10 most difficult time riddlesAstronomy quiz
What is the highest time zone?
Time zones range from UTC-12 to UTC+14. UTC+14 stretches as far as 30° east of the 180° longitude line and creates a large fold in the International Date Line. In Kiribati (UTC+14), the local time is the same as in Hawaiʻi (UTC−10:00), but the date is one day ahead. It is also 26 hours ahead of Baker Island (UTC−12:00).
In what period of time does the Sun make a full turn around the center of the Milky Way?
within every 225 million years
within 250 million years
within 300 million years
within 350 million years
The sun performs a full turn around the center of our galaxy during 225 million years.
What was the exposure time of this photo?
about 10 seconds
about 10 minutes
about 1 hour
about 8 hours
The length of stars trails is pretty much the same as the distance travelled by an hour hand of clock during 30 minutes. But the Earth rotates twice as slow compared to the hour hand of a clock (one rotation per day, while clock's hour hand makes two).
What are the most luminous objects in the universe?
A quasar is an extremely energetic source of radiation powered by accretion disc around galaxy's central supermassive black hole. Quasars were much more common in the early universe, as all known quasars are extremely distant.
World's fastest high-speed cameras were built to take photos of specific objects. What kind of objects?
nuclear bomb explosions
The rapatronic cameras are capable of recording a still image with an exposure time as brief as 10 nanoseconds (that would give 100 million frames per second if the camera was capable to do multiple pictures). The camera uses two polarizing filters mounted with their polarization angles at 90° to each other and a Faraday cell which briefly changes the polarization plane of light passing through it, acting as a shutter.
Which large country uses UTC +5:30 time zone?
India is one of the few countries that use single time zone with a 30-minute increment from UTC. The country's east–west distance covers 28 degrees of longitude, resulting in two hours difference in astronomical time. Since authorities decided to have one time zone for the whole country, they had to adjust it precisely.
What is the stellar day?
23 h 56 min 05 s
24 h 10 min 07 s
25 h 22 min 09 s
26 h 05 min 11 s
Sidereal time is a time-keeping system astronomers use to keep track of the direction to point their telescopes to view a given star in the night sky. It is a time scale that is based on the Earth's rate of rotation measured relative to the fixed stars rather than the Sun.