Εμφάνιση ενός μόνο μηνύματος
  #3725  
Παλιά 16-01-17, 10:29
Το avatar του χρήστη pazo
pazo Ο χρήστης pazo δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: Σήμερα 15:05
Φύλο: Άντρας
Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

16 January 2017




Geostationary Highway through Orion

Image Credit & Copyright: James A. DeYoung


Explanation: Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth and it will orbit once in 24 hours. Because that matches Earth's rotation period, it is known as a geosynchronous orbit. If that orbit is also in the plane of the equator, the satellite will hang in the sky over a fixed location in a geostationary orbit. As predicted in the 1940s by futurist Arthur C. Clarke, geostationary orbits are in common use for communication and weather satellites, a scenario now well-known to astroimagers. Deep images of the night sky made with telescopes that follow the stars can also pick up geostationary satellites glinting in sunlight still shining far above the Earth's surface. Because they all move with the Earth's rotation against the background of stars, the satellites leave trails that seem to follow a highway across the celestial landscape. The phenomenon was captured last month in this video showing several satellites in geostationary orbit crossing the famous Orion Nebula.

Tomorrow's picture: moon plane

ΠΗΓΗ: http://apod.nasa.gov/apod/astropix.html
__________________
VmF Skisters of Mercy ©
An eye for an eye, will make us all blind... Mahatma Ghandi
Απάντηση με παράθεση