of radio emitting gas ...
- Sun Jan 17, 2021 3:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Mountains of NGC 2174 (2021 Jan 16)
- Replies: 6
- Views: 3427
Re: APOD: The Mountains of NGC 2174 (2021 Jan 16)
The caption claims the "scene spans about 6 light-years". If that is correct there seems to be an extraordinary number of stars for that small a span. Obviously a few of the stars may be in the foreground, but many are partially darkened meaning they must be within the same local gas and ...
- Sat Jan 16, 2021 8:24 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Plutonian Landscape (2021 Jan 15)
- Replies: 35
- Views: 14891
Re: APOD: A Plutonian Landscape (2021 Jan 15)
You need to be very cautious comparing a photograph to what your eye sees. Again, photos are normalized to span the range from black to white, i.e. from the minimum to the maximum value that a pixel can have. Your eyes/brain dynamically process a very wide dynamic range and build a perceptual image...
- Sat Jan 16, 2021 4:56 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Plutonian Landscape (2021 Jan 15)
- Replies: 35
- Views: 14891
Re: APOD: A Plutonian Landscape (2021 Jan 15)
Ever look at black asphalt in bright sunlight immediately after walking out of a dark building? At nighttime, the Moon (and planets, if any) are the only objects in direct sunlight, while your eyes are adjusted to seeing things in the dark. During the daytime, the Moon looks a little brighter than ...
- Sat Jan 16, 2021 3:10 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Plutonian Landscape (2021 Jan 15)
- Replies: 35
- Views: 14891
Re: APOD: A Plutonian Landscape (2021 Jan 15)
Whoa there! So, are you saying that if the moon were entirely paved over with a layer of freshly laid black asphalt, a full moon would look as bright to us as it currently does? If so, that might be the most surprising thing I've heard about space in a long long time! But, since the maria and non-m...
- Fri Jan 15, 2021 4:38 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Plutonian Landscape (2021 Jan 15)
- Replies: 35
- Views: 14891
Re: APOD: A Plutonian Landscape (2021 Jan 15)
It is amazing that we can get such a picture of Pluto! Astonishing feat! Question though: was the light in the picture enhanced or is that the natural amount of light on Pluto? Virtually every photograph, even of ordinary terrestrial things like flowers, is adjusted so that the brightest areas map ...
- Fri Jan 15, 2021 3:05 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Plutonian Landscape (2021 Jan 15)
- Replies: 35
- Views: 14891
Re: APOD: A Plutonian Landscape (2021 Jan 15)
When I first saw Sputnik Planum I thought 'Ooh that looks a lot like a meteorite crater. Those mountains to the left look like they were one of the debris lobes thrown out from the impact. Or it could have been some gaseous bulge that rose up and then collapsed as stuff leaked out the sides. If it ...
- Fri Jan 15, 2021 3:00 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Plutonian Landscape (2021 Jan 15)
- Replies: 35
- Views: 14891
Re: APOD: A Plutonian Landscape (2021 Jan 15)
https://apod.nasa.gov/apod/calendar/S_210115.jpg A Plutonian Landscape Explanation: This shadowy landscape of majestic mountains and icy plains stretches toward the horizon on a small, distant world. It was captured from a range of about 18,000 kilometers when New Horizons looked back toward Pluto ...
- Thu Jan 14, 2021 7:52 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Aurora Slathers Up the Sky (2021 Jan 14)
- Replies: 13
- Views: 5623
Re: APOD: Aurora Slathers Up the Sky (2021 Jan 14)
There is a strange dark red band in the upper left part of the dark sky, and some other artifacts left and right of it. What are they? Parts of the International Space Station! The octagonal shapes at the top are probably solar panels, or maybe sun shields. Not sure what the black things on the lef...
