Annapurna Star Trails (APOD 2009 November 28)

[neufer]

http://apod.nasa.gov/apod/ap091128.html

Annapurna is a Sanskrit name which literally means "full of food"

Solo New Route on Annapurna South: April 2009
By Dougald MacDonald / The Mountain World

The line taken by Slovakian Dodo Kopold on the southeast side of Annapurna South (7,219m).
The true summit is to the left, marked by a small red dot. Arrows mark his descent route.


The Slovakian Dodo Kopold has soloed the southeast side of 7,219-meter Annapurna South (Annapurna Dakshin) in a 40-hour continuous push. He traversed a ridge to the west to reach the main summit, and then returned to the saddle and descended steep snow and ice slopes to the south. Kopold carried only a 40-meter 6mm rope, eight pitons, eight ice screws, 10 quickdraws, three energy bars, some dried meat, and a stove for water. Several expeditions had attempted a line on the “south face” of Annapurna South, and a Russian team completed the line in winter in the mid-1990s. However, the Russian line appears to have been far to the west of Kopold’s ascent, possibly more on the western aspect of the main peak than the south.

[PhilBerardelli]

Just a nitpick, but the caption to the photo states that "the stars do not move." The stars are moving, in some cases much faster than Earth, but they are so far away that they appear to retain the same relative position in the sky night after night.

[NoelC]

A mind with freer associations than yours one will not meet, Neufer.

The APOD is a STUNNING photo!

-Noel

[neufer]

Just a nitpick, but the caption to the photo states that "the stars do not move." The stars are moving, in some cases much faster than Earth, but they are so far away that they appear to retain the same relative position in the sky night after night.

Of course the mountains are moving not the stars....

Annapurna South uplift ~ 5 mm per year

As seen from ~ 10 kilometers away:
Annapurna proper motion ~ 0.10 arcsec/yr.
Polaris proper motion ~ 0.05 arcsec/yr.

The Himalayas are among the youngest mountain ranges on the planet and consist mostly of uplifted sedimentary and metamorphic rock. According to the modern theory of plate tectonics, their formation is a result of a continental collision or orogeny along the convergent boundary between the Indo-Australian Plate and the Eurasian Plate. This is referred to as a fold mountain.



The collision began in the Upper Cretaceous period about 70 million years ago, when the north-moving Indo-Australian Plate, moving at about 15 cm per year, collided with the Eurasian Plate. About 50 million years ago, this fast moving Indo-Australian plate had completely closed the Tethys Ocean, the existence of which has been determined by sedimentary rocks settled on the ocean floor and the volcanoes that fringed its edges. Since these sediments were light, they crumpled into mountain ranges rather than sinking to the floor. The Indo-Australian plate continues to be driven horizontally below the Tibetan plateau, which forces the plateau to move upwards. The Arakan Yoma highlands in Myanmar and the Andaman and Nicobar Islands in the Bay of Bengal were also formed as a result of this collision.

The Indo-Australian plate is still moving at 67 mm per year, and over the next 10 million years it will travel about 1,500 km into Asia. About 20 mm per year of the India-Asia convergence is absorbed by thrusting along the Himalaya southern front. This leads to the Himalayas rising by about 5 mm per year, making them geologically active.>>

[Chris Peterson]

As seen from ~ 10 kilometers away:
Annapurna proper motion ~ 0.10 arcsec/yr.
Polaris proper motion ~ 0.05 arcsec/yr.

But in the context of this image, you should perhaps have continued your calculations to include the apparent motion of each over the 30-minute exposure time, and compare that to the image pixel scale.

[DavidLeodis]

Is anybody else having a problem with the Jia Hao link in the credit I have tried the link but get a message stating "Object not found! The requested URL was not found on this server. The link on the referring page seems to be wrong or outdated. Please inform the author of that page about the error. If you think this is a server error, please contact the webmaster. Error 404". If there is a fault it does though seem too minor a thing to contact the webmaster.

The picture is terrific and would still be so even without the star trails.

