Search found 63 matches
- Tue Apr 09, 2024 6:20 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon's Shadow over Lake Magog (2024 Apr 09)
- Replies: 13
- Views: 2155
Re: APOD: Moon's Shadow over Lake Magog (2024 Apr 09)
We got very lucky with the weather, just had some thin high clouds.
- Mon Feb 05, 2024 9:16 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: In the Core of the Carina Nebula (2024 Feb 05)
- Replies: 13
- Views: 4615
Re: APOD: In the Core of the Carina Nebula (2024 Feb 05)
Based on Wikipedia (first attachment), I think it's as indicated by the arrow in the second attachment.johnnydeep wrote: ↑Mon Feb 05, 2024 7:42 pm What I really need is an overlay showing where this close-up is in the whole Carina Nebula, and where Eta Carina is!
- Wed Dec 20, 2023 8:35 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 1499: The California Nebula (2023 Dec 19)
- Replies: 8
- Views: 5669
Re: APOD: NGC 1499: The California Nebula (2023 Dec 19)
Are there any estimates of the mass or average density of the California Nebula, and the average density of its surrounding medium? The mass is probably that of several tens of Suns. The density is that of a very hard vacuum. I know the density of interstellar space can vary greatly, but using an &...
- Tue Dec 19, 2023 11:47 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 1499: The California Nebula (2023 Dec 19)
- Replies: 8
- Views: 5669
Re: APOD: NGC 1499: The California Nebula (2023 Dec 19)
Are there any estimates of the mass or average density of the California Nebula, and the average density of its surrounding medium?
- Mon Dec 04, 2023 11:38 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Setting Behind Teide Volcano (2023 Dec 03)
- Replies: 18
- Views: 4101
Re: APOD: Moon Setting Behind Teide Volcano (2023 Dec 03)
Very good!
Here's a version with different background music, the conclusion to Beethoven's Moonlight Sonata:
Here's a version with different background music, the conclusion to Beethoven's Moonlight Sonata:
Click to play embedded YouTube video.
- Thu Sep 14, 2023 3:37 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 7331 and Beyond (2023 Sep 14)
- Replies: 21
- Views: 4364
Re: APOD: NGC 7331 and Beyond (2023 Sep 14)
It is really very interesting that NGC 731 is seen right in front of the galaxy group known as the Deer Lick Group, which is at least 8 times farther away from us than NGC 7331 (some 300-350 million light-years away versus some 40 million light-years away for NGC 7331). I find it interesting that t...
- Mon Aug 28, 2023 8:14 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Season of Saturn (2023 Aug 25)
- Replies: 28
- Views: 5256
Re: APOD: A Season of Saturn (2023 Aug 25)
Your mama warned you about those crossed eyes. Keep doing that and they'll be stuck that way forever! :lol2: Crossing your eyes on this image gives an effect, but it is inverted. You get the correct effect if you relax your eyes so that you are focusing on a point beyond your screen (imagine lookin...
- Fri Aug 25, 2023 8:28 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Season of Saturn (2023 Aug 25)
- Replies: 28
- Views: 5256
Re: APOD: A Season of Saturn (2023 Aug 25)
It helps if you adjust your image size so that adjacent Saturns appear about 5-6 cm apart on your screen.
- Fri Aug 25, 2023 7:33 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Season of Saturn (2023 Aug 25)
- Replies: 28
- Views: 5256
Re: APOD: A Season of Saturn (2023 Aug 25)
You get a neat 3-D effect if you relax your eyes and focus on a more distant spot, like what you do for stereoscopic image pairs. Click below to give it a try. It helps if you adjust your image size so that adjacent Saturns appear about 5-6 cm apart on your screen. [attachment=0]SeasonSaturnapodacas...
- Mon Mar 20, 2023 10:03 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M1: The Expanding Crab Nebula (2023 Mar 20)
- Replies: 20
- Views: 3426
Re: APOD: M1: The Expanding Crab Nebula (2023 Mar 20)
What portion is expanding at the rate of 1000 km/s? Presumably the expansion rate falls off as radius squared from the source? So whatever feature is expanding at 1000 km/s it must have moved about 1/20th of a light-year in 14 years.
- Thu Jan 19, 2023 12:20 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Enhanced (2023 Jan 16)
- Replies: 11
- Views: 2737
Re: APOD: Moon Enhanced (2023 Jan 16)
Wikipedia says it's 1.5 km high - https://en.wikipedia.org/wiki/Mons_La_Hire I don't know. What can we deduce from a close-up of the Google Moon map showing a shadow an a 10 mi scale: Guess we can conclude that a 1-mile-high mountain casting a shadow 100 miles long would need the sun to be only 0.6...
- Wed Jan 18, 2023 12:13 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Enhanced (2023 Jan 16)
- Replies: 11
- Views: 2737
Re: APOD: Moon Enhanced (2023 Jan 16)
Wikipedia says it's 1.5 km high - https://en.wikipedia.org/wiki/Mons_La_Hire So your height calculation seems to be off. I'll let others figure out why. I know my height can't be correct, that's what I was asking. To put it another way, why does the shadow of the 1.5 km mountain appears to be 80 km...
