A 5km Asteroid May Briefly Occult the Brightest Star in the Night Sky | Hacker News Reader

A 5km Asteroid May Briefly Occult the Brightest Star in the Night Sky

arstechnica.com

59 pointsrbanffy19 comments

There is a flying telescope built on a 747SP, a joint enterprise of NASA and the German space agency, called SOFIA. It is able to fly to see events like this that can only be observed from a limited range of locations.

https://www.abc.net.au/news/2019-02-01/sofia-flying-telescop...

I think SOFIA is used mainly for Infrared astronomy. By flying above most of the atmosphere it can observe in the infrared, where Earth based telescopes are severely limited.

The purpose of SOFIA is to fly above as much of the water vapour in the atmosphere as possible to do astronomy in the far infrared and terrahertz regimes: frequencies that are absorbed by water. Near infrared astronomy can easily be done from the ground. As the grandparent mentioned, it is also used as a mobile telescope to do observations of stellar occultations. The purpose of this is to get a measure, for example, of Pluto's atmosphere as it passes in front of a star. I doubt it would be used for an occultation by an asteroid as you wouldn't gain anything by the measurement.

I suppose you could get information about the asteroid's shape?

Indeed they do. You can see some of the analysis here [1], by calculating the time period of the occultation and the transit location of the star across the body of the asteroid. I don't know how they account for rotation or how they so precisely know where the asteroid will be relative to the star.

[1] https://www.google.com/search?tbm=isch&sa=1&q=asteroid+shape...

That is an excellent article about SOFIA thanks heaps for sharing it.

“Look,” whispered Chuck, and George lifted his eyes to heaven. (There is always a last time for everything.)

Overhead, without any fuss, the stars were going out.

From “The Nine Billion Names of God“ by [edit, wrong: Isaac Asimov].

Almost made me cry the first time I read those last lines.

Indeed from "The Nine Billion Names of God", but this classic of SF was by Arthur C. Clarke, not Isaac Asimov.

However, Isaac Asimov did write "Nightfall", another classic, which describes what happens when, as the result of an eclipse, the stars come out, rather than go out...

"Nine Billion..." is a great short read on the perils of being on-site IT support.

...and 'Nightfall' is for certain an example of the perils of astronomy.

Loved them both when I read them as a kid.

For others, the complete text:

https://urbigenous.net/library/nine_billion_names_of_god.htm...

It's short, only takes a few minutes to read.

That is a Sirius total eclipse :-)

s/occult/occlude/g

Edit: Wow, see below - today I learned something.

Verb meaning for occult is "to cut off from view by interposing something".

https://en.m.wikipedia.org/wiki/Occultation

You were technically wrong, but good luck ever using 'occult' as a verb anywhere but intellectual and special interest message boards.

The best kind of wrong? :)

Interestingly Sirius' illustration on the page seems to be moving due to optical illusion.

Damned occults gotta ruin my stargazing too?!

Reply on news.ycombinator.com