Discoveries using the telescopes on Mauna Kea

[TomK]

Thanks for that, HOTPE. It's a shame UKIRT is in wide-field mode at the moment because with the Cassegrain instruments we might have been able to determine if it's rock or man-made. We spent some time doing this sort of stuff a few years ago with NASA because UKIRT has a uniquie suite of instruments that are well-suited to this sort of study but unfortunately it's takes several days of heavy engineering to switch between modes (and a lot of money). We should be able to figure out what it is soon I hope. There's quite a bit of difference in the thermal properties of rocks and metal so once it's in orbit and undergoes changes between day and night we should be able to work it out.

[HereOnThePrimalEdge]

The Atlas Telescope and Pan-STARRS-1 on Haleakala were two of the observatories around the world that witnessed what has been called the spaghettification of a star by a black hole.  As the black hole's gravity pulled at the star, the star stretched into a long strand as it was absorbed.  I'm no astronomer, but from my experience with spaghetti and other try-this-at-home items, I might personally call it the Play-Doh-afication of a star.  Spaghetti already starts as a long strand, whereas Play-Doh is rolled into a round lump, then pulled and stretched into a ribbon, one hand symbolizing the star, the other hand a black hole.  Here's the detailed explanation from researchers, with an artist's rendering of the event:

“The idea of a black hole ‘sucking in’ a nearby star sounds like science fiction. But this is exactly what happens in a tidal disruption event,” says Matt Nicholl, a lecturer and Royal Astronomical Society research fellow at the University of Birmingham, UK, and the lead author of the new study. But these tidal disruption events, where a star experiences what’s known as spaghettification as it’s sucked in by a black hole, are rare and not always easy to study.
https://sciencesprings.wordpress.com/202...lack-hole/

And for even more detail:
https://academic.oup.com/mnras/article/4...82/5920142

[HereOnThePrimalEdge]

NASA to Announce New Science Results About Moon

NASA will announce an exciting new discovery about the Moon from the Stratospheric Observatory for Infrared Astronomy (SOFIA) at a media teleconference at 12 p.m. EDT Monday, Oct. 26.
https://www.nasa.gov/press-release/nasa-...about-moon

This event sounds like it might be right up your alley TomK.  Infrared research, and another news site says there’s a Mauna Kea connection.  Any teasers that aren’t embargoed?

Prior to starting her postdoctoral research, Dr Honniball measured water levels on the moon using SOFIA and NASA's InfraRed Telescope Facility on Mauna Kea in Hawaii.
https://www.newshub.co.nz/home/world/202...xpert.html

[terracore]

"Dr Honniball measured water levels on the moon using SOFIA and NASA's InfraRed Telescope Facility on Mauna Kea in Hawaii"

This isn't that Dr Honniball Lecter guy is it?

[TomK]

HOTPE - I don't know anything about the discovery but my guess is they've found lots of water on the moon, or more likely, within it. While we're in wide-field mode the moon is far too bright to observe, the light would simply fry our detectors.

For the sci-fi fans, observing the moon would lead to a cascade effect that blows up all the other observatories on the mountain and lead to an alien invasion, so that's what they want us to do.

[randomq]

So, you're not able to look at the **supposed** moon landing site because it's too bright? All those Punatics must be right...

[HereOnThePrimalEdge]

but my guess is they've found lots of water on the moon, or more likely, within it

Thanks TomK.  I'm looking forward to the announcement on Monday.  Our idea of what's true or not true about the moon has certainly changed dramatically in my lifetime.

[HereOnThePrimalEdge]

Water on the moon.
One small step for former UH graduate student Casey Honniball, one giant leap for lunar astronauts of the future:

“Prior to the SOFIA observations, we knew there was some kind of hydration,” Casey Honniball, the lead author who published the results from her graduate thesis work at the University of Hawaii at Mānoa in Honolulu, said in the announcement. “But we didn’t know how much, if any, was actually water molecules...
https://thehill.com/policy/technology/52...ce-of-moon

“This discovery reveals that water might be distributed across the lunar surface and not limited to the cold shadowed places near the lunar poles,” Paul Hertz, the director of NASA’s astrophysics division, said during a news conference on Monday.
Such ice might not only provide water for future astronauts to drink, but water molecules can also be broken apart into their constituent hydrogen and oxygen atoms. The oxygen would give the astronauts something to breathe. Hydrogen and oxygen can also be used as rocket propellant for trips home to Earth or even some day to Mars and beyond.
https://www.nytimes.com/2020/10/26/science/moon-ice-water.html?action=click&module=News&pgtype=Homepage


Casey Honniball rockin’ (pohaku-in’?) her Mauna Kea cap, outside the SOFIA research plane:
https://twitter.com/nasamoon/status/1320723634797699073

[TomK]

This is interesting because there have been attermpts to detect water on the Moon before and they haven't really led to much. I haven't read the paper yet, but suspect it's a detection of water ice using "reflection" spectroscopy. Sunlight reaches the moon's surface and is reflected off the surface. Some of that light is absorbed by frozen water at specific wavelengths (around two and three microns and also longer mid-infrared wavelengths, but they are tough to observe, even using Sofia which observes very high up in the atmosphere). What surprtised me in the announcemernt is that the ice was detected in sunlight. It means the water can still be dcetected in high temperatures envirtonments which tells me there is probably quite a lot of ice, especially in the shadier places on the moon.

We used this technique on an asteroid a couple of decades ago at UKIRT and came up with a tentative detection of water ice. I can't remermber if it was published in a peer-reviewed journal, but do remember it made a bit of news in the astro community at the time.

[TomK]

In other news...

An asteroid might hit us.

For those of us planning to be around in 2068, we have an asteroid that might collide with us decades from now. Apophis - a near-Earth asteroid was going to come close to us in 2029. However, something called Yarkovsky acceleration means it might impact us in 2068. Fortunately, we have a lot of warning.

The Yarkovsky effect is basically caused by something heating up and when it cools down it releases photons, or light, generally in the infrared. Although photons have no mass, they carry energy and therefore have momentum. The release of infrared photons while the asteroid cools down acts like a very weak thruster and changes the orbit of the asteroid. The change is minute but over time becomes important.

We've now detected this tiny change in an asteroid that comes close to the Earth and might cause a collision in 2068. The good news is we have plenty of time to plan how to deal with it. The bad news is some people want to shut down astronomy in Hawaii.

Details from the UH here:

https://www.hawaii.edu/news/2020/10/26/n...-findings/