626. Milkyway belongs to a cluster of some 24 galaxies called?
Local group
627. Energy is transferred from the Sun to Earth mainly by?
electromagnetic waves
628. The best evidence that Earth spins on its axis is provided by?
apparent shifts in the swing of a Foucault pendulum
629. Existence of galaxies beyond milky way was first demonstrated by?
Edwin Hubble
630. Galaxies are also called?
island of universe
631. Father of Indian Astronomy?
Aryabhata
632. The system of astronomy based on Heliocentre (sun centred) universe was presented by?
Copernicus
633. The astronomer who presented the system of astronomy based on a geo centric (earth centred) universe?
Ptolemy
634. The first who attempted to measure stellar distances?
James Gregory
635. The length of an Earth day is determined by the time required for approximately one?
Earth rotation
636. The apparent rising and setting of the Sun, as viewed from Earth, is caused by?
Earth’s rotation
637. The apparent daily path of the Sun changes with the seasons because?
Earth's axis is tilted
638. An inter stellar cloud of dust, hydrogen, helium and other ionized gases are called?
Pulsars
639. First pulsar was discovered by?
Jacelyn Bell
640. The pieces of rocks, which move around the sun are called?
Meteoroids
641. The tilt of the Earth on its axis is a cause of the Earth’s?
changing length of day and night
642. Compared to the distances between the planets of our solar system, the distances between stars are usually?
much greater
643. Why does the moon appear to move across the sky during the night?
Earth rotates on its axis.
644. What time of year is the sun farthest from the earth?
Summer in the Northern Hemisphere.
645. As per Microwave Anisotropy Probe (MAP) what is the exact age of the universe?
13.7 billion year after the theoretical Big Bang
646. Name the British astronomer who, told that the Universe was not limited to the solar system, but is much vaster than that?
Sir William Herschel
647. Stars whose brightness increases to 20 magnitude or more due to explosion in the star is called?
Supernovae
648. What is a star?
A star is a gaseous self-luminous body in space
649. What is a parsec?
The word "parsec" is made up of the parts of the words "parallax" and "second". It means the distance from the Earth to a star whose parallax is one second of arc.
650. What does magnitude mean?
Magnitude is the measure of the brightness of a star or of any luminous body in the heaven