Posts: 10,227
Threads: 345
Joined: Apr 2009
"
Setting Sights on the Stars"
Another nice article about Hawaiian children getting opportunities to get involved in real astronomical research using the observatories on Mauna Kea, this time from Molokai:
https://themolokaidispatch.com/setting-s...the-stars/
"
“Shoot for the stars” is advice often given to youth, but three Molokai High School students have earned the chance to take the phrase literally. They were awarded a once-in-a-lifetime opportunity to observe the stars through the one world’s best telescopes atop Maunakea."
Posts: 5,640
Threads: 101
Joined: Dec 2008
Always great to see the local youth showing interest in astronomy. It's a mind blowing subject.
(That blurb grates on me though. Literally? Once in a lifetime? They're being used too much and usually incorrectly!)
As for Tiangong-1, surely it has to be on Easter day now, it just seems right somehow.
Posts: 10,227
Threads: 345
Joined: Apr 2009
"That blurb grates on me though. Literally? Once in a lifetime? They're being used too much and usually incorrectly!"
The "blurb" is actually quite accurate. Unless the students become professional astronomers, when's the next time they get to use a major international telescope on Mauna Kea?
Posts: 10,227
Threads: 345
Joined: Apr 2009
Missing dark matter
This is a real mystery. It's pretty obvious from observations of galaxies that the universe consists mostly of "dark matter", stuff we can't see directly but can infer exists due to its gravitational effects. However, using the Keck and Gemini telescopes on Mauna Kea, we've discovered a galaxy that seems to have little or no dark matter. It's a real puzzle.
https://www.gemini.edu/node/21048
"
“It’s like you take a galaxy and you only have the stellar halo and globular clusters, and it somehow forgot to make everything else,” van Dokkum said. “There is no theory that predicted these types of galaxies. The galaxy is a complete mystery, as everything about it is strange. How you actually go about forming one of these things is completely unknown.”"
"That blurb grates on me though. Literally? Once in a lifetime? They're being used too much and usually incorrectly!"
The "blurb" is actually quite accurate. Unless the students become professional astronomers, when's the next time they get to use a major international telescope on Mauna Kea?
this is fun.. A "quite accurate" answer lies in your question Tom.
Posts: 11,023
Threads: 750
Joined: Sep 2012
Missing dark matter
Thanks TomK,
That's a story you can really wrap your mind around.
Something we can't see, dark matter, is missing - - in a newly discovered galaxy.
Do you think as we find out more about the nature of dark matter, it will help us to understand the role it plays in forming galaxies? And then how a galaxy might form and exist without it?
If you want to combine the dual pleasures of insanity and social acceptance, religion is your only choice. - Last Aphorisms
"I'm at that stage in life where I stay out of discussions. Even if you say 1+1=5, you're right - have fun." - Keanu Reeves
Posts: 10,227
Threads: 345
Joined: Apr 2009
"Do you think as we find out more about the nature of dark matter, it will help us to understand the role it plays in forming galaxies? And then how a galaxy might form and exist without it?"
Those are hard questions. I'll do a bit of research and get back to you.
Posts: 5,640
Threads: 101
Joined: Dec 2008
"Once in a lifetime" implies it can only happen, well, once in a lifetime. There is nothing stopping this event from happening again.
That phrase gets overused, it's becoming meaningless e.g. "win a once-in-a-lifetime trip to Disneyland!". But anyway, unimportant.
Dark Matter has me completely baffled.
Agreed, i think most here could say they have experienced "once in a lifetime" events multiple times.
Particularly on this island.
10 years from now lets all talk about dark matter and see if is really matters anyway.
Posts: 10,227
Threads: 345
Joined: Apr 2009
HOTPE - I did a little reading as this is not my area of expertise, I'm more of a Galactic astronomer, but this is basically what I learned:
Without dark matter, the universe would have been much more uniform whereas, in order for galaxies to form, you need some type of "clumpiness", i.e., regions in space that essentially have more gravitational force than others. This then attracts gas and a little dust which over millions of years collapses into dense clumps and forms stars and galaxies. This has led to what's known as the "standard model" in cosmology. Therefore, to find a galaxy that has little or no dark matter is hard to explain, although clearly, it's very different to others because you can see through it, so it's not very dense. But how it formed in the first place is the mystery.
It's a bit of a technical read, but you can see more here:
https://arxiv.org/pdf/0909.2021.pdf
Paul - I was thinking more of a once in a lifetime event for the specific students, which it'll probably be unless they go on to become professional astronomers. And even then, it's not easy to get time on those telescopes. Not so much that the opportunity itself was happening just once.
