Hello Space Fans and welcome to another edition
of Space Fan News.
In this episode, NASA learns that the cameras
on TESS won’t focus at cold temperatures
but will launch anyway; the Dark Energy Survey
reveals the most accurate measurement of dark
matter structure in the universe; a new storm
is found on Neptune by the Keck Telescope;
and beware dangerous solar glasses being sold
for the upcoming solar eclipse.
On July 26th, NASA confirmed that the four
cameras onboard the Transiting Exoplanet Survey
Satellite or TESS Spacecraft, won’t focus
properly when brought down to the temperatures
it will operate under in space.
TESS 
will survey 200,000 of the brightest stars
nearest the sun to search for transiting exoplanets,
just like Kepler did in the constellation
Cygnus, only TESS will look at the entire
sky.
The mission is scheduled to launch no later
than June 2018.
TESS scientists expect the mission will catalog
more than 2,000 planet candidates and vastly
increase the current number of known exoplanets.
Of these, approximately 300 are expected to
be Earth-sized and super-Earth-sized exoplanets,
which are worlds no larger than twice the
size of Earth.
TESS will find the most promising exoplanets
orbiting our nearest and brightest stars,
giving future researchers a rich set of new
targets for more comprehensive follow-up studies.
At least that’s the idea but recent testing
of the cameras revealed that they won’t
focus as designed when they are cooled to
their operating temperatures.
NASA has not said what they think the cause
of the focus problem is, but they think it
may be due to crystallization of the glue
used to bond the detector arrays in place.
He said project engineers didn’t expect
the focus to continue to drift after the temperature
stabilized.
NASA has downplayed the problem and said that
since the science mission of the spacecraft
is to measure tiny dips in brightness as an
exoplanet passes between the star and the
cameras, the focus is nowhere near as critical
as the resolution of the cameras, which isn’t
affected by the temperature.
So what this means is that the TESS mission
will proceed with the cameras as they are
and mission planners expect that they will
only lose about 10 percent of the science
they wanted to do in the first place if the
cameras could be focussed properly.
So I guess this means we can say goodbye to
200 of the 2,000 planet candidates they were
expecting to find and 30 of the Earth-sized
worlds won’t be found by TESS.
I’m not sure how I feel about that, but
I know I’m very glad the mission is still
going forward.
Ninety percent is better than zero percent.
Next, the Dark Energy Survey is currently
looking at over 5,000 square degrees of sky
in the southern hemisphere with a 525 mega-pixel
camera they are calling the Dark Energy Camera,
or DECam.
With these observations, the survey created
a map of the amount and “clumpiness” of
dark matter in the present-day cosmos and
were made with a precision that, for the first
time, rivals that from the early universe
by the European Space Agency’s orbiting
Planck observatory.
The new DES result is very close to “forecasts”
made from the Planck measurements of the distant
past, allowing scientists to understand more
about the ways the universe has evolved over
14 billion years.
This is a bit confusing I know.
Planck measured clumpiness from the Cosmic
Microwave Background, which was when the universe
was only 400,000 years old.
From that initial clumpiness, Planck scientists
made a prediction or forecast of what the
present universe may look like.
And the Dark Energy Survey was looking at
the clumpiness of the present day universe,
and has done it with a precision never before
achieved, and their map
confirms the forecasts made by Planck.
The DES measurements, when compared with the
Planck map, support the simplest version of
the dark matter/dark energy theory, and matched
the Planck results to within 7 percent.
Now we may not like this but this result supports
the theory that 26 percent of the universe
is in the form of mysterious dark matter and
that space is filled with an also-unseen dark
energy, which is causing the accelerating
expansion of the universe and makes up 70
percent of the universe.
I say we may not like it because dark matter
and dark energy are uncomfortable topics because
while they fit the observations of our universe
quite nicely, the fact that they are so elusive
is highly annoying.
Still, we can’t ignore the data, so well
done DES.