[geckzilla]

David, that's actually supposed to be his email address. Someone left out "mailto:"

[DavidLeodis]

David, that's actually supposed to be his email address. Someone left out "mailto:"

Thanks geckzilla for your reply. I would guess that Jia Hao may be unhappy the link is faulty, or possibly not!

[neufer]

<<Cabeus crater is relatively old, 100 km in diameter, and contains significant areas of permanent shadow. Such regions are of great interest because they may harbor significant deposits of ices (water, methane, etc). Cabeus crater is most famous as the site of the LCROSS Centaur impact (9 October 2009) that was intended to excavate and eject any volatiles that may be in the regolith (what we call the lunar soil). Though analyses of data collected during the impact are still ongoing, preliminary results suggest that yes, significant amounts of water ice may be trapped in these shadowed regions (at least at this one spot).


Two and a half days after the LCROSS impact the LRO spacecraft slewed 70° back towards Cabeus crater to allow LROC to acquire an overview image of a portion of the northern rim. The large mountain (or massif) in the right background (full panorama below) is a portion of the ancient rim of the South Pole-Aitken basin, it rises some 6000 meters above the surrounding plains, and more than 9200 meters above the floor of Cabeus crater -- taller than any mountain on the Earth.


On the Moon mountains are formed in only minutes as huge amounts of energy are released when asteroids and comets slam into the surface at velocities greater than 16 km per second (more than ten times faster than a speeding bullet). In contrast, mountains on the Earth typically form over millions of years during slow-motion collisions of tectonic plates.>>

[KEIKO]

We see the trails for the 24 hours rotation of the Earth, why do we not see star trails left and right for the Earths 365 day movement around the Sun.

[neufer]

We see the trails for the 24 hours rotation of the Earth, why do we not see star trails left and right for the Earths 365 day movement around the Sun.

If you mean by "left and right" the quasi linear motion of the earth around the sun
there is only a small (~ 20 arcsecond) 365 day epicycle aberration effect
(on top of a small 365 day epicycle individual parallax effect for close stars).

Rotationally, however:
the sun affects the (23h 56m 4.1s) spinning top of the Earth
[observed as a (23h 56m 4.1s) spinning of the stars around Polaris]

by a slow (~ 26,000 year) precession of the equinoxes
[observed as a (26,000 year) spinning of the stars around Draco].

But you will need the patience of Brahma if you want a photo.

The lifespan of Brahma is 100 Brahma years, equivalent to 311,040,000,000,000 solar years. At the end of His lifespan, there will be a gap of 100 Brahma years, after which another Brahma or creator will begin the process of creation anew. This cycle is thought to repeat without end.

[Chris Peterson]

We see the trails for the 24 hours rotation of the Earth, why do we not see star trails left and right for the Earths 365 day movement around the Sun. :?:

Because our orbital motion is too small compared with the distance to the stars for the shift of the stars to be visible in a wide field image. In fact, looking at fairly nearby stars with high magnification, it is possible to see them shift back and forth with our annual motion. The effect is called stellar parallax.

Our day length of 24 hours is derived from a combination of our planetary rotation and orbital motion. The actual rotation time of the Earth is about 23 hours, 56 minutes, 4 seconds. So if you look at the sky at the same time every night (every 24 hours), the stars will have shifted position a little, rotating through 360° over a year- another way of seeing our orbital movement in the sky.

[neufer]

Our day length of 24 hours is derived from a combination of our planetary rotation and orbital motion. The actual rotation time of the Earth is about 23 hours, 56 minutes, 4 seconds. So if you look at the sky at the same time every night (every 24 hours), the stars will have shifted position a little, rotating through 360° over a year- another way of seeing our orbital movement in the sky.

As the stars smoothy circle widdershins (counter-clockwise)
The sun is stuck in an ∞ analemma loop:


http://antwrp.gsfc.nasa.gov/apod/ap081221.html
http://antwrp.gsfc.nasa.gov/apod/ap071204.html
http://antwrp.gsfc.nasa.gov/apod/ap071002.html
http://antwrp.gsfc.nasa.gov/apod/ap070617.html

http://antwrp.gsfc.nasa.gov/apod/ap050713.html