QUESTION:
What special features of a planet or star is the KAO especially good at
detecting?

ANSWER from Allan Meyer on November 1:
As you know, almost all of the observing on the KAO was done at infrared
wavelengths.  Infrared radiation contains a wealth of information about the
objects it comes from.  Infrared is radiant heat (like the heat you can feel
from the sun), and infrared observations permit measurement of the temperature
of objects.  Very hot objects like stars also emit visible light, and
astronomers were able to determine the temperatures of stars before there
was infrared astronomy and the KAO.

However, there are some stars and other objects in space that are not
white hot, but rather only red hot or even quite cold.  The KAO has been
used to measure the temperature of the planets much farther from the warmth
of the sun, and also to measure the temperature of cool stars and other
objects in space as cold as about 400 degrees Fahrenheit below zero!  Some
of these very cold objects are dark clouds of dust in space, that are warmed
up only a little by the light of distant stars.  There are also clouds that
surround stars, and are so thick that the stars inside cannot be seen.
But the light from the stars inside warm up the clouds, and sometimes gas
evaporating from the stars stirs up the surrounding cloud.  The infrared
from these clouds contains lots of useful information about the atoms,
molecules and dust in these warm clouds.  There are many such dust clouds
throughout our galaxy, and you can see yourself how they block some of the
glow of the Milky Way, if you look from a dark place.  But infrared radiation
passes through these clouds, so infrared sources in all parts of our galaxy
were studied from the KAO, including a still unexplained, very powerful
source of infrared and radio waves at the very center of our galaxy.

The KAO permitted detailed studies of the chemical makeup of the atmospheres
of the planets and other objects in the solar system.  Some very small amounts
of chemicals like phosphine (PH), germane (GH) and water vapor (H2O) were
measured in the atmospheres of Jupiter and Saturn.  Water vapor evaporating
from comets was also studied from the KAO, including when a comet hit
Jupiter last year.

The KAO was also used very successfully in another way to study the
atmospheres of solar system objects.  This was done by the occultation
technique: measuring the dimming of the visible light from a star as a
solar system object passed in front of it.  The stars do not twinkle at
KAO flight altitudes, so momentary changes in the brightness of a star near
the edge of a planet must be due to the other planet's atmosphere.
Also, the  KAO was the only observatory that could move itself to wherever
such rare events were visible, and pretty much guarantee a cloud-free view
at the crucial moment!  The planets Mars through Pluto have all been studied
from the KAO using this technique, and also the comet-like object Chiron.
Yours, Allan Meyer