The Naked Scientists

The Naked Scientists Forum

Author Topic: can constellations be seen everywhere at the same time?  (Read 14693 times)

Offline kdlynn

  • Neilep Level Member
  • ******
  • Posts: 2851
    • View Profile
for example, if i can see the big dipper, can karen see it at the same time? what about seany? could we all look up and see the same stars at the same time?


 

paul.fr

  • Guest
can constellations be seen everywhere at the same time?
« Reply #1 on: 23/05/2007 07:20:17 »
The quick answer is no, i will explain more when i get home.
 

Offline daveshorts

  • Moderator
  • Neilep Level Member
  • *****
  • Posts: 2583
  • Physics, Experiments
    • View Profile
    • http://www.chaosscience.org.uk
can constellations be seen everywhere at the same time?
« Reply #2 on: 23/05/2007 09:01:58 »
The stars are just distributed in space. We are all standing on a globe and because the ground gets in the way you can only see half of the stars at a time. If you are at the north or south pole you will only see one half of stars all the time. If you live on the equator as the earth spins you should be able see all the stars over a day. However during the day they will be overwhelmed by sunlight so on any one night you will not be able to see all the stars. During the year the direction of the sun will change so you will be able to see different sets of stars at different times.
 

paul.fr

  • Guest
can constellations be seen everywhere at the same time?
« Reply #3 on: 23/05/2007 09:25:56 »
Just to add to what Dave has already mentioned. Depending on which hemesphere you are in you will see different constellations, Some of them are unique to one hemesphere. For example the southern cross can only be seen from the southern hemesphere.

There are a total of 88 constellations, 50 of which are visable in the northern hemesphere, although some of these are seasonal.

Information on all of the constellations, can be found here: http://www.intute.ac.uk/sciences/spaceguide/constellations.html
 

another_someone

  • Guest
can constellations be seen everywhere at the same time?
« Reply #4 on: 23/05/2007 10:05:43 »
In fact, if you could see the same stars everywhere at the same time, then the stars would be useless for navigation.  Navigating by stars depends on your seeing different stars at different parts of the world, and hence being able to tell where in the world you are by looking up and seeing which constellations are visible, and where, in the sky above you.
 

Offline eric l

  • Hero Member
  • *****
  • Posts: 514
    • View Profile
can constellations be seen everywhere at the same time?
« Reply #5 on: 23/05/2007 13:47:27 »
Two or three other questions :
  • 1 :  did the constellations have similar names in other cultures ?  If my memory does not fail me in this, the Chinese had not only other names for their constellations, but they grouped the stars otherwise too.
  • 2 :  would the star map be the same if seen from an other planet in our solar system - or (much farther in the future no doubt) from some habitable planet in an other galaxy.
  • 3 :  has the star map changed since the days when man started looking at the skies.  After all,we are not in the center of the universe, and if all objects are moving away from the location of the big bang, the perspective must be changing constantly, or not ?
 

another_someone

  • Guest
can constellations be seen everywhere at the same time?
« Reply #6 on: 23/05/2007 14:05:47 »
As you say, in some ways the grouping of the stars into constellations is somewhat arbitrary, so it is certainly possible that other civilisations grouped them differently (although I believe there was more contact between China and the Middle East than one gives credit for, so it is plausible that they would have borrowed the star groupings from each other - or greater interest is how the prehistoric Americans would have grouped the stars).

I am not aware that stars have entered or left constellations in the short time we have been on this planet, although certainly the position of the stars in the sky has changed a little over time, but as far as I am aware that is more to do with changes in the orbit and rotation of the Earth rather than appreciable changes in the position of the stars.

I doubt that the stars would look very different from other planets in our solar system, although no doubt slight shifts would occur, but I doubt it is enough to regroup the stars.  Moving substantially outside of our solar system, I would imagine that one could see enough movement in the view of the stars to require regrouping the constellations.

No doubt others can give numbers to my vague guesses, and either show me to be wrong, or reinforce with more detail what I have said.
 

paul.fr

  • Guest
can constellations be seen everywhere at the same time?
« Reply #7 on: 23/05/2007 18:03:17 »
Two or three other questions :
  • 1 :  did the constellations have similar names in other cultures ?  If my memory does not fail me in this, the Chinese had not only other names for their constellations, but they grouped the stars otherwise too.
Quote
Take, for example, the Big Dipper, perhaps the most recognizable star pattern in the sky. The Big Dipper is not actually a constellation itself, but is part of a larger pattern known to the Greeks as Ursa Major, the Great Bear. The seven stars of the Big Dipper have inspired many stories, perhaps because they are bright and located so near the north celestial pole, around which the stars rotate during the course of the night. But not everyone calls it a Dipper. The British call it a Plough. In Southern France, it is a Saucepan. The Skidi Pawnee Indians saw a stretcher on which a sick man was carried. To the ancient Maya, it was a mythological parrot named Seven Macaw. Hindu sky lore called it the Seven Rishis, or Wise Men. To the early Egyptians, it was the thigh and leg of a bull. The ancient Chinese thought of it as a special chariot for the Emperor of the Heaven or some other celestial bureaucrat. For the Micmac Indians of Canada's Maritime Provinces, along with several other North American Indian tribes, the bowl of the Big Dipper was a bear, and the stars in the handle represented hunters tracking the bear. And in the nineteenth century, the Big Dipper became a symbol of freedom for runaway slaves, who "followed the Drinking Gourd" to the northern states.

[/list]
 

The Naked Scientists Forum

can constellations be seen everywhere at the same time?
« Reply #7 on: 23/05/2007 18:03:17 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums