APOD: 2024 December 22 Б The Local Fluff
Explanation:
The stars are not alone.
In the disk of our
Milky Way Galaxy,
about 10 percent of visible matter is in the form of gas
called the
interstellar medium (ISM).
The ISM is
not uniform
and shows
patchiness even near our
Sun.
It can be quite difficult to detect the
local ISM because it is so tenuous and emits so little light.
This mostly
hydrogen gas, however, absorbs some very
specific colors that can be detected in the light of the
nearest stars.
A working map of the local
ISM within 20 light-years,
based on ongoing observations and particle detections
from the Earth-orbiting
Interstellar Boundary Exporer satellite
(
IBEX), is
shown here.
These observations indicate that our
Sun is moving through a
Local Interstellar Cloud as this cloud flows outwards from the
Scorpius-Centaurus Association star forming
region.
Our Sun may exit the
Local Cloud, also called the Local Fluff, during the next 10,000 years.
Much remains unknown about the local
ISM,
including details of its distribution,
its origin, and how it affects the
Sun and the
Earth.
Unexpectedly, IBEX
spacecraft
measurements indicate that the
direction
from which neutral
interstellar particles flow
through our Solar System
is changing.
APOD Year in Review:
Night Sky Network Presentation for 2024
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