- Mon Jan 16, 2023 11:34 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Enhanced (2023 Jan 16)
- Replies: 11
- Views: 2737
Re: APOD: Moon Enhanced (2023 Jan 16)
There is a feature on the upper left near the terminator that casts a shadow of around 40 miles (if my estimate is correct). Based on its distance from the terminator, the sun is about 10 degrees above the horizon, meaning the feature's height is about (40 miles) x tan (10 deg) = 7 miles. What am I ...
- Sat Dec 31, 2022 7:02 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon over Makemake (2022 Dec 31)
- Replies: 13
- Views: 3373
Re: APOD: Moon over Makemake (2022 Dec 31)
Very nice rendering. Do we have any sense of how the sun and background starts would actually appear to a human at that location? I think our pupils would shut down because of the sun's brightness (the apparent magnitude of the sun at that distance is around -18). However, it would be easy to block...
- Sat Dec 31, 2022 6:08 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon over Makemake (2022 Dec 31)
- Replies: 13
- Views: 3373
Re: APOD: Moon over Makemake (2022 Dec 31)
Very nice rendering. Do we have any sense of how the sun and background starts would actually appear to a human at that location? I think our pupils would shut down because of the sun's brightness (the apparent magnitude of the sun at that distance is around -18). However, it would be easy to block ...
- Thu Sep 15, 2022 8:17 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Planets of the Solar System: Tilts... (2022 Sep 11)
- Replies: 41
- Views: 7697
Re: APOD: Planets of the Solar System: Tilts... (2022 Sep 11)
Thanks!!johnnydeep wrote: ↑Thu Sep 15, 2022 8:06 pm
Interesting questions! The first is answered here (though not sure how accurate it is) - https://astronomy.stackexchange.com/que ... tem-planet:
- Thu Sep 15, 2022 7:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Planets of the Solar System: Tilts... (2022 Sep 11)
- Replies: 41
- Views: 7697
Re: APOD: Planets of the Solar System: Tilts... (2022 Sep 11)
We know what Earth's north star is. What are the approximate north stars of each planet? And what is the sun's north star?
Do all moons have the same tilt as their planet?
Do all moons have the same tilt as their planet?
- Tue Jun 21, 2022 9:00 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Satellites Behind Pinnacles (2022 Jun 14)
- Replies: 12
- Views: 3000
- Tue Jun 21, 2022 8:37 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Analemma over Taipei (2022 Jun 21)
- Replies: 24
- Views: 5760
Re: APOD: Analemma over Taipei (2022 Jun 21)
I had the same question. I could imagine some slight misalignment, but they're not close at all. No, the equinox points do not coincide. Earth's orbital eccentricity creates the asymmetric figure 8 as pointed up earlier. For a perfectly circular orbit (eccentricity = 0), the equinox points would co...
- Tue Jun 21, 2022 3:23 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Analemma over Taipei (2022 Jun 21)
- Replies: 24
- Views: 5760
- Wed Mar 30, 2022 4:32 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Animation: Odd Radio Circles (2022 Mar 30)
- Replies: 8
- Views: 14803
Re: Sad news…
Condolences and prayers.
- Tue Feb 15, 2022 3:40 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Terminator Moon (2022 Feb 15)
- Replies: 19
- Views: 20202
Re: APOD: Terminator Moon (2022 Feb 15)
Very nice. How about a "Zenith Moon" with images assembled when the sun is at Lunar noon for each Lunar latitude? Although probably not as interesting since the shadows only appear near the limb in full moon images.
- Sun Mar 22, 2020 2:02 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Setting Behind Teide Volcano (2020 Mar 22)
- Replies: 12
- Views: 4608
Re: APOD: Moon Setting Behind Teide Volcano (2020 Mar 22)
Here's a version with a bit more lively music: the conclusion to Beethoven's Moonlight Sonata. Enjoy!
Click to play embedded YouTube video.
- Tue Jan 21, 2020 3:41 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Parker: Sounds of the Solar Wind (2020 Jan 21)
- Replies: 8
- Views: 4113
Re: APOD: Parker: Sounds of the Solar Wind (2020 Jan 21)
'
"What does the solar wind sound like?" The video below gives the true answer.
Translating particle impact and variable-field data of the solar wind into "sound" is about as meaningful as translating them into Japanese.
"What does the solar wind sound like?" The video below gives the true answer.
Translating particle impact and variable-field data of the solar wind into "sound" is about as meaningful as translating them into Japanese.
Click to play embedded YouTube video.
- Thu Jan 09, 2020 5:21 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perihelion to Aphelion (2020 Jan 09)
- Replies: 30
- Views: 9678
Re: APOD: Perihelion to Aphelion (2020 Jan 09)
Neat comparison! The diameter of the sun as measured from the image only increases by 1.4% from aphelion to perihelion (attached). The measured area increases by 2.8%, which is also the measured increase in "apparent diameter." It is now apparent to me that "apparent diameter" is...