To make these ultraprecise measurements, the
DES team developed new ways to detect the
tiny lensing distortions of galaxy images,
an effect not even visible to the eye, enabling
revolutionary advances in understanding these
cosmic signals.
In the process, they created the largest guide
to spotting dark matter in the cosmos ever
drawn.
The new dark matter map is 10 times the size
of the one DES released in 2015 and will eventually
be three times larger than it is now.
Next amazing images of a storm system nearly
the size of Earth have caught astronomers
by surprise after pinpointing its location
near Neptune’s equator, a region where no
bright cloud has ever been seen before.
Using the Keck Observatory, astronomers observed
a massive storm system about 9,000 kilometers
in length, or 1/3 the size of Neptune’s
radius, spanning at least 30 degrees in both
latitude and longitude.
They observed it getting much brighter between
June 26 and July 2.
The astronomers say that historically, very
bright clouds have occasionally been seen
on Neptune, but usually at latitudes closer
to the poles, around 15 to 60 degrees north
or south but never before has a cloud been
seen at, or so close to the equator, nor has
one ever been this bright.
What you may not know is that Neptune is the
windiest planet in our solar system, with
the fastest observed wind speeds at the equator
reaching up to a violent 1000 miles per hour.
To put this into perspective, a Category 5
hurricane has wind speeds of 156 miles per
hour.
Neptune orbits the Sun every 160 years, and
one season is about 40 years.
What they think might be happening is a huge,
high-pressure, dark vortex system anchored
deep in Neptune’s atmosphere may be what’s
causing the colossal cloud cover.
As gases rise up in a vortex, they cool down.
When its temperature drops below the condensation
temperature of a condensable gas, that gas
condenses out and forms clouds, just like
water on Earth.
On Neptune though this won’t be water, but
methane clouds.
As with every planet, winds in Neptune’s
atmosphere vary drastically with latitude,
so if there is a big bright cloud system that
spans many latitudes, something must hold
it together, such as a dark vortex.
Otherwise, the clouds would shear apart.
If it is not tied to a vortex, the system
may be a huge convective cloud, similar to
those seen occasionally on other planets like
the huge storm on Saturn that was detected
in 2010.
Although one would also then expect the storm
to have smeared out considerably over a week’s
time.
Finally, if you’re like me, and you live
in the Unites States, then you’re making
plans to see the total solar eclipse later
this month.
I’ll talk more about the eclipse as the
date approaches but I wanted to warn you about
some possibly dangerous solar eclipse viewers
that are being marketed.
I’ve put a link to both NASA’s statement
on this as well as the American Astronomical
Society’s warning, but I wanted to give
you a heads up and show you how you can tell
if yours are any good.
The basic rule of thumb is that if you can
see anything through them at all that isn’t
the sun, then they’re junk.
You should only be able to see the sun through
them and NOTHING ELSE.
Here’s a pair I’ve had since my days at
the High Altitude Observatory in Boulder.
They are made of cardboard and have two bits
of silver mylar that goes over your eyes.
I can’t see anything through them if I’m
looking at a lamp in my office or a pair of
car headlight.
If you can see the lamp through yours, throw
them away and get a better pair.
I’ve included a link to reputable brands
selling viewers in the description box below.
If you want to learn more about how to view
the eclipse, please watch our Telescope Talk
Hangout next Tuesday at 3pm ET on August 8th
and we’ll help you with any of your questions
then.
In the meantime, to summarize, if you can
see anything at all but the sun through your
glasses, get rid of them.
Also take a look periodically for any pinholes
or tears in the mylar before you put them
on.
The only safe time to look directly at the
sun with your naked eyes is during the time
of totality, when the moon is directly between
you and sun.
If you’re outside the path of totality,
then the is no safe time for you to look directly
at the sun.
Well, that’s it for this week Space Fans.
SFN is made possible from support of Patreon
Patrons and I want to personally thank Deep
Astronomy sponsors Robyn Ringuette and Soekul
for your generous support this month.
Thanks to all of you for watching and as always,
Keep Looking Up!
