Space weathering occurs on airless bodies like the Moon and asteroids due to bombardment by cosmic rays, solar wind particles, and micrometeorites. This damages surface materials over time, darkening and reddening them. It reduces absorption band depths in spectral signatures. Studying lunar craters shows fresh ejecta becoming darker with age. Space weathering products on the Moon include agglutinates and glass splashes. It likely occurs slower and less severely on asteroids due to weaker impacts and solar wind. Mercury's weathering may produce nanophase iron from its high temperatures and fast micrometeorites.

1. Space
Weathering

2. INTRODUCTION
• Space weathering is the damage that occurs to any object
exposed to the harsh environment of outer space. Bodies
without atmospheres (including the Moon, Mercury, the
asteroids, comets, and most of the moons of other planets)
incur many weathering processes:
 Collisions of galactic cosmic rays and solar cosmic rays,
 irradiation, implantation, and sputtering from solar wind
particles, and
 bombardment by different sizes of meteorites and
micrometeorites.
• Space weathering is important because these processes affect
the physical and optical properties of the surface of many
planetary bodies.
• Therefore, it is critical to understand the effects of space
weathering in order to properly interpret remotely sensed
data.

3. HISTORY
• Much of our knowledge of the space weathering
process comes from studies of the lunar samples
returned by the Apollo program, particularly the lunar
soils.
• The first products of space weathering that were
recognized in lunar soils were "agglutinates".
• These are created when micrometeorites melt a small
amount of material, which incorporates surrounding
glass and mineral fragments into a glass-welded
aggregate ranging in size from a few micrometers to a
few millimeters.
• Space weathering also produces glass splashes;
implanted hydrogen, helium and other gases.
• Until the 1990s there were no improved instruments

5. Effects on spectral properties
• On the Moon, the spectral effects of space weathering are
threefold: as the lunar surface matures it becomes darker
(the albedo is reduced), redder (reflectance increases with
increasing wavelength), and the depth of its diagnostic
absorption bands are reduced.
• The darkening effects of space weathering are readily seen
by studying lunar craters.
• Young, fresh craters have bright ray systems, because they
have exposed fresh, unweathered material, but over time
those rays disappear as the weathering process darkens the
material.

8. Space weathering on asteroids
• Space weathering is also thought to occur on
asteroids,though the environment is quite different
from the Moon.
• Impacts in the asteroid belt are slower, and therefore
create less melt and vapor.
• Also, fewer solar wind particles reach the asteroid belt.
• And finally, the higher rate of impactors and lower
gravity of the smaller bodies means that there is more
overturn and the surface exposure ages should be
younger than the lunar surface.

9. • Therefore, space weathering should occur more
slowly and to a lesser degree on the surfaces of
asteroids
• There is evidence to suggest most of the color
change due to weathering occurs rapidly, in the first
hundred thousands years, limiting the usefulness of
spectral measurement for determining the age of
asteroids.

10. Space weathering on Mercury
• The environment at Mercury also differs
substantially from the Moon.
• For one thing, it is significantly hotter in the day
(diurnal surface temperature ~100 °C for the
Moon, ~425 °C on Mercury) and colder at night,
which may alter the products of space
weathering.
• In addition, because of its location in the Solar
System, Mercury is also subjected to a slightly
larger flux of micrometeorites that impact at
much higher velocities than the Moon.

11. • The UV/Vis spectrum of Mercury, as observed
telescopically from Earth, is roughly linear, with a
red slope.
• There are no absorption bands related to Fe-bearing
minerals, such as pyroxene.
• This means that either there is no iron on the surface
of Mercury, or else the iron in the Febearing
minerals has been weathered to nanophase iron.

12. Presented By:-
Himadri Samal
M.Sc 1st Year
Reference: WIKIPEDIA
WEB
Presented by:
Himadri Samal
M.Sc 1st Year
Space
Weathering
FLOOD
MANAGEMENT
BY:
HIMADRI SAMAL
M.Sc Applied Geology
1st SEMESTER
Sambalpur University