- Thu Jan 14, 2021 7:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Aurora Slathers Up the Sky (2021 Jan 14)
- Replies: 13
- Views: 5623
Re: APOD: Aurora Slathers Up the Sky (2021 Jan 14)
How accurate is it to describe a vehicle moving through Earth's atmosphere by essentially falling around the planet as a space station? That's equivalent to someone who jumps up being regarded as an astronaut. Accurate enough. The ISS is orbiting at 400 km. By legal convention, space starts at 100 ...
- Thu Jan 14, 2021 2:56 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Aurora Slathers Up the Sky (2021 Jan 14)
- Replies: 13
- Views: 5623
Re: APOD: Aurora Slathers Up the Sky (2021 Jan 14)
https://apod.nasa.gov/apod/calendar/S_210114.jpg Aurora Slathers Up the Sky Explanation: Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this 2017 June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting stati...
- Tue Jan 12, 2021 4:29 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Historic Brazilian Constellation (2021 Jan 12)
- Replies: 8
- Views: 4253
Re: APOD: A Historic Brazilian Constellation (2021 Jan 12)
Folklore of the night sky is important for many reasons, including that it records cultural heritage and documents the universality of human intelligence and imagination. ...and the universality of humans seeing things that aren't there, and seeing patterns where there are none. Tragically, this is...
- Mon Jan 11, 2021 9:40 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Phases in 2021 (2021 Jan 11)
- Replies: 15
- Views: 5855
Re: APOD: Moon Phases in 2021 (2021 Jan 11)
The LRO records both optical data and also laser altimetry. The final output is a dataset that defines points on the Moon by reflectivity and height. From this, an image can be synthesized for any solar angle. The shadows are cast digitally. The landscape is created digitally. The frames in this vi...
- Mon Jan 11, 2021 7:08 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Phases in 2021 (2021 Jan 11)
- Replies: 15
- Views: 5855
Re: APOD: Moon Phases in 2021 (2021 Jan 11)
Nice video, but I'm really confused. The text says the images were taken by the Lunar Reconnaissance Orbiter. Now, that is in orbit about the moon , so how are we supposed to end up with what purports to be the phases and librational motion of the moon as seen from the earth ? Or am I misunderstand...
- Mon Jan 11, 2021 6:29 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Phases in 2021 (2021 Jan 11)
- Replies: 15
- Views: 5855
Re: APOD: Moon Phases in 2021 (2021 Jan 11)
Nice video, but I'm really confused. The text says the images were taken by the Lunar Reconnaissance Orbiter. Now, that is in orbit about the moon , so how are we supposed to end up with what purports to be the phases and librational motion of the moon as seen from the earth ? Or am I misunderstandi...
- Sun Jan 10, 2021 10:27 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Star Cluster R136 Breaks Out (2021 Jan 10)
- Replies: 28
- Views: 10344
Re: APOD: Star Cluster R136 Breaks Out (2021 Jan 10)
He's talking about the two red structures in the cavity, which look like a square and a triangle (or a square and square that is partly blocked from view along its diagonal). So yes, they do look a bit like tiles. But that's just pareidolia and our brain looking for patterns. It's a region of ioniz...
- Sun Jan 10, 2021 6:13 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Star Cluster R136 Breaks Out (2021 Jan 10)
- Replies: 28
- Views: 10344
Re: APOD: Star Cluster R136 Breaks Out (2021 Jan 10)
unusual to see spiked stars in another galaxy. They are bright and the LMC galaxy is near. I wonder what large ghostly red tiles in the background of the top half of the left cavity can be. They don't feel astronomic at all. "Ghostly red tiles"? I don't see them. Can you point them out wi...
- Sun Jan 10, 2021 4:26 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Star Cluster R136 Breaks Out (2021 Jan 10)
- Replies: 28
- Views: 10344
Re: APOD: Star Cluster R136 Breaks Out (2021 Jan 10)
Professor Paul Crowther, University of Sheffield , wrote about the data that had been collected about R136a by STIS: The ultraviolet STIS spectral survey of all stars more massive than ~25 solar masses has revealed: a) the bulk of the visual brightest members of R136 are O2-3 stars b) comparison of...