ppt on space class 8-10 space travel download it,it will be different or see the youtube video

1. SPACE
by
shyamswara
n

2. space
Space is the boundless three-dimensional extent in
which object and events have relative position and
direction. Physical space is often conceived in
three linear dimensions, although modern physicists usually
consider it, with time, to be part of a boundless four-
dimensional continuum known as spacetime. The concept of
space is considered to be of fundamental importance to an
understanding of the physical universe. However, disagreement
continues between philosophers over whether it is itself an
entity, a relationship between entities,

3. Space travel
Space exploration is the ongoing discovery and exploration of celestial structures in outer
space by means of continuously evolving and growing space technology. While the study of
space is carried out mainly by astronomers with telescopes, the physical exploration of
space is conducted both by unmanned robotic space probes and human spaceflight.
While the observation of objects in space, known as astronomy, predates reliable recorded
history, it was the development of large and relatively efficient rockets during the mid-
twentieth century that allowed physical space exploration to become a reality. Common
rationales for exploring space include advancing scientific research, national prestige,
uniting different nations, ensuring the future survival of humanity, and developing military
and strategic advantages against other countries.

5. •A "falling star" or a "shooting star" has nothing at
all to do with a star! These amazing streaks of light
you can sometimes see in the night sky are caused
by tiny bits of dust and rock called
meteoroids falling into the Earth's atmosphere and
burning up.
FALLING STAR

6. SUN
• The Sun is the star at the center of the Solar System. It is a nearly perfect
sphere of hot plasma,[13][14] with internal convective motion that generates
a magnetic field via a dynamo process.[15] It is by far the most important source
of energy for life on Earth. Its diameter is about 109 times that of Earth, and its
mass is about 330,000 times that of Earth, accounting for about 99.86% of the
total mass of the Solar System.[16] About three quarters of the Sun's mass
consists of hydrogen (~73%); the rest is mostly helium (~25%), with much
smaller quantities of heavier elements, including oxygen, carbon, neon,
and iron

7. Distance to Earth: 149.6 million km
• Escape velocity (from the surface): 617.7 km/s; 55 ×
Earth
• Equatorial surface gravity: 274.0 m/s2; 27.94 g;
27,542.29 cgs; 28 × Earth
• Mean radiance (I_sol): 2.009×107W·m−2·sr−1
• Age: ≈ 4.6 billion years
• Luminosity (L_sol): 3.828×1026 W; ≈
3.75×1028 lm; ≈ 98 lm/W efficacy
sun

8. MOON
• The Moon is an astronomical body that orbits planet Earth, being Earth's only permanent natural
satellite. It is the fifth-largest natural satellite in the Solar System, and the largest among planetary
satellites relative to the size of the planet that it orbits (its primary). Following Jupiter's satellite Io,
the Moon is second-densest satellite among those whose densities are known.
• The average distance of the Moon from the Earth is 384,400 km (238,900 mi),[10][11] or 1.28 light-
seconds.
• The Moon is thought to have formed about 4.51 billion years ago, not long after Earth. There are
several hypotheses for its origin; the most widely accepted explanation is that the Moon formed
from the debris left over after a giant impact between Earth and a Mars-sized body called Theia

9. GALAXY
• A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar
gas, dust, and dark matter.[1][2]The word galaxy is derived from
the Greek galaxias (γαλαξίας), literally "milky", a reference to the Milky Way.
Galaxies range in size from dwarfs with just a few billion (109) stars to giants with one
hundred trillion (1014) stars,[3] each orbiting its galaxy's center of mass. Galaxies are
categorized according to their visual morphology
as elliptical,[4] spiral and irregular.[5] Many galaxies are thought to have black holes at
their active centers. The Milky Way's central black hole, known as Sagittarius A*, has a
mass four million times greater than the Sun.[6]As of March 2016, GN-z11 is the oldest
and most distant observed galaxy with a comoving distance of 32 billion light-
years from Earth, and observed as it existed just 400 million years after the Big Bang

10. COMET
• A comet is an icy small Solar System body that, when passing close to the Sun, warms
and begins to evolve gasses, a process called outgassing. This produces a visible
atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects
of solar radiation and the solar wind acting upon the nucleus of the comet. Comet
nuclei range from a few hundred metres to tens of kilometres across and are composed
of loose collections of ice, dust, and small rocky particles. The coma may be up to 15
times the Earth's diameter, while the tail may stretch one astronomical unit. If
sufficiently bright, a comet may be seen from the Earth without the aid of a telescope
and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed
and recorded since ancient times by many cultures.