The document discusses three mysteries: auroras, black holes and cosmic X-rays, and comets. It provides background on each mystery and notes that auroras involve distinct magnetosphere processes, black holes can be studied through polarized X-ray measurements, and comets may have brought water to Earth and studying comet material may reveal secrets about the origins of the universe.

2. The Mystery of Auroras

3. The Mystery of Auroras
If you are standing in Alaska, Canada, or the
Northern United States on a clear dark night and
looking up into the sky, you may see a bright
greenish-white band of light that stretches
across the sky from the East to the West. You
are seeing the Northern Lights, also known as
the Aurora Borealis. These types of lights also
occur near the South Pole, where they are known
as the Southern Lights and Aurora Australis.

4. The Mystery of Auroras
On a lucky night, you may watch this auroral
band continue to brighten as it moves toward
the South. Then, within minutes, you may see the
band of light break into many bands of light
some of which will move back overhead and to
the North, dancing rapidly and turning red,
purple, and white. If you've been lucky to see
this sequence of events, you have witnessed the
beginning phases of an auroral substorm.

5. The Mystery of AurorasThe Mystery of AurorasThe Mystery of Auroras
When we see these dancing auroral lights
evolve suddenly from a slowly moving auroral arc
across the sky, we know that there are two distinct
processes occurring in Earth's magnetosphere.
But which one triggered the abrupt
change from a calm aurora to a dancing
aurora?
Learn more here .

6. The Study of Black Holes, Cosmic
X-ray Mysteries

7. The Study of Black Holes, Cosmic
X-ray Mysteries
NASA has selected a science mission that will allow astronomers
to explore, for the first time, the hidden details of some of the
most extreme and exotic astronomical objects, such as stellar and
supermassive black holes, neutron stars and pulsars.
Objects such as black holes can heat surrounding gases to
more than a million degrees. The high-energy X-ray radiation
from this gas can be polarized – vibrating in a particular
direction. The Imaging X-ray Polarimetry Explorer (IXPE)
mission will fly three space telescopes with cameras capable of
measuring the polarization of these cosmic X-rays, allowing
scientists to answer fundamental questions about these
turbulent and extreme environments where gravitational,
electric and magnetic fields are at their limits.

8. The Study of Black Holes, Cosmic
X-ray Mysteries
“We cannot directly image what’s going on near objects like
black holes and neutron stars, but studying the polarization of X-
rays emitted from their surrounding environments reveals the
physics of these enigmatic objects,” said Paul Hertz,
astrophysics division director for the Science Mission Directorate at
NASA Headquarters in Washington. “NASA has a great history of
launching observatories in the Astrophysics Explorers Program
with new and unique observational capabilities. IXPE will open a
new window on the universe for astronomers to peer through.
Today, we can only guess what we will find.”
Learn more here .

9. Exploring the Mysteries of Comets

10. Exploring the Mysteries of Comets
Comets are formed of dust and icy gases. They travel
highly elliptical orbits that bring them close to the Sun,
then swing them back, deep into space. Usually the farthest
point of their journey is beyond the distance of Pluto's orbit.
Close to the heat of the Sun, comets develop tails
millions-of-miles in length, some creating easily viewable
spectacles as they visit the vicinity of Earth.

11. Exploring the Mysteries of Comets
In centuries past, comets seemed to appear suddenly,
generating excessive reactions from people who did not
understand them. They were blamed for everything from the
death of kings to the demise of great empires to the creation of
plagues. The passage of Halley's Comet in 1066, for example,
appeared to foretell of the English loss at the Battle of Hastings.
More recently, during its 1910 passage, the infant science of
spectroscopy discovered toxic gases in Halley's Comet. Fearing
that the Earth would pass through the poisonous tail, charlatans
sold comet insurance policies and homeopathic medicines for the
coming "comet fever."

12. Exploring the Mysteries of Comets
To probe the mysteries of comets, the NASA
Stardust spacecraft will fly close to a comet
and, for the first time ever, bring material back to Earth for analysis
by scientists worldwide. This cometary material, it is
hoped, will help unlock some of the secrets of these small
bodies that are often described as "dirty ice balls" hurling through
space. By learning something about these little bits of a comet,
scientists hope it may be possible to discover more far reaching
secrets about the materials that make up our universe
and possibly more about its origins. A big question that scientists
hope to better answer is whether comets brought water to
the Earth.
Learn more here .

13. Sources
https://www.nasa.gov/mission_pages/themis/auroras/
https://www.nasa.gov/press-release/nasa-selects-mis
https://www.nasa.gov/mission_pages/stardust/